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REVISION NOTES IN NEUROSURGERY FOR MBCHB STUDENTS NEUROSURGERY CLERKSHIP KENYATTA NATIONAL HOSPITAL Course Description: Students are required to take neurological surgery clerkship during their third and fifth year. The neurological surgery clerkship emphasizes the development of skills in neurological examination, functional neuroanatomy, practical interpretation of neuroimaging and the identification of emergent neurological conditions, as well as the medical and surgical management of cranial, spinal and peripheral nerve disease. Course Objectives: At the end of this rotation, students will be able to acquire skills in neurological examination, functional neuroanatomy, practical interpretation of neuroimaging and the identification of emergent neurological conditions, as well as the medical and surgical management of cranial, spinal and peripheral nerve disease. take a patient history including pertinent neurological review of systems, past medical history, family history and social history . reliably perform a general neurological examination including mental status, cranial nerve, cerebellar, Motor, Sensory, and reflex subcomponents calculate the Glasgow Coma Score (GCS) for any given patient calculate the functional status of any given patient according to the Karnofsky Performance Scale identify and neuroanatomically localize common neurological deficits including lobar lesions, brain stem lesions, myelopathy, radiculopathy, and peripheral nerve deficits become familiar with the common neurological diseases that must be considered in the differential diagnosis of patients presenting with varying combinations of, and time courses for, neurological symptoms and examination findings become familiar with the various tests that are used for neurological evaluation, when these tests are appropriate, as well as their limitations identify the presence or absence of skull fracture, intracranial hemorrhage, hydrocephalus, and/or a lesion causing mass effect on a cerebral neuroimage identify the presence or absence of spinal fracture, spinal cord compression, or a significantly herniated disc on a spinal neuroimage . become familiar with the neurocritical care concepts and monitoring techniques for measuring intracranial pressure, cerebral perfusion pressure, and cerebral artery vasospasm, syndrome of inappropriate antidiuretic hormone release, cerebral salt wasting syndrome, diabetes insipidus, and vasogenic cerebral edema. become familiar with the medical and surgical management of neurological emergencies, including acute spinal cord compression, elevated intracranial pressure, intracerebral hemorrhage, seizures and stroke. become familiar with the basic types of operations performed to assist in the diagnosis and treatment of patients with neurological disease. become familiar with ethical and quality of life issues including, loss functional independence, alterations in body image, issues surrounding limitation or withdrawal of care decisions, informed consent, and organ donation, that are inherent in major neurological illness and injury as well as neurological surgery Key Topics:

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Neuroanatomical localization Alteration in consciousness Functional and quality of life impact of disease and injury Ethical implications of surgery, as well as neurological disease and injury Basic practical interpretation of neuroimaging Recognition and management of neurological emergencies Traumatic brain and spine/spinal cord injury along with neurocritical care Cerebrovascular disease Neuro-Oncology Degenerative spine disease Competencies: Neurological history Neurological examination Neuroanatomical localization Common tests utilized to evaluate neurological disease Basic interpretation of neuroimaging Differential diagnosis of neurological presentations and findings Identification and treatment of neurological emergencies Role of surgery in neurological disease Appreciation & familiarity with concepts & techniques unique to neurocritical care Professional and ethical approach to patients and families Attitudes and Commitments: An understanding of the integrity, commitment, and work ethic required to become an effective and successful neurological clinician. An organized, rational, systematic and thorough approach to patient evaluation and diagnosis. The need and means to effectively manage the complexities of our health care system, policies and procedures in order to maximize the potential outcome for patients in the setting of urgent medical conditions. An understanding of the importance of multidisciplinary and multi-departmental integration and cooperation for optimizing care for patients with complex disease. An understanding of the importance of new and often expensive technology in advancing the diagnosis and treatment of neurological disease. An understanding of the critical importance of compassion, effective communication, and the highest ethical standards in assisting patients and families with the major issues and decisions surrounding high-risk surgery as well as major neurological disease and injury. An understanding of the great promise that advancing basic neuroscience holds for further advancements in translational clinical neuroscience. A willingness to emulate the neurosurgical faculty when it comes to integrity, work ethic, professional and ethical behavior, and personal commitment to learning as well as individual patient care. Educational Activities: The neurological surgery clerkship is fourteen weeks in length (3rd and 5th year). It includes daily inpatient ward and neurosurgical intensive care unit service exposure for work and educational rounds and patient care. On the inpatient service, each student will be fully integrated into the overall neurosurgical team. They will participate in inpatient

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and emergency room consultations during regular working hours, and will follow and write progress notes on cases assigned to them. Each group will be assigned to one neurosurgical faculty mentor. They will meet with this mentor as a group at least once per week. They will accompany that mentor to his or her outpatient ambulatory clinic as well as the operating room for any scheduled surgical case. On days where their mentor is not scheduled for clinic or surgery, the students may attend the clinic or surgery of one of the other department consultants after having completed their inpatient service responsibilities. Thursday is an academic day for the department and attendance at all teaching conferences for the day is mandatory, as is attendance at the weekly meeting with the rotation mentor. The assigned faculty mentor will be responsible for completing the student evaluations for each rotation with input from the postgraduate residents and the other neurosurgical faculty. A post-rotation test will be administered to assess the effectiveness of the rotation in meeting our educational goals and our responsibility to our students. Students should review the elements of the neurological history and examination and basic neurology and neurosurgery from the lecture notes (Prof Mwang’ombe). Clinical Responsibilities of the Student: Procedures to be Learned by the Student: lumbar puncture, arterial lines, intravenous lines (central and peripheral), intracranial monitors and ventriculostomies, as well as basic surgical technique Official Evaluation Policy: The student will be evaluated on attendance, participation, knowledge base, clinical skills, motivation, professionalism, and interpersonal skills. Course Hours Summary:

20 Patient care actives 10 Laboratory & Imaging 6 Lecture 12 Conference 24 Clinic 8 Grand Rounds 28 Inpatient 46 Preceptorship (surgery) 6 Small Group 28 Ward Rounds 2 Exams 162 Total (including night calls)

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Neurosurgical Division Kenyatta National Hospital Clinical Teaching Program Monday: 8:00 am – 11:00 am WR/PG Teaching; PW, PM,DO,MQ

Monday: 2:00pm- 5:00 pm NSOPC (No. 24) MBChB 5-Clinical Teaching NM, JK, PA, CM, PM

Tuesday: 8:00 am-11:00 am MBChB 5-Wd Teaching: (JK). WR/PG teaching; JK Theatre whole day: NM, PA, PM

Tuesday: 2:00 pm-5:00 pm NSOPC (No. 24) DO, PW, PL, MQ. Theatre whole day: NM,PA, PM

Wednesday: 8.00 am-9.00 am: PGyr 2 PoS, (NM). 9:00 am – 10:00 am: MBChB 3-lecture: (NM) 10:00 am-11:00 am: MBChB 3-wd teaching (PA/DO) WR/PG teaching; PA/DO Theatre-whole day: DO,PW, MQ

Wednesday: Theatre-whole day: DO, PW,MQ

Thursday: Academic Day 8:00 am-9:00 am Neuroradiology Conference (Rad. Dept.) 9:00 am-11:00 am Grand Round (NM) MBChB 5-wd teaching (CM) 11 am-1 pm: Neurosurgery lectures, Journal Club/ M&M conference (Surg Dept)

Thursday: Academic Day 2:00 pm-3:00 pm Case Conference

Friday: 7.00 am-8.00 am Neuropathology Conference (Dept. Path) Theatre-whole day ( PL, CM, JK)

Friday: Theatre-whole day (PL, CM, JK)

WR; ward round. PG; post graduate. M&M; mortality and morbidity. wd; ward. PoS; principles of surgery. PGyr; post grad year. NM; Prof Mwang’ombe. PA; Dr. Akuku. CM; Dr. Musau. DO; Mr. Olunya. JK; Dr. Kiboi. PL; Dr. Lubanga. PW; Dr. wanyoike. PM; Dr. Mwangi. MQ; Mr. Qureshi.

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Neurological History and Physical Examination "From the brain and the brain only arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, griefs, and tears.... These things we suffer all come from the brain, when it is not healthy, but becomes abnormally hot, cold, moist or dry." —Hippocrates Taking the patient's history is traditionally the first step in virtually every clinical encounter. A thorough neurologic history allows the clinician to define the patient's problem and, along with the result of physical examination, assists in formulating an etiologic and/or pathologic diagnosis in most cases. Solid knowledge of the basic principles of the various disease processes is essential for obtaining a good history. As Goethe stated, "The eyes see what the mind knows." To this end, the reader is referred to the literature about the natural history of diseases. The purpose of this article is to highlight the process of the examination rather than to provide details about the clinical and pathologic features of specific diseases. The history of the presenting illness or chief complaint should include the following information: Symptom onset (eg, acute, subacute, chronic, insidious) Duration Course of the condition (eg, static, progressive, or relapsing and remitting) Associated symptoms, such as pain, headache, nausea, vomiting weakness, and seizures Pain should be further defined in terms of the following: Location Radiation Quality Severity or quantity Precipitating factors Relieving factors Important miscellaneous factors of the history include the following: Results of previous attempts to diagnose the condition Any previous therapeutic intervention and the response to those treatments A complete history often defines the clinical problem and allows the examiner to proceed with a complete but focused neurologic examination. Neurologic Examination The neurologic examination is one of the most unique exercises in all of clinical medicine. Whereas the history is the most important element in defining the clinical problem, neurologic examination is performed to localize a lesion in the central nervous system (CNS) or peripheral nervous system (PNS). The statement has been made, "History tells you what it is, and the examination tells you where it is." The history and examination allow the neurologist to arrive at the etiology and pathology of the condition, which are essential for treatment planning. Unlike many other fields of medicine in which diseases are visible (eg, dermatology, ophthalmology) or palpable (eg, surgery), neurology is characterized by conditions that may be detected only by applying specific examination techniques and logical deduction, except when telltale cutaneous markers or other stigmata (see Media files 1-8) suggest

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the diagnosis. Considerable insight and intuition are required to interpret the symptoms and signs observed during neurologic examination. These features make the neurologic history and physical examination both challenging and rewarding. A properly performed neurologic examination may take 90 minutes or even longer for the novice. Experienced neurologists take substantially less time and can frequently grasp the essential features of a clinical condition quickly. What might appear to be a complex problem of localization for the referring physician may turn out to have a simple explanation, and the neurologic consultation may help to avoid extensive testing. Neurologic examination in the year of imaging With the advent of CT scanning in the early 1970s, the future clinical role of the neurologist was questioned. During one of his visits to the United States, Dr. McDonald Critchley was asked what he thought would be the future of neurology in the era of CT. His answer was most enlightening: "CT scanning will take away the shadows of neurology, but the music will still remain." These prophetic words still ring true despite the advent of MRI, positron emission tomography (PET), and functional neuroimaging of all types. It has been said that "neurology owes more to its disorders than those disorders owe to neurology." This is because much knowledge has come from previous observations of neurologic conditions, because the eponyms for the diagnoses were sometimes long, and because so little was previously offered in the terms of cures such that the specialty was ridiculed as one that was "long on diagnosis and short on treatment." Fortunately, technologic advances have changed that perception. Steps in the neurologic examination In examining a patient, abnormalities of function lead to localization and, eventually, to the pathophysiology. For the purpose of simplicity, the neurologic examination is divided into several steps. When mastered, these steps become second nature to the examiner, and the process of evaluating the patient proceeds smoothly, even though the steps are not always necessarily performed in the same order. These steps include the following: Higher functions Cranial nerves (CNs) Sensory system Motor system Reflexes Cerebellum Meninges System survey Tools required In addition to the stethoscope and the usual office supplies (eg, gloves, tongue depressors), the neurologist should have an ophthalmoscope, a reflex hammer, and a tuning fork. A pin (Wartenberg) wheel was once a favorite tool of many neurologists because it was easy to use for sensory (pinprick) testing. Unless it is disposable (commercially available), this wheel is no longer recommended because of the risk of transmitting infection. The use of sterile safety pins (to be discarded after each use) is recommended. The final section of this article includes a Definition of Terms. Examination of the Higher Functions

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Higher functions include gait, speech, and mental status. These are referred to as higher functions because human bipedal gait, receptive and expressive speech, and cognitive function are more sophisticated than similar functions of any other member of the animal kingdom. Gait Gait is the attitude of a person in the upright position. Abnormal types are described below. Hemiparetic gait In hemiparesis, facial paresis may not be obvious. In mild cases, subtle features of facial paralysis (eg, flattening of the nasolabial fold on 1 side compared to the other, mild asymmetry of the palpebral fissures or of the face as the patient smiles) may be sought. The shoulder is adducted; the elbow is flexed; the forearm is pronated, and the wrist and fingers are flexed. In the lower extremities, the only indication of paresis may be that the ball of the patient's shoe may be worn more on the affected side. In severe cases, the hand may be clenched; the knee is held in extension and the ankle is plantar flexed, making the paralyzed leg functionally longer than the other. The patient therefore has to circumduct the affected leg to ambulate. In hemiplegic patients in whom all the paralysis is on the same side of the body, the lesion is of the contralateral upper motor neuron. In most cases, the lesion lies in the cortical, subcortical, or capsular region (therefore above the brainstem). In the alternating or crossed hemiplegias, CN paralysis is ipsilateral to the lesion, and body paralysis is contralateral. In such cases, CN paralysis is of the lower motor neuron type, and the location of the affected CN helps determine the level of the lesion in the brainstem. Therefore, paralysis of CN III on the right side and body paralysis on the left (Weber syndrome) indicates a midbrain lesion, whereas a lesion of CN VII with crossed hemiplegia (Millard-Gubler syndrome) indicates a pontine lesion, and CN XII paralysis with crossed hemiplegia (Jackson syndrome) indicates a lower medullary lesion. Ataxic gait In ataxia, the patient spreads his or her legs apart to widen the base of support to compensate for the imbalance while standing or walking. In severe cases, patients stagger as they walk. The heel-to-toe or tandem walking maneuvers and standing on 1 leg uncover subtle forms of ataxia. Ataxia results from midline lesions of the cerebellum and may be isolated or associated with other cerebellar findings (see Cerebellar signs). When the lesion is unilateral, the patient may veer to the side of the lesion. With bilateral cerebellar involvement, the patient may fall to either side. Shuffling gait The individual takes short steps to the point of practically not moving forward or making little progress. In other words, the patient appears to shuffle his or her legs rather than put them forward. In some patients, the steps (albeit short) and pace may vary with a tendency for the patient to accelerate (festinating gait) as he or she walks. Both types are seen in Parkinson disease and may be associated with other extrapyramidal signs. Steppage gait In steppage (high-stepping, slapping), the individual takes high steps as if climbing a flight of stairs while walking on a level surface. This peculiar gait pattern results from the patient trying to avoid injury to the feet (from dragging them) by stepping high. However,

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as the patient puts the feet down 1 by 1, they slap the ground, hence the description of a foot-slapping gait. This is 1 condition that can be diagnosed even before the patient enters the room because the sound is so characteristic. Steppage gait is seen in chronic peripheral neuropathies and can be the result of the functional elongation of the legs due to bilateral drop foot. Spastic or scissor gait In this condition, the legs are held in adduction at the hip and the thighs rub against each other as the patient walks. Spasm of the inner thigh muscles also occurs. If the spasm is severe, with each advancing step the knees tend to slide over each other like the blades of a pair of scissors. This is typically seen in cerebral diplegia, a form of cerebral palsy. Antalgic gait Patient favors the affected painful (usually lower) extremity and walks, putting weight on the normal leg. The hand held over hip on the affected side is typical in patients with radicular pain. Speech Speech enables communication between individuals. Abnormalities include dysphonia, dysarthria, and dysphasia or aphasia. Dysphonia or aphonia Dysphonia is the impairment or inability to phonate. As a result, the voice becomes hoarse. In extreme cases, it is absent, and the patient is mute. The most frequent cause of this problem is the common cold, which results in dysphonia due to inflammation of the larynx. Dysphonia may also occur in patients with hypothyroidism, as a result of thickening of the vocal cords from amyloid deposits. Neurologic causes include unilateral recurrent laryngeal nerve paralysis and lesions of the vagus nerve. Intermittent hoarseness may affect patients with vagus nerve stimulator implants, which are used for the treatment of certain medically intractable forms of epilepsy (MIE) and pharmacoresistent depression (PRD). Dysarthria or anarthria Dysarthria is the inability to articulate spoken words. The quality of oration is impaired, but the content remains intact (eg, slurred speech). The patient's ability to understand and synthesize speech remains intact. It results from paralysis of pharyngeal, palatal, lingual, or facial musculature. It also is observed with cerebellar lesions and/or disease (eg, scanning or staccato speech). Dysphasia or aphasia In dysphasia, the ability to process language is impaired, resulting in an inability to understand (ie, receptive or sensory or Wernicke aphasia), transfer signals from the Wernicke to the Broca area (ie, conduction aphasia), or properly execute speech (ie, expressive, motor, or Broca aphasia). The combination of Broca and Wernicke aphasias is referred to as global aphasia.

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Table 1 summarizes the essential features of common dysphasias (aphasias). Table 1. Essential Features of Common Dysphasias Type of Dysplasia Fluency Comprehension Naming Localization Broca Nonfluent Intact Impaired Broca area Wernicke Fluent Impaired Impaired Wernicke area Conduction Fluent Intact Impaired Arcuate fasciculus Global Nonfluent Impaired Impaired Broca and Wernicke areas Transcortical aphasias Another function that is impaired in all 4 of the aphasias mentioned above is repetition. This finding is important in the diagnosis of transcortical aphasias. When repetition is preserved in a patient with Broca aphasia, it signifies transcortical motor aphasia, and the lesion is anterior to the Broca area. When repetition is preserved in Wernicke aphasia, it is called transcortical sensory aphasia, and the lesion is posterior to the Wernicke area. Transcortical mixed aphasia and global aphasia are similar except for the preservation of repetition, and results from combined lesions anterior to the Broca and Wernicke areas, respectively. Mental status Mental status evaluation includes testing of memory, orientation, intelligence, and the other aspects of the patient's psychic state. Only the first 3 are discussed here. When overt symptoms or signs of a psychic disturbance are present, psychiatric evaluation should be considered. Memory Memory is the ability to register and recall prior sensory input. Recent and remote memory functions are differently affected depending on the disease process. Remote memory is relatively preserved in chronic dementing processes, with major disturbances in the attention span and recent memory. On the contrary, all aspects of memory are impaired in acute encephalopathies. Orientation Orientation is an individual's cognitive sense of his status in time, place, and person. These functions are affected in the same order as they are in organic disease. In other words, the sense of time is first to be impaired in organic dysfunction, and the sense of person is the last to be lost. However, the order may be disturbed in psychological dysfunction. A patient who does not know who he or she is, but at the same time can tell the time and is oriented in place, is more likely to have a psychological disturbance than to have an organic etiology for the condition. Nonetheless, rare cases of isolated amnesia have been reported. Intelligence Intelligence is the ability to quickly and successfully apply previous knowledge to a new situation and to use reason in solving problems. Vocabulary, fund of knowledge, calculations (eg, serial-7 calculations), abstraction (eg, use of proverbs), and judgment (eg, what to do with a found wallet) are good indicators of intelligence. Psychological disturbances

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A brief survey of the other aspects of psychological function may be helpful in revealing abnormalities of thought process (eg, circumstantiality and tangentiality); of perception (eg, illusions and hallucination); or of thought content (eg, delusions of grandeur). Patients with these findings should be referred for appropriate evaluation. Examination of the Cranial Nerves Of the 12 CNs, some are named according to their function. Examples of these are the olfactory (smell), optic (vision), oculomotor (eye movements), abducens (abduction of the eye), facial (facial expression), and vestibulocochlear or statoacoustic (hearing and balance) nerves. Others are named for their relationship to neighboring structures (trochlear nerve), appearance (trigeminal nerve), extent of distribution (vagus nerve), composition (spinal accessory nerve), or location (hypoglossal nerve). Trochlear: Its midsection extends over a trochlea or pulley to reach its insertion on the inferior aspect of the globe. Trigeminal: The nerve divides into 3 divisions distal to the Gasserian ganglion. Vagus: The vagabond or wanderer, it travels long distances in the body. Spinal accessory: This nerve is composed of rootlets from the spinal cord in addition to its medullary component. Hypoglossal: Its course is sublingual in the neck. Knowing the names of the CNs makes it easy to remember their function, thereby making their examination self-evident. The following mnemonic is helpful in recalling the names of the CNs: Oh, oh, oh; to trek and feel a great valley; ah! ha! Another is this: On old Olympus towering tops, a Finn and German viewed some hops. Olfactory nerve - CN I The olfactory nerves consist of small unmyelinated axons that originate in the olfactory epithelium in the roof of the nasal cavity; they pierce the cribriform plate of the ethmoid and terminate in the olfactory bulb. Lesions of the nerve result in parosmia (altered sense of smell) or anosmia (loss of smell). The common cold is the most frequent cause of dysfunction. Dysfunction can be associated with fractures of the cribriform plate of the ethmoid bone. Frontal lobe tumors may compress the olfactory bulb and/or tracts and cause anosmia, but this is rare occurrence. Olfactory function is tested easily by having the patient smell common objects such as coffee or perfume. Commercially available scented scratch papers may also be used. Optic nerve - CN II The optic nerve is a collection of axons that relay information from the rods and cones of the retina. The temporal derivations reach the ipsilateral and the nasal derivations the contralateral superior colliculi and the lateral geniculate bodies. From there, axons extend to the calcarine cortex by means of the optic radiation, traversing the temporal (Myer loop) and parietal lobes. Fibers responsible for the pupillary light reflex bypass the geniculate body and reach the pretectal area, from where they innervate the parasympathetic (midline) portion of the third-nerve nucleus, enabling the consensual pupillary reflex. The following testing is appropriate: Acuity, by using the Snellen chart (near and distant vision) Visual fields, by means of confrontation or perimetry if indicated

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Color, with use of an Ishihara chart or by using common objects, such as a multicolored tie or color accent markers Funduscopy Lesions of the visual pathways result in blindness and pupillary abnormalities, such as the Marcus-Gunn pupil (retinal or optic nerve disease), scotomata, quadrant or hemianopsias (optic tract and radiation), and hemianopsias with macular sparing (calcarine cortex). Oculomotor nerve - CN III The oculomotor nucleus of the nerve is located in the midbrain and innervates the pupillary constrictors; the levator palpebrae superioris; the superior, inferior, and medial recti; and the inferior oblique muscles. Lesions of CN III result in paralysis of the ipsilateral upper eyelid and pupil, leaving the patient unable to adduct and look up or down. The eye is frequently turned out (exotropia). In subtle cases, patients complain of only diplopia or blurred vision. Lesions at the nucleus of the third nerve cause bilateral ptosis, in addition to the findings mentioned above. The exotropia seen in CN III paralysis can be distinguished from that in internuclear ophthalmoplegia because in the latter convergence is preserved. Paralysis of CN III is the only ocular motor nerve lesion that results in diplopia in more than 1 direction, distinguishing itself from CN IV paralysis (which also can result in exotropia). Pupillary involvement is an additional clue to involvement of CN III. Pupil-sparing CN III paralysis occurs in diabetes mellitus, vasculitides of various etiologies, and certain brainstem lesions such as due to multiple sclerosis. Trochlear nerve - CN IV The nucleus of the nerve is located in the midbrain. It innervates the superior oblique muscle, which incycloducts and infraducts the eye. Trochlear nerve typically allows a person to view the tip of his or her nose. An isolated right superior oblique paralysis results in exotropia to the right (R), double vision that increases on looking to the (L), and head tilt to the right (R). The mnemonic is R, L, R (ie, the marching rule). The rule is L, R, L for left superior oblique paralysis. This rule and the lack of ptosis and/or pupillary involvement allow easy distinction of the exotropia of CN IV paralysis from that seen in CN III paralysis. Trigeminal nerve - CN V The nucleus of the nerve stretches from the midbrain (ie, mesencephalic nerve) through the pons (ie, main sensory nucleus and motor nucleus) to the cervical region (ie, spinal tract of the trigeminal nerve). It provides sensory innervation for the face and supplies the muscles of mastication. Paralysis of the first division (ophthalmic; V1) is usually seen in the superior orbital fissure syndrome and results in sensory loss over the forehead along with paralysis of CN III and CN IV. Paralysis of the second division (maxillary; V2) results in loss of sensation over the cheek and is due to lesions of the cavernous sinus; it also results in additional paralysis of V1, CN III and CN IV. Isolated V2 lesions result from fractures of the maxilla. Complete paralysis of CN V results in sensory loss over the ipsilateral face and weakness of the muscles of mastication. Attempted opening of the mouth results in deviation of the jaw to the paralyzed side. Abducens nerve - CN VI The nucleus of the nerve is located in the paramedian pontine region in the floor of the fourth ventricle. It innervates the lateral rectus, which abducts the eye. Isolated paralysis

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results in esotropia and inability to abduct the eye to the side of the lesion. Patients complain of double vision on horizontal gaze only. This finding is referred to as horizontal homonymous diplopia, which is the sine qua non of isolated CN VI paralysis. Paralysis of CN VI may result from increased intra cranial pressure without any lesion in the neuraxis, and it may result in false localization if one is not aware of it. Facial nerve - CN VII The nucleus of the nerve lies ventral, lateral, and caudal to the CN VI nucleus; its fibers elevate the floor of the fourth ventricle (facial colliculus) as they wind around the CN VI nucleus. The nerve leaves the cranial cavity through the stylomastoid foramen and innervates the muscles of facial expression and the stapedius. Although it is considered a pure motor nerve, it also innervates a small strip of skin of the posteromedial aspect of the pinna and around the external auditory canal. The nervus intermedius of Wrisberg conducts taste sensation from the anterior two thirds of the tongue and supplies autonomic fibers to the submaxillary and sphenopalatine ganglia, which innervate the salivary and lacrimal glands. A lower-motor-neuron lesion of the nerve, also known as peripheral facial paralysis, results in complete ipsilateral facial paralysis; the face draws to the opposite side as the patient smiles. Eye closure is impaired, and the ipsilateral palpebral fissure is wider. In an upper motor neuron lesion, also known as central facial paralysis, only the lower half of the face is paralyzed. Eye closure is usually preserved. In peripheral facial paralysis, different types of clinical presentations are seen with nerve lesions at 4 levels, as described below. Lesions of the meatal or canalicular segment: Facial paralysis with hearing loss (without hyperacusis) and loss of taste in the anterior two thirds of the tongue imply lesions in the internal auditory canal from fracture of the temporal bone or at the cerebellopontine angle from compression by a tumor. Lesions of the labyrinthine or fallopian segment Lesions that spare hearing (with hyperacusis) indicate lesions further down the course of the nerve. Loss of taste in the anterior two thirds of the tongue and loss of tearing imply lesions that involve the chorda tympani and the secretomotor fibers to the sphenopalatine ganglion in the labyrinthine segment, proximal to the greater superficial petrosal nerve. With lesions distal to the greater superficial petrosal nerve, lacrimation is normal but hyperacusis is still present. Geniculate lesions in this segment cause pain in the face. Lesions of the horizontal or tympanic segment: The lesion is proximal to the departure of the nerve to the stapedius and results in hyperacusis, loss of taste in the anterior two thirds of the tongue, and facial motor weakness. Lesions of the mastoid or vertical segment: Hyperacusis is present if the lesion is proximal to the nerve to the stapedius. It is absent if the lesion is distal to the nerve to the stapedius, and only loss of taste and facial paralysis occur. If the lesion is beyond the chorda tympani in the vertical segment (as in lesions of the stylomastoid foramen), taste is spared and only facial motor paralysis is seen. Vestibulocochlear nerve - CN VIII The vestibulocochlear or statoacoustic nerve enters the brainstem at the pontomedullary junction and contains the incoming fibers from the cochlea and the vestibular apparatus, forming the eighth CN. It serves hearing and vestibular functions, each of which is

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described separately. Hearing loss may be conductive or sensorineural. Three tests help in evaluating the auditory component of the nerve. The Weber test involves holding a vibrating tuning fork against the forehead in the midline. The vibrations are normally perceived equally in both ears because bone conduction is equal. In conductive hearing loss, the sound is louder in the abnormal ear than in the normal ear. In sensorineural hearing loss, lateralization occurs to the normal ear. The sensitivity of the test can be increased (up to 5 dB) by having the patient block his or her external ear canals by simultaneously pressing the index fingers at the introit. To perform the Rinne test, the vibrating tuning fork is placed over the mastoid region until the sound is no longer heard. It is then held at the opening of the ear canal on the same side. A patient with normal hearing should continue to hear the sound. In conductive hearing loss, the patient does not continue to hear the sound, since bone conduction in that case is better than air conduction. In sensorineural hearing loss, both air conduction and bone conduction are decreased to a similar extent. In the Schwabach test, the patient's hearing by bone conduction is compared with the examiner's hearing by placing the vibrating tuning fork against the patient's mastoid process and then to the examiner's. If the examiner can hear the sound after the patient has stopped hearing it, then hearing loss is suspected. The vestibular portion of the nerve enters the brainstem along with the cochlear portion. It transmits information about linear and angular accelerations of the head from the utricle, saccule, and semicircular canals of the membranous labyrinth to the vestibular nucleus. Linear acceleration is monitored by the macules in the utricles and saccules; angular acceleration is monitored by the cristae contained in the ampullae in the semicircular canals. These signals reach the superior (Bechterew), lateral (Deiters), medial (Schwalbe), and inferior (Roller) nuclei and project to the pontine gaze center through the medial longitudinal fasciculus; to the cervical and upper thoracic levels of the spinal cord through the medial vestibulospinal tract; to the cervical, thoracic, and lumbosacral regions of the ipsilateral spinal cord through the lateral vestibulospinal tract; and to the ipsilateral flocculonodular lobe, uvula, and fastigial nucleus of the cerebellum through the vestibulocerebellar tract. The Romberg test is performed to evaluate vestibular control of balance and movement. When standing with feet placed together and eyes closed, the patient tends to fall toward the side of vestibular hypofunction. When asked to take steps forward and backward, the patient progressively deviates to the side of the lesion. Results of the Romberg test may also be positive in patients with polyneuropathies, and diseases of the dorsal columns, but these individuals do not fall consistently to 1 side as do patients with vestibular dysfunction. Another test is to ask the patient to touch the examiner's finger with the patient's hand above the head. Consistent past pointing occurs to the side of the lesion. Provocative tests include the Nylen-Bárány test and caloric testing (see Ancillary signs). Glossopharyngeal nerve - CN IX The nucleus of the nerve lies in the medulla and is anatomically indistinguishable from the CN X and CN XI nuclei (nucleus ambiguous). Its main function is sensory innervation of the posterior third of the tongue and the pharynx. It also innervates the pharyngeal musculature, particularly the stylopharyngeus, in concert with the vagus nerve.

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Vascular stretch afferents from the aortic arch and carotid sinus, as well as chemoreceptor signals from the latter, travel in the nerve of Herring to join the glossopharyngeal nerve; they reach the nucleus solitarius, which in turn is connected to the dorsal motor nucleus of the vagus and plays a part in the neural control of blood pressure. Lesions affecting the glossopharyngeal nerve result in loss of taste in the posterior third of the tongue and loss of pain and touch sensations in the same area, soft palate, and pharyngeal walls. CN IX and CN X travel together, and their clinical testing is not entirely separable. Therefore, examination of CN IX is discussed with that of the vagus nerve. Vagus nerve - CN X Starting in the nucleus ambiguous, the vagus nerve has a long and tortuous course providing motor supply to the pharyngeal muscles (except the stylopharyngeus and the tensor veli palati), palatoglossus, and larynx. Somatic sensation is carried from the back of the ear, the external auditory canal, and parts of the tympanic membrane, pharynx, larynx, and the dura of the posterior fossa. It innervates the smooth muscles of the tracheobronchial tree, esophagus, and GI tract up to the junction between the middle and distal third of the transverse colon. The vagus provides secretomotor fibers to the glands in the same region and inhibits the sphincters of the upper GI tract. Along with visceral sensation from the same region, the nerve participates in vasomotor regulation of blood pressure by carrying the fibers of the stretch receptors and chemoreceptors (ie, aortic bodies) of the aorta and providing parasympathetic innervation to the heart. The pharyngeal gag reflex (ie, tongue retraction and elevation and constriction of the pharyngeal musculature in response to touching the posterior wall of the pharynx, tonsillar area, or base of the tongue) and the palatal reflex (ie, elevation of the soft palate and ipsilateral deviation of the uvula on stimulation of the soft palate) are decreased in paralysis of CN IX and CN X. In unilateral CN IX and CN X paralysis, touching these areas results in deviation of the uvula to the normal side. Unilateral paralysis of the recurrent laryngeal branch of CN X results in hoarseness of voice. Bilateral paralysis results in stridor and requires immediate attention to prevent aspiration and its attendant complications. Spinal accessory nerve - CN XI From the nucleus ambiguous, the spinal accessory nerve joins the vagus nerve in forming the recurrent laryngeal nerve to innervate the intrinsic muscles of the larynx. The spinal portion of the nerve arises from the motor nuclei in the upper 5 or 6 cervical segments, enters the cranial cavity through the foramen magnum, and exits through the jugular foramen, and provides motor innervation to the sternocleidomastoid (SCM) and the mid and upper thirds of the trapezius. In testing, functional symmetry of the SCM and the trapezius muscles should be evaluated. Have the patient push the face against resistance to the right and to the left. When the right SCM is weak, pushing to the opposite (ie, left) side is impaired, and vice versa. Shrugging of the shoulder is impaired ipsilaterally when the trapezius is weak. Hypoglossal nerve - CN XII The nucleus of this nerve lies in the lower medulla, and the nerve itself leaves the cranial cavity through the hypoglossal canal (anterior condylar foramen). It provides motor innervation for all the extrinsic and intrinsic muscles of the tongue except the

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palatoglossus. To test the hypoglossal nerve, have the patient protrude the tongue; when paralyzed on 1 side, the tongue deviates to the side of paralysis on protrusion. Examination of the Sensory and Motor Systems Sensory system Noncortical sensory system This is constituted by the peripheral nerves with their central pathways to the thalamus. Light touch, pain, heat, cold, and vibration sensations can be included in this group. Light touch is tested by touching the skin with a wisp of cotton or tissue. Pain is tested by using a sharp object such as an open safety pin. Temperature can be tested by touching the patient's skin with 2 test tubes, 1 with warm water and the other with cold water. Compare the 2 sides and also to a benchmark, such as the patient's own forehead (assuming sensation there is normal). Vibration is tested with a tuning fork, preferably with a frequency of 128 Hz. Compare findings on the 2 sides, and also compare findings with those in the same body part of the examiner. Cortical sensory system The cortical sensory system includes the somatosensory cortex and its central connections. This system enables the detection of the position and movement of the extremities in space (ie, kinesthetic sensation), size and shape of objects (ie, stereognosis), tactile sensations of written patterns on the skin (ie, graphesthesia), and tactile localization and tactile discrimination on the same side or both sides of the body. Position sensation is tested with the patient's eyes closed. The examiner moves various joints, being sure to hold the body part in such a way that the patient may not recognize movement simply from the direction in which the patient may feel the pressure from the examiner's hand. Stereognosis is tested by placing some familiar object (eg, ball, cube, coin) in the patient's hand while his or her eyes are closed and asking the patient to identify the object. Inability to recognize the size or shape is referred to as astereognosis. Agraphesthesia is the inability to recognize letters or numbers written on the patient's skin. These abilities are impaired in lesions of the right parietal region. Motor system Trophic state Assess the 3 S s: size, shape, and symmetry of a muscle. Atrophy, hypertrophy, or abnormal bulging or depression in a muscle is an important diagnostic finding in the presence of different muscle diseases or abnormalities. Hypertrophy occurs with commensurate strength from use and exercise; on the other hand, hypertrophy with weakness is seen commonly in Duchenne muscular dystrophy. The shape may also be altered when the muscle or tendon is ruptured. Muscle tone Muscle tone is the permanent state of partial contraction of a muscle and is assessed by passive movement. The muscle may be hypotonic or hypertonic. Hypotonia is defined as decreased tone and may be seen in lower motor neuron lesions, spinal shock, and some cerebellar lesions. Hypertonia may manifest as spasticity or rigidity. Pyramidal lesions result in spasticity that may manifest as a clasp-knife phenomenon (ie, resistance to passive movement with sudden giving way, usually toward the completion of joint flexion or extension). Bilateral frontal lobe lesions may result in paratonia or gegenhalten (German for against-stop), in which resistance increases throughout flexion

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and extension. Rigidity refers to increased tone associated with extrapyramidal lesions; it may result in a cogwheel (stepwise) or lead-pipe (uniform) resistance to passive movement. Muscle strength Use this muscle-strength scale when assessing and documenting muscle strength (Table 2). Table 2. Muscle-Strength Scale Score Description 0 Absent voluntary contraction 1 Feeble contractions that are unable to move a joint 2 Movement with gravity eliminated 3 Movement against gravity 4 Movement against partial resistance 5 Full strength Involuntary movements Involuntary movements include fibrillations, fasciculations, asterixis, tics, myoclonus, dystonias, chorea, athetosis, hemiballismus, and seizures. Fibrillations are not visible to the naked eye except possibly those in the tongue. Fasciculations may be seen under the skin as quivering of the muscle. Although fasciculations are typically benign (particularly when they occur in the calf), if widespread, they can be associated with neuromuscular disease, including amyotrophic lateral sclerosis (ALS). Asterixis can be elicited by having the patient extend both arms with the wrists dorsiflexed and palms facing forward and eyes closed. Brief jerky downward movements of the wrist are considered a positive sign. Asterixis is commonly seen with metabolic encephalopathies. Tics are involuntary contractions of single muscles or groups of muscles that result in stereotyped movements. Gilles de la Tourette syndrome can manifest with multiple tics and elaborate, complex movements and vocalizations. Myoclonus, as the word implies, is a muscle jerk; it is a brief (<0.25 seconds), generalized body-jerk, which is sometimes asymmetric. These occur alone or in association with various primarily generalized epilepsies. Dystonias are muscle contractions that are more prolonged than myoclonus and result in spasms. Examples include blepharospasm, spasmodic torticollis, oromandibular dystonia, spasmodic dysphonia, and writer's cramp. In athetosis, the spasms have a slow writhing character and occur along the long axis of the limbs or the body itself; the patient may assume different and often peculiar postures. The term chorea means dance. Quasi-purposeful movements affect multiple joints with a distal preponderance. Hemiballismus is a violent flinging movement of half of the body. It is associated with lesions of the subthalamic nucleus (ie, body of Louis). Seizures may result in orofacial or appendicular automatisms, repeated eye blinks, or tonic or clonic motor activity. Examination of Reflexes, Cerebellum, and Meninges

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Reflexes The different reflex responses may be grouped into 3 categories on the basis of their clinical significance. Primitive reflexes These include the glabellar tap, rooting, snout, sucking, and palmomental reflexes. As a rule, these signs are generally absent in adults. When present in the adult, these signs signify diffuse cerebral damage, particularly of the frontal lobes (hence the term frontal-lobe release signs). Superficial reflexes These are segmental reflex responses that indicate the integrity of cutaneous innervation and the corresponding motor outflow. These include the corneal, conjunctival, abdominal, cremasteric, anal wink, and plantar (Babinski) reflexes. The corneal and conjunctival reflexes may be elicited by gently touching the appropriate structure with a sterile wisp of cotton. The normal response is bilateral winking. Absence of such a response implies CN V paralysis. Blinking of only 1 eye suggests weakness of CN VII on the side that does not wink. The abdominal reflex can be elicited by drawing a line away from the umbilicus along the diagonals of the 4 abdominal quadrants. A normal reflex draws the umbilicus toward the direction of the line that is drawn. The cremasteric reflex is elicited by drawing a line along the medial thigh and watching the movement of the scrotum in the male. A normal reflex results in elevation of the ipsilateral testis. The anal wink reflex is elicited by gently stroking the perianal skin with a safety pin. It results in puckering of the rectal orifice owing to contraction of the corrugator-cutis-ani muscle. The best known of this group of reflexes is the plantar reflex. This reflex may be elicited in several ways, each with a different eponym. The most commonly performed maneuver is stroking the lateral aspect of the sole with a sharp object. The normal response is plantar flexion of the great toe, which is considered an absent (negative) Babinski sign. Dorsiflexion of the great toe (Babinski sign present) suggests an upper motor neuron lesion and also is referred to as a positive Babinski sign. Dorsiflexion of the big toe also may be associated with fanning out of the other toes, as detailed in Babinski's original description, but most neurologists consider this an unnecessary accompaniment of an abnormal response. Flexion of the knee and hip may occur in the paretic leg with urinary and fecal incontinence. This is referred to as the en-mass reflex. Lack of either response may indicate absence of cutaneous innervation in the S1 segment or loss of motor innervation in the L5 segment ipsilaterally. Deep tendon reflexes These are monosynaptic spinal segmental reflexes. When they are intact, integrity of the following is confirmed: cutaneous innervation, motor supply, and cortical input to the corresponding spinal segment. These reflexes include the biceps, brachioradialis, triceps, patellar, and ankle jerks. The musculocutaneous nerve supplies the biceps muscle. The radial nerve supplies the brachioradialis and triceps. The femoral nerve supplies the quadriceps femoris, which enables the knee jerk, and the tibial nerve supplies the gastrocnemius and the soleus.

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Spinal roots that subserve these reflexes are listed below. Table 3. Muscles and Spinal Roots Muscle Spinal Roots Biceps C5, 6 Brachioradialis C6 Triceps C7 Patellar L2-4 Achilles S4 On occasion, these root numbers are offset by 1 when the cervical and/or lumbosacral plexuses are prefixed or postfixed. Several systems for reflex grading exist. An example is provided below. Table 4. Reflex-Grading System Score Reflexes 0 Absent 1 Hypoactive or present only with reinforcement 2 Readily elicited with a normal response 3 Brisk with or without evidence of spread to the neighboring roots 4 Associated with a few beats of unsustained clonus 5 Sustained clonus All textbooks now use a 0-4 scale to grade deep tendon reflexes, without a number assigned for sustained clonus. The addition of the number 5 allows for easy representation by using a stick figure. For a quick method of recording the reflex pattern, see Media file 1. Cerebellar signs The cerebellum provides an important feedback loop for coordination of muscle activity by integrating the functions of the cortex, basal ganglia, vestibular apparatus, and spinal cord. Midline cerebellar dysfunction results in ataxia of gait, difficulty in maintenance of upright posture, and truncal ataxia. Acute neocerebellar hemispheric lesions result in additional signs. The following are various cerebellar signs: Ataxia, atonia, and asthenia Intention tremor Dyssynergia (incoordination) Dysmetria Dysrhythmia Dysdiadochokinesis Dysarthria (staccato or scanning speech) Gait is tested by having the patient walk normally and in tandem. In the latter, the patient is asked to walk with 1 foot immediately in front of the other (ie, heel to toe). A tendency to sway or fall to 1 side indicates ataxia, suggesting ipsilateral cerebellar dysfunction.

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Atonia and asthenia can occur in other lesions of the nervous system and are not specific to the cerebellum; their testing is described elsewhere. Intention tremor refers to an oscillating tremor that accelerates in pace on approaching the target. Dyssynergia or incoordination results in loss of smoothness of execution of a motor activity. Dysmetria results in overshooting or undershooting of a target while attempting to reach an object. All 3 of these can be elicited by having the patient attempt to touch alternately his or her nose and the examiner's finger. Dysrhythmia refers to the inability to tap and keep a rhythm. It can be tested by tapping the table with a hand (or the floor with a foot) and asking the patient to repeat the maneuver. Dysdiadochokinesis is the inability to perform rapid alternating movements; it can be tested by asking the patient to tap 1 hand on the other (or on the thigh) repeatedly while simultaneously pronating and supinating the hand. Various combinations of the above signs appear, depending on the extent and location of the lesion in the cerebellum. Dysarthria is usually a sign of diffuse involvement of the cerebellum. It is characterized by poor modulation of the volume and pitch of the speech, causing oscillations of these 2 qualities. Meningeal signs Signs of meningeal irritation indicate inflammation of the dura; these signs are described below. Nuchal rigidity or neck stiffness is tested by placing the examiner's hand under the patient's head and gently trying to flex the neck. Undue resistance implies diffuse irritation of the cervical nerve roots from meningeal inflammation. The Brudzinski sign is flexion of both knees during the maneuver to test nuchal rigidity. This indicates diffuse meningeal irritation in the spinal nerve roots. The Kernig sign is elicited by flexing the hip and knee on 1 side while the patient is supine, then extending the knee with the hip still flexed. Hamstring spasm results in pain in the posterior thigh muscle and difficulty with knee extension. With severe meningeal inflammation, the opposite knee may flex during the test (see Media file 2). The Lasègue or straight-leg raising (SLR) sign is elicited by passively flexing the hip with the knee straight while the patient is in the supine position. Limitation of flexion due to hamstring spasm and/or pain indicates local irritation of the lower lumbar nerve roots. Reverse SLR is elicited by passively hyperextending the hip with the knee straight while the patient is in the prone position. Limitation of extension due to spasm and/or pain in the anterior thigh muscles indicates local irritation of the upper lumbar-nerve roots. System Survey and Ancillary Signs System survey Autonomic nervous system Autonomic dysfunction results in abnormalities in the following: sweating, skin temperature, cyanosis or pallor, trophic changes of skin or nails, and postural changes in blood pressure. Observation (and any necessary additional testing) easily demonstrates the presence or absence of these signs. Understanding these signs helps the examiner assess the patient's neurologic condition. Neurovascular system The following may be tested by palpation of the pulses and use of appropriate instruments:

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Brachial plexus and bilateral blood pressures Cranial and peripheral pulses Arterial bruits Neurocutaneous system Several neurologic conditions have telltale cutaneous stigmata. Evaluation for the following can provide valuable diagnostic clues: loss of skin pigmentation as in vitiligo, white hair-lock in Vogt-Harada-Koyanagi disease, cutaneous tumors or ash-leaf spots in tuberous sclerosis (see Media file 3), and cutaneous eruptions over a dermatome which may signify herpes zoster (see Media file 4). Coffee-brown pigmented (ie, caf é; au lait) spots of varying sizes, usually greater than 1.5 cm in diameter, and axillary freckling (see Media file 5) are seen in neurofibromatosis. These are observed in addition to or in the absence of the characteristic blubbery subcutaneous tumors that give the condition its name. Tufts of hair (satyr's tail), dimples, and large moles along the spine may indicate spina bifida occulta or diastematomyelia of the spinal column. Skeletal system - Cranium, spine, bones, joints Palpation of the skull can reveal congenital anomalies that may indicate underlying abnormalities of the brain. In cephaloplegia, one half of the skull may be smaller than the other, possibly signifying asymmetric brain development. Microcephaly or macrocephaly may be detected by measuring the circumference of the head. Observation of the spine may reveal the presence of myelomeningocele, scoliosis, and/or kyphosis. In cases of prenatal brain injuries, the length of the long bones may be reduced on the side opposite the cephaloplegia. Trophic changes in the joints can be associated with denervation in tabes dorsalis or Charcot-Marie-Tooth (CMT) disease. The distal muscular atrophy seen in CMT disease gives the legs the appearance of inverted champagne bottles (see Media file 6). Muscular atrophy seen in the region of the temporalis muscles and facial musculature associated with frontal balding is typical of myotonic dystrophy (see Media file 7). Pes cavus deformity (see Media file 8) can be associated with spina bifida and other spinal dysraphisms. A young person with mental retardation, genu valgum, pes cavus, and stroke may have homocystinuria, an inborn error of metabolism typically associated with mental retardation (usually severe) and intimal thickening and necrosis of the media of blood vessels, resulting in strokes and coronary artery disease. Ancillary signs Anisocoria This refers to pupillary asymmetry, which may result from sympathetic or parasympathetic dysfunction. Sympathetic dysfunction results in Horner syndrome, in which the pupil is small but reacts to light. Hippus, a series of oscillating pupillary contractions seen in response to light, is a benign condition. Argyll-Robertson pupil, seen in neurosyphilis, is irregular and small; it does not react to light, but does accommodate. In parasympathetic paralysis, the affected pupil is larger and reacts poorly or not at all to light. Injury to the ciliary ganglion or short ciliary nerves results in a tonic pupil, which is large and has slow or absent reaction to light. A benign form of tonic pupil is seen in Adie syndrome, Holmes-Adie syndrome (ie, tonic pupil with absent patellar and Achilles reflexes), and Ross syndrome (ie, tonic pupil with hyporeflexia and progressive segmental hypohidrosis).

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Anosognosia This refers to denial of illness and typically is seen in patients with right frontoparietal lesions, resulting in left hemiplegia that the patient denies. A form of visual anosognosia (Anton syndrome) is seen in patients with bilateral occipital lobe infarctions; these patients with double hemianopsia (bilateral cortical blindness) deny that they are blind. Asterixis This is seen in patients with metabolic encephalopathies. Momentary loss of tone and flapping of the hand are seen when the patient extends his arms in front with the wrists dorsiflexed. Ataxia Heel-to-toe tandem gait is tested by asking the patient to walk with 1 foot directly in front of the other. Ataxia can be demonstrated in this manner. Beevor sign This is seen with bilateral lower abdominal paralysis that results in upward deviation of the umbilicus when the patient tries to raise his head and sit up from the supine, recumbent position. Benediction hand This is seen with lesions of the median nerve in the axilla and upper arm. When present, the index finger remains straight and the middle finger partially flexes when the patient tries to make a fist (assuming the position of the hand of a clergyman while saying the benediction). Bielschowsky sign This refers to increasing separation of the images seen when a patient's head is tilted toward the side of a superior oblique (trochlear nerve) paralysis. This sign by itself is not diagnostic and should be used only as a supplement to other tests in suspected CN IV paralysis. Chvostek sign This is seen in hypocalcemia. Tapping the cheek at the angle of the jaw precipitates tetanic facial contractions. Cogan sign This is seen in myasthenia gravis. It refers to transient baring of the sclerae above the cornea as the patient resumes the primary eye position after looking down. Dalrymple sign This refers to the upper-lid retraction seen in thyroid ophthalmopathy. Doll's-eye maneuver This refers to turning the head passively with the patient awake and fixated or when the patient is in a coma. In the former, the eyes remain fixated at the original focus when all gaze pathways are normal; in the latter, the eyes deviate in the opposite direction when the brainstem is intact. Gower sign This sign, seen in severe myopathies, occurs when the patient attempts to stand up from the floor. Patients first sit up, then assume a quadrupedic position, and then climb up their own legs by using their arms to push themselves up. Heterochromia iridis

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This term refers to the difference in color of the 2 irides. It indicates early injury to the sympathetic system. Ipsilateral to the injury the iris is blue or green, while the contralateral iris is darker. Jaw jerk This is elicited by placing the examiner's index finger on the patient's lower jaw and then striking it with the reflex hammer. An exaggerated reflex indicates the presence of a pontine lesion. When the rest of the examination findings are normal, it may indicate physiologic hyperreflexia. Kayser-Fleischer ring This is a brownish ring around the limbus of the cornea. It is best demonstrated during an ophthalmologic slitlamp examination. Lhermitte sign This refers to the sensation of electricity associated with cervical spinal cord lesions during passive or active flexion and extension of the neck. Once considered pathognomonic of multiple sclerosis, it simply is the result of electricity generation by the hypersensitive, demyelinated, or injured spinal cord; this sign can be associated with any lesion in or around the cord. Marcus-Gunn pupil This sign requires a swinging-flashlight test to assess. As the flashlight swings from 1 eye to the other, the abnormal pupil dilates as the light swings back from the normal side. No anisocoria is seen. The phenomenon is also called a paradoxical pupillary reflex and indicates an afferent (optic nerve) pupillary defect. Milkmaid's grip This refers to the inability to maintain a sustained grip commonly seen in patients with chorea. Moebius sign This refers to weakness of ocular convergence (associated with proptosis) seen in dysthyroid ophthalmopathy. Myerson sign Patients with Parkinson disease, particularly those with bilateral frontal lobe dysfunction, continue to blink with repeated glabellar taps. Nylen-Bárány sign This is elicited by having the patient quickly lie down from the sitting position with the head turned to 1 side and hanging down 30o below the horizontal over the edge of the examining table. The procedure is then repeated with the head turned to the other side. The test is positive when the patient experiences vertiginous discomfort and exhibits nystagmus after a latency period of about 10 seconds. The nystagmus increases for about 10 seconds then fatigues in peripheral vestibular disease. In central lesions, nystagmus may occur with the head turned to either side, without discomfort to the patient, and without latency of onset or fatigue. Ondine curse This refers to the failure of autonomic control of breathing when the patient falls asleep. Oommen sign Have the patient close the eyes and place a pebble the size of an M&M candy on the palm of the examiner's left hand. Cross the patient's middle finger over the index finger on its dorsal aspect. With the examiner's right hand, hold the patient's crossed fingers and have

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the patient's 2 (crossed) fingertips touch the pebble at the same time. Ask the patient how many pebbles are in the examiner's hand. With normal stereognosis, the patient should answer that there are 2 pebbles. In cases of astereognosis, the patient reports feeling only 1 pebble. Opsoclonus This refers to large-amplitude saccadic oscillations of the eyes in all directions, often exacerbated by refixation. They persist during sleep and are associated with brainstem and cerebellar lesions as well as a remote effect of certain carcinomas. Optokinetic nystagmus This is elicited by using a rotating, striped drum or a moving, striped piece of cloth. As the patient's eyes fixate on a stripe, nystagmus seen in healthy individuals is due to the optokinetic reflex. Lesions in the anterior aspects of the visual pathways decrease the response, and lesions of the vestibular system result in a directional preponderance to the elicited nystagmus. Phalen sign This refers to the aggravation of paresthesia and pain when the wrist is held in flexion (in patients with carpal tunnel syndrome). Roger sign This is numbness of the chin in patients with lymphoreticular (and other types of) malignancies. Stellwag sign This refers to decreased blinking frequency seen in thyroid ophthalmopathy. Summerskill sign This refers to the bilateral upper- and lower-lid retraction associated with severe liver disease. Tinel sign This refers to the tingling sensation elicited by tapping along the path of a regenerating nerve following injury. It helps to delineate the extent of nerve regeneration. The Tinel sign also can be observed in tardy ulnar palsy (palpation at the elbow) and carpal tunnel syndrome (tapping at the wrist). Trendelenburg sign This refers to the pelvic tilt toward the side of the unaffected raised leg when walking in patients with lesions of the superior gluteal nerve. Trombone tongue This is seen in patients with chorea. It refers to the unsteadiness of the tongue when the patient tries to protrude it outside the mouth. Tullio phenomenon This refers to the induction of vertigo and nystagmus with acoustic stimuli in patients with labyrinthine disease. von Graefe sign This refers to the lid lag on down gaze in patients with thyroid ophthalmopathy. Definition of Terms Apoplexy - Stroke (see definition of Stroke) Cataplexy - Sudden fall, usually due to loss of muscle tone; may be precipitated by sudden changes in affect or mood in narcolepsy (see definition of Narcolepsy) Cerebritis - Inflammation of the cerebral hemispheres

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Encephalitis - Inflammation of the brain and brainstem structures Encephalopathy - Dysfunction of the brain Epilepsy - Recurrent seizures (see definition of Seizure) Mononeuropathy - Dysfunction of individual nerves Mononeuritis multiplex - Dysfunction of multiple single nerves Myelitis - Inflammation of the spinal cord Myelopathy - Dysfunction of the spinal cord Myopathy - Primary muscle disease Myositis - Inflammation of the muscles Narcolepsy - Sudden attacks manifesting as an uncontrollable urge to sleep Neuronopathy - Dysfunction of the cortical, cranial, or spinal neurons Neuropathy - Dysfunction of the cranial or spinal nerves Polyneuropathy - Bilateral symmetric ascending (stocking and glove) or descending dysfunction of the peripheral nerves Radiculopathy - Dysfunction of the nerve roots Seizure - Subjective or objective behavioral manifestation of an abnormal and excessive electrical discharge in the CNS Stroke - Sudden onset of a neurological deficit, also known as a cerebrovascular accident 1. HEAD INJURY Head injury is an exceptionally common form of injury world-wide. Avoidance of head injury is an exceptionally difficult task to address in the short term but obviously needs major attention. An approach to the head injured should be one that addresses the avoidable complications and recognizes these complications so that early treatment can be embarked upon. The most important area of concern is the awareness of the pathophysiologic events that follow the primary injury. The primary injury is the immediate insult to the tissues of the head including the intracranial contents. This primary insult could be focal or diffuse. The damage done in the brain by the primary injury can for all intents and purposes not be undone. It has been found that this primary injury very often is complicated by secondary injury. It is the secondary injury that is avoidable. It is therefore vitally important to know about the causes of secondary brain injury. Secondary Brain Injury: Systemic causes: hypotension, hypoxia, hypoglycaemia, anaemia, hypothermia, hyperthermia, hypocapnea, hypercapnea, hyperglcaemia, acid-base disturbance, electrolyte disturbance. Intracranial cause: Mass lesion, cerebral swelling, cerebral blood flow alterations, cerebral vasospasm, seizures, infection, hydrocephalus. The aim of early treatment is therefore to prevent secondary damage by early detection of the formation of mass lesion, by preventing damaging secondary events caused by ischaemia, hypotension and seizures etc. The management of head injury is heavily dependent in many cases on the availability of specialized facilities.

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There are vast distances that have to be covered to transfer critically injured patients in this country. In many critically injured patients with head injury these factors all play major roles in eventual outcome. The Glasgow Coma Scale (GCS) is the only internationally recognized clinical grading system and is used extensively in this country. The Glasgow Coma Scale was developed in order to standardize the neurologic assessment of patients with head injury. It was specifically designed to be easily performed based upon clinical data, and to have a low rate of interobserver variability. In addition, the Glasgow Coma Scale score is correlated with outcome in that patients with a higher Glasgow Coma Scale score have a statistically better outcome than patients with a lower Glasgow Coma Scale score. The Glasgow Coma Scale score is determined by adding the values for eye opening, verbal response, and motor response. Possible values range from 3 to 15. Note that this scale rates the best response only. In patients who are intubated, in whom assessment of best verbal response cannot be performed, notation of this is made in the Glasgow Coma Scale score by adding a "t" to the end of the score. In patients who are intubated, the best possible score would therefore be 11t. Certain numerical values of the Glasgow Coma Scale have particular clinical significance. Patients with a Glasgow Coma Scale of 7 or less are considered to be comatose. Patients with a Glasgow Coma Scale score of 8 or less are considered to have suffered a severe head injury. Glasgow Coma Scale:

Points Best Eye Opening

Best Verbal Response Best Motor Response

6 - - Obeys

5 - Oriented Localizes pain

4 Spontaneous Confused Withdraws to pain

3 To speech Inappropriate Flexor (decorticate)

2 To pain Incomprehensible Extensor (decerebrate)

1 None None None The following table illustrates the Glasgow Coma Scale (GCS): 3 clinical areas are assessed. Eye opening designated E. Verbal response designated V. Motor response designated M. E = 1 if there is no eye opening. E = 2 if there is eye opening as a response of painful stimulus. E = 3 if there is eye opening in response to the spoken word. E = 4 spontaneous eye opening. V = 5 oriented V = 4 confused/disoriented V = 3 inappropriate words

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V = 2 incomprehensible V = 1 no verbalization. M = 6 obeys commands M = 5 localizes stimulus M = 4 withdraws from stimulus M = 3 spastic flexion response (posturing) M = 2 spastic extension response (posturing) M = 1 no response. By using the above the injuries can be graded into severity scale. Severity category Glasgow Coma Sore Minimal 15. No loss of consciousness or amnesia. 14. or 15 plus amnesia or Mild brief (<5mins) LOC, or impaired alertness or memory. Moderate 9-13, or LOC>5mins., or focal neurologic deficit. Severe 5-8 Critical 3-4 LOC = Loss of Consciousness. With all the above in mind the following approach is suggested. Assess patient with the use of GCS and also pupillary signs and other neurological signs. 1. Head injury – minimal (GCS = 15) The injury site is treated appropriately. Symptomatic treatment is given. The patient can be discharged with the advice of a good rest, at home, overnight. A head injury chart could be very helpful. 2. Head injury – mild (GCS 14-15) Treat the injury site. In the case of an open wound a skull x-ray id helpful to exclude underlying fracture. These cases should be observed for 24 hours or longer depending on progress. If in any doubt regarding improvement or if deterioration supervenes a computerized tomography (CT) of the brain should be obtained. 3. Head injury – moderate (GCS 9-13) All must be admitted and observed neurologically. A CT scan of the brain must be obtained. Skull x-rays are not necessary but cervical x-ray may be indicated depending on the clinical evaluation. If on CT scan mass lesion is diagnosed the patient will have to be sent to a neurosurgical unit. If CT brain scanning facilities are not available and the patient has signs of papillary inequality, localizing signs or if any doubt exists regarding urgency of the case, no time should be wasted and the patient should be transferred to the applicable referral center. Arrangements must be made with the trauma unit and the Neurosurgical doctor on call. These cases have to be transferred with an adequate intravenous line and oxygen per face mask. Emergency room management A quick thorough assessment is made.

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A. Systemic survey: Vital signs. Other injuries (cervical, chest, etc) Mechanism of injury (include velocity, caliber, distance, homicide or suicide) Baseline neurological state (always grade with Glasgow Coma Score) Document the head wounds. B. Resuscitation: This proceeds simultaneously with the above systemic survey. Airway: In all cases of Glasgow Coma Score (GCS) < 8 intubate. If there is no breathing problem allow patient to breath spontaneously via the tube and give oxygen per tube. If there is apnea of hypocapnia ventilate. N.B. do not hyperventilate. Normoventilation should be instituted. Cardiovascular: prevent hypotension and hypovolaemia. Keep normovolaemic. If at all possible place a central line for measuring central venous pressure and this also provides a reliable line for fluid therapy. Control Haemorrhage: external scalp haemorrhage is not a frequent problem with compressive bandage. C. Neurological Assessment: GCS. Document in the standard way i.e. E. = -/4.,V. + -/5., M. = -/6. Total score = -/15 Pupillary size. Brainstem signs. Localizing signs. All patients should be loaded with an anticonvulsant e.g. Phenytoin Sodium (Epanutin) 10mg/Kg body weight (in adults a dose of 1 gm in 200ml of normal saline is infused over 30-60 minutes). D. Radiologic Evaluation: If you are in peripheral hospital do not waste time refer to a center with Neurosurgical facilities. If in a hospital with neurosurgical facilities the patient should be sent for a brain CT and cervical x-rays. A chest x-ray is of course mandatory if central line has been placed and or if chest injury is suspected. E. Salvageability: If GCS = 3-5 following adequate stabilization the prognosis is usually poor. However, keep in mind the possibility of using cases as an organ donor and treat appropriately. Patients with a GCS = 6-8 may have a reasonable prognosis and should be referred for neurosurgical assessment. F. Other important issues: List all medication and times given. Provide telephone numbers of relatives and if possible get relatives to sign consent for surgical procedures. Give broad spectrum prophylactic antibiotic Do not ventilate unless there is a specific reasons. Indications for ventilation. 1. Respiratory indications other than of head injury. 2. Signs of pending cerebral herniation. 3. Hypercapnea. 4. Poor tolerance of endotracheal tube would need sedation. The sedation may well cause further respiratory problems in the face of head injury and therefore it may be safer to ventilate this patient. NB sedation can cause hypotension, keep eye on CVP.

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If ventilation is required – do not hyperventilate but normoventilation is what should be strived for. Special Situations/Precautions. 1. Children. Refer all children with significant head injury and associated alteration in level of consciousness to a neurosurgical unit. Special care and expertise is required when intubating children. This is in fact a highly specialized task and should be undertaken by an experienced critical care doctor or anesthetist. If there is no expertise in intubation do not intubate but use nasopharyngeal tube/airway and supply oxygen per mask. Position patient on side or semi prone. Take care of cervical spine and the patient must be fitted with a cervical brace. Intravenous fluids in children have to be monitored carefully. Maintain normal intake or monitor with CVP. Do not overhydrate, this can cause rapid cerebral swelling and compromise outcome significantly. Know normal haemodynamic parameters in children of all ages. 2. The intoxicated head injury patient. If these patients have a GCS < 8 they should be referred for a CT scan. 3. The deteriorating head injury patient. The patient has a dilated pupil and altered level of consciousness. Also may have localizing signs. a. If distance is too far to referral center, do emergency burrholes and if mass lesion is found e.g. extradural haematoma/subdural haematoma – proceed to craniectomy and evacuate. Once patient is stable transfer to Neurosurgical or any critical care unit for further evaluation and CT scan of brain. Do not hesitate to use lines of communication for assistance. b. If no facilities available (i.e. theatre facilities) contact nearest Neurosurgical/critical care unit for advice. c. If within 1 hour away from a specialized unit a case could be made out for using a diuretic (Mannitol is drug of choice). Give 0.25 to 1 gram/kg body weight, of Mannitol by intravenous route immediately. Make sure that patient is catherized. Make sure that this patient is normal to slightly hypervolaemic. Management of Concussion, Brain Contusion and Diffuse Axonal Injury. Concussion. Cerebral concussion is a diffuse brain injury thought to be caused by acceleration-deceleration injury to the brain. Cerebral concussion is a spectrum of injuries, ranging from mild to severe. Mild concussion is defined as no loss of consciousness with transient neurologic disturbance. Moderate concussion is defined as loss of consciousness with complete recovery occurring in less than 5 minutes. Severe cerebral concussion is defined as unconsciousness lasting greater than 5 minutes. Evaluation and treatment of patients with cerebral concussion remains controversial. Workup includes complete history and physical examination, with neurological examination. Other tests include cervical spine x-rays and other radiographs as indicated, blood alcohol level and urine drug screen, and CT scan of the head in all patients except those who are completely asymptomatic and neurologically normal. Treatment of patients with cerebral concussion who have a Glasgow Coma Scale score of 14 or 15 is usually expectant. Most patients should undergo hospital admission with frequent neurological examinations. These include all patients with an abnormal CT scan, history of loss of consciousness, decreased or decreasing level of consciousness, severe headache, under the influence of alcohol or drugs, have physical examination

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evidence of CSF rhinorrhea or otorrhea, significant associated injuries, no reliable companion at home, unable to return promptly, or are amnestic for the injury. Only those patients who do not manifest any of the prior criteria should be considered for discharge from the hospital. If hospital discharge is considered, any of the previously listed signs or symptoms should prompt a return to the hospital. A written head injury "warning sheet" should be issued. Neurosurgical follow-up should be scheduled. In addition to frequent neurologic examinations, patients admitted after cerebral concussion may be treated with Tylenol or very mild doses of narcotic pain medication for headache. Nausea and vomiting, which are frequently present after mild or severe concussion, should be treated with non-phenothiazine antiemetic medication. Discharge may be considered when the patient is neurologically normal, nausea and vomiting has ceased, and headache has ceased or is adequately controlled. All patients who have suffered a cerebral concussion should be counseled regarding the possible occurrence of "post concussive syndrome". Prominent symptoms include headache, mild impairment of memory, dysequilibrium, and alteration of mood. These symptoms usually regress spontaneously but may persist for weeks to months. Diffuse axonal injury. Diffuse axonal injury is the most severe form of diffuse brain injury. It is felt to be the most common cause of prolonged posttraumatic coma that is not due to mass lesion or ischemia. Diffuse axonal injury is characterized by focal hemorrhagic lesions involving the corpus callosum, rostral mid brain, superior cerebellar peduncles combined with microscopic evidence of widespread axonal damage. Patients with diffuse axonal injury frequently manifest decorticate or decerebrate posture and autonomic dysfunction in addition to their prolonged coma. Elevated intracranial pressure is frequently absent. Care is primarily supportive. In patients with prolonged coma, the prognosis is generally poor, with a 50% mortality and with an approximately 25% incidence of favorable outcome. Cerebral Contusion. A cerebral contusion is a focal brain injury caused primarily by impact of the brain surface and the bony ridges of the calvarium. Cerebral contusions are frequently found in the region of the frontal poles, anterior skull base, adjacent the sphenoid ridge, and at the temporal poles. Other locations include the cerebellar hemispheres and the occipital poles. A characteristic pattern of cerebral contusion called the "coup and contrecoup" injury is frequently seen. The coup contusion occurs at the sight of impact and the contrecoup contusion occurs in the brain at the point diametrically opposite the point of impact. Treatment of cerebral contusion is guided by the neurologic examination. The patient should be admitted to the hospital for observation and frequent neurologic examinations. Intracranial pressure monitoring and treatment should be instituted for the comatose patient. While surgical treatment, consisting of debridement of the contused brain tissue, is not routinely recommended, it can be considered in patients with refractory intracranial hypertension. Management of Acute Subdural and Epidural Hematoma. Subdural hematoma. In the acute traumatic subdural hematoma, blood collects between the dura mater and surface of the brain. Most commonly, the bleeding results from tearing of bridging veins

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located over the convexity of the brain surface. Bleeding originating from a small cortical artery represents the second most common source. Associated intracranial lesions, particularly cerebral contusions, are found in at least 50% of patients with acute traumatic subdural hematoma. Patients presenting with acute traumatic subdural hematoma may range from normal to deeply comatose. Unlike the epidural hematoma, to be described later, the most common presentation of the patient with an acute traumatic subdural hematoma is that of a patient rendered unconscious at the time of injury without regaining consciousness prior to presentation. Neurologic findings may be secondary to mass effect, elevated intracranial pressure, and/or associated brain injuries. Elevated intracranial pressure is a common finding and evaluation and treatment of elevated intracranial pressure, as outlined above, should be instituted immediately. The acute traumatic subdural hematoma is most commonly treated surgically. Observation should only be considered in those patients with small (less than 10 mm thick) subdural hematomas who are neurologically intact. Because the acute traumatic subdural hematoma consists of solid blood clot, burr hole drainage is inadequate for relief of mass effect. A craniotomy should be performed and all easily assessable blood clots should be removed. Postoperatively, patients frequently manifest intracranial hypertension, and this should be treated. Outcome after treatment of acute traumatic subdural hematoma is related to a number of factors, particularly preoperative neurologic status. Mortality ranges from greater than 75% in those patients who present with a GCS of 3 to 5 to minimal in patients who present with GCS of 12 to 15. Time from injury to surgical decompression, elevated intracranial pressure, and associated brain lesions also have a detrimental effect on outcome. Epidural hematoma. In the acute epidural hematoma, blood collects between the inner surface of the calvarium and the dura mater. Most commonly, the acute epidural hematoma results from fracture of the skull, stripping the dura mater from the inner table of the skull, and causing laceration of meningeal vessels or dural sinuses. Bleeding from the middle meningeal artery is responsible for many supratentorial epidural hematomas. In contrast to the subdural hematoma, the patient harboring an acute epidural hematoma may have an initial loss of consciousness, followed by a brief "lucid" interval, followed by progressive neurologic decline. This presentation is seen in approximately 1/3 of patients having an acute epidural hematoma. Treatment of acute epidural hematoma is generally surgical. Patients with small epidural hematomas not traversing a meningeal artery vein or major sinus, who present greater than 6 hours after injury may be considered for a nonoperative therapy. However, admission with frequent neurologic examination and a low threshold for repeat CT scanning is mandatory. For all other patients, operative treatment is recommended. As with the acute subdural hematoma, the acute epidural hematoma is comprised of a solid blood clot. Therefore, burr hole drainage is inadequate for removing the intracranial mass. A craniotomy should be performed and the entire blood clot evacuated. Postoperatively, the patient is monitored for signs of elevated intracranial pressure. Elevated intracranial pressure, if detected, is treated. As in the acute traumatic subdural hematoma, outcome after treatment of acute epidural

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hematoma is related to a variety of factors, the most important being preoperative neurologic status. Mortality ranges from less than 15% in those patients who present with GCS of less than 8 to very low in patients who present with GCS 8 to 15. Management of Elevated Intracranial Pressure in Head Trauma: Brain injury after acute head trauma can be divided into two categories. The first category is primary injury, which is suffered at the time of impact. The second category is secondary injury, which may occur at any time from that point forward. One of the most important causes of secondary brain injury in head trauma is felt to be elevated intracranial pressure (ICP). In treatment of the patient with head trauma, the possibility of elevated intracranial pressure should always be considered. Management of the traumatized patient begins with the primary survey and resuscitation. Airway patency with cervical spine control: It is important to establish the presence of a patent airway. If such an airway is not present, one should be established. This may include the use of chin lift or jaw thrust, clearance of foreign bodies, endotracheal intubation, or creation of a surgical airway. It is important to consider that the cervical spine may be injured and that it should be maintained in a neutral position during any of the above maneuvers. Breathing control. The chest should be examined and the rate and depth respiration determined. Inadequacy may indicate the need for mechanical ventilation. High concentrations of oxygen should be administered. Pneumothorax should be treated. Circulatory and hemorrhage control. The quality, rate, and regularity of the pulse should be determined. Sights of major hemorrhage should be identified and treated. Disability. A brief neurologic examination should be performed. The Glasgow Coma Scale should be determined. Pupils should be assessed for size, equality, and reaction. During the secondary survey, a more complete neurologic examination should be performed including evaluation of the patient’s strength, sensation, reflexes, and remaining cranial nerves. Following the secondary survey, appropriate imaging studies should be obtained. In a patient with obvious craniofacial trauma, mechanism of injury sufficient to produce brain injury, or a disturbed level of consciousness, a CT scan of the head without contrast should be performed. The presence of fractures, foreign bodies, space occupying lesions, or hemorrhage should be noted, as well as the ventricular size. Intracranial pressure monitoring should be considered in the following situations: Patients with an abnormal admission CT scan and Glasgow Coma Scale score of 3 to 8 after cardiopulmonary resuscitation, or, patients with a normal head CT with a Glasgow Coma Scale score of 3 to 8 and the presence of two or more of the following features: Age over 40 years, unilateral or bilateral motor posturing, systolic blood pressure less than 90 mmHg. The current preferred modality for monitoring of intracranial pressure is the placement of a ventricular catheter (ventriculostomy). Use of fiberoptic or strain gauge pressure monitors can be considered. Elevated intracranial pressure has been shown to have definite prognostic implications in a patient with severe brain injury. In addition, it is generally held that treatment of elevated intracranial pressure may improve outcome in the patient with severe brain injury. The currently recommended threshold for treatment of elevated intracranial pressure is 20 to 25 mmHg. Interpretation and treatment of intracranial pressure based on

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this threshold value should be corroborated by frequent clinical examination and assessment of the cerebral perfusion pressure. Current recommendations suggest that CPP should be a minimum of 60 to 70 mm of mercury. It is important to consider that, while MAP is an important determining factor in the CPP, it has also been shown that low MAP is an independent predictor of poor outcome. After elevated intracranial pressure has been identified, treatment should be initiated. In general, treatment should proceed in a stepwise fashion, beginning with the least onerous treatment modalities. Escalation of treatment should proceed only after failure of less onerous modalities. The suggested hierarchy of treatment includes the following therapeutic modalities: Body positioning. The head should be elevated 30 degrees. The neck should be maintained in a neutral position. Compression of the jugular veins should be avoided. Maintenance of homeostasis. Euvolemia should be established. Arterial blood gases should be measured with the goal of maintaining the PO2 in the 90 to 100-mm mercury range and the PCO2 in the 35 to 40-mm mercury range. Mild sedation. This is most frequently carried out using a combination of benzodiazepines and/or narcotics. External ventricular drainage. At this stage, placement of a ventriculostomy, if not done previously for ICP measurement, should be considered. The reservoir is generally placed 5 to 10 cm above ear level or, alternatively, placed at ear level and opened at regular intervals. Use of osmotic diuretics. Mannitol is the most commonly used osmotic diuretic. It is most frequently given in a dose of 0.25 to 1.0 grams/kg I.V. over 15 minutes. If the effect of treatment with Mannitol is transient, the dose may be repeated, so long as the serum osmolality remains less than or equal to 320 mOsm/L and the patient remains euvolemic. Moderate hyperventilation. At this stage, moderate hyperventilation to a PCO2 of 30 to 35 mm of mercury can be considered. Second tier therapies including barbiturate therapy. At this stage, barbiturate therapy can be considered. Pentobarbital is the most commonly used barbiturate for the treatment of refractory intracranial hypertension. Recommended loading dose is 10 mg/kg over 30 minutes followed by a maintenance dose of 1 mg/kg per hour as a continuous infusion. The dose is then titrated to achieve serum Pentobarbital levels in the range of 3 to 4 mg/dl or an electroencephalographic pattern of burst suppression. Potential complications of this modality of treatment are numerous, with hypotension being the primarily dose-limiting toxicity. Barbiturate treatment of refractory intracranial hypertension has been shown to decrease mortality but has not been shown to improve neurologic outcome. The above treatment algorithm assumes that all significant cranial space-occupying lesions have been appropriately surgically treated. During implementation of the above algorithm, it is important to consider the possibility that a new intracranial lesion has developed. Because of this, a repeat CT scan of the head should be considered prior to escalation of therapy. Note that the above treatment algorithm does not include the use of corticosteroids. The use of glucocorticoids is not recommended for improving outcome or reducing intracranial pressure in patients with severe head injury. The routine use of prophylactic anticonvulsant medication is not recommended for the prevention of posttraumatic seizures in the patient without a premorbid seizure disorder. The use of anticonvulsants

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may be considered, in the first 7 days after injury, to prevent early posttraumatic seizures in patients who are at high risk. Phenytoin and carbamazepine are the most commonly used agents. Finally, nutritional support of brain injured patients should be instituted within 7 days of injury. Anti epileptics Load all of the following patients with Phenytoin (Diphenylhydantoin/Epanutin) 10mg-20mg per Kg as IV infusion. Usually in adults we give 1 gram in 200ml of Saline (NB – Phenytoin is not compatible with any glucose containing fluid) over ½ hour – 1 hour. In children <2 years – Phenobarbitone 10mg per Kg as slow IVI injection should be given. Indications for anti epileptics in acute head trauma: 1. Severe head injury – GCS < 8. 2. Head injury with localizing signs. 3. In-driven skull fracture. 4. Any case where an intracranial mass lesion has been diagnosed. 5. Any case of intracerebral contusion. Brain Herniation Syndromes in Trauma: Distortion of the midline brain structures secondary to brain trauma may lead to specific combinations of signs and symptoms which are collectively referred to as herniation syndromes. In general, these symptoms result from the distortion of midline brain structures secondary to brain swelling, hydrocephalus, or intracranial mass lesions. While numerous herniation symptoms have been described, the two most commonly seen syndromes in the setting of trauma are uncal herniation and tonsillar herniation. Uncal herniation: Most often results from a laterally placed mass displacing the brain stem contralaterally and pushing the uncus of the temporal lobe medially over the tentorial edge. Early Sign: Ipsilateral pupillary dilation Late Signs: Complete ipsilateral third nerve palsy,loss of consciousness,contralateral hemiplegia (secondary to mass), ipsilateral hemiplegia (secondary to compression of contralateral cerebral peduncle against edge of tentorium (Kernohan’s notch), flaccid paralysis’ Tonsillar herniation: Results from downward displacement of the cerebellar tonsils through the foramen magnum, causing compression of the cervicomedullary junction. Frequently secondary to posterior fossa mass. May be precipitated by lumbar puncture in the presence of such a mass. Signs: Head tilt/neck pain, respiratory arrest, loss of consciousness, flaccid paralysis. PENETRATING MISSLE INJURY TO THE HEAD Pathology Can be defined into: high and low velocity injuries. For practical purposes high velocity injuries to the head are usually fatal. Factors which influence the severity of injury are: Muzzle velocity, distance of flight, caliber, trajectory through cranium, eloquence of damage brain, vascular injury, and subsequent complications.

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Primary injury is the injury caused by the impact. The damage done by the primary insult cannot be reversed. The direct impact causes crushing and laceration of tissue as the missile penetrates skin, skull and brain. Bits of fragmented bone can act as secondary missiles and cause more widespread damage. High-speed shockwaves are generated when missile enters a tissue medium and causes a pulsating temporary cavity. The size of the cavity can be may times the size of the missile. The cavity essentially forms a tract, which contains blood clot, in-driven debris, necrotic and contused brain tissue. The pulsations of the cavity generate pressure waves, which radiate to distant locations. Secondary injury is caused by a number of systemic disturbances which may accompany severe head injury. These are hypotension, hypoxia, hypo/hyper-glycaemia, hypo/hyper-capnia. There are also a number of secondary intracranial events that add to the primary injury. These include intracranial haematoma, raised intracranial pressure, seizures to name a few. It is quite clear that the primary injury cannot be reversed but secondary injuries can be prevented, and some diagnosed and treated early to prevent the effects of some of the secondary events. Penetrating Trauma. Penetrating injuries include all injuries where the scalp and skull are violated by foreign objects including knives, sticks, pencils, arrows, and bullets. Low velocity injuries, such as those produced by a knife blade, produce brain injury along the tract of the knife. High velocity injuries, such as those produced by a bullet, produce both local injury along the tract of the bullet, as well as remote injury in the cavity produced in the wake of the bullet. The size of the cavity produced by a bullet is related to its kinetic energy, as well as its shape. The kinetic energy is proportional to the mass of the bullet as well as the square of its velocity. The shape of the bullet not only affects the velocity, but also its ability to transfer its kinetic energy to the brain tissue. Bullets that tumble or deform on impact transfer a greater proportion of their kinetic energy to brain tissue and thus produce a more severe injury. After resuscitation and primary survey, an evaluation of the patient with a penetrating injury includes a thorough physical examination and neurological examination. The location of entry and exit wounds should be well documented. Extent of tissue loss should likewise be documented. All patients who have had penetrating brain injury should undergo a CT scan of the head. Coronal CT scan of the head should be considered in patients with involvement of the anterior skull base. Cerebral angiography should be considered in patients where vascular injury is suspected. Cerebral angiography should be given particular consideration where the tract of the injury passes close to a major vascular structure or in patients with a significant subarachnoid hemorrhage or delayed hematoma. As in patients with severe non-penetrating brain injury, elevated intracranial pressure should be suspected. The algorithm for this is described above. In addition, in patients with penetrating brain injury, intracranial pressure monitoring is indicated when it is not possible to assess the neurological examination accurately or when the need to evacuate a mass lesion is unclear.

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As with the open depressed skull fracture, most penetrating brain injuries require surgical treatment. Entrance and exit wounds. Treatment of small bullet entrance wounds where the scalp is not devitalized and the patient has no significant intracranial pathology may be treated with local wound care and closure. More extensive wounds with nonviable scalp, bone, or dura may require operative debridement before primary closure and dural grafting. Watertight dural closure is recommended. This includes patients with significant fragmentation of the skull. Intraparenchymal lesions. Intraparenchymal lesions resulting in significant mass effect may require debridement of necrotic brain tissue and removal of easily accessible bone fragments. This includes patients with significant intracranial hematomas. Injuries resulting in communication between an open-air sinus and the intracranial space should be closed in a watertight fashion. Routine removal of bone fragments or missile fragments remote from the entry site is not recommended. Vascular injuries detected on arteriography may require surgical or endovascular treatment as indicated. Cerebrospinal fluid leaks which do not close spontaneously or which do not resolve after the primary surgery should be treated with temporary CSF diversion. Those which do not respond to temporary CSF diversion may require surgical treatment. Patients with penetrating brain injury should be administered broad-spectrum antibiotics prophylactically. The duration of this treatment is somewhat controversial. Finally, the use of anti-seizure prophylaxis in the first week of penetrating brain injury is recommended to prevent early posttraumatic seizures. As with severe non-penetrating brain injury, long-term prophylactic treatment with anticonvulsants to prevent late posttraumatic seizures is not recommended. Principles of Management of Open, Closed, and Basilar Skull Fractures. Open skull fractures. The treatment of skull fractures with overlying laceration is primarily based on whether the fracture is depressed or non-depressed. Open non-depressed fractures may be treated with inspection, cleansing, and scalp suturing with an acceptably low rate of infection. Open depressed skull fractures present a significant risk of infection. They are generally treated with operative irrigation, debridement, and removal of the depressed fragments. Frequently, this will necessitate further surgical procedures to correct the resulting cosmetic deformity. Closed fractures. Closed skull fractures require no specific treatment. As noted above, the patient harboring a skull fracture is at increased risk of formation of epidural hematoma. Patients harboring this injury should be treated as for those patients with severe concussion, unless symptoms of elevated intracranial pressure develop. Traditionally, closed depressed skull fractures were treated surgically to elevate the depressed fragments. It has since been shown that this practice does not result in a decreased incidence of posttraumatic epilepsy and has therefore been abandoned. Treatment of patients with depressed, closed fractures, except where there is a significant cosmetic deformity, should be treated as outlined above for closed, non-depressed fractures. Basilar skull fractures. A basilar skull fracture involves the cranial base. The most common sites are the floor of anterior cranial fossa and the temporal bone. Evidence that a patient may have suffered a

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basilar skull fracture includes "raccoon eyes" and "battle sign" (bruising posterior to the ear, possibly including the mastoid process). Most basilar skull fractures do not require treatment in the absence of associated brain injury. They are a sign that a significant blow has been delivered to the cranium. Most patients with significant basilar skull fracture should be observed with frequent neurological examinations for 24 hours after the injury. Occasionally, complications of basilar skull fracture may result. These include posttraumatic cerebrospinal fluid leakage, optic nerve injury, and facial nerve injury. The incidence of posttraumatic cerebrospinal fluid leak after a closed head injury is approximately 2%. The most common sites of cerebrospinal fluid egress are the nose (CSF rhinorrhea) and ear (CSF otorrhea). Most traumatic CSF leaks resolve with nonoperative treatment including head elevation. It is important to insure that the CSF leakage does resolve, as persistent CSF rhinorrhea carries with it an approximately 25% risk of meningitis, as well as a risk of tension pneumocephalus. Posttraumatic CSF leak. Treatment of the posttraumatic CSF leak which does not resolve with head elevation includes repeated high volume lumbar punctures, as well as continuous catheter CSF drainage. There is a finite risk of inducing tension pneumocephalus using those modalities. For leaks which persist despite these measures, surgical treatment should be considered. Wound Care Patients who have lacerations, abrasions and cuts of the scalp have appropriate standard wound care. Sepsis is associated with poor primary wound care. All debris in the wound should be meticulously removed and washed out with saline or antiseptic. In cases of open in-driven skull fracture with dural penetration the wounds should be primanly washed out with N Saline and debrided locally. Do not remove bone fragments. Refer the patients for CT scan and to neurosurgical center. MANAGEMENT OF CHRONIC SUBDURAL HEMATOMA. As described above, the chronic subdural hematoma is a collection of blood and blood products between the inner surface of the dura mater and the outer surface of the brain. Unlike the acute traumatic subdural hematoma, onset of symptoms and detection of the subdural hematoma occurs much later in the course. The hallmark of the chronic subdural hematoma is blood products, visualized on the CT scan, which are isodense or hypointense with respect to brain tissue. It is theorized that, like the acute traumatic subdural hematoma, the source of the blood products is lacerated bridging veins resulting from acceleration-deceleration forces applied to the skull. While this is usually the result of trauma, trauma may be mild, remote, and not remembered by the patient or family. Many patients who present with a chromic subdural hematoma have one or more risk factors. These risk factors include; advanced age and cerebral atrophy, male sex, coagulopathy. intracranial hypotension secondary to CSF shunting procedures, chronic alcoholism. Chronic subdural hematomas tend to enlarge slowly over time. The most common mechanism of enlargement appears to be multiple episodes of re-bleeding, however, other mechanisms may also be important. Symptoms at presentation include symptoms of increased intracranial pressure (headache, papilledema, decreased level of consciousness), as well as those of hemispheric mass effect (hemiparesis, dysphasia, tremors, and dystonia. Seizures occur occasionally.

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Treatment of chronic subdural hematoma is generally surgical. While treatment with prolonged bedrest, head elevation, and osmotic diuretics has produced acceptable results, the risks of prolonged immobilization in these generally debilitated patients frequently outweigh the benefits. There are multiple surgical options for the treatment of chronic subdural hematoma including; twist drill hole and drainage, multiple burr holes and drainage, craniotomy and drainage with stripping of membranes. Hematomas that are not fully liquefied may require craniotomy. In addition, recurrence rate after evacuation of chronic subdural hematoma is substantial. Postoperatively, elevated intracranial pressure is unusual. Patients are generally maintained supine with minimal elevation of the head for at least 24 hours to allow some re-expansion of the brain. Because of the substantial rate of recurrence, neurosurgical follow-up is essential. Chronic subdural hematoma in children. Like the adult chronic subdural hematoma, blood and blood products, in the childhood chronic subdural hematoma, accumulate between the inner surface of the dura and the brain surface. In children, it is particularly important, and sometimes difficult, to distinguish between the chronic subdural hematoma and the subdural hygroma, in which cerebrospinal fluid collects between the dura and arachnoid membrane. Furthermore, low-density fluid may collect between the arachnoid and pia mater secondary to communicating hydrocephalus. While trauma is the most common cause of chronic subdural hematoma in children, the possibility of non-accidental trauma (child abuse) must always be considered, particularly in children less than 2 years of age. Coagulopathy remains a major risk factor. In children, presenting symptoms are usually those of elevated intracranial pressure including vomiting, lethargy, irritability, or increase in the head size. Seizures are also seen. The treatment of chronic subdural hematoma in children is different than that of adults. Unlike adult patients, very young patients may have an open fontanel, facilitating percutaneous aspiration of the subdural hematoma. Failure of this treatment modality generally requires placement of a subdural to peritoneal shunt. MANAGEMENT OF PAEDIATRIC TRAUMATIC BRAIN INJURY PATHOPHYSIOLOGY The disproportionately larger and heavier head and weak neck muscles of children render them particularly prone to head injury after trauma. The primary cause of head injury varies with age. In infants, non-accidental injury should be considered; toddlers frequently suffer falls, whereas road traffic accidents and sports related injuries are more common in older children and adolescents. Primary Brain Injury Occurs at the time of in initial injury, and may result in brain contusion, laceration, and haematoma formation or diffuse axonal injury. Younger children are more likely to develop subdural haematomas and diffuse cerebral oedema without a skull fracture, whereas in adolescents, skull fractures, contusions and extradural haematomas are more common. Secondary Brain Injury

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Occurs in the minutes to days after the initial injury and may be due to hypotension, raised intracranial pressure or cerebral ischaemia. Secondary brain injury is worsened by hypoxia, hypercarbia, anaemia, pyrexia, hypoglycaemia or hyperglycaemia. Secondary brain injury may be modified by simple clinical interventions, the most important of which are avoidance of hypotension and hypoxia. Intracranial pressure The brain is enclosed within the rigid skull. The intracranial pressure (ICP) is determined by the volume of the brain tissue, the cerebrospinal fluid (CSF) volume, and the cerebral blood volume. Increase in the volume of the intracranial contents, for instance due to cerebral oedema or an extradural, subdural or intracerebral haematoma, will result in increased intracranial pressure. Compensation is possible for small rises in ICP by increased CSF absorption and a reduction in intracranial blood volume. Infants can compensate for slow increases in intracranial pressure because of their open fontanelles and suture lines; however sudden acute changes in intracranial pressure are not well tolerated at any age. If compensatory mechanisms are overwhelmed, intracranial pressure will increase rapidly and the brain will herniate through the structures within the skull or the foramen magnum (‘coning’) to cause coma and death. Cerebral perfusion pressure The cerebral perfusion pressure (CPP) is the effective blood pressure that perfuses the brain and is defined as: CPP = MAP – ICP where MAP is the mean arterial pressure. The MAP and therefore CPP vary with age, as does the ICP. Table 1 shows the normal systolic BP in children, also the optimal level systolic BP to be achieved in children with traumatic brain injury, that is, >95th centile for age. Cautious fluid resuscitation and infusion of vasoconstrictors such as noradrenaline may be required. Table 1. Normal systolic blood pressure and optimal systolic blood pressure in children with traumatic brain injury.

Age Normal systolic BP (mmHg)

Optimal systolic BP in traumatic brain injury (mmHg)

<1 year 70-90 >100 1-5 years 80-100 >95 6-11 years 90-110 >105 >12 years 100-120 >120

Typical intracranial pressures are 8–18mmHg in adults and 2–10 mmHg in children. The venous pressure is low under normal circumstances and does not affect the CPP, but abnormally raised venous pressure will reduce CPP. Cerebral blood flow Under normal conditions, cerebral blood flow is maintained at a constant level to meet the metabolic demands of the brain over a wide range of MAP by the process of autoregulation. The autoregulation range for adults is 50-140 mmHg. The autoregulation range is not known in infants and children, but is likely to be around 40-90 mmHg. Cerebral autoregulation is impaired by acute brain injury; in this situation, cerebral blood flow follows cerebral perfusion pressure passively. It is vital to keep the blood pressure

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within the ‘high normal’ range in head injured patients, as hypotension will result in cerebral ischaemia. In the absence of invasive measurement of intracranial pressure, cerebral perfusion pressure should be maintained between 50-70 mmHg, that is, MAP 70-90 mmHg, assuming the intracranial pressure to be 20 mmHg. The MAP may be calculated from: systolic/diastolic BP: MAP = DBP + (SBP-DBP/3). Cerebral perfusion pressure less than 50 mmHg has been demonstrated to be a predictor of poor outcome in severe traumatic brain injury in adults and children. Extreme hypertension will result in increased cerebral blood flow and cerebral oedema and should also be avoided. OTHER FACTORS AFFECTING CEREBRAL BLOOD FLOW AND INTRA CRANIAL PRESSURE Oxygen An adequate supply of oxygen is essential to meet the metabolic requirements of the brain. In addition, hypoxia results in cerebral vasodilatation and increase in cerebral blood flow and hence intracranial pressure. Cerebral blood flow begins to rise when PaO2 falls to 6.7kPa (50mmHg), and doubles at PaO2 of 4kPa (30 mmHg). Hypoxia must be avoided at all times in patients with head injury. Carbon dioxide retention Is a potent cause for cerebral vasodilatation and increase in intracranial pressure. Conversely, hyperventilation resulting in hypocarbia results in cerebral vasoconstriction and at extreme levels will cause cerebral ischaemia. It is important to maintain the carbon dioxide levels within normal range as much as possible (4.5-5.5 kPa). Remember, end tidal CO2 measurements usually underestimate arterial CO2, especially if there is coexisting lung injury or disease. Modest hyperventilation may be used to reduce intracranial pressure in an emergency (but keep PaCO2 > 4KPa, and definitely not below 3.5). Body temperature Has an important effect on cerebral blood flow. For every 1°C increase in body temperature, there is a 5% increase in cerebral metabolic rate leading to an increase in cerebral blood flow and intracranial pressure. Pyrexia should be avoided in the head injured patient, and normothermia/moderate hypothermia is desirable. Excessive hypothermia therapy below 33°C may increase mortality. Blood glucose The brain is critically dependent on a normal blood supply of glucose for metabolism and only has a very small store of glucose in the form of glycogen. Children are more susceptible to hypoglycaemia as the cerebral metabolic rate is higher in children than adults (peak at 6 years). Conversely, hyperglycaemia should be avoided after head injury as it induces lactic acidosis and production of oxygen free radicals and worsens outcomes. It is important therefore to actively seek and treat hypoglycaemia and hyperglycaemia. Seizures Seizures increase the metabolic demands (and therefore oxygen requirements) of the brain and must be treated promptly. Fluid and electrolyte abnormalities

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Hypotonic fluids must be avoided in children with head injury as a fall in plasma sodium will exacerbate cerebral oedema. Plasma sodium and plasma osmolality must be maintained within the high normal range (aim for plasma sodium 150 mmol/l in severe head injury). Children with traumatic brain injury are susceptible to a variety of abnormalities of plasma sodium: Inappropriate antidiuretic hormone (ADH) – hyponatraemia, low plasma osmolality, high urinary osmolality, normo/hypervolaemia, potential cerebral oedema. Treat with fluid restriction if asymptomatic or hypertonic saline if symptomatic (1-2 ml/Kg 3% saline bolus) Cerebral salt wasting – hyponatraemia, high urinary osmolality, hypovolaemia and hypotension. Treat with normal saline bolus Diabetes insipidus – hypernatraemia, high plasma osmolality, low urinary osmolality, hypovolaemia and hypotension Diabetes insipidus occurs as a result of failure of blood supply to the posterior pituitary with loss of ADH production in the posterior pituitary – it should be treated by administration of DDAVP (Desmopressin), however, DI is a late sign in head injury and often heralds brain stem death. Coagulopathy Penetrating injury is associated with release of brain tissue into the circulation, which may result in disseminated intravascular coagulation. Autonomic changes Intense peripheral vasoconstriction and hypertension are often seen in severe head injury. Neurogenic pulmonary oedema Severe head injury may be associated with sudden onset of severe pulmonary oedema leading to hypoxia. Analgesia and anaesthetic agents Pain and anxiety increase metabolic demands and should be treated, avoiding excessive doses of agents that may cause respiratory depression, or alternatively, ventilating the patient electively to allow for this. A small percentage of children with head injury may require surgery to evacuate intracranial haematoma. Volatile anaesthetic agents reduce the metabolic requirements but increase cerebral blood flow and ICP. Halothane increases ICP more than isoflurane and should be avoided if possible. Intravenous anaesthetic agents reduce the cerebral metabolic rate, and also reduce cerebral blood flow and ICP, with the exception of ketamine, which increases ICP. Ketamine should be avoided in head injury patients if possible; thiopentone or propofol are the intravenous agents of choice, along with judicious doses of opioids to obtund the reflex cardiovascular responses to intubation. Suxamethonium will increase ICP transiently only. Suxamethonium is indicated for rapid sequence induction in head injured patients. ASSESSMENT OF NEUROLOGICAL DISABILITY All children suspected of head injury should have regular neurological assessments and assessment of pupil responses. Modified Glasgow Coma Scale for Children

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Rapid neurological assessment of patients with head injury may be made using the AVPU score (Alert, responds to Verbal commands, responds to Pain, Unresponsive). The Glasgow coma scale is a more sophisticated method of assessing and describing level of consciousness and has been modified for use in children (table 2). The motor response is the most accurate predictor of poor outcome; any child with a reduction in motor score below “localizing pain” should be treated as having a severe head injury. Table 2. Modified Glasgow coma score for children

Score Infant/nonverbal child Verbal child Eye Opening: 4

3 2 1

Spontaneous To speech To pain None

Spontaneous To speech To pain None

Verbal: 5 4 3 2 1

Babbles and coos normally Spontaneous irritable cries Cries to pain Moans to pain No response

Oriented Confused Inappropriate words Incomprehensible sounds No response

Best motor response:

6 5 4 3 2 1

Normal spontaneous movement Withdraws to touch Withdraws to pain Abnormal flexion to pain Extension to pain No response

Obeys command Localizes pain Flexion withdrawal Abnormal flexion Extension to pain No response

Table 3. Severity of head injury Severity of head injury Glasgow coma score Mild 13-15 Moderate 9 -12 Severe </=8

Pupil responses Pupil responses are an important clinical sign and should be assessed regularly in all children with head injuries. · Normal response – pupils react symmetrically to light and accommodation · Bilateral fixed and dilated pupils – inadequate cerebral perfusion, possibly irreversible brain injury · Bilateral pupil constriction – early brain herniation through the foramen magnum, injury to the brainstem, side effect of opioids · Unilateral fixed and dilated pupil – herniation of the brain through the tentorium cerebelli within the skull on the same side, optic nerve injury · Unilateral pupil constriction – unilateral brainstem injury, Horner’s syndrome

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MANAGEMENT Children with head injury must be assessed and appropriate management started immediately. Delays, particularly in management of hypoxia and hypotension, worsen outcome. In a child thought to have suffered a minor head injury only, the following signs are worrying and merit admission of the child to hospital for close monitoring, including regular neurological assessments: · Patients who are not fully alert · Persistent vomiting, severe headaches Children with moderate to severe head injury should all be admitted for rapid assessment. The following features in the history and clinical condition indicate the possibility of a severe head injury: · History of a fall from a height, a high-speed road traffic accident, or road traffic accident where the child is a pedestrian or a cyclist · Loss or reduced level of consciousness · External sign of skull fracture, including base of skull fracture (‘panda eyes’, blood or CSF in the ear, bruising of the mastoid process behind the ear) · A Glasgow coma score of </= 8 or loss of ability to localise pain on the motor category Immediate management of a child with moderate to severe traumatic brain injury Assess the conscious level and pupil responses at the same time as attending to ‘ABC’ as follows: · Airway with cervical spine immobilisation · Breathing and ventilatory control · Circulation and control of obvious external bleeding · Disability and neurological status, including pupil responses · Exposure – secondary survey with top to toe examination to detect associate injuries (consider non-accidental injury) The first priority is stabilisation of the airway and the cervical spine. Airway patency should be established, taking care of the cervical spine (jaw thrust +/- airway adjuncts), and high flow oxygen should be administered. Cervical spine injuries are uncommon and only occur in about 1% of severe head trauma patients. However, children should have cervical spine immobilisation if there is a suspicion of cervical spine injury, for instance a significant mechanism of injury, a history of loss of consciousness, neck pain or tenderness, another severe (“distracting”) injury or a history of intoxication. A child who is restless and disoriented should not be forced to wear a rigid cervical collar or forcibly restrained as this may increase fighting, anxiety and intracranial pressure. Breathing Should be assessed by clinical examination of respiratory pattern and rate, chest auscultation and oxygen saturation. A Chest X-ray should be obtained as part of the initial essential imaging. Arterial blood gas analysis should be obtained if possible. The child will require intubation and ventilation in the ICU in the following situations: · Reduced level of consciousness with a Glasgow coma score ?8 · Inadequate breathing (saturation persistently <95% in oxygen), hyperventilation or hypoventilation (PaO2 <9kPa in air/<13kPa in oxygen or PaCO2 <3.5/>6kPa) · Loss of protective laryngeal reflexes · Significant facial or neck injuries

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· Seizures An intubated child with a head injury in the ICU will require sedation and analgesia; midazolam and morphine are the usual drugs of choice. A muscle relaxant may be required if it is difficult to control the ventilation. The child should be ventilated to obtain a normal PaCO2. An appropriately trained nurse or anaesthetist should always be present with the child. Circulation Hypotension must be actively sought and treated. Venous access should be established early and blood samples taken for full blood count, electrolytes and group and save. Two cannulae should be inserted, and intraosseous access or venous cutdown should be considered if venous access is difficult. A useful formula for expected blood pressure in children is: Expected systolic BP (mmHg) = 80 + (age in years x 2). As discussed above, a higher than normal blood pressure should be maintained to ensure adequate cerebral perfusion. Normal saline or Ringers are the fluid of choice for initial resuscitation. An initial fluid bolus of 10 ml/kg should be given, followed by another 10 ml/kg if the child remains hypotensive. Overhydration must be avoided, as this will promote cerebral oedema formation. If the haemoglobin is less than 7g/dl then extracranial causes of blood loss should be considered (or chronic anaemia). The child may require blood transfusion. Of note however, an intracranial bleed in a neonate may cause hypovolaemia and a fall in haemoglobin (before signs of raised ICP become apparent). Disability and exposure Assess the GCS and pupil responses. Other injuries should be sought and treated. Scalp lacerations may result in significant blood loss. If the child remains cardiovascularly unstable and requiring volume resuscitation, consider other sites of blood loss: chest, abdomen, pelvis or major limb fracture. Indications for CT scanning A CT scan is the gold standard imaging in assessing patients with head injury, if available. The CT scan will pinpoint a surgically remedial lesion such as subdural or extradural haematoma, and give an indication of severity of brain injury (presence of cerebral oedema, contusions, intracerebral bleeds etc). However, this is an expensive facility and may not always be available at the receiving hospital. The indications for CT scanning are as follows: · A clinical suspicion of severe head injury, such as reduced conscious level, amnesia, abnormal drowsiness · Skull fracture, either basal or open or depressed skull fracture · Seizures, other neurological deficits or persistent vomiting · A dangerous mechanism of injury · Suspicion of non-accidental injury As cervical spine X-rays are rarely adequate in children wearing cervical collars, a CT of the head should be extended to include the neck too. Indications for referral for surgery 10 – 20% of patients with severe traumatic brain injury have a surgically treatable condition such as extradural haematoma requiring burr hole; neurosurgical intervention

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may be life saving in this situation. A surgical opinion should be sought if the CT scan shows an intracranial haematoma or there is clinical suspicion of an intracranial haematoma, such as progressive focal neurological signs. A surgical opinion should also be sought in the case of depressed skull fracture, CSF leak or penetrating injury. Tertiary neurosurgical centres are able to offer interventions to manage severe raised intracranial pressure (see below). Intensive care management The primary goal of intensive care management in severe traumatic brain injury is prevention of secondary brain injury by maintaining adequate cerebral perfusion and oxygenation and controlling raised intracranial pressure. Children with severe traumatic brain injury should be transferred to an intensive care unit if at all possible. Secondary and tertiary centres will be able to undertake advanced techniques such as invasive blood pressure monitoring, use of inotropes and intracranial pressure monitoring, as well as CSF drainage or decompressive craniotomy for patients who deteriorate due to diffuse cerebral oedema. Such treatments are expensive and will not be possible in most resource poor environments. General supportive measures should be possible in all intensive care units. General intensive care management All patients with head injury should have simple measures instituted as follows: · Nurse the child in 30° head up position with neutral head positioning · Maintain SpO2 >95% · Maintain CO2 4.5-5.0 kPa · Maintain blood pressure in the high/normal range · Avoid excessive fluid loads · Avoid hypotonic fluids containing dextrose. Aim for plasma sodium 145-150 mmol/l · Use inotropes if necessary to maintain blood pressure (noradrenaline) · Provide adequate sedation and analgesia · Maintain blood sugar in normal range · Maintain normal temperature, treat pyrexia aggressively · Control seizures · Provide adequate nutrition via a nasogastric tube (start early). Special treatment for raised intracranial pressure, tertiary centres: · Institute intracranial pressure monitoring using a bolt or extradural or intraventricular catheter if possible. Rising intracranial pressure should be managed aggressively, particularly ICP>20mmHg · CSF drainage via intraventricular drain · Mild hyperventilation to PaCO2 < 4.5 kPa · Consider osmotic therapies to reduce intracranial pressure such as mannitol or 3% hypertonic saline · Consider barbiturate-induced coma with refractory intracranial pressure elevation if the child is cardiovascularly stable. · Profound hyperventilation to PaCO2 < 3.9 kPa may be used temporarily pre-craniotomy · Decompressive craniectomy may be considered in children with diffuse cerebral oedema, within 48 hours of injury, with no sustained episodes of intracranial pressure >40mmHg and secondary clinical deterioration with evolving cerebral herniation Conclusion

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Immediate airway management (with cervical spine control) and cardiopulmonary resuscitation are the most important early steps in management of traumatic brain injury in children. The importance of avoiding hypotension and hypoxia and of detection and rapid treatment of surgically remediable lesions cannot be over emphasised. Children are best managed in experienced paediatric trauma centres if at all possible. This may require transfer to another centre over long distances. Excellent communication and multidisciplinary approach is essential to produce the best outcomes. References and further reading: 1. Hatch and Sumner. Trauma and transport Textbook of Paediatric Anaesthesia (3rd Edition): 635-645, 2. Hatch and Sumner. The central nervous system Textbook of Paediatric Anaesthesia (3rd Edition): 95-108, 3. Orliaguet, Meyer and Baugnon. Management of critically ill children with traumatic brain injury, Paediatric Anaesthesia 2008;(18):455-461 4. Giza, Mink and Madikians. Pediatric traumatic brain injury: not just little adults. Current Opinions in Critical Care 2007;(13):143-152 5. Lam and Mackersie. Paediatric head injury: incidence, aetiology and management. Paediatric Anaesthesia 1999; (9): 377-385 2. SPINAL CORD COMPRESSION DUE TO TUMOURS. HISTORICAL PERSPECTIVE The first successful operation for a spinal cord tumour was performed in 1888 by Victor Horsley and Gowers at the National Hospital for Neurology and Neurosurgery, Queen’s Square, London. It was an intradural extramedallary tumour. Surgery was based entirely on clinical diagnosis and localization. In 1907, Dr. Elsberg performed the first successful operation for an intra medullary tumour. Further advances were to await the introduction of myelography by Walter Dandy in 1919. This allowed pre-operative localization of the tumour to be done. In 1921, Sicard and Forestier introduced positive contrast myelography as opposed to air-myelography which had been introduced by Dandy. After this it was possible to accurately localize spinal cord lesions before surgery. Other advances of importance were the introduction of bi-polar coagulation in the 1940’s (which was later modified by Malis) and the introduction of the operating microscope in 1964. INCIDENCE Spinal cord tumours are rare. Figures available in the Western literature indicate that there are three to ten spinal cord tumours per hundred thousand population. They make up about 1/5 all the tumours of the Central Nervous System. The commonest spinal cord tumours are neurilemomas (30%), meningiomas (25%), ependymomas (13%), and astrocytomas (7%). Other rarer tumours which may cause spinal cord compression are sarcomas (12%) vascular tumours i.e. hemangioblastomas & a-v malformation (6%) and

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other rarer tumours such as dermoid, epidermoid, teratomas and chordomas (8%). 16% of spinal cord tumours are intramedullary and 84% are extramedullary. In the Western World, metastatic tumours are the commonest cause of spinal cord compression. Mwang’ombe & Ouma (EAMJ July 2000) showed that spinal cord tumours accounted for about 15% of all CNS tumours treated at the Kenyatta National Hospital between 1985-1994. Most of the patients in their study had total paralysis of the limbs at the time of presentation. Meningiomas and neurofibromas were the commonest cause of cord compression. The mean grade of presentation was 37 years. SURGICAL ANATOMY The spinal cord is an ovoid neural structure within the vertebral canal which extends from the foramen magnum to the inter-vertebral disc between the first and second lumbar vertebra. (L 3 at birth). The cord is enlarged in two areas, cervical enlargement and lumbar enlargement. There are 31 pairs of spinal nerves; 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 cocygeal. The first pair exits between the atlas and the skull. All the 31 pairs of spinal nerve have dorsal root ganglia except C1 and coccygeal nerve. Spinal cord segment C1 and cervical vertebra C1 are at the same level. After this the cord level becomes progressively higher that the corresponding vertebral level. The cord is surrounded by fibrous tissue called pia-matter. It is suspended within the vertebral canal by 21 pairs of lateral dentate ligaments which are attached to the dura matter. The dentate ligaments lie midway between the ventral and the dorsal roots. The filum terminale runs from the posterior inferior aspects of cornus medullaris to inferior insertion on the dorsal aspect of the coccyx. BLOOD SUPPLY There are 31 pairs of radicular artery branches which enter the vertebral canal through inter-vertebral foramen. These are of three types; the proper radicular branches which end within the roots, the pia matter radicular branches and the spinal branches which enter the cord. The blood supply of the cord may be divided into three large arterial areas. 1. Cervical thoracic which lies between cervical and T2/3 junction; this is supplied by the anterior spinal artery from the vertebral artery. 2. The mid thoracic region between T3 and T8. This is supplied by a single radicular artery from T7. 3. Thoraco-lumbar region between T8 and lumbar enlargement. This is supplied by a single radicular artery from T12/L1 junction. PATHO-PHYSIOLOGY & CLINICAL PRESENTATION A patient with a spinal cord tumour may present at any of these stages; 1. First Stage. In the early stages the patient presents with root and segmental sensory loss or motor disturbance.

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2. Second Stage. Later, the patient presents with features of Brown-Sequard syndrome or incomplete transection syndrome. 3. In the late stages patients present with complete transection. Clinical examination will reveal the following features: a) Disturbances of motor function. This may be gradual in which case the patient presents with spastic paresis or rapid in which case the patient presents with flaccid paresis. Gradual onset is common in slow growing tumours i.e. meningiomas and neurilimomas. Rapid presentation is common in first growing tumours e.g. metastatic tumours. Patient will usually complain of progressive weakness of the extremities and tiredness. (b) Disturbance of sensory long tracts (collectively or individual). This may involve the posterior column (vibration and positions sense are effected) or the antero-lateral tracts (loss of pain and temperature). Compression of the dorsal surface of the cord by meningiomas and neurilimomas will result in affection of all modalities of superficial sensation, position and vibration sense. This is common in extra medullary tumours. In intramedullary tumours the patient may present with paresthesias and numbness which may be associated with painful dysethesia. Patients with intra-medullary tumours may also present with bilateral dissociative Sensory loss; loss of pain and temperature but touch and position intact. c) Root symptoms. This may be unilateral pain at the level of the dermatome supplied by the root. The pain is worse at night and when the patient is supine or during valsalva manouvre. Other features which may be observed are fasciculations, paresis and amyotrophy. Clinical presentation may be further categorized at the cord level into; 1. High cervical cord. In tumours in this region patient may present with neck pain, headache in greater occipital nerve distribution, respiratory distress/weakness and intercostals breathing which is due to the involvement of the phrenic nerve. 2. Lower cervical tumours. Patient presents with pain in the arm or shoulder. This may resemble cervical disc disease and cervical spondylosis with myelopathy. 3. Thoracic cord tumours. Patients present with funicular pain (dysesthesia), long tract motor disturbances, root symptoms, Beevor’s sign may be positive (presence of T9 & T10 roots, absence of T11 & T12 leads to upward movement of umbilicus with Contraction of abdominal muscles). A complete sensory deficit usual indicates the Location of the tumour. 4. Conus medullaris/Cauda equina tumours. In tumours of this region there is early loss of bladder and bowel control. There is also symmetrical saddle anaesthesia Commonly seen in ependymomas. INVESTIGATIONS 1. Plain radiography. The following features may suggest the presence of a spinal cord tumour; widening of the interpeduncular distance, widening of the neural foramina, scalloping of the vertebral bodies, loss of a pedicle, or evidence of bone

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destruction or blastic changes in the vertebral bodies (malignant extraduaral lesion). 2. Myelography. Lumbar puncture should not be done before myelography as it may cause cord shift and incarceration and collapse of subarachnoid space. Do Queckenstedt test, if there is free flow remove csf for analysis, if there is a block do not remove (Froin’s syndrome, high protein and low cell count; suggestive of block due to tumour). Features which may be observed during myelography and which are suggestive of spinal cord tumour are; Extradural tumours show features of paint brush appearance or hour glass deformity. Intradural tumours show cupping defect. Intramedullary tumours shows fusiform widening of the cord shadow 3. Computerized tomography (CT) scan/myelography. This is the investigation of choice where available. 4. Magnetic resonance imaging (MRI). This is superior to CT scan for the study of spinal cord pathology, but is rather expensive and rarely available in developing countries. 5. Spinal angiography. This is important where one suspects the presence of haemangioblastomas, arteriovenous malformations and occipital meningiomas. TREATMENT SURGERY The definitive treatment for spinal cord tumours is surgical excision through laminectomy. Total removal is possible for extradural and intraduaral extamedullary tumours. Total removal also may be possible in some intramedullary tumours. EPENDYMOMA. Most frequent intra-medullary spinal cord tumour in adult patients in Western World. MRI does not always differentiate between astrocytoma and ependymoma. Therefore surgery is always necessary so as to rule out epenymoma. Post-operation radiotherapy not necessary. Symptoms are usually subjective peripheral sensory disorders of the limb or trunk. (MRI has a high degree of accuracy for visualizing non-glial tumours e.g. haemangioblastomas, dermod and epidermod tumours and lipomas but not epenymomas). Classified as Grade II (WHO) tumours. They are benign slowly growing tumours that may grow to considerate size e.g. affecting entire spinal cord (holocord ependymoma), before becoming clinically detectable. Most commonly affect cervical cord, with extension to thoracic area or medulla, followed by thoracic and then conus medullaris. Surgical Technique: Somato-sensory potentials are recorded during surgery. Intra-operative ultrasonography. Microscopic dissection through dorsal median sulcus (post-spinal vein). Spread posterior columns apart and retract them. Biopsy sample is obtained and histological examination. If inftrating or malignant tumour; further surgery. Tumour removal.

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ASTROCYTOMAS These are less common than ependymomas. They may present as microcysts or large syrinxes. Treatment is decompression with aspiration of cysts followed by radiotherapy. NEURILEMOMAS/NEUROFIBROMA These are the most common tumours making up 30% of all spinal cord tumours. Male to female ratio is equal. 70% are intradural extramedullary and 15% are extradural. 14% are dumbbell and 1% are intramedullary. Thoracic site is the commonest followed by cervical, but rare in lumbar region. They are found mainly in the 4th & 5th decade. MENINGIOMAS These are the second most common tumours making up approximately 20% of all spinal cord tumours. 80% are found in women and occur mainly in the 4th, 5th and 6th decade. Two thirds occur in the thoracic area. 85% are intradural/extramedullary. 15% are extradural. METASTATIC TUMOURS These are most common in patients over 50 years. Mainly from lung, breast, prostate, kidney, sarcomas and lymphomas. If the primary tumour is known and there is no motor weakness the patient is put on steroids and radiotherapy. In cases of prolonged paraplagia surgery is useless. Surgery is also of no benefit in patients in poor general condition with wide spread metastases. Other causes of spinal cord compression of surgical importance are infection and trauma. TUMOURS OF THE SPINAL CORD IN CHILDREN Incidence: Same as in adults: One sixth are affected male that of intracranial tumours more commonly than females by ratio of approximately 7:5. Patients with Von Recklinghawsens disease have an increased incidence of gliomas, neurinomas, and meningiomas. Commonly present between the ages of 3 and 5 years because of the high incidence of congenital neoplasms in childhood. Distribution of intraspinal tumours in children differs from that in adults and there is a greater number of intrinsic spinal cord neoplasms (intramedullary) especially astrocytomas (35 percent) and lesser incidence of intradural-extramedullary neoplasms. Such as neurinomas and meningiomas (30 percent) while extradural tumours make up 30 percent. (In adults intradural extramedullary, 60 percent, extradural 25 percent and intramedullary 15 percent). 40 Percent of intraspinal tumours in children are found in the thoracic area and 60 percent evenly distributed in the cervical and lumbosacral regions.

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70 percent of intraspinal tumours in children are benign and slowly growing. The most common histological types are astrocytomas (25 percent), dermoids (15 percent), epidermoids (10 percent) and lipomas (5 percent). Secondary medulloblastomas that seed the spinal subarachnoid space are seen. Symptoms and signs. The symptoms and signs produced by these tumours may be observed in conditions such as cerebral palsy, congenital torticollis, idiopathic scoliosis, spina bifida occulta, transverse myelitis, Guillain Barre Syndrome, brain tumour, brachial plexus palsy, idiopathic enuresis, meningitis and appendicitis. Most common manifestation is motor weakness, (two thirds of the cases). This may present as increased fatigability while running or climbing stairs. Back or root pain may be seen in 40 to 50 percent of children. In older patients, it is accentuated by coughing, sneezing, flexion of the spine, or strength leg raising. Sensory disturbances and bladder and bowel dysfunction may be seen in 30 percent of children at the time of clinical presentation. Thorough sensory examination may be difficult in the very young subjects, but perianal anesthesia and segmental hypalgesia should be looked for. Delayed development of sphincter control or loss of established bladder or bowel control may be significant in the history. Tumours in the cervical and thoracic segments of the spinal cord produce a small spastic bladder. Patient voids in frequent small amounts. Tumours in the conus medullaris and cauda equina produce a large flaccid bladder with stress incontinence of urine and faeces. Musculoskeletal deformities as a result of neuromuscular imbalance and somatic growth are seen in slowly growing neoplasms. These may be in the form of torticollis, scoliosis, kyphosis and foot deformities. Hydrocephalus may be seen in high cervical intramedullary gliomas. Recurrent meningitis may be seen where there is a connecting sinus tract. The organisms are usually Escharichia Coli and Staphylococcus aureus. 3. DIAGNOSIS AND MANAGEMENT OF BRAIN TUMOUR CLASSIFICATION OF BRAIN TUMORS TUMORS OF NEUROGLIAL CELLS A. Tumors of Glial Cells Astrocytic tumors Astrocytoma Glioblastoma multiforme Oligodendroglioma Ependymoma - choroid plexus papilloma B. Neuronal Tumors Ganglioglioma Gangliocytoma Central neurocytoma

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C. Embryonal Tumors Medulloblastoma MENINGEAL TUMORS Meningioma TUMORS OF CRANIAL AND SPINAL NERVES Schwannoma Neurofibroma MESENCHYMAL TUMORS Sarcoma Hemangioblastoma CEREBRAL LYMPHOMAS GERM CELL TUMORS Teratoma Craniopharyngioma TUMORS OF THE PITUITARY GLAND Pituitary adenoma METASTATIC TUMORS WHO GRADING SYSTEM

Grade I-Pilocytic astrocytoma Benign cytological features-see below

Grade II-Low-grade astrocytoma

Moderate cellularity-no anaplasia or mitotic activity

Grade III- Anaplastic astrocytoma Cellularity, anaplasia, mitoses

Grade IV-Glioblastoma Same as Grade III plus microvascular proliferation and necrosis

Neuroepithelial tumors Astrocytoma Astrocytomas, which arise from astrocytes, are the most common primary brain tumor. Astrocytomas are histologically graded based on cellularity, anaplasia, mitotic figures, endothelial proliferation and necrosis. Well-differentiated astrocytomas (WDA) have mild hypercellularity and minimal nuclear pleomorphism. They typically occur in children and young adults who present with a seizure or headaches. On CT or MRI scan they usually appear as a non-enhancing mass lesion. Anaplastic Astrocytomas (AA) have moderate cellularity and nuclear pleomorphism with mitotic activity. Moderate endothelial proliferation can be present but no necrosis. These lesions are typically found in mid-life as enhancing lesions with mass effect. They often present with seizures, headaches and/or focal neurological findings. Glioblastoma multiforme (GBM) is characterized by hypercellularity, dramatic nuclear pleomorphism, endothelial proliferation, mitotic figures and necrosis. These patients are usually older adults who present with headaches, seizures or focal neurologic findings. On CT or MRI scan a GBM typically appears as an irregular ring-enhancing lesion with significant mass effect and edema.

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Survival correlates with grade: WDA 5-10 years, AA 2-3 years and GBM 1-1.5 year. Astrocytomas can initially present as a low-grade tumor and subsequently convert to a higher grade. De novo AA and GBM tumors occur as well. Treatment is based on grade. Controversy exists for the optimal treatment of WDA. Most agree that a WDA in non-eloquent brain with mass effect should be resected. A stereotactic brain biopsy for diagnosis is an option for symptomatic lesions in areas of the brain where open surgery carries an increased risk of causing a deficit. Radiation is controversial in stable tumors but is often used if growth is demonstrated. AA and GBM are typically treated by surgical resection followed by radiation and BCNU chemotherapy. Surgery is indicated for diagnosis, to relieve mass effect, and, possibly, to decrease the "tumor burden". AA or GBM in the motor strip, language areas or other eloquent brain regions are often biopsied rather than resected because of the high risk of surgery in these areas. It has been difficult to prove that the extent of tumor resection has an effect on patient survival. As a rule, surgery is never curative. BCNU impregnated wafers implanted in the tumor bed after resection of a recurrent AA or GBM have proven to be efficacious. Recurrence within a centimeter or two of the resection site is typical regardless of the treatment given after surgical resection. Surgery for recurrent AA and GBM is controversial. Most surgeons agree that reoperation is indicated for the relief of headaches or neurological deficits due to mass effect. Pathologically, several types of astrocytomas exist, such as fibrillary, protoplasmic and gemistocytic astrocytomas. Glioblastomas also have giant cell and gliosarcoma variants. A separate group of astrocytoma is the juvenile pilocytic astrocytoma (JPA). This group is either not graded or considered Grade 0. JPA are distinct because they behave in a more benign fashion and when completely resected can be cured by surgery alone. The are typically discrete cystic lesions with an enhancing mural nodule. Histologically, JPA are composed of loose and dense regions of stellate astrocytes. These have Rosenthal fibers that indicate slow growth. JPA are typically found in children and young adults. They tend to occur in the cerebellar hemisphere, optic nerve, hypothalamus and brainstem. Cerebellar JPA often present with signs of increased intracranial pressure (headache, nausea, vomiting) due to hydrocephalus. JPA also can present with cerebellar dysfunction such as gait ataxia or ipsilateral extremity dysmetria. Rarely, JPA can undergo malignant degeneration. Subarachnoid seeding does occur rarely with JPA and probably carries a poorer prognosis. This has been seen with hypothalamic tumors. Optic nerve JPA and WDA tumors are associated with neurofibromatosis type II. Pleomorphic xanthoastrocytomas are astrocytic neoplasms found in young adults with a long history of seizures. They are usually superficial in the cerebral cortex and may consist of a mural nodule associated with a cyst. They are typically slow growing but malignant transformation does occur. Subependymal giant cell astrocytomas are typically found at the foramen of Monro in patients with tuberous sclerosis. Gliomatosis cerebri is a condition where there is diffuse infiltration of the entire brain with an astrocytic tumor. Oligodendroglial tumors The majority of oligodendrogliomas present in young adulthood with the onset of seizures. Radiographically, calcifications are typical. The classic histologic appearance is of homogeneously appearing cells with a "fried egg" appearance and "chicken wire" vessel pattern. Similar to WDA, patients can have long term survival. Malignant

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transformation does occur. These tumors are called anaplastic oligodendrogliomas. In general, surgical resection is recommended when possible for diagnosis, to relieve mass effect, and resect as much tumor as safely as possible. Radiation therapy is controversial, but is probably beneficial. PCV (procarbazine, CNU, & vincristine) chemotherapy has been shown to be beneficial in the treatment of oligodendrogliomas. Ependymal tumors Ependymomas typically arise from the lining of the ventricular system and usually occur in children and young adults. The floor of the fourth ventricle is a common location. Ependymomas typically present with hydrocephalus and increased ICP. Presenting symptoms include nausea, vomiting, headache, gait ataxia, diplopia and vertigo. Ependymomas have a significant potential for CSF seeding and thus "drop metastasis". Complete surgical resection has been shown to improve survival and should be attempted if there is minimal brainstem invasion. Postoperative radiation and chemotherapy is usually administered. No clear consensus exists for grading ependymomas but the term anaplastic ependymoma is sometimes used for more malignant appearing tumors. Paradoxically, intramedullary spinal cord ependymomas, which are histologically identical, may be cured by surgery alone. Myxopapillary ependymomas are a variant of ependymomas. This tumor occurs in the conus or filum terminale of the spinal cord. Complete resection is probably curative. Subependymomas occur in anterior lateral ventricles or posterior fourth ventricle. They are benign slow growing tumors that are typically found incidentally at autopsy. However subependymomas can cause hydrocephalus from obstruction of cerebrospinal fluid pathways. Symptomatic or enlarging tumors should be removed. In elderly patients insertion of a VP shunt is a viable option if obstruction of CSF pathways is present. Mixed gliomas Mixed gliomas occur and appear histologically as a combination of neoplastic oligodendrocytes and astrocytes. These tumors are referred to as oligo-astrocytomas or anaplastic oligo-astrocytomas. Often the name is shortened to the dominant cell type only. Choroid plexus tumors Tumors of the choroid plexus are called choroid plexus papillomas (CPP). In children less than 2 years of age, they usually are located in the lateral ventricle and present with hydrocephalus. In adults CPP usually occur in the fourth ventricle, foramen of Luschka or cerebellopontine angle. The treatment is surgical resection, though elderly patients with an asymptomatic cerebellopontine angle tumor may be followed with serial imaging studies. Recurrence should be treated aggressively with reoperation, when possible, due to a favorable prognosis. One or two percent of choroid plexus tumors are carcinomatous. Choroid plexus carcinoma carries a poor prognosis. Neuronal and mixed Neuronal-glial tumors Gangliocytoma is a tumor composed of large abnormal mature neurons. They are primarily supratentorial with the most common location being the temporal lobe. The majority of patients are in their first two decades of life. Surgical resection, when complete, is curative. Variable radiographic features occur, ranging from an enhancing mural nodule to a ring enhancing mass with calcifications. Dysplastic gangliocytoma of the cerebellum (Lhermite Duclos Disease) is a non-neoplastic mass of hypertrophic granular cell neurons which expands the cerebellar folia.

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These tumors can cause mass effect and hydrocephalus and typically occur in young adults. Resection (total or subtotal) and/or shunting are therapeutic options. Dysembryoplastic neuroepithelial tumors (DNET) are a "hamartomatous", supratentorial, predominantly temporal lobe lesion composed primarily of glial cells. They usually present with seizures. Radiographically these tumors often lack edema and have a multinodular appearance. Inner table skull erosion or deformation may be present. Gangliogliomas are tumors consisting of large mature neurons and a neoplastic glial component. This tumor affects patients of all ages with the majority diagnosed in young adults who often have a long history of seizures. Surgical resection even if subtotal can be curative. Surgery is recommended for diagnosis and, on occasion, for control of seizures. Pineal tumors Pineal tumors are tumors arising from pineocytes. The well-differentiated pineocytoma occurs in mid-life as a discrete contrast enhancing mass in the posterior third ventricle/pineal region. The poorly differentiated pineoblastoma has a similar location and enhances with contrast but shows signs of local invasion and is prone to CSF dissemination. The complex of pineoblastoma and bilateral retinoblastoma is called trilateral tumor. In general, pineocytomas have a good prognosis while pineoblastomas with subarachnoid spread are aggressive and carry a poor prognosis. Pineal tumors often present with hydrocephalus due to obstruction of the aqueduct of Sylvius. Compression of the dorsal midbrain by a pineal tumor can result in Parinaud’s syndrome of pupillary mydriasis, paralysis of upgaze, and convergence retractorius. Embryonal tumors Neuroblastoma is a small cell neoplasm with neuroblastic differentiation arising in the deep cerebral hemispheres of young children (<5 yrs. of age). A variant is the ganglioneuroblastoma that has a preponderance of ganglion appearing cells. The olfactory neuroblastoma (esthesioneuroblastoma) is a neuroblastic tumor arising from the nasal epithelium with cribiform plate involvement. There is a bimodal age distribution in adolescents and older adults. Patients present with nasal obstruction and or epistaxis. Complete surgical resection with combined cranio-facial resection is the treatment of choice, with a generally favorable prognosis. Adjuvant radiation therapy is generally recommended. Ependymoblastoma is a rare small cell embryonal neoplasm with prominent ependymoblastic rosettes. It typically occurs in the cerebrum of children less than five years of age. Its propensity for craniospinal dissemination often leads to death within a year. Retinoblastoma is a retinal neoplasm that occurs in children < 3 years of age. Ophthalmoscopic exam is diagnostic, giving the characteristic white reflex. These tumors have both hereditary (earlier onset and bilateral) and sporadic forms. Surgical resection with or without radiation can be curative. Medulloblastoma or primitive neuroectodermal tumor (PNET) of the cerebellum is a small cell neoplasm believed to arise from the external granular layer of the cerebellum. This tumor arises in the vermis of children and young adults although cases in older patients have been reported. Radiographically, these are homogeneously enhancing masses of the cerebellar vermis. CSF tumor seeding can produce drop metastases, even at the time of diagnosis. Surgical resection, combined with radiation and chemotherapy,

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may lead to significant long-term survivals. Rarely, metastasis to bone, lymph nodes and lung have been reported. Variants include desmoplastic medulloblastoma, medullomyoblastoma, and melanocytic medulloblastoma. Medullomyoblastoma occurs in children, with a propensity for boys. Cerebral (supratentorial) and spinal PNET’s occur, but with much less frequency. Mesenchymal tumours: Haemangioblastoma Hemangioblastoma is a benign tumor of middle age. In fact, it is the most common primary intra-axial tumor of the posterior fossa in adults. About 20% are associated with Hippel-Lindau disease, and hereditary factors have been implicated in another 20%. The cerebellum and vermis are the common sites, but hemangioblastomas can also be found in the medulla and spinal cord. Multiplicity is a well-known feature but is present in only about 10% of cases. Histologic examination reveals a meshwork of capillaries and small vessels. The classic MR appearance of hemangioblastoma is a cystic mass with a brightly enhancing nodule. About 60% are cystic, so solid lesions are not uncommon. Calcification is rare. Hemangioblastomas are sharply marginated and induce minimal surrounding parenchymal reaction. The tumor nodules are hypervascular and the vascular pedicle often produces a characteristic flow void on MR. Von Hippel-Lindau Disease is an autosomal dominant disease, associated with hemangioblastomas of the cerebellum and retina, cysts of the liver and pancreas, pheochromocytomas, and tumors of the kidneys. It is linked to VHL, a tumor suppressor gene on chromosome 3p. The product of this gene is involved in mRNA transcription. Tumors of cranial and spinal nerves Schwannomas Schwannomas (neurinoma, neurilemmoma) are tumors composed of Schwann cells that arise along cranial or spinal nerves. The vestibular schwannoma (acoustic neuroma) is probably the most common schwannoma and arises typically from the superior vestibular nerve. Vestibular schwannomas typically present with tinnitus and sensori-neural hearing loss. Facial numbness follows when the tumor reaches approximately 2.5 cm. Ipsilateral coordination difficulties and mild facial nerve weakness typically do not occur until the tumor diameter is greater than 3 cm. Radiographically, these tumors enhance with contrast and extend into the internal auditory canal. Complete surgical resection is curative. Hearing and facial nerve preservation is dependent on tumor size and preoperative level of nerve function. In older patients or poor surgical candidates, stereotactic radiosurgery is an effective treatment for tumor size < 2.5cm. Some proponents of radiosurgery feel that it should be used as the primary treatment for all but the largest tumors. Bilateral vestibular schwannomas occur with neurofibromatosis type II. Neurofibromas Neurofibromas are a nerve sheath tumor composed of Schwann cells, fibroblasts and perineural cells. This tumor can occur in isolation or in associated with neurofibromatosis. This tumor may be solitary, plexiform or occur as a mixed neurofibroma/schwannoma. These tumors arise from nerves in the subcutaneous tissue or in the neuroforamena. Classic spinal tumors have a dumbbell appearance when they extend across the neuroforamena. Surgical resection is indicated in symptomatic lesions.

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Malignant transformation in neurofibromas is rare but should be suspected with increasing size or pain. Malignant peripheral nerve sheath tumors Malignant peripheral nerve sheath tumors: neurogenic sarcoma, anaplastic neurofibroma, and malignant schwannoma are rare malignant tumors arising from the non-neural elements of nerves. These have a poor prognosis with death resulting within the year. Complete resection is usually not feasible. Tumors of the meninges Meningioma (subtypes: meningothelial, transitional, fibrous, psammomatous, angiomatous, microcystic, secretory, clear cell, choroid, lymphoplasmacyte-rich, metaplastic variants, atypical, anaplastic). Meningiomas are typically solitary, benign, slow growing, extra-axial tumors arising from arachnoid cap cells in the cranium and spine. The most common locations are parasagittal, convexity, tuberculum sella and sphenoid ridge. A small percentage may be intraventricular. Meningiomas rarely occur in children but when they do there is a predilection for the posterior fossa and ventricle. Less than five percent of meningiomas are malignant, characterized by brain invasion and increased mitotic activity. Meningiomas are most common in middle age and elderly women. Common symptoms include headache, seizures, weakness, and mental status changes. Focal neurologic deficits on presentation depend on the site of origin of the tumor. Radiographically these tumors are well circumscribed, homogeneously enhancing lesions. There may be hyperostosis of the underlying skull. There is often a tail of dural enhancement at the edge of the tumor after contrast administration on imaging studies. The primary treatment of symptomatic surgically accessible tumors is surgical resection. Surgery if complete is often curative. Large lesions may require embolization of intra-operatively inaccessible vascular supply prior to surgical resection to decrease intraoperative bleeding. Small or asymptomatic meningiomas in older individuals can be followed and treatment recommended if growth is demonstrated. Radiation therapy and/or radiosurgery are treatment alternatives for recurrent tumors or if surgery carries an increased risk of complications. There is an association between meningiomas and neurofibromatosis type 2 and an abnormality in the long arm of chromosome 22. Cysts and tumor-like lesions Numerous cysts and tumor-like lesions can occur in the brain including Rathke’s cleft cyst, epidermoid cyst, dermoid cyst, colloid cyst of the third ventricle, enterogenous cyst (neuroenteric cyst), neuroglial cyst, other cysts, lipoma, granular cell tumor (choristoma, pituicytoma), hypothalamic neuronal hamartoma, nasal glial heterotopias. Tumors of the anterior pituitary Pituitary adenomas are slow growing, benign tumors that arise in the anterior pituitary gland. Pituitary tumors are divided into hormone secreting tumors and non-secretors. Tumors less than 1 cm in diameter are referred to as microadenomas while tumors larger than 1 cm are called macroadenomas. Prolactinomas are pituitary adenomas that secrete the hormone prolactin. Prolactinomas often present with amenorrhea in women and loss of libido in men. The primary treatment for prolactinomas is medication, usually bromocryptine analogues. Bromocryptine often results in a decrease in tumor size but does not kill tumor cells. It usually must be continued for life or tumor recurrence is the rule. Adenomas that secrete growth hormone produce gigantism if present before puberty

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and acromegaly if present after puberty. ACTH secreting adenomas result in Cushing’s disease. Hypercortisolism is characterized clinically by centripetal obesity, moon facies, buffalo hump, glucose intolerance, hypertension and impaired wound healing. Non-secreting macroadenomas with suprasellar extension can compress the optic chiasm. Compression of the optic chiasm from below often produces a bitemporal hemianopsia. Spontaneous hemorrhage or infarction of a pituitary adenoma is referred to as pituitary apoplexy and can result in sudden visual loss or hypocortisolism. Emergent surgery is sometimes necessary for pituitary apoplexy. The primary treatment for patients with secreting pituitary adenomas producing Cushing’s disease, acromegaly, or symptomatic non-secreting tumors is surgical resection. Surgery is typically performed through the transsphenoidal route. Cavernous sinus invasion by adenoma cells often makes a surgical cure difficult. Recurrent tumors or those with cavernous sinus invasion can be treated with re-operation or radiation therapy. Metastasis Metastases are the most common brain tumor. Tumors that frequently spread to the brain, in order of decreasing incidence are: lung, breast, skin, colon, and kidney. Commonly, lung, thyroid, renal cell and melanoma metastases can become hemorrhagic. The treatment of solitary lesions is surgical resection followed by radiation therapy. For patients with multiple asymptomatic lesions, surgery is reserved for diagnosis only. For patients with controlled systemic disease but multiple brain metastases, a large symptomatic accessible lesion could be considered for resection. Whole brain radiation is generally given for multiple brain metastases. 4. BRAIN ABSCESS Brain abscesses arise by several mechanisms including hematogenous spread, penetrating trauma, surgery, or local spread from the paranasal sinuses, mastoid air cells or emissary veins. The peak incidence is in young men due to the occurrence of middle ear and paranasal sinus infections in addition to congenital heart disease. Other predisposing factors include Osler-Weber-Rendu syndrome with pulmonary arteriovenous fistulae, endocarditis, congenital heart disease, dental work and immunosuppression. Symptoms consist of headache, fever, seizures and/or neurological deficit. The majority of brain abscesses are solitary. Most patients present with signs of mass effect rather than those of infection. The clinical manifestation is also dependent on factors such as virulence of the organisms, patient immune status, and the location of the abscess. Aerobic and anaerobic bacterial abscesses occur. Abscess cultures in one third of patients grow multiple organisms. Common organisms based on the site of origin include Streptococcus species from the frontal/ethmoid sinus; Bacteroides fragilis from chronic mastoiditis/otitis; Staph. aureus or enterobacteriacea following penetrating trauma or surgery; Strep. viridans and Strep. pneumonia in cases of congenital heart disease; Staph aureus and Strep. pneumonia in cases of endocarditis. In immunosuppressed patients, toxoplasma gondii, nocardia, mycobacteria, yeast and fungal abscesses occur. Outside the US, tuberculomas, cysticercosis, echinococcus, schistosomiasis and strongoloidiasis are more common. In the first stage of brain infection, there is inflammation of the brain, termed early cerebritis. This stage occurs in the first 3-5 days after inoculation. The CT scan appearance of cerebritis is that of an ill-defined hypodense contrast enhancing area. This

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coalesces to a late cerebritis stage during days 4-13 with irregular rim enhancement. This is followed, at approximately day 14, by a collagen reticulum encapsulation with a necrotic center (early capsule stage) On CT scan or MRI scan this appears as a ring enhancing mass often with the abscess wall facing the ventricle appearing the thinnest. The final stage is the late capsule stage in which there is a three-layer capsule: an outer gliotic layer, a middle collagenous layer and an inner granulation layer. These can persist for months on imaging studies before ultimate resolution. Antibiotics are the mainstay of treatment in all cases. Empiric treatment of a presumed bacterial abscess requires coverage for both aerobes and anaerobes. Surgery is usually indicated to confirm the diagnosis of an abscess and for culture and sensitivity of specific organisms. Stereotactic aspiration is the treatment of choice. Aspiration may need to be repeated before resolution occurs. Often two to three weeks of antibiotic treatment are needed before a size decrease is seen on imaging studies. In general 4 – 6 weeks of intravenous antibiotics are often used, followed by a period of oral antibiotics. Patients with nocardia abscesses, or patients in whom treatment has failed after the third aspiration, should consider surgical resection when accessible. Often, aspiration alone can treat significant mass effect and prevent rupture of the abscess into the ventricular system. Ventricular rupture of a bacterial brain abscess is often fatal. 5. DIAGNOSIS AND MANAGEMENT OF HEADACHES The major causes of intracranial hemorrhage are vasculopathy in the aged (hypertension and amyloidosis), aneurysm, vascular malformation, tumor, and coagulopathy. Hypertension.Spontaneous intracerebral hemorrhage may occur with both acute and chronic hypertension. Acute hypertension sufficient to produce spontaneous intracerebral he morrhage is sometimes seen with eclampsia and drug intoxication with sympathomimetic drugs Chronic hypertension may lead to vascular changes of the basal perorating arteries including formation of Charcot-Bouchard aneurysms. The most common locations for theshemorrhages are (in decreasing order of frequency) basal ganglia, thalamus, pons, cerebellum, cerebral white matter, brainstem. Amyloid angiopathy.This is characterized by a deposition of beta amyloid protein within the meningeal and cortical vessels. The clinical course is characterized by multiple lobar intracerebral hemorrhages. Risk factors include advanced age and Down’s syndrome. Definitive diagnosis requires pathologic examination. Aneurysm. Cerebral aneurysms result from weakening of the wall of major intracranial arteries. These aneurysms are generally saccular, though fusiform aneurysms also occur. Saccular aneurysms usually occur at branch points along the arterial tree. When a saccular aneurysm ruptures, it most commonly produces subarachnoid hemorrhage. Intracerebral, intraventricular, and subdural hemorrhage are also seen. Common sites of aneurysm rupture include (in decreasing order of frequency) anterior communicating artery, posterior communicating artery, middle cerebral artery, basilar artery, vertebral artery. Multiple aneurysms are seen in approximately one-fourth of patients. Risk factors include hypertension, smoking, family history, and collagen vascular disease. Vascular malformation.Vascular malformations include the high flow arteriovenous malformation, cavernous angioma, venous angioma, and capillary telangiectasias. The high flow arteriovenous malformation results from a direct communication between the arterial blood supply and draining veins without normal interposed capillaries. These are

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usually visible on arteriography. Saccular aneurysm are frequently seen on feeding vessels. Intraparenchymal hemorrhage is most commonly seen, though subarachnoid and subdural hemorrhage may occur. Cavernous angiomas consist of irregularly formed vascular channels, without intervening brain parenchyma. Flow is usually low and these lesions, therefore, do not routinely manifest themselves on arteriography. Hemorrhage, when it occurs, is typically intraparenchymal. Family history is a risk factor. Venous angiomas result from a cluster of normal medullary veins draining into a central enlarged venous channel. The arterial system is uninvolved. Hemorrhage is infrequent and usually intraparenchymal. Many are associated with cavernous angiomas. Capillary telangiectasias are clusters of dilated capillaries with low flow. They are not visible on arteriography. They are sometimes associated with Osler-Weber-Rendu syndrome, Louis-Barr syndrome, Myburn-Mason syndrome, and Sturge-Weber syndrome. Tumor. Both primary and metastatic tumors may hemorrhage. Of the malignant primary brain tumors, glioblastoma multiforme most commonly presents with hemorrhage. While lung carcinoma is the most common hemorrhagic cerebral metastasis, melanoma, choriocarcinoma, and renal cell carcinoma are the most likely metastases to present with cerebral hemorrhage. Most hemorrhages are intraparenchymal. Coagulopathy. Even in the absence of underlying cerebral pathology, coagulopathy, either secondary to underlying medical disease or iatrogenically induced, increases the risk for intracranial hemorrhage. Particularly in elderly patients, subdural hematoma is the most common manifestation. Intraparenchymal hemorrhage may also occur, particularly in the setting of anticoagulation after cerebral infarction. Subarachnoid hemorrhage. The most common symptom of subarachnoid hemorrhage is explosive onset of severe headache. The headache is described by the patient as "the worst headache of my life". The patient may complain of neck pain and stiffness, as well as photophobia. Low back pain may also be present. Nausea and vomiting may be present. There may be a history of transient loss of consciousness. Signs of subarachnoid hemorrhage include nuchal rigidity, positive Kernig’s sign, and/or positive Brudzinski’s sign. A depressed level of consciousness may also be present. Ocular manifestations include hemorrhages and papilledema (secondary to elevated intracranial pressure). Focal neurologic deficit, particularly third nerve palsy ipsilateral to the site of aneurysm rupture, may be present and in some instances may help to localize the aneurysm. Intracerebral hemorrhage. Headache may be present after intracerebral hemorrhage. Patients with nondominant hemorrhages may complain of weakness or numbness on their nondominant side. Signs of intracerebral hemorrhage are typically those of hemispheric neurologic deficit. Patients with dominant-sided lesions are frequently found to have hemiparesis and hemianesthesia. Dysphasia is usually present, though the patient may present with frank aphasia. Patients with nondominant lesions typically have contralateral hemiparesis and hemianesthesia. While speech is frequently normal, neglect may be profound. If the hemorrhage is large, the patient may present with signs of elevated intracranial pressure including depressed level of consciousness, decorticate or decerebrate posturing, or flaccid areflexia. Cerebellar Hemorrhage. The awake patient with cerebellar hemorrhage may complain of severe headache, which may be localized to the suboccipital or upper cervical region. Symptoms include those of cerebellar and lower brainstem dysfunction, as well as

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hydrocephalus, which is frequently present. Signs of cerebellar dysfunction include ipsilateral dysmetria, nystagmus when looking to the side of the lesion, and difficulties with speech. Lower brainstem dysfunction typically manifests as difficulty with swallowing. In the presence of hydrocephalus, signs of elevated intracranial pressure may ensue. These include a decreased level of consciousness, decorticate or decerebrate posturing, and flaccid areflexia. Evaluation of Acute Headache (CT, MRI, and Lumbar Puncture). In the patient who presents with the "worst headache of my life" a subarachnoid hemorrhage should always be suspected. After initial resuscitation and complete neurologic examination, head CT without contrast is mandatory. In addition to verifying the presence or absence of subarachnoid blood, the CT scan should be carefully scrutinized for other intracranial pathology, including hydrocephalus. If the CT scan is positive for subarachnoid hemorrhage, the patient should undergo cerebral arteriography. The arteriogram should be scrutinized for the location of the aneurysm, as well as for any associated lesions including additional unruptured aneurysms, arteriovenous malformations, and the presence or absence of vasospasm. If the initial head CT is negative for subarachnoid hemorrhage, and the patient has a history that is highly suspicious for subarachnoid hemorrhage, a lumbar puncture should be performed. A small needle should be utilized and only a small volume of fluid should be withdrawn. Non-clotting blood, xanthochromia, or a red blood cell count greater than 100,000 which does not drop significantly from the first to the last tube are all highly suggestive of subarachnoid hemorrhage. If the lumbar puncture meets any of these criteria, the patient should undergo arteriography as described above. If the cerebral arteriogram is negative, in the face of a CT scan indicative of subarachnoid hemorrhage or a positive lumbar puncture, the patient should be admitted to the hospital for observation. At this point, an MRI scan of the brain with and without contrast should be considered. MRI arteriography, if available, should be included. The purpose of this study is to rule out other structural causes of subarachnoid hemorrhage including angiographically occult vascular malformations and tumor. If no bleeding source is identified with the MRI scan, most clinicians recommend repeating the arteriogram in 7 to 14 days. Occasionally, an intracranial aneurysm that was obscured by mass effect, thrombosis, or vasospasm, may be detected. Natural History and Broad Treatment Strategies of Intracranial Aneurysms and Vascular Malformations. Intracranial aneurysms - natural history. Ruptured intracranial aneurysms. In the patient who survives their initial aneurysm rupture, the most serious complication is rebleeding. The rate of rebleeding is approximately 4% in the first 24 hours and decreases to 1 to 2% per day for the first two weeks. After the first two weeks, the rate of rebleeding drops to approximately 3% per year. A second potential serious complication of aneurysmal subarachnoid hemorrhage is a vasospasm. Vasospasm is defined as delayed narrowing of large and medium size arteries at the base of the brain. If severe, this may lead to cerebral infarction. The risk of symptomatic cerebral vasospasm is maximum between 4 and 11 days of subarachnoid hemorrhage. The incidence of vasospasm, detected by angiography, is approximately 70%. The incidence of symptomatic vasospasm (resulting in neurologic deficit) is approximately 25 to 30%. The

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major risk factor for the development of vasospasm is the amount and location of subarachnoid blood visualized on the CT scan. This is graded using the Fisher system;

Group Blood on CT Scan

1 No blood detected 2 Diffuse or vertical layers < 1mm thick

3 Localized clot and/or vertical layer >= 1mm thick 4 Intracerebral or intraventricular clot with diffuse or no SAH

Unruptured intracranial aneurysm - natural history. Occasionally aneurysms are discovered prior to rupture. Again, the primary risk is rupture. The available information suggests that the annual rate of rupture for an unruptured intracranial aneurysm is between 1% and 3% per year. The risk of rupture is affected by several factors. Larger aneurysms, particularly those greater than or equal to 10 mm in diameter, have a higher rate of rupture. Aneurysms located in the posterior communicating artery, vertebrobasilar/posterior cerebral artery, and in the basilar tip are more likely to rupture. Treatment strategies for intracranial aneurysms. The goal of intracranial aneurysm treatment is to prevent bleeding or rebleeding. Additionally, in the patient with a ruptured intracranial aneurysm, treatment is also instituted to lessen the risk of symptomatic vasospasm. In patients with subarachnoid hemorrhage due to aneurysm rupture, outcome is related to the modified Hunt-Hess grade. Higher-grade patients have a statistically poorer outcome.

Grade Description 0 Unruptured aneurysm

1 Asymptomatic, or mild headache and slight nuchal rigidity

1a No acute meningeal/brain reaction, but with fixed neurologic deficit

2 Cranial nerve palsy (e.g. III, IV), moderate to severe headache, nuchal rigidity

3 Mild focal deficit, lethargy, or confusion

4 Stupor, moderate to severe hemiparesis, early decerebrate rigidity

5 Deep coma, decerebrate rigidity, moribund appearance *Add one grade for serious systemic disease (e.g. HTN, DM, severe atherosclerosis, COPD), or severe vasospasm on arteriography

The patient with aneurysmal subarachnoid hemorrhage should be admitted to the neurological intensive care unit. Adequate oxygenation and respiration should be assured. The patient should be maintained normotensive. Hypertension should not be treated unless the systolic blood pressure rises above 160 mm of mercury. Hydrocephalus, which

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is present in at least 15% of patients with subarachnoid hemorrhage, should be treated with cautious external ventricular drainage if symptomatic. Routine use of external ventricular drainage is controversial. Cerebral selective calcium channel blockers lessen the risk of symptomatic vasospasm and are started at this time. Use of anti-fibrinolytic agents and corticosteroids may be considered. Treatment of the ruptured intracranial aneurysm should at this point be entertained. Direct surgical exclusion of the aneurysm from the circulation (craniotomy and clipping) remains the "gold standard". Endovascular obliteration of the aneurysm through the use of detachable coils may be considered in certain situations (difficult or "unclippable" aneurysms, medically unstable patient). The long-term results of this modality of treatment are unknown and currently under study. Treatment of unruptured aneurysms takes into account both the risk of rupture, as well as age of the patient, severity and progression of symptoms, and treatment alternatives. Older patients have a statistically shorter life span and therefore lower cumulative risk of rupture. Recent recommendations suggest that symptomatic intradural aneurysms of all sizes should be considered for treatment. Unruptured aneurysms of all sizes in patients with subarachnoid hemorrhage due to another treated aneurysm should be considered for treatment. Treatment for unruptured small (less than 10 mm) aneurysms is not generally recommended except in special circumstances. These include aneurysms near the 10 mm size, those with daughter sac formation, and in patients with family history of aneurysm or aneurysmal subarachnoid hemorrhage. Asymptomatic aneurysms greater than or equal to 10 mm in diameter warrant strong consideration for treatment. Arteriovenous Malformations - Natural History Risks. The primary risk of arteriovenous malformations is rupture. The rate of rupture has been estimated to be approximately 4% per year for symptomatic arteriovenous malformations and 2% per year for asymptomatic arteriovenous malformations. The rate of arteriovenous malformation rupture appears to be higher in small malformations than in large malformations. The second risk of arteriovenous malformation is seizures. Nearly 60% of patients with an arteriovenous malformation have a history of seizures. Larger malformations are associated with a greater risk of preoperative seizures. Treatment strategies for arteriovenous malformations. Trnt for arteriovenous malformations is recommended when the risk of subsequent hemorrhage is greater than the risk of treatment. The risk of treatment may be estimated using the Spetzler-Martin classification:

Graded Feature Points Assigned

Size of arteriovenous malformation

Small (<3cm) 1 Medium (3-6cm) 2

Large (>6cm) 3 Eloquence of adjacent brain

Noneloquent 0

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Eloquent 1

Pattern of venous drainage 0 Grade = [size] + [eloquence] + [venous drainage] There are several treatment options for arteriovenous malformations. These include craniotomy and direct surgical excision, embolization using interventional radiologic techniques, and Gamma Knife radiosurgery. Because the risk of treatment rises with increasing Spetzler-Martin grade, the following recommendations have been made: Grade I or II arteriovenous malformations should be treated. Grade III lesions should be treated if symptomatic. Grade IV or V arteriovenous malformations should be treated only when significant or repetitive intracerebral hemorrhage has occurred or the patient is experiencing progressive neurologic disability. The treatment modality of choice remains controversial. Surgical removal remains the "gold standard". With all treatment modalities, the goal remains complete removal or obliteration of the arteriovenous malformation. This goal should be pursued until it has been achieved. Migraine, Cluster, and Tension Headache, and Sinusitis Headache. Migraine headache. Features of classical migraine headache include: Onset in childhood, adolescence or early adulthood, positive family history, more common in females, usually unilateral, throbbing pain, nausea and vomiting common, scintillating scotomata, duration of several hours. Cluster headache. Much more common in men, pain severe and retro-orbital or temporal, usually unilateral, pain at night, accompanied by lacrimation, rhinorrhea, periorbital edema, duration of pain 20 to 60 minutes and may recur several times within a 24-hour period. Pain-free period of months to years is typical. Tension headache. Onset in adolescence or young adulthood, non-familial, pain is typically bilateral, bifrontal, bitemporal, or suboccipital, pain described as throbbing or a sensation of "pressure", nausea and vomiting rare, no lacrimation or rhinorrhea, more frequent in afternoon or evening, duration hours to days. precipitated by stress, depression, or anxiety. Sinusitis. History of allergic background or frequent prior sinusitis, unilateral or bilateral, localized pain and tenderness over affected sinuses common, associated conditions include nasal obstruction, fevers, and chills, history of scintillating scotomata, nausea, or vomiting. Headache persists until sinusitis is cleared. Diagnosis and Management of Ischemic Cerebrovascular Disease Knowledge of the symptoms and signs of occlusive cerebrovascular disease is necessary for effective diagnosis and management of these patients. Symptoms are often transient, may be subtle, and can be unappreciated by both patient and physician. As most occlusive cerebrovascular is secondary to atherosclerosis of the internal carotid artery, the following brief review will focus on patients with this particular problem. Transient Ischemic Attack Transient ischemic attack (TIA), a transient neurological deficit secondary to dysfunction of a part of the cerebral hemisphere because of a lack of blood flow, is the most common symptom in patients with atherosclerotic carotid artery disease. TIA has been traditionally defined as lasting less than 24 hours. Vague symptoms such as dizziness, confusion and blurred vision are not TIAs. Unilateral

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weakness, clumsiness and numbness are the most common symptoms but dysphasia and dysarthria may also occur. The diagnosis is based on a careful history, as most patients will not have discernible neurological deficits when being examined. Many conditions, including seizures, intracranial tumors and hematomas, cardiac dysrhythmias, hypoglycemia and migraine may produce symptoms similar to TIAs. These other etiologies must be considered in a patient suspected of having TIAs. Amaurosis Fugax Amaurosis fugax (AF), a transient loss of vision involving one eye, is the second most common presenting symptom in patients with atherosclerotic carotid artery disease. This can be confused with a transient visual problem involving both eyes in one visual field and careful questioning will be necessary to differentiate between the two. Many patients will not have tested each eye separately during an episode of visual loss, in which case differentiation may be impossible. Evaluation of atherosclerotic Carotid Artery Disease General As indicated above, patients with suspected carotid artery stenosis need a careful history to identify symptoms suggestive of AF or TIA and to assess their risk factors for generalized atherosclerotic vascular disease. Such risk factors include advanced age, smoking, diabetes, hypertension, hyperlipidemia, peripheral vascular occlusive disease, coronary artery disease and a positive family history of stroke or myocardial infarction. General physical and neurological examinations looking for evidence of peripheral and cerebrovascular arterial stenosis or neurological deficit is done following a careful medical history. The presence of a cervical bruit on auscultation of the neck may indicate carotid artery stenosis producing turbulent blood flow. This is the most common physical finding in patients with clinically significant atherosclerotic carotid artery disease but its absence does not rule out the diagnosis. Diminished peripheral pulses may indicate generalized atherosclerotic vascular disease. Fundoscopic Examination Cholesterol emboli may occasionally be seen in retinal vessels of patients with atherosclerotic carotid artery disease with or without AF. Laboratory Evaluation Patients with TIAs should have a study such as a cranial CT or MRI scan to rule out intracranial lesions. Imaging of the carotid arterial system with carotid duplex ultrasonography, magnetic resonance angiography, CT angiography or digital subtraction angiography should also be done if atherosclerotic carotid artery disease is suspected from the history and/or examination. Echocardiography may also be indicated to look for a cardiac source of embolism. Screening laboratory evaluation to look for evidence of coagulopathy (PT, PTT, INR), vasculitis (ESR) or hyperlipidemia should also be considered. Indications for Carotid Endarterectomy Patients with symptomatic atherosclerotic carotid artery disease producing a 70% or greater diameter stenosis of the internal carotid artery disease benefit from surgery if the perioperative morbidity and mortality is less than 7%. Patients with asymptomatic disease and greater than 60% stenosis benefit from surgery if perioperative complications are less than 3%. If in doubt as to the potential benefit of carotid endarterectomy patients should be referred to skilled cerebrovascular surgeon for evaluation.

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6. DIAGNOSIS AND MANAGEMENT OF SPINAL CORD INJURY. Mechanism of Injury: Motor vehicle crashes: 45% Falls: 22% Sports: 14% Violence: 14% Other: 5% Most patients (75%) are males. Sixty percent are between the ages of 16 and 30. Slightly more than half of all patients with cervical spine trauma will present with signs of neurologic injury. Up to 10% of patients with cervical spine trauma will develop signs of neurologic injury after presentation. Association with other injuries Five to ten percent of unconscious patients who have been involved in a fall or motor vehicle accident will have a cervical spine injury. Conversely, 60% of patients with a cervical spine fracture will have at least one major associated injury. Five to fifteen percent of patients with a cervical spine fracture will have a second vertebral column fracture. History and physical examination clues to the presence of spinal injury Pain local pain, due to bone/soft tissue injury radicular pain, due to nerve root compression bradycardia indicating loss of sympathetic input to the heart from cervical or high thoracic lesion hypotension due to loss of sympathetic input to systemic vasculature ("spinal shock") External tenderness, bruising, or swelling due to local soft tissue damage palpable step-off due to malalignment paraspinous muscle spasm torticollis due to muscle spasm or unreducedvertebral dislocation Weakness partial vs. complete level: motor level is defined as the most caudal level with grade III (antigravity) strength, assuming that more cranial levels have grade IV strength Sensation decreased vs. absent vs. hyperesthesia level : sensory level is defined as the most caudal dermatome with normal sensation saddle region needs to be tested - may be the only region of preserved sensation ("sacral sparing") Reflexes normal vs. absent vs. increased absent may indicate the presence of spinal shock increased may indicate the presence of an older complete or incomplete injury Sphincter decreased or absent tone loss of voluntary contraction loss of bulbocavernosis reflex In the comatose or intoxicated patient The comatose or intoxicated may be unable to transmit information regarding pain or cooperate with strength or sensory testing. Intracranial injury may co-exist with spinal

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injury. Therefore one must assume that all comatose or intoxicated trauma patients have a spinal injury until proven otherwise. Clues to the presence of a spinal injury in such a patient include: flaccid areflexia diaphragmatic breathing loss of grimace to painful stimuli below specific level loss of withdrawal response below a specific level loss of spontaneous movement below a specific level loss of sphincter tone priapism Frankel Grading System.

Frankel Grade Designation Definition

Complete neurological injury

A No motor or sensory function detected below level of lesion

Preserved sensation only B

No motor function detected below level of lesion, some sensory function below level of lesion preserved

Preserved motor, nonfunctional C

Some voluntary motor function preserved below level of lesion but too weak to serve any useful purpose, sensation may or may not be preserved

Preserved motor, functional D Functionally useful voluntary motor function

below level of injury is preserved Normal motor function E Normal motor and sensory function below

level of lesion, abnormal reflexes may persist Radiologic studies Plain x-rays Static: Need to see down to the C7-T1 disc space on the lateral plain x-rayof the cervical spine Anterior-Posterior and Lateral (Cervical/Thoracic/Lumbar) Evaluate for the presence of: Prevertebral soft tissue swelling Malalignment Vertebral body fractures or loss of vertebral body height Posterior element fractures (spinous process, transverse process, lamina, facet) Widening of interpedicular distance Fracture of dens Open Mouth Odontoid (Cervical) Evaluate for the presence of: Fracture of dens Widening of lateral masses of C1 Dynamic (Flexion/Extension):

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Performed only if static x-ray are normal but there is a high suspicion of ligamentous injury not be visible on static x-rays Can only be performed in the conscious cooperative patient Evaluate for the presence of: Vertebral subluxation Widening of distance between dens and arch of C1 Abnormal kyphosis or opening up of posterior elements in flexion Computed axial tomography Has largely replaced conventional polytomography Most useful for assessing bone detail; poor visualization of neural elements Usually performed whenever the plain x-rays are abnormal in order to more completely characterize a known fracture, rule out spinal canal compromise due to indriven bone fragments with a known fracture, rule out occult fracture in the presence of known ligamentous injury. Used to image the lower cervical spine when this cannot be done using plain x-rays May be combined with intrathecal contrast (myelography) in order to visualize neural elements when MRI is contraindicated or not available Magnetic resonance imaging (MRI) Most useful for visualizing soft tissue structures Resolution of bone inferior to computed axial tomography May be performed when plain x-rays are abnormal in order to rule out: spinal cord injury/hematomyelia, traumatic intervertebral disc herniation, hematoma, ligamentous injury. Acute management of spinal cord injury Immobilization Cervical. Traumatic cervical spine injury should be presumed to be present until it is ruled out by physical examination and appropriate radiographic studies. In order to prevent new or additional neurologic injury, immobilization of the cervical spine should be instituted as soon as possible. Patients with a known or suspected cervical spine injury, or those who are comatose or intoxicated at the scene of injury, should ideally be placed in a cervical orthosis at the scene. Alternatively, if an appropriate cervical orthosis is not available, the head and neck may be immobilized by placing sandbags or towel rolls on either side of the head. If a cervical spine injury is found radiographically, it is usually imperative that cervical spine immobilization be continued until definitive management is complete. In some patients this may consist of continued treatment in a cervical orthosis, combined with bed rest. In other patients, especially those with neurologic injury, cervical spinal instability, or unreduced cervical spinal dislocation, in-line cervical traction may be used. Cervical traction is frequently applied using Gardner-Wells tongs secured to the skull. Five pounds of weight are initially applied. More weight is occasionally added in an attempt to reduce a spinal dislocation. While the patient is in cervical traction, neurologic examinations should be performed frequently. Radiographic examinations should be performed after the initial application of weight and after any subsequent change to assess for changes in

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spinal alignment and the presence of overdistraction (pulling apart of the spine). Weight should be immediately reduced if a decline in the neurologic examination or overdistraction occurs. Cervical traction is contraindicated in certain highly unstable cervical injuries, as well as in occipital-cervical dislocation. Finally, some patients may initially be placed in a halo vest. In addition to effective immobilization of the upper and middle cervical spine, placement in a halo vest may constitute definitive therapy for a variety of lesions. Thoracolumbar As with the cervical spine, thoracolumbar spine fracture should be presumed to be present until it is ruled out by physical examination and appropriate radiographic studies. Present extrication and transport techniques emphasize maintenance of a neutral position during the prehospital phase. Most commonly, patients are transported to the hospital on a backboard. They should not be allowed to sit or stand prior to evaluation. During the physical examination, patients should be carefully logrolled by multiple personnel for examination of the back. Unless the patient has a highly unstable lesion, the backboard may be removed while the patient is flat in bed. Whenever the patient is moved, for example to the CT or MRI scanner, the patient should be carefully placed back onto the backboard. Steroids in Spinal cord injury Results of the NASCIS II study showed that patients with spinal cord injury who were treated with methylprednisolone within eight hours of injury had significantly greater improvement in their neurologic function (motor, pinprick sensation, and touch sensation) than those given a placebo. The dose administered in the study was 30mg/kg given as a bolus over 15 minutes, followed by an infusion of 5.4 mg/kg/hr for 23 hours, begun 45 minutes after completion of the bolus. Results of a follow-up study, NASCIS III, concluded that patients with acute spinal cord injury who receive methylprednisolone within 3 hours of injury should be maintained on the treatment regimen for 24 hours. When methylprednisolone is initiated 3 to 8 hours after injury, patients should be maintained on steroid therapy for 48 hours. Gunshot wounds to the spinal cord No data from randomized, controlled studies. However, a recent retrospective study of 254 patients reported no neurological benefit from intravenously administered steroids after a gunshot wound to the spine (C1-L1). Both infectious and noninfectious complications were more frequent in the group receiving steroids. It was recommended that patients with spinal cord injury secondary to a gunshot wound to the spine not be treated with steroids. Respiratory Maintenance of an adequate airway and breathing remains the first priority in the trauma patient. Spinal cord injured patients may suffer from inadequate respiratory function due to paralysis of the intercostal muscles or diaphragm. Concomitant injuries may also compromise respiratory function. Maintenance of spinal alignment is critical during intubation. If endotracheal intubation is needed, it is best performed in conjunction with in-line cervical traction, nasotracheally (if there is no evidence of basilar skull fracture) or fiberoptically. Cardiac After airway and breathing abnormalities are treated, adequate perfusion must be assured.

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Hypotension in the patient with a spinal injury may be due to intravascular volume loss due to bleeding or spinal cord injury. These two processes may co-exist. Identification and control of bleeding is the first priority. Hypotension, due to loss of sympathetic vascular tone, and bradycardia, due to loss of sympathetic innervation of the heart, are the most important elements of spinal shock due to spinal cord injury. Initial treatment of spinal shock consists of intravascular volume expansion. In patients refractory to this therapy, sympathomimetic drugs may be needed Genitourinary Placement of an indwelling urinary catheter is mandatory in the severely injured patient for monitoring of urine output volume. In the patient with a spinal injury, urinary catheterization during the period between identification of the injury and definitive treatment facilitates nursing care and avoids unnecessary patient movement. In the neurologically injured patient, the bladder may not function normally. Continuous urinary drainage prevents the complication of bladder rupture due to overdistension. Management principles of the unstable spine Unstable spine: Definition Spinal instability has been defined as "the loss of the ability of the spine under physiologic loads to maintain relationships between vertebrae in such a way that there is neither damage nor subsequent irritation to the spinal cord or nerve roots and , in addition, there is no development of incapacitating deformity or pain due to structural changes." Notice that this is a clinical definition. Numerous sets of radiographic criteria have been developed in an attempt to predict which patients are or will become unstable after a spinal injury. The most commonly used is the three-column model of Denis. In this model, the spine is divided into a posterior, middle, and anterior column. The posterior column includes all of the posterior bony and ligamentous elements while the middle column includes the posterior longitudinal ligament and all of the elements comprising the posterior one third of the vertebral body and intervertebral disc. The anterior column is comprised of the remaining portions of the vertebral body and intervertebral disc, as well as the anterior longitudinal ligament. Injuries with incompetence of two or three columns are inferred to be unstable. The three-column theory applies to the thoracolumbar spine only. Management principles As described above, initial management of the unstable spine consists of immobilization of the injured vertebral segment while the patient is being stabilized and other injuries are being ruled out. After this initial phase, management decisions are generally based on three factors: Need for decompression of neural elements. General indications for neural decompression will be discussed in the next section. It is important to consider that, in some cases, decompressive procedures may further destabilize the unstable spine or render the stable spine potentially unstable. Need to mobilize the patient as soon as possible. Some unstable spinal injuries may be potentially treatable with prolonged bed rest. However, by avoiding prolonged periods of bed rest, early surgical stabilization of the unstable spine may help to prevent atelectasis, pneumonia, deep venous thrombosis, and decubiti. In addition, early stabilization allows the patient to begin rehabilitation earlier,

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potentially reducing the complications of joint contracture and deconditioning, as well as potentially reducing time off work. Need to stabilize the spine that is not likely to heal without surgical intervention. In general, injuries that are not likely to heal include those with widely displaced fractures, unreduced or unreducible dislocations, severe deformity, or severe ligamentous injury. Also included in this group are injuries which have been treated with prolonged bed rest or bracing which have not healed correctly. Surgical stabilization has two components. The first component is arthrodesis, or fusion. The goal of fusion is to induce adjacent vertebrae above and below the injury to heal together into a solid block of bone, eliminating any potential movement between them. This usually involves placement of bone graft between the vertebrae. Bone graft may be placed anteriorly, between adjacent vertebral bodies, or posteriorly, between adjacent laminae, facets, or transverse processes. The second component of surgical stabilization involves internal fixation (instrumentation). This provides immediate strength and maintains anatomic alignment during the time it takes for fusion to occur. Internal fixation usually involves the implantation of some combination of wire, hooks, screws, and/or rods. Internal fixation is not a substitute for fusion. A general principle is that all internal fixators will eventually fail if fusion does not occur. Management principles in spinal cord injury. Indications for surgery The most compelling indication for decompressive surgery in spinal cord injury is the presence of an incomplete neurologic injury with persistent neural compression at the site of injury. Compression may be due to indriven bone fragments, traumatic disc herniation, epidural hematoma, or persistent vertebral malalignment. While there is currently debate regarding the most appropriate timing of decompression in the presence of a stable neurologic examination, most clinicians agree that it should be done emergently in the presence of a rapidly declining neurologic examination. The goal of decompressive surgery is restoration of a normal spinal canal without additional injury to the neural elements. This, in theory, will facilitate neurologic recovery. A review of the most common causes of neural compression reveals that most are ventral processes. Therefore, technically demanding ventral decompressive procedures are frequently necessary. As has been previously stated, these procedures may further destabilize the unstable spine or render the stable spine potentially unstable. Treatment of medical complications associated with cord injury Skin: Patients with spinal cord injury are at particular risk for skin breakdown due to inability to sense pain and prolonged periods of bed rest. This may be further aggravated by incontinence and the necessity of wearing an orthosis. All insensate regions should be surveyed regularly. While in bed, spinal cord injured patients should be turned every two hours. Bony prominences (sacrum, heels) should be protected. Shearing forces, which frequently occur during transfers, should be avoided. Bowel and bladder dysfunction should be treated accordingly as described below. All orthoses and wheel chairs should be fitted appropriately and adjusted to accommodate weight loss or gain. Bladder: Patients with spinal cord injury frequently suffer from some form of urinary bladder

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dysfunction. This may manifest as a lower motor neuron bladder with overflow incontinence and urinary retention. Alternatively, an upper motor neuron bladder may be present with incontinence and reduced bladder capacity. In either instance, the goals of treatment are to maintain a functional lower urinary tract free of infection and to preserve renal function. As has been described above, the initial treatment of urinary bladder dysfunction is usually placement of an indwelling urinary catheter. After the acute period, sterile, intermittent catheterization is preferable to the long-term use of an indwelling urinary catheter. Intermittent catheterization should initially be performed every 4 hours and urinary volumes should not be permitted to exceed 450cc. If possible, patients may be taught to perform self-catheterization. Renal function should be closely monitored long-term. Bowel movement: Patients with spinal cord injury also frequently suffer from some form of bowel dysfunction. The goals of management are for the patient to be free of incontinence and to develop a predictable bowel routine without fecal impaction. Patients with lower motor neuron bowels frequently require manual removal of feces. Those with upper motor neuron bowels may require daily digital rectal stimulation or suppositories. Adequate daily fluids and fiber intake facilitate development of a bowel routine. Diarrhea may be due either to excessive laxative intake or fecal impaction. Respiratory: All trauma patients are susceptible to atelectasis and pneumonia during the acute phase. This is especially true in the patient with concomitant traumatic brain injury. Incentive spirometry should be instituted early in treatment. If the patient is not able to participate, consideration should be given to the use of intermittent positive pressure breathing (IPPB). Additional problems arise in the spinal cord injured patient. The phrenic nerve is supplied by the C3, C4, and C5 roots. Patients with a C4 or higher level of injury most often require placement of a tracheostomy and the assistance of a ventilator. Patients with a C6 or higher level of injury will require some assistance with cough and clearing of secretions. Patients with a low cervical or thoracic level of injury remain at higher risk for atelectasis, pneumonia, and respiratory failure, despite normal phrenic nerve function, due to dysfunction of the intercostal musculature. All should be started on incentive spirometry, as well as exercise programs to increase strength in the remaining muscles of inspiration. Prophylactic clearing of secretions should be encouraged. 7. DIAGNOSIS AND MANAGEMENT OF HYDROCEPHALUS AND SPINAL DYSRAPHISM Hydrocephalus Definition of acute and chronic hydrocephalus: Hydrocephalus is the imbalance between spinal fluid production and absorption leading to a build-up of cerebrospinal fluid (CSF). Normal physiology and pathophysiology of hydrocephalus: Cerebrospinal fluid (CSF) is a liquid that normally surrounds the brain and spinal cord, serving to cushion the nervous tissue as well as wash away metabolic byproducts. It probably serves other functions, which are not as well understood. CSF is made within the brain by choroid plexus. This specialized modified cuboidal epithelium secretes CSF

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at a constant rate of .37 cc/minute, or roughly 500 ccs per day. The CSF production rate is energy dependent and constant. The composition of this fluid is similar to an ultrafiltrate of plasma. Choroid plexus in found within the 4 ventricles of the brain, the two lateral ventricles, the midline third ventricle and the fourth ventricle of the posterior fossa. The CSF normally circulates through these ventricles by way of communication pathways. The two lateral ventricles join the third ventricle by way of the Foramena of Monro. The third ventricle joins the fourth ventricle by way of the Aqueduct of Sylvius, and CSF exits the fourth ventricle by way of the midline foramen of Magendie and the lateral Foramina of Luschka. CSF then circulates up over the convexity of the cerebral hemispheres where it is absorbed by another specialized tissue, the arachnoid granulations. The arachnoid granulations are a single cell layer of cuboidal epithelium which allow CSF to cross into the venous system in an energy passive process by forcing fluid across the membrane, utilizing the pressure differential between the intracranial pressure (ICP) and the pressure within the venous sinuses. Normally, the arachnoid granulations can absorb several times more than that which is produced; however, if the arachnoid granulations become scarred because of trauma or infection, or if they become obstructed by blood products from a hemorrhage, then CSF can no longer be absorbed well and begins to build up in the subarachnoid spaces, putting pressure on the brain. If CSF flow is blocked at this level, this is termed "communicating hydrocephalus". If the CSF pathways are blocked elsewhere, such as at the level of the aqueduct of Silvius, then this is termed obstructive hydrocephalus. As the intracranial pressure begins to rise in response to a build up of CSF, the patient becomes symptomatic. Symptoms of hydrocephalus Acute: If the blockage of CSF flow happens rapidly, such as following a sudden hemorrhage, the brain has little time to compensate and the intracranial pressure rises rapidly and to a sufficient degree to cause rapid deterioration into coma. Patients will typically experience headache, nausea and vomiting, followed in a period of a few hours by confusion, agitation and then somnolence. If acute hydrocephalus is not treated emergently, the patient’s intracranial pressure will reach the point at which cerebral perfusion is compromised and the patient will deteriorate from coma to death. Chronic: If there is partial obstruction or partial blockage to CSF absorption such that CSF pressure builds gradually, then the brain accommodates to this change at first, and the onset of symptoms is more insidious. This is typically seen in patients with slow growing tumors. They typically develop headaches and nausea at night or upon awakening in the morning, with improvement in their symptoms as they get up and walk around. In infants with open sutures, chronic hydrocephalus manifests by increased head growth, which crosses percentiles on the growth curve. Signs of hydrocephalus Acute: In the young child with an open fontanelle, an infant will develop a bulging fontanelle and separation of the cranial sutures. Rapid head growth is noted in premature and newborn infants. These young infants may also have intermittent episodes of bradycardia and apnea. They may develop crossing of the eyes in response to stretching of the abducens nerves or may develop a conjugate downgaze, termed the "setting sun" sign. In

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the young infant, irritability and somnolence is a late occurrence. In older children and adults, the development of papilledema occurs over hours to days and may not be seen in the acute state. Severe headache, vomiting and alteration of mental status are followed by somnolence as cortical perfusion becomes further compromised. Chronic: Chronic hydrocephalus beyond infancy often manifests similarly to the syndrome of Normal Pressure Hydrocephalus in which the patient presents with an ataxic gait, urinary incontinence, and either dementia or a decline in short-term memory. Patients may describe intermittent headaches which are typically worse upon arising first thing in the morning or which awaken them from sleep at night. They may have chronic papilledema or optic atrophy with constriction of their visual fields. Radiographic diagnosis of hydrocephalus Skull x-ray: Skull radiographs can demonstrate findings of raised intracranial pressure, are inexpensive, and are readily available in most physicians’ offices. Separation of the cranial sutures, demineralization of the sella turcica, or a J-shaped sella may indicate chronically raised intracranial pressure. Ultrasound: In the newborn infant with an open fontanelle, sonography at the bedside can demonstrate the ventricular size and large subdural collections. Small subdurals can be missed. Insonation through the mastoid can image the posterior fossa and rule out 4th ventricular masses. Computerized tomography: This is the imaging modality of choice for screening for hydrocephalus. It is relatively inexpensive and is of sufficient detail to rule out most tumors which might obstruct the ventricular system. Magnetic resonance imaging: MRI gives the highest resolution image of the brain. It has the advantage of multiplanar imaging, which can be useful in determining subtleties such as agenesis of the Foramen of Monro or aqueductal stenosis. With resolution down to 0.5mm, a MRI is unlikely to miss even the smallest of tumors. Differential diagnosis of hydrocephalus Acute: The differential diagnosis of acute hydrocephalus is age dependent. In the premature infant, it will most commonly be secondary to a spontaneous intraventricular hemorrhage. In the newborn, it may be secondary to a congenital abnormality of the CSF pathways, may be secondary to neonatal meningitis, or may be caused by a congenital brain tumor. Chronic: Chronic hydrocephalus is caused by a slowly growing brain tumor until proven otherwise. It may be secondary to a congenital abnormality such as aqueductal stenosis, or possibly to one of the chronic meningitides, but CT or MRI must rule out a mass lesion first. Treatment of hydrocephalus: The treatment of hydrocephalus is dependent upon its cause. Acute hydrocephalus

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secondary to hemorrhage or infection is often transient and can be managed by temporary CSF drainage, either by serial lumbar punctures (LPs) or by placement of a temporary ventricular drain until the underlying pathology has been dealt with. Chronic hydrocephalus has classically been treated by a shunt, which is a plastic tube and valve system which offers a manmade plumbing system to replace the natural one which is no longer working. This most commonly involves placement of a tube into the ventricle which exits the skull through a drilled hole (burr hole) and is connected to a one way pressure regulating valve and then a distal tube which drains excess fluid into another body cavity where it can be absorbed. Most often, this is the peritoneum. Spina Bifida Definition of Spina Bifida: Spina bifida is a developmental abnormality in which there is incomplete fusion of the dorsal elements composing the roof of the spinal canal. If this birth defect is skin covered, it is termed "occulta". If the defect is open and the neural elements are exposed, it is termed "cystica" or "aperta". Normal development and abnormal development related to spina bifida: In the course of normal development, the human embryo at day 18 of gestation is composed of 3 primordial layers of tissue, the ectoderm, the mesoderm, and the endoderm. Shortly thereafter, the ectoderm begins to develop two raised areas, one on either side of the primitive streak. These folds of tissue comprise the neural crest tissue, which curves together and fuses across the midline. This fusion expands in both the rostral and caudal directions to form the neural tube. The anterior neuropore closes at around day 24 of life and the posterior neuropore around day 28. Failure of closure of the anterior neuropore will cause anencephaly, whereas failure of closure of the posterior neuropore is associated with spina bifida cystica. Signs of spina bifida Open: Spina bifida cystica of aperta is being increasingly diagnosed by prenatal ultrasound. When not diagnosed prenatally, it generally becomes readily apparent at birth, with the fetus being born with a large head and a myelomeningocele. This condition is usually associated with additional abnormalities such as pes cavus deformity of the feet and neurogenic bowel and bladder. Closed: Spina bifida occulta can be a variant of normal, with 5% of the population demonstrating incomplete fusion of the neural arches on spine x-ray. Most of the time, this is not associated with neural abnormalities. At times, the incomplete arch is accompanied by other midline lumbar ectodermal abnormalities. These include an abnormal pit in the skin, representing a rudimentary sinus tract, an abnormal lipomatous collection, a tuft of hair, or an area of cutis aplasia (abnormal skin similar to a birth mark). When found on screening physical exam, this should alert the physician to the possibility of an underlying dysraphism. The filum terminale is the terminal extension of the pia of the spinal cord. It forms a small linear structure, which normally connects the end of the conus medullaris to the dura at the end of the thecal sac. In the fetus, the spinal cord extends to the end of the sacral spinal canal, but over time, there exists a differential rate of growth between the vertebrae and the neural elements such that the end of the spinal

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cord migrates rostrally within the spinal canal. At birth, the end of the conus in normally around L3, and by six months of age, it is normally between T12 and L2. In cases of abnormal development, a thickened filum terminale, a spinal lipoma, or the bony spicule associated with diastematomyelia may serve to tether the spinal cord and prevent the normal rostral migration. This tethering will lead to progressive dysfunction of the distal spinal cord, that which controls bowel and bladder function, sexual function, and distal lower extremity function. Symptoms of spina bifida Open: Spina bifida aperta is generally too obvious to be symptomatic. The infant has deformity of the lower extremities, an enlarged head circumference, and a neural tube defect, which is obvious. In some instance, these infants may develop symptoms of hindbrain compression secondary to a Chiari malformation. This malformation is commonly found in patients with spina bifida aperta and results in their brainstem structures being in their cervical spinal canal. Chiari symptoms at this age may consist of drooling, feeding difficulties, a hoarse or high pitched cry, vocal cord paralysis or other signs of lower cranial nerve dysfunction. Closed: The symptomatic spina bifida occulta typically becomes symptomatic beyond infancy, typically following a growth spurt. Classically, the young child who has become toilet trained begins to experience urinary incontinence and urgency. This is often accompanied by back pain exacerbated by exercise, similar to the syndrome of lumbar pseudoclaudication seen in elderly adults. Numbness of the legs, dysesthesias in the lower extremities and motor symptoms can also be seen. Most of these children will have a history of chronic constipation. Radiographic diagnosis of spina bifida Plain radiographs: Plain radiographs of the spine are generally diagnostic. Occasionally, more subtle abnormalities will be found such as the midline upper lumbar calcification of diastematomyelia or widening of the pedicles from a chronic intraspinal mass such as a spinal arachnoid cyst. Ultrasound: In the newborn period, the dorsal arches of the spine are cartilaginous and have yet to ossify. In the first few weeks of life, ultrasound over the distal spine can adequately image the spinal canal and cord to determine the level of the conus medullaris, detect intraspinal lipomas and fluid collections such as syringomyelia. At this age, a thickened filum terminale can also be detected. CT and CT myelography: The CT scan is an excellent mode of imaging abnormal bone anatomy and is important in defining abnormal segmentation defects such as butterfly vertebrae or diastematomyelia. In the MRI era, myelography is only rarely performed in the child. MRI: This is the imaging modality of choice for defining abnormalities of the neural elements associated with spina bifida occulta or tethering of the spinal cord. In the newborn period MRI may be difficult due to respiratory and cardiac motion artifact. If the infant is

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clinically stable, most pediatric neurosurgeons prefer to wait until the infant is 3-6 months old to perform this study. Treatment: In the infant born with a myelomeningocele, repair is usually performed within the first 48 hours of life. The early repair of a leaking myelomeningocele is believed to prevent the development of meningitis. Ninety percent of these infants will also have hydrocephalus and will require placement of a ventriculo-peritoneal (VP) shunt. The repaired myelomeningocele always scars into the walls of the spinal canal at the site of repair; therefore, all of these infants have, by definition, a tethered spinal cord. Over time, at least a fourth of children with spina bifida will become symptomatic from this tethering and will require further surgeries to untether the spinal cord. In the asymptomatic infant noted to have spina bifida occulta detected by a midline lumbar cutaneous signature mark, treatment continues to be controversial. Most pediatric neurosurgeons will untether the asymptomatic infant due to reports of progressive neural dysfunction noted in many infants, which are followed over time without treatment. Given that all neonates are incontinent, it is difficult to assess bowel and bladder function at this age, and once lost, surgical intervention cannot reliably restore function, but can only halt the deterioration; therefore, adequate evidence exists to support prophylactic untethering. 8. DIAGNOSIS AND MANAGEMENT OF NON-TRAUMATIC NECK AND BACK PROBLEMS. Categories of Symptoms: In order to have an orderly approach to the patient with spine related complaints, the physician needs to be familiar with the broad categories of symptoms with which patients will present. The differential diagnosis of spine related pain is extensive. Although the vast majority of patients have benign, non-surgical problems, very serious medical illness can present with the chief complaint of back, neck, or extremity pain. With experience, common presenting syndromes emerge, and allow more rational triage of patients into groups who need further evaluation, and perhaps surgical referral, and those who are best managed without extensive testing and referrals. Axial Spine Pain Pain in the spine with or without radiation into the extremities is the most common presenting compliant related to spinal disease. Initial evaluation should center on obtaining a detailed history of the patient’s complaints and previous medical history. A history of recent trauma should raise the suspicion of a fracture. Character, severity, frequency, inciting and relieving events should be thoroughly explored. Inquiry about associated symptoms, such as fever and visceral pain can suggest diagnoses and avenues of investigation. The timing of pain can also lead to appropriate investigation. Morning stiffness and pain that relents as the day progresses suggests an inflammatory disorder, where nocturnal pain associated with recumbency is a much more ominous symptom, being seen with malignant, destructive lesions. Activity-related back pain without neurologic symptoms or findings is quite common. In the absence of other worrisome symptoms or findings, most patients can be successfully managed with a brief reduction in activity level and analgesics. The optimum duration and content of non-operative treatment is controversial. Some practitioners advocate strict bed rest, while others avoid it. Reduction of general activity level while avoiding

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any specific inciting events, coupled with non-steroidal agents, is the mainstay of most clinicians’ first line therapy. Evaluation for pure axial spine pain that does not resolve with conservative measures can include plain radiographs, magnetic resonance imaging, computed tomography, myelography, electrophysiologic studies, and discography. A set of plain films can exclude fracture, and identify serious bony pathology such as a destructive tumor. However, for soft tissue imaging the MRI is the study of choice. CT can give detailed information about bony anatomy. Myelography is sensitive to canal and foraminal pathology, and when paired with a post-myelogram CT scan, can be very useful in the patient in whom an MRI is not an option. Discography is controversial, and will not be discussed at length. Radiculopathy Referred pain into the upper or lower extremities often accompanies back or neck pain. Referred pain can be the initial symptom of a compressed nerve root by a ruptured disc or neural foraminal stenosis from osteophytes. Radicular pain is usually described as sharp or even shock-like, and may be associated with certain activities or positions. The distribution of the pain may not always be classic, and often doesn’t respect dermatomal distributions. Sensory changes are also often seen, with complaints of tingling and numbness being very common. On examination decreased sensation to pinprick and light touch are found in a dermatomal distribution in many patients. It is interesting that areas of referred pain and sensory loss often are different. Making determinations of level of nerve root compression solely from pain or sensory distribution is often difficult. Motor weakness is also seen in nerve root compression syndromes. Muscle innervation is more constant and has less overlap than sensory innervation and is better at predicting level of pathology. Motor deficits that are of a more long-standing nature can have significant wasting. Hyporeflexia in the appropriate distribution is also seen. Cervical Cervical radiculopathy can present acutely, as with a traumatic ruptured disc, or can be of a more chronic and intermittent nature, as is seen in foraminal narrowing from osteophytes. Typically, the inferior nerve root is affected (e.g. C5-6 disc abnormalities affect the C6 nerve root). C5-6 and C6-7 are the most commonly affected segments. A C5 radiculopathy typically presents with pain in the shoulder and the upper part of the lateral arm. Paresthesias are often seen in the more distal part of the affected dermatome. Deltoid weakness is seen commonly with a C5 radiculopathy. Biceps or brachioradialis weakness can be seen with a C6 radiculopathy along with the appropriate hyporeflexia. Paresthesias and frank sensory loss are more distal, and can extend into the hand. Root compression at C7 produces triceps weakness and a decreased triceps reflex. Pain extending into the distal forearm or hand is common. Sensory loss is commonly seen in the hand. Lumbar Sciatica is a classic syndrome of lower lumbar nerve root compression. Low back pain, that may or may not have been associated with some sort of trauma, is commonly antecedent to the onset of leg pain by days to a few weeks. Pain tends to be more proximal, and in a slightly different distribution than sensory changes. Motor weakness is also seen, but can be missed if dynamic testing is not done. All patients should be asked

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to stand on their toes and heels, as confrontational testing will miss subtle motor deficits in the lower extremities. As in the cervical spine, the pathologic level usually affects the caudal nerve root (e.g. L5-Sl disc produces an S1 radiculopathy). L5-S1 and L4-5 are overwhelmingly the most common levels affected. The upper lumbar spine is affected less frequently. The classic S1 radiculopathy results in pain down the back of the leg and into the heel or foot. Sensory loss is usually over the lateral aspect of the foot. Plantar-flexion weakness is seen, but can be subtle. A loss of the Achilles reflex is also fairly specific to S1. The L5 radiculopathy produces similar pain, but the sensory symptoms tend to be over the dorsum of the foot. Weakness in dorsiflexion of the foot (or more specifically extensor hallicus longus) is the motor finding associated with L5. There is not a reliably reproducible reflex associated with L5. Cauda Equina Syndrome The cauda equina syndrome is important to recognize, as prompt surgical attention may be necessary in cases of acute pathology. Patients typically present with low back pain and diffuse lower extremity complaints. Minimal or absent leg pain is seen, in contrast to the predominance of extremity pain seen in the radicular syndromes. Bowel, and, more commonly, bladder dysfunction, are also seen. In many patients this goes unrecognized until bladder distention leads to overflow incontinence. Because of the vague nature of the complaints, and the common lack of severe pain associated with a large disc herniation producing a cauda syndrome, delay in diagnosis is not uncommon. Patients with back pain and complaints of lower extremity weakness should be carefully examined to rule out a cauda equina syndrome. Weakness can be diffuse, and vary from subtle to paraplegia. Sensory findings are variable, but often found in the perineal area. Checking a post void residual can give a quick initial assessment of bladder function, and should be done prior to placing a foley. Reflex changes are variable, but in general reveal diffuse hyporeflexia. Patients in whom the diagnosis is suspected should undergo urgent imaging with MRI or a myelogram. Recovery from a severe cauda equina syndrome, even with prompt surgical management, can be very slow and incomplete. Bladder function is often the slowest symptom to improve. This is another reason to keep a high index of suspicion for this uncommon entity in patients presenting with back pain and complaints of lower extremity weakness. Myelopathy Myelopathy is the clinical presentation of pathology affecting spinal cord function. The differential diagnosis for causes of myelopathy is large and includes trauma, metabolic, degenerative, inflammatory, toxic, infectious, and neoplastic etiologies. Degenerative conditions of the spine may produce the symptoms of myelopathy. In many instances the onset of the myelopathy is insidious, and symptoms and signs subtle. Longstanding myelopathy, unfortunately, is rarely reversible. Early identification of patients with progression of myelopathy is essential to prevent permanent loss of neurologic function. Therefore, in patients who present with neck or thoracic spine pain, the history and physical exam should be tailored to exclude myelopathy. The most general signs of myelopathy are those of upper motor neuron dysfunction. Subtle symptoms include difficulty with fine motor control of the hands and fingers, gait problems and instability, and numbness. Hyperreflexia, increased tone, and weakness are the hallmarks of the clinical exam. Abnormal plantar response and Hoffman’s sign are

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frequent abnormal reflexes seen in patients with myelopathy. Urinary dysfunction, such has hesitancy, frequency, and incontinence, is also seen, but tends not to be severe. Chronic Progression of the myelopathy can be very slow and gradual, or stepwise. It is not uncommon for the onset to be so insidious that patients are quite disabled before they seek medical evaluation for their symptoms. Careful history and examination can direct the level of suspicion. In general, symptoms that affect the hands and upper extremities should prompt cervical evaluation, while isolated lower extremity symptoms and a trunk sensory level are more suspicious for a thoracic lesion. Often in chronic myelopathy the distinction can be difficult. In patients with chronic myelopathy an MRI is the study of choice to evaluate the spinal canal. In patients who are unable to have an MRI, myelography and CT myelography is adequate and gives good information about the spinal canal. Acute Degenerative disease may lead to acute onset of myelopathy. Acute disc herniation can be seen in the setting of trauma, but also without significant injury. Patients who present with the acute onset of myelopathic symptoms deserve urgent evaluation with MRI or myelography. If pathology such as an acutely ruptured disc causing spinal cord compression is found, surgical evaluation should be sought. Unfortunately, patients with complete spinal cord injuries only infrequently make full recoveries. Acute worsening of cervical myelopathy in the setting of cervical stenosis can be seen in the face of fairly minor trauma. In patients with acute myelopathy without obvious fracture, but significant degenerative disease, cervical stenosis should be suspected. Specific Conditions The Herniated Disc The central portion of the intervertebral disc is the nucleus pulposus. Under certain pathologic conditions it may rupture through the annulus fibrosis and into spaces occupied by neurologic structures. Central, large disc rupture causing compression of the spinal cord or cauda equina may be seen. It is, however, much more common to find a posterior-lateral rupture producing nerve root compression and radiculopathy. Mechanisms producing radicular pain are poorly understood. Direct compressive effects certainly play a role. The dorsal root ganglion appears especially sensitive to compressive effects. Recent animal models have suggested a role for biochemical factors leading to inflammation. Increasingly, experimental evidence suggests that the mechanisms leading to pain generation are more complex than once thought. Lumbar Lumbar radiculopathy is commonly known as sciatica. The classic presentation is in younger patients who will present with a history of back pain followed in a few days to weeks by intense leg discomfort, paresthesias, and radicular weakness as described in the previous section. Soft disc herniations in the lumbar spine leading to radicular complaints are seen most often in the 3rd through 6th decade of life. Estimates of prevalence vary widely in the literature, from as low as 2% to high as 40%. Non-surgical therapies for symptoms due to lumbar disc herniation are plentiful. The natural history of radiculopathy is one of improvement in many individuals. A variety of therapies are successful in helping patients get through very painful periods. Oral or

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epidural steroids can be quite successful in managing lumbar radiculopathy, although the results are often temporary. Physical therapy, chiropractic manipulation, and a host of other devices and regimens are used and promoted. Definitive evidence on the superiority of any particular approach to non-surgical therapy is lacking. All patients without severe neurologic deficit should undergo a trial of non-surgical therapy. The duration of non-surgical therapy is not set, and is often driven by the patient’s ability to continue to tolerate their symptoms. Frequently 4 weeks, and, preferably 2-3 months of non-surgical treatment are recommended., It is, however, common for patients with severe pain or neurologic deficit to be operated upon more quickly. The lumbar laminectomy for discectomy is one of the most widely performed spinal procedures. Despite this, indications continue to be debated. Except for patients with a cauda equina syndrome, non-operative therapy is always an option. There is prospective data from Weber that would suggest that patients that undergo discectomy improve more quickly over the short term. This benefit appears to dissipate by 4 years. With those disclaimers, most spine surgeons would agree that reasonable operative indications would include 1) large midline disc herniation with resulting cauda equina syndrome; 2) nerve root compression with pain and significant motor and sensory deficit; 3) nerve root compression with or without neurologic deficit and incapacitating pain that fails to improve with non-surgical measures; 4) recurrence of incapacitating episodes of LBP and sciatica that prevent the patient from leading a normal life. In patients with clinical radiculopathy and concordant imaging findings a successful surgical outcome can be expected in 80-95% of patients. Recurrence rates are reported at 2-12%. The incidence of serious complications is very low (<2%). Cervical Cervical radiculopathy from nerve root compression can be caused by a herniated disc or from foraminal narrowing from osteophytes. The root compression syndromes produced by these conditions have been described above. Neck pain associated with degenerative disc disease and osteophytes will improve in the majority of people without invasive treatment; although there is certainly a group that will go on to have chronic symptoms. The natural history of cervical radiculopathy is not as well characterized as that of cervical myelopathy from degenerative disease. Radiculopathy will improve with time in many patients. However, it is impossible to define strict rules on the length of non-surgical therapy to undertake before surgery should be considered. Cervical radiculitis from a soft disc herniation may be less likely to improve spontaneously as that due to osteophytes. Non-surgical therapy can include oral or epidural steroids, cervical traction, physical therapy, bracing, and many others. In carefully selected patients with radicular symptoms and evidence of nerve root compression on their imaging studies, more than 90% can expect a favorable outcome with careful surgical management. Serious complications are rare (<1%). Spinal Stenosis Spinal stenosis is the narrowing of the cross-sectional diameter of the spinal canal to such an extent that neurologic symptoms or signs are produced. The syndromes produced by lumbar and cervical stenosis are quite distinct and will be discussed separately. Lumbar Lumbar stenosis classically produces neurogenic claudication. Neurogenic claudication is leg pain produced by walking or standing that is typically relieved by a change of

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position such as squatting, leaning over or sitting down. Leg pain can be in a variety of distributions, and becomes quite debilitating. Patients often report associated paresthesias. Neurologic examination may be normal at rest, though sensory deficits and hyporeflexia are sometimes seen. When motor weakness is found it can be associated with wasting, as stenosis is usually a slowing progressive disease. Approximately 2/3 of patients with symptomatic spinal stenosis will present with some variety of the classic picture of neurogenic claudication. Acquired spinal stenosis is caused by advanced degenerative disease of the disc, facets and ligaments. The hypertrophy of the facets and associated ligaments, such as the ligamentum flavum, combine with bulging discs to produce both central and lateral narrowing. Most patients with acquired lumbar stenosis are in their 6th to 7th decade or beyond. Surgical treatment for lumbar stenosis involves decompressive laminectomy and may require medial facetectomies for lateral recess stenosis and foraminal stenosis. More recently, surgeons have been exploring the role of lumbar fusion in the treatment of spinal stenosis in the older population. The role of fusion and instrumented fusion in this setting is yet to be fully determined. The reader is referred to the suggested readings for more on this topic. Early improvement after surgery for lumbar spinal stenosis is the rule (>90%) in patients with a postural component to their pain. However, late progression of symptoms is not uncommon. A large review by Turner et al. suggests that good results are maintained in approximately 64% of patients over time. Cervical Cervical spondylotic myelopathy (CSM) is the clinical entity produced by cervical stenosis. CSM usually progresses slowly, in a stepwise fashion. This myelopathy can be quite subtle in the early stages, and some patients will have significant disability before seeking appropriate medical care. The most common presenting complaints include neck pain, gait difficulties, and hand numbness and clumsiness. Loss of bowel and bladder control is uncommon early in CSM. Occasionally patients will present with acute and profound spinal cord injury after mild trauma (usually a hyperextension injury). More common is a stepwise decline in spinal cord function. The typical patient with CSM is older than 50 and male. Men are seen nearly twice as often as women. Myelopathic findings dominate the physical examination of patients with CSM. Increased reflexes in both the upper and lower extremities with lower extremity spasticity are common. Pathologic reflexes such as Babinski and Hoffman are also often positive. Lhermitte’s sign (electric, shock-like pain radiating down the spine on neck flexion) is classically described, but occurs in a small minority of patients. Complicating the clinical picture in CSM is the lower motor neuron findings that can be seen secondary to nerve root compression. Wasting, fasciculations, and hypoactive reflexes can be seen in the upper extremities due to nerve root compression. The differential diagnosis of CSM includes multiple sclerosis, syringomyelia, spinal cord tumor, subacute combined degeneration, and normal pressure hydrocephalus. Special care should be taken in patients with both upper and lower motor neuron signs, as amyotrophic lateral sclerosis and CSM can be difficult to distinguish. Surgical decompression of the cervical spinal cord will be recommended by most neurosurgeons in the setting of any signs of myelopathy and significant cervical canal

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stenosis. Deficits acquired by patients with CSM are rarely completely corrected by surgery, so most surgeons will tend to offer decompression as early as possible. In patients with significant cervical stenosis without signs or symptoms of myelopathy operative indications are less clear. The role of fusion in the treatment of CSM is debated, and is beyond the scope of this chapter. Surgical results in the large series available suggest that in 75-90% of cases the myelopathy can be stabilized or improved. The incidence of worsening of myelopathy with surgery is low (<1%). Other complications are approach- related and the reader is referred to the suggested readings. Diagnosis and Management of Peripheral Nerve Injury and Entrapment This review is intended to present a set of general principles which can be applied clinically to both evaluate and treat a broad spectrum of peripheral nerve problems which include traumatic injuries and associated entrapment neuropathies. Peripheral nerve injuries Clinical evaluation Peripheral nerve injury or disease can cause symptoms of pain, dysesthesias, and either partial or complete loss of sensory and motor function. A thorough clinical history, physical examination, electrodiagnostic evaluation, and relevant radiographic studies should be performed to distinguish a peripheral nerve problem from one involving the spinal cord or brain, bone, or soft tissues. In addition, early neurosurgical consultation should be obtained. The strength of individual muscles or muscle groups is graded. A sensory exam is performed which includes testing for light touch, pinprick, two-point discrimination, vibration, and proprioception accordingly. It is helpful to test sensation in the autonomous zones of a nerve where there is minimal overlap from adjacent nerves. The presence of Tinel's sign is useful to localize a nerve injury. The Tinel's sign refers to paresthesias elicited by tapping along the course of a nerve. Progressive distal advancement of a Tinel's sign over time can be useful clinically to follow the course of regenerating sensory axons. However, the presence of a Tinel’s sign does not guarantee motor recovery. Return of sweating in an autonomous zone signifies sympathetic nerve fiber regeneration. Reflex changes are also sensitive and early indicators of nerve damage. Both electromyography (EMG) and nerve conduction studies (NCS) are useful to distinguish an upper from lower motor neuron disorder as well as diagnose a primary muscle disease. For EMG studies, a needle electrode is placed through the skin into a specific muscle and the activity at rest and electrical response to graded muscle contractions are determined. The nerve conduction study involves stimulation and recording along the course of peripheral nerves. This allows one to measure the velocity and amplitude of the propagating nerve action potential. An understanding of the functional anatomy of the peripheral nervous system can often permit the clinician to localize nerve injuries and lesions with a high degree of accuracy: The brachial plexus typically originates from the fifth through eighth cervical spinal nerve roots as well as the first thoracic root and innervates all of the muscles of the upper extremity. These nerve roots join to form trunks, which further subdivide into divisions, then cords, then, more distally, individual peripheral nerve branches. Severe trauma

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transmitted to the most proximal portions of the brachial plexus may produce a preganglionic injury with avulsion of spinal nerve roots from the spinal cord. It is important to determine whether avulsion of the ventral or dorsal roots has occurred, since direct repair of a peripheral nerve whose contributing spinal roots have been disconnected from the spinal cord will not restore function. A Horner's syndrome, characterized by ptosis, miosis, and anhidrosis indicates avulsion of the ipsilateral proximal C8 and/or T1 spinal nerve roots. Other physical signs of proximal nerve root avulsion are elevation of the ipsilateral hemidiaphragm (phrenic nerve), scapular winging (long thoracic nerve), and weakness of the rhomboid muscles (dorsal scapular nerve). All of these nerves originate proximally along spinal nerves. The lumbo-sacral plexus arises from the first lumbar through the fourth sacral spinal nerves. The femoral and obturator nerves arise from the anterior divisions of L2-4. The sciatic nerve is the largest nerve in the body and arises from the L4-S4 spinal nerves. This nerve passes through the sciatic notch and travels down the back of the leg where it branches into peroneal and tibial nerves usually just above the popliteal fossa. Imaging of peripheral nerve lesions Imaging techniques such as X-rays, CT, and, most recently, MRI can be valuable diagnostic tools in evaluating peripheral nerve lesions. Cervical spine fractures are frequently associated with brachial plexus injuries, as well as injuries of the proximal spinal nerves and roots. Chest radiographs may show unilateral elevation of the diaphragm as a signature of phrenic nerve paralysis (C3-5) from injury to the proximal upper cervical spinal nerves and roots. Mid-humeral fractures are associated with radial nerve injuries while midforearm fractures of the ulna or radius are associated with median or ulnar nerve injuries, respectively. Hip and proximal femur fractures are associated with sciatic nerve injuries while more distal femur fractures are associated with peroneal or tibial nerve injuries. Myelography in conjunction with a CT scan are useful to visualize meningeal diverticula and abnormalities of the spinal nerve roots, findings of which also indicate a spinal nerve root avulsion injury. CT is able to delineate soft tissue mass lesions such as tumors. MRI has proven to be much more effective in resolving the fine anatomical detail of soft tissues. Using conventional and enhanced MRI techniques, it has been possible to visualize both normal and abnormal peripheral nerve structures. New techniques such as MRI "neurography" make it possible to image and reconstruct the complex peripheral nerve anatomy as well as pinpoint regions of pathology. MRI can also be used to image signal changes in denervated muscle. Grading of peripheral nerve injury The severity or grade of a peripheral nerve injury is determined by the magnitude and duration of the applied forces of injury. Seddon defined 3 grades of nerve injury (neurapraxia, axonotmesis, and neurotmesis ) based on the extent of injury to the three structural components of the peripheral nerve described above. Neurapraxia, the mildest grade of nerve injury, is characterized by a reduction or complete blockage of conduction across a segment of nerve. Axonal continuity is maintained and nerve conduction is preserved both proximal and distal to the lesion but not across the lesion. Neurapraxia can result from direct mechanical compression, ischemia secondary to vascular compromise, metabolic derangements, or diseases or

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toxins causing demyelination of the nerve. Conduction is restored once either the metabolic derangement is corrected or remyelination occurs. Neurapraxic injuries are usually reversible and a full recovery can occur within days to weeks. Axonotmesis represents a more severe grade of nerve injury and is characterized by interruption of the axons with preservation of the surrounding connective tissue "highway" which can support axonal regeneration. Distal Wallerian degeneration (axon and myelin degenerate distal to site of injury) of the axons occurs over a several day period after which direct electrical stimulation of the disconnected distal nerve stump will not give rise to a nerve conduction or muscle response. Recovery can occur through axonal regeneration due to the preservation of the connective tissue "highway" which consists of Schwann cells and their basal lamina. The Schwann cells proliferate and form longitudinal conduits (i.e. the bands of Bungner) through which axons regenerate. Axonotmetic injuries usually recover over a period of months. The timing and degree of recovery depends on several factors which include the extent of retrograde axonal loss, as well as the time to regenerate and reinnervate target muscles and/or sensory end organs. As a general rule, peripheral nerve fibers regenerate at a rate of approximately 1 mm per day or 1 inch per month. Therefore, more proximal injuries require longer time intervals for regenerating axons to reinnervate their targets. Neurotmesis is the severest grade of peripheral nerve injury. Neurotmetic injuries are characterized by disruption of the axon, myelin, and connective tissue "highway" components of the nerve. Therefore, recovery through regeneration cannot occur. This grade of injury encompasses nerve lesions where external continuity of the nerve is preserved but intraneural fibrosis occurs and blocks axonal regeneration. Neurotmetic injuries also include nerves whose continuity has been completely interrupted. Since the necessary "highways" for axonal regeneration are absent, surgery is required to remove any intervening roadblocks in the form of scar tissue as well as to re-establish continuity of the nerve. On the basis of clinical symptoms and physical findings alone, it is often difficult to differentiate neurapraxic, axonotmetic, and neurotmetic grades of nerve injury, especially in the acute setting. Nerve conduction studies, both sensory and motor, are useful during and after the first week following an injury to distinguish neurapraxic from axonotmetic and neurotmetic grades. Treatment Strategies: Trauma is the most frequent cause of peripheral nerve lesions. Nerve injuries are caused by traction, compression, sharp laceration, and missile injury (gun shot wounds). Traction injury is often associated with a fracture or dislocation.. An understanding of the mechanism of injury is extremely helpful in determining the severity of the lesion and to guide clinical management. Traumatic peripheral nerve injuries can be classified into open and closed injuries. Decision making for open injuries is relatively straightforward. Immediate repair of acute sharp lacerating injuries (i.e. glass or knives) should be undertaken with the goal of performing a primary end to end suture repair. However, not all transecting injuries lead themselves to a primary repair. It the ends are ragged or contused, a delayed repair is preferable to demarcate normal from abnormal neural tissue. The decision making process in treating closed traumatic peripheral nerve injuries is more complex. The majority of closed traumatic injuries are due to stretch and/or

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compressive forces. An associated expanding hematoma producing a compartment syndrome may require emergent surgery to avoid irreversible nerve injury. Because nerves are often contained in a neurovascular bundle, there is potential for combined vascular and neural trauma A delayed onset of a neural deficit due to a traumatic pseudoaneurysm may also require urgent attention. An angiogram is necessary when damage to vascular structures is suspected clinically. In the majority of closed traumatic injuries, however, nerves are not actually transected. Instead, a "lesion in continuity" representing the damaged segment of nerve may be produced which results in either a neurapraxic, axonotmetic, neurotmetic, or combination of these grades of injury. In the case of compression or stretching, it if often not possible to immediately determine the grade of the injury. A partial nerve injury associated with muscle denervation usually indicates an axonotmetic grade of injury. Patients with such injuries should be followed with serial clinical and electrodiagnostic examinations to document recovery and confirm the diagnosis. These patients do not require immediate surgical intervention. An enlarging hematoma can convert a partial nerve injury into a complete injury. Complete nerve injuries produce severe muscle denervation and may represent either an axonotmetic or neurotmetic grade of injury. It is critical to distinguish between these two grades of injury over time, since the latter requires a surgical repair for recovery to occur. Patients are therefore followed closely over a several month period looking for clinical and electrodiagnostic evidence of nerve regeneration and muscle reinnervation. Muscles should be reinnervated within two years following a traumatic nerve injury if recovery of useful motor function is to occur. Beyond this point, denervated muscles undergo irreversible atrophy and replacement with fat. Therefore, it is necessary to time a surgical exploration so that a successful nerve repair results in muscle reinnervation within two years of the injury. A useful rule of thumb is to follow a patient for 3 to 4 months to allow any element of neurapraxia to resolve as well as permit axonal regeneration to occur beyond the point of injury. If there is no clinical or electrodiagnostic evidence of muscle reinnervation, then a surgical exploration using intraoperative electrophysiological monitoring should be performed. Another approach in the management of these traumatic peripheral nerve injuries is to operate "early" (i.e. as soon as medically feasible). The rationale for this approach is the following: 1) less scarring and thereby easier dissection of peripheral nerve elements; and 2) intraoperative evaluation of anatomical and electrophysiological continuity. However, it remains controversial whether an earlier surgical repair leads to a better recovery of peripheral nerve function. Entrapment neuropathies Peripheral nerve entrapment describes the mechanical irritation by which a specific peripheral nerve becomes locally injured in a vulnerable anatomic site. Peripheral nerve entrapments produce focal disturbances of nerve function. Nerve entrapment may occur at any site as a result of non-specific local lesions including fracture callus, hematomas, and benign or malignant tumors. There are several anatomical sites where peripheral nerves run in relatively confined spaces and are therefore at increased risk of compression. The differential diagnosis of entrapment neuropathies includes any disease process that damages nerves in a focal manner: i.e. degenerative, hereditary, vascular, inflammatory, and metabolic. Predisposing factors include repetitive activities involving the affected extremity, tenosynovitis, rheumatoid arthritis, acromegaly, alcoholism,

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amyloidosis, mucopolysaccharidosis, gout, sarcoid, vitamin B6 deficiency, diabetes, trauma, and conditions altering fluid balance including pregnancy, oral contraceptives, and hypothyroid myxedema. Carpal tunnel syndrome Median nerve compression beneath the flexor retinaculum of the wrist is the most common entrapment neuropathy. Women>men 2:1 Symptoms;Intermittent numbness and paresthesias along flexor aspects of thumb, index, and middle fingers, as well as radial side of 4th finger with or without pain, pain may radiate to the forearm and upper arm, symptoms are worse with repetitive use of the hand, pain awakens patients from sleep Examination; Phalen’s maneuver (flexion of wrist with elbow extended for 60 seconds reproducing symptoms, reverse Phalen’s maneuver (extension of wrist for 60 seconds), tinel’s sign (localized pain or paresthesia in the cutaneous distribution of the nerve when it is percussed), sensory loss in median nerve distribution (altered light touch and later two-point discrimination), thenar muscle wasting (LOAF muscles: lumbricals I,II, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis) Diagnostic studies; nerve conduction studies show localized slowing of nerve conduction velocity or decreased sensory amplitude in the sensory fibers across the wrist, signs of muscle denervation of thenar musculature on EMG (electromyogram) with advanced disease Differential Diagnosis; C6 radiculopathy, proximal median nerve compression, anterior interosseus syndrome, lateral cord of brachial plexus compression, raynaud’s disease / vascular, generalized peripheral neuropathy, amyotrophic lateral sclerosis Treatment Nonsurgical; Avoid precipitating activity, volar wrist splint in neutral position,short course of nonsteroidals or prednisone,local steroid injection into carpal tunnel, diuretic if premenstrual, recommended for patients with mild, intermittent, or acute symptoms. Surgical; Carpal Tunnel release. Indicated for thenar muscle weakness or atrophy, denervation by EMG (axonotmesis), failure of nonsurgical management Ulnar Nerve Entrapment Ulnar nerve entrapment in the region of the elbow is the second most frequently seen compression neuropathy. As the ulnar nerve descends down the arm it becomes superficial behind the medial epicondyle at the elbow. At this point it travels between the heads of flexor carpi ulnaris (cubital tunnel) and finally passes through the ulnar tunnel (Guyon’s canal) to enter the hand. The anatomic cubital tunnel is a fibroosseous ring formed by the medial epicondyle and the proximal part of the ulna. The ulnar nerve is vulnerable to compromise from compression, scar fixation, or traction, as it winds around the medial epicondyle. Patients subjected to immobilization (e.g. anesthesia, coma, restrained positions) are at risk for prolonged pressure on the ulnar nerve. Symptoms; Pain at the elbow, paresthesias in ulnar side of 4th and 5th digits (palm and dorsum),exacerbated with repetitive flexion Diagnosis; Weakness of pinching, grip, 4th and 5th flexors, positive Froment’s sign (Inability to adduct the thumb against the index finger without flexing the interphalangeal joint), weakness of third palmar interosseous with abduction of 5th digit (Wartenberg’s sign), clawing posture of little and ring fingers (benediction posture), point tenderness

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(Tinel’s sign) above elbow (ligament of Struthers), at elbow (trauma), or below elbow (cubital tunnel), with radiation into the 4th and 5th fingers. Electrodiagnostics show motor nerve conduction slowing across the elbow, reduced sensory action potential, and denervation in ulnar innervated muscles (intrinsic hand muscles) Differential Diagnosis; ulnar neuropathy at Guyon’s canal in the hand,C8 radiculopathy, thoracic outlet syndrome (medial cord of brachial plexus C8-T1), Raynaud’s disease Treatment; Nonsurgical; Avoid repetitive flexion and pressure on the nerve, splint elbow in extension, elbow pad. Surgical; Ulnar nerve decompression and/or anterior transposition (subcutaneous, intramuscular, or submuscular) if progressive deficits or objective weakness Thoracic outlet syndrome The brachial neurovascular bundle goes through the thoracic outlet to enter the arm. Thoracic outlet syndrome is caused by bony, fascial, and muscular structures that interfere with the neurovascular bundle. A fibrous band within the scalenius anterior muscle, a cervical rib, or its remnant may result in angulation or compression of the lower trunk of the brachial plexus or C8/T1 roots and subclavian vessels. Diagnosis; Paresthesias in forearm and hand commonly precede the development of pain, atrophy of intrinsic hand muscles, pain or paresthesias when arms held overhead, sensory loss in territories of ulnar and medial cutaneous nerves, Adson’s maneuver (obliteration of the pulse with a full breath and head in extension or turned to side) Treatment; Nonsurgical; Corset to prevent elevation of the arms or hands, mild Symptoms may respond to stretching physiotherapy Surgical; Exploration for refractory symptoms Meralgia Paresthetica Entrapment of the lateral femoral cutaneous nerve is referred to as meralgia paresthetica (meros=thigh; algo=pain). The lateral femoral cutaneous nerve is a branch of the L2 and L3 nerve roots and is purely sensory. It exits the pelvis to enter the thigh at the upper lateral end of the inguinal ligament. The most frequent location of entrapment is medial to its origin on the anterior iliac spine. Symptoms; Numbness, burning, or tingling of lateral thigh, positive Tinel’s at the level of the inguinal ligament, worse standing or extending the leg, better sitting, associated with obesity and/or pregnancy Treatment; Nonsurgical; Weight loss, remove constricting binders, corsets, tight belts, tight jeans Surgical; Steroid/local anesthetic test infiltration around the nerve at the inguinal ligament, lateral femoral cutaneous nerve surgical decompression (high recurrence rate) or proximal transection of nerve