Chapter 15 Disorders of the Central Nervous and Peripheral Nervous Systems and Neuromuscular Junction Traumatic Brain Injury Brain Trauma Major head trauma A traumatic insult to the brain possibly producing physical, intellectual, emotional, social, and vocational changes Transportation accidents Falls Sports related event Violence Brain Trauma Closed (blunt, nonmissile) trauma more common Hit a hard surface or rapidly moving object Dura remains intact and brain tissues are not exposed Causes focal (local) or diffuse (general) brain injuries Brain Trauma Diffuse Brain Injury (no major broken blood vessels) DAI-Diffuse axonal injury: concussion Most common type 75 to 90% mild Moderate & severe Table 15-2 Physical consequences, cognitive deficits, behavioral manifestations: page 381 diffuse axonal injury accounts for 50% of injuries Focal injuries >2/3 deathsw Mechanisms of Brain Injury Primary : neural injury, primary glial injury, and vasculat responses Secondary : consequence of primary Altered cerebral blood flow, hypoxia, ischemia, inflammation, cerebral edema, increased ICP, & herniation Tertiary : days/months later due to primary/secondary injury Pneumonia, fever, infection, immobility Maximum Force Concussion microscopic stretching & tearing at the cellular level Confusion Amnesia Headache Dizziness Ringing in the ears Nausea or vomiting Slurred speech Fatigue Change in personality Concussion Grade school Junior high High school College NFL brain heals by scaring Muhhahad Ali Brain Trauma Classic cerebral concussion Consciousness: lost for up to 6 hours, falls with loss of reflexes Vital signs: transient (BP, HR, R) Retrograde and antegrade amnesia with confusion x hours to days Head pain, nausea, fatigue, mood & affect changes Brain Trauma Post concussive syndrome Headache, nervousness/anxiety, irritability, insomnia, depression, inability to concentrate, forgetfulness and fatigability Reassurance and symptomatic relief with 24 of close observation Brain Trauma Focal Brain Injury ( broken blood vessels ) : contusion; 2/3 of deaths, visible Direct contact (severe blunt trauma) Epidural hematoma Subdural hematoma Intracerebral hematoma(subarachnoid) Injury related to amount of energy transmitted Coup or/and contrecoup brain edema - ICP with infarction and necrosis Meninges Brain Trauma: coup- contracoup Brain Trauma - hematomas Extradural (epidural) middle meningeal artery (temporal lobe) 85% 20 to 40 year olds MVA Subdural venous bleeding between dura mater and arachnoid Fall in the elderly, MVA, Shaken Baby Syndrome Subacute (2 days 2 weeks), chronic (elderly, ETOH ) Intracebral(subarachnoid) frontal and temporal lobes Penetrating injury and shearing force traumatizes small blood vessels Natasha Richardson : Epidural hematoma Subdural (Acute) Hematomas Bret Michaels : subarachnoid hemorrhage etiology ? (type I DM, cocaine, EtOH) Hematomas Spinal Cord Trauma 12,000 per year: 81% men at 33.4 years (MVA(41%, sports, violence), falls in the elderly (27% injuries) Vertebral injuries (trauma) neural tissue damage Most common C 1,2,4-7 and T 10 L 2 (most mobile)* 1. Simple transverse or spinous process 2. Compression wedged 3. Comminuted shattered 4. Dislocation *cervical-lumbar Spinal Cord Trauma Gray matter hemorrhage with necrosis - loss of perfusion and remains altered White matter edema (swelling) So: perfusion ischemic areas (returns 24 hours) Injury: maximal at the level of injury and 2 cord segments above/below Cord swelling degree of dysfunction Temporary or permanent Life threatening phrenic nerve C 3-5 Vegetative function (medulla) Spinal Cord Trauma Spinal shock (7 to 20 days) Normal activity of the spinal cord ceases at and below the level of injury. Sites lack continuous nervous discharge from the brain. Complete loss of reflex function (skeletal, bladder, bowel, sexual, thermal and autonomic control) below level of lesion. Spinal Cord Trauma Paraplegia Injury to thoracic cord Lower body and both legs Quadriplegia injury to cervical cord All 4 extremities Autonomic hyperreflexia (dysreflexia) Massive uncompensated cardiovascular response to stimulation of the sympathetic nervous system Stimulation of the sensory receptors below the level of the cord lesion Degenerative Disorders of the Spine Degenerative joint disease (DJD ) Degenerative disk disease (DJD) Herniated nucleus pulposis Spondylolysis Neural arch of the vertebra Spondylolisthesis Vertebra slides forward Spinal stenosis Trauma or arthritis Degenerative Disorders of the Spine Herniated intervertebral disk protrusion of part of the nucleus pulposus through a tear in the posterior rim of the annulus fibrosus Trauma, degenerative disk disease, or both Most common L 5 S 1 and L 4-5 Vertebral Column New Spinal Disc Stroke Cerebrovascular Disorders Most frequent occurring neurological disorder Third leading cause of death in the U.S.A. Abnormalities Ischemia = infarction (death of brain tissue) Hemorrhage Cerebrovascular accident (CVA, stoke) sudden non-convulsive focal neurological deficit Stroke Stroke: Ischemic Cerebrovascular Accidents Mainly > 65 years old(75%): 28% women: Blacks 2: Whites 1 HTN & DM 2- 4X increase & 8X mortality Spectrum: minimal (unnoticed) severe state (hemiplegia, coma and death) Classified 2 to pathophysiology 1. Global hypoperfusion (shock) 2. Ischemia (thrombotic or embolic) 3. Hemorrhagic See risk factors page 388 Cerebrovascular Disorders Cerebrovascular accidents (CVAs) Thrombotic stroke Arterial occlusions caused by thrombi formed in arteries supplying the brain or in the intracranial vessels Transient ischemic attacks (TIAs) Embolic stroke Fragments that break from a thrombus formed outside the brain Cerebrovascular Disorders Hemorrhagic strok e (intracranial hemorrhage) Mass of blood displaces and compresses adjacent brain tissue Lacunar stroke Small, < 1 cm, involve small perforating arteries Subcortical location pure motor/sensory Cerebrovascular Disorders Cerebral infarction (lost blood supply) Ischemic: discoloration, softens in 6 12 hours Necrosis, swelling liquefaction Necrosis (Figure 3-27) hours Cerebral hemorrhage ( HTN ) Arteriosclerosis (small arteries) necrosis and microaneurysms rupture (ventricles) Resolution: macrophage and astrocytes clear blood, leaving a cavity Cerebrovascular Disorders Intracranial aneurysm Saccular (berry) 2% population highest rupture age 20 50 Fusiform (giant) basilar arteries of terminal portion of the internal carotid arteries Intracranial Aneurysms Intracranial Aneurysm Cerebrovascular Disorders Vascular malformations Arteriovenous malformation (AVM) tangled mass of dilated blood vessels between arterial venous systems: A-V fistula 50% have seizures 50% have intracerebral, subarachnoid or subdural hemorrhage Cerebrovascular Disorders Subarachnoid hemorrhage (inflammation) Blood escapes from defective or injured vessel into the subarachnoid space:stiff neck, photophobia, blurred vision, restlessness & low-grades fever Manifestations Kernigs sign Brudzinski's sign See classification Table 15-7 Infection and Inflammation of the CNS Meningitis infection of the meninges Bacterial Pia mater, arachnoid, subarachnoid space, ventricles and CSF Systemic or bloodstream or direct extension from an infected area Meningococcus (Neisseria meningitidis Pneumoccus (Streptococcus pneumoniae) Meningitis Clinical Manifestations Systemic infection Fever, tachycardia, chills & petechial rash Meningeal irritation Kernig & Brudzinskis sign Neurologoc signs Decreased consciousness, cranial nerve palsies, focal neurologic deficits & seizures Infection and Inflammation of the CNS Meningitis Aseptic (viral meningitis nonpurulent) Enteroviral viruses, mumps, herpes simplex, encephalitis virus (California, St. Louis, West Nile, Venezuela) Colorado tick fever, Epstein-Barr, influenza type A & B Fungal Chronic, less common Histoplasmosis, cryptococcosis, coccidioidomycosis, candidiasis, aspergillosis Infection and Inflammation of the CNS Encephalitis Acute febrile illness, usually of viral origin with nervous system involvement Most common form of encephalitis are caused by arthropod-borne viruses and herpes simplex type 1 Meningeal involvement is present in all encephalitides Review Table 15-9 & West Nile Virus p.396 Neurologic Complications of AIDS T-helper CD 4 Receptors HIV associated dementia HIV myelopathy-spinal cord degeneration HIV peripheral neuropathy-sensory Aseptic viral meningitis Opportunistic infections-bacterial, viral, fungal CNS neoplasms Degenerative Diseases Multiple sclerosis -1/580 Colorado Progressive, inflammatory, demyelinating disorder of CNS Autoimmune disorder, develops after a viral insult to the CNS in a genetically susceptible individual Gene for syncytin activated in astrocytes released with inflammatory proteins and free radicals that kills oligodendrites Symptoms Mixed (general) Spinal Cerebellar Treatment: New Modalities Tysabri-natalizamab Integrin : transmembrane protein Adhesion communication Monoclonal antibody : part of a mouse antibody Integrin protein injected into mice (foreign protein) Ab Fuse the mouse plasma cell to a human myeloma(special cancer cell # produce Ab) to make the monoclonal antibody Infuse into patients with MS Degenerative Diseases Amyotrophic lateral sclerosis (ALS) Classic ALS (Lou Gehrig disease) Degeneration of lower and upper motor neurons (without inflammation) Disease leads to progressive weakness leading to respiratory failure and death Patient has normal intellectual and sensory function until death. Lou Gehrig: July 4,1939 -speech Stephen Hawking Neuromuscular Junction Disorders Myasthenia gravis Chronic autoimmune disease An IgG antibody is produced against acetylcholine receptors: blocking and destroying Weakness and fatigue of muscles of the eye and the throat diplopia, difficulty chewing, talking, swallowing Neuromuscular Junction Disorders Myasthenic crisis : severe muscle weakness, respiratory insufficiency danger Respiratory Arrest Cholinergic crisis : anticholinesterase drug toxicity XS accumulation of Ach danger Respiratory Arrest Central Nervous System Tumors Cranial tumors- Table Primary intracerebral tumors Gliomas Astrocytoma -most common Oligodendroglioma Epenclymoma Primary extracerebral tumors Meningioma Nerve sheath tumor Metastatic carcinoma Central Nervous System Tumors Spinal cord tumors Intramedullary tumors Extramedullary tumors Intradural Extradural Manifestations Compressive syndrome Irritative syndrome