Neurology for the Non-Neurologist, SIXTH...

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Neurology for theNon-NeurologistWILLIAM J. WEINER, MDProfessor and ChairmanDepartment of NeurologyUniversity of Maryland School of MedicineDirector, Maryland Parkinson’s Disease and Movement Disorders CenterBaltimore, Maryland

CHRISTOPHER G. GOETZ, MDProfessor of Neurological Sciences and PharmacologyRush Medical CollegeSenior PhysicianRush University Medical CenterChicago, Illinois

ROBERT K. SHIN, MDAssociate Professor of NeurologyAssociate Professor of Ophthalmology and Visual SciencesUniversity of Maryland School of MedicineBaltimore, Maryland

STEVEN L. LEWIS, MDProfessor and Associate ChairmanDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

SIXTH EDITION

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For my parents who would have enjoyed the outcomeWilliam J. Weiner

To my family, Monica, Celine, Peter, and ElenaChristopher G. Goetz

To my parents who gave me every opportunity, and to Tricia who stayed up with me

Robert K. Shin

To Julie, for all of her support, and to David, Michael, Adam, and ElliotSteven L. Lewis

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iv

Contents

Contributors vi

Preface ix

Acknowledgments xi

1. The Neurologic Examination 1Robert K. Shin and Neil C. Porter

2. An Approach to Neurologic Symptoms 20Steven L. Lewis

3. Clinical Use of Neurologic Diagnostic Tests 33Madhu Soni

4. Fundamentals of Neuroradiology 43Robert E. Morales and Dishant G. Shah

5. Neurologic Emergencies 63Tricia Y. Ting and Lisa M. Shulman

6. Examination of the Comatose Patient 89Jordan L. Topel and Steven L. Lewis

7. Cerebrovascular Disease 105Roger E. Kelley and Alireza Minagar

8. Headache Disorders 127Amy Wilcox Voigt and Joel R. Saper

9. Epilepsy 143Donna C. Bergen

10. Sleep Disorders 156Ružica Kovacevic -Ristanovic and Tomasz J. Kuzniar

11. Multiple Sclerosis 192Peter A. Calabresi and Scott D. Newsome

12. Parkinson Disease 222Bradley J . Robottom, Lisa M. Shulman, and Wil l iam J . Weiner

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Contentsv

13. Hyperkinetic Movement Disorders 241Gonzalo J. Revuelta, William J. Weiner, and Stewart A. Factor

14. Alzheimer Disease and Other Dementias 287Neelum T. Aggarwal and Raj C. Shah

15. Behavioral Neurology 307Robert S. Wilson and Christopher G. Goetz

16. Traumatic Brain Injury 324Michael J. Makley

17. Neuromuscular Diseases 344Dianna Quan and Steven P. Ringel

18. Peripheral Neuropathy 375Joshua Gordon and Morris A. Fisher

19. Neurologic Evaluation of Low Back Pain 398Megan M. Shanks

20. Dizziness and Vertigo 412Robert K. Shin and Judd M. Jensen

21. An Approach to the Falling Patient 427Kathryn A. Chung and Fay B. Horak

22. Neurotoxic Effects of Drugs Prescribed by Non-Neurologists 446Katie Kompoliti

23. Neurologic Complications of Alcoholism 470Allison L. Weathers

24. Central Nervous System Infections 486Larry E. Davis

25. Neurologic Aspects of Cancer 499Deborah Olin Heros

26. Eye Signs in Neurologic Diagnosis 516Robert K. Shin and James A. Goodwin

27. Principles of Neurorehabilitation 551David S. Kushner

28. Medicolegal Issues in the Care of Patients with Neurologic Illness 572Maria R. Schimer and Lois Margaret Nora

Index 588

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vi

ContributorsNeelum T. Aggarwal, M.D.Associate Professor of Neurological SciencesRush UniversityClinical Core Leader, Rush Alzheimer’s Disease

Research CenterRush University Medical CenterChicago, Illinois

Donna C. Bergen, M.D.ProfessorDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

Peter A. Calabresi, M.D. Professor of Neurology The Johns Hopkins University School of Medicine Director, The Johns Hopkins Multiple Sclerosis Center Baltimore, Maryland

Kathryn A. Chung, M.D.Assistant ProfessorDepartment of NeurologyOregon Health and Science UniversityPortland, Oregon

Larry E. Davis, M.D. Professor of Neurology University of New Mexico School of Medicine Chief, Neurology Service, New Mexico VA Health

Care System Albuquerque, New Mexico

Stewart A. Factor, D.O.Professor of Neurology and Riley Family Chair in

Parkinson's Disease Emory University School of Medicine Director, Movement Disorders Program of Emory

University Atlanta, Georgia

Morris A. Fisher, M.D.Professor of NeurologyLoyola University Medical CenterMaywood, IllinoisActing Chief of NeurologyEdward Hines, Jr. VA Medical CenterHines, Illinois

Christopher G. Goetz, M.D.Professor of Neurological Sciences and PharmacologyRush University Medical CenterChicago, Illinois

James A. Goodwin, M.D.Associate Professor of OphthalmologyUniversity of Illinois at ChicagoDirector, Neuro-ophthalmology ServiceUniversity of Illinois Eye and Ear InfirmaryChicago, Illinois

Joshua Gordon, M.D.Assistant Professor of NeurologyLoyola University Medical CenterChicago, IllinoisAssistant Professor of NeurologyEdward Hines, Jr. VA Medical CenterHines, Illinois

Deborah Olin Heros, M.D.Associate Professor of Clinical Neurology and

Neuro-OncologyUniversity of Miami Leonard M. MillerSchool of Medicine Chief of NeurologyUniversity of Miami HospitalMiami, Florida

Fay B. Horak, Ph.D., P.T.Research ProfessorDepartment of NeurologyOregon Health and Science UniversityPortland, Oregon

Judd M. Jensen, M.D.Penobscot Bay Medical Center Rockport, Maine

Roger E. Kelley, M.D. Professor and Chair of Neurology Tulane University School of Medicine New Orleans, Louisiana

Katie Kompoliti, M.D.Associate Professor of Neurological SciencesRush University Medical CenterChicago, Illinois

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Ružica Kovacevic-Ristanovic, M.D.Clinical Associate Professor of NeurologyUniversity of Chicago Medical CenterChicago, IllinoisAttending Medical Director, Sleep Disorders CenterEvanston HospitalEvanston, Illinois

David S. Kushner, M.D. Associate Professor of Rehabilitation Medicine University of Miami Leonard M. Miller School

of Medicine Miami, Florida

Tomasz J. Kuźniar, M.D., Ph.D.Assistant Professor of MedicineNorthwestern UniversityChicago, IllinoisAttending PhysicianNorth Shore University Health SystemEvanston, Illinois

Steven L. Lewis, M.D.Professor and Associate ChairmanDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

Michael J. Makley, M.D. Assistant Professor of Neurology University of Maryland School of Medicine Director, Traumatic Brain Injury Unit, Kernan

Hospital Baltimore, Maryland

Alireza Minagar, M.D.Associate Professor of Neurology Louisiana State University Health Sciences Center Shreveport, Louisiana

Robert E. Morales, M.D.Assistant Professor of RadiologyUniversity of Maryland School of MedicineDirector, NeuroimagingUniversity of Maryland Medical Center Baltimore,

Maryland

Scott D. Newsome, D.O.Assistant Professor of Neurology The Johns Hopkins University School of Medicine Baltimore, Maryland

Lois Margaret Nora, M.D., J.D.President and Dean, College of MedicineNortheastern Ohio Universities Colleges of Medicine

and PharmacyRootstown, Ohio

Neil C. Porter, M.D. Assistant Professor of Neurology University of Maryland School of Medicine Baltimore, Maryland

Dianna Quan, M.D. Associate Professor of Neurology University of Colorado Health Sciences Center Director, Electromyography Laboratory, University

of Colorado Hospital Denver, Colorado

Gonzalo J. Revuelta, D.O. Movement Disorders Fellow, Department of

Neurology Emory University School of Medicine Atlanta, Georgia

Steven P. Ringel, M.D.Professor of Neurology University of Colorado Health Sciences Center Director, Neuromuscular Unit, University of

Colorado Hospital Denver, Colorado

Bradley J. Robottom, M.D.Assistant Professor of NeurologyUniversity of Maryland School of Medicine

Baltimore, Maryland

Joel R. Saper, M.D. Clinical Professor of Medicine-Neurology Michigan State University Director, Michigan Headache & Neurological

Institute Ann Arbor, Michigan

Maria R. Schimer, M.P.H., J.D.Associate Professor of Community Health

SciencesNortheastern Ohio Universities Colleges of

Medicine and PharmacyRootstown, Ohio

Dishant G. Shah, M.D.Fellow, Diagnostic NeuroradiologyUniversity of Maryland Medical CenterBaltimore, Maryland

Raj C. Shah, M.D.Assistant ProfessorFamily Medicine and Rush Alzheimer’s Disease

CenterRush University Medical CenterChicago, Illinois

Contributorsvii

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viiiContributors

Megan M. Shanks, M.D.Assistant ProfessorDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

Robert K. Shin, M.D. Associate Professor of Neurology Associate Professor of Ophthalmology and Visual

Sciences University of Maryland School of Medicine Director, Neuro-Ophthalmology, University

Eye Care Baltimore, Maryland

Lisa M. Shulman, M.D. Eugenia Brin Professor of Parkinson's Disease and

Movement Disorders and the Roslyn Newman Distinguished Scholar in

Parkinson's Disease University of Maryland School of Medicine Co-Director, Maryland Parkinson's Disease Center Baltimore, Maryland

Madhu Soni, M.D.Assistant ProfessorDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

Tricia Y. Ting, M.D. Assistant Professor of Neurology University of Maryland School of Medicine Director, Ambulatory ServicesUniversity of Maryland Epilepsy Center Baltimore, Maryland

Jordan L. Topel, M.D.Associate ProfessorDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

Amy Wilcox Voigt, M.D.FellowJefferson Headache CenterThomas Jefferson UniversityPhiladelphia, Pennsylvania

Allison L. Weathers, M.D.Assistant ProfessorDepartment of Neurological SciencesRush University Medical CenterChicago, Illinois

William J. Weiner, M.D.Professor and ChairmanDepartment of NeurologyUniversity of Maryland School of MedicineDirector, Maryland Parkinson’s Disease and Movement

Disorders CenterBaltimore, Maryland

Robert S. Wilson, M.D., Ph.D.Professor of Neurological and Behavioral SciencesRush Alzheimer’s Disease CenterRush University Medical CenterChicago, Illinois

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ix

PrefaceThis sixth edition of Neurology for the Non-Neurologist carries on a tradition of medicaleducation that began over 20 years ago withthe first edition of this book. All editions havebeen anchored in an ongoing commitment todemystify neurology, so that its principles andever-growing knowledge base are accessible tononspecialists. Clearly, brain, spinal cord,nerve, and muscle disorders are encountered byprimary care physicians, including internists,family practitioners, hospitalists, and pediatri-cians. Likewise, because of the interplay ofbrain and mind function as well as the neces-sary adaptations that patients endure fromneurologic disorders, psychiatrists also seemany neurologic patients. As the core group ofphysicians for whom this book is written, thesecolleagues have embraced the former editionsof Neurology for the Non-Neurologist, and wehope this new version will likewise meet theireducational and practice-based needs.

Structurally, the new edition is similar to thelast edition, but with several significant addi-tions. The major neurologic disorders are cov-ered with an attention to the more commonlyencountered diseases, but with careful signal-ing to signs or symptoms that can suggest moreunusual disorders. We begin the textbook withthree overview chapters on Neurologic Symp-toms, Neurologic Examination, and Diagnos-tic Tests. These chapters orient readers to thesignificance of typical patterns of patient de-scriptions, the different clustering of neuro-logic signs that help clarify diagnosticcategories, and the panoply of neurologic in-vestigations available to define a likely singlediagnosis. Subsequent chapters focus on majorneurologic dilemmas that non-neurologists willencounter, ranging from Epilepsy, Dementia,Infections, and Sleep Disorders to Peripheral

Neuropathy, Neuromuscular Disease, Move-ment Disorders, including Parkinson’s Disease,Multiple Sclerosis, and Cerebrovascular Dis-ease, including stroke. We also cover topicsbased primarily on patient complaints: Vertigoand Dizziness, Headaches, Low Back Pain, andFalls. Most of these chapters stand as inde-pendent discussions, but they are integratedwith chapters that cross individual disease-based categories and therefore have broad ap-plications to other chapters: Neuroradiology,Behavioral Neurology, Drug-induced Disor-ders, Medical-legal Issues, Neurologic Emer-gencies, Eye Signs in Neurologic Diagnosis,and Rehabilitation. With these different levelsand approaches, we hope to cover the majorareas of neurology from the perspective of thenon-neurologist who is likely to be the first-linephysician with primary responsibility for man-aging neurologic problems within a full med-ical context.

As editors, we have asked authors to followa template that is consistent from chapter tochapter. Each chapter begins with a few KeyPoints that can be reviewed before launchinginto the full text. Each chapter presents thegeneral pattern of neurologic signs pertinent tothe topic and this text is interspersed with high-lighted Special Clinical Points to focus thereader on the most important details. Neurol-ogy is anchored in a two-part discipline ofdefining the anatomy of a syndrome and thenestablishing an etiology or cause. This principleis carried through each chapter text. Authorsalert readers to Special Considerations in theHospitalized Patient and When a Non-neurol-ogist Should Consider Referring to a Neurolo-gist. Finally, we close each chapter with asection, termed Always Remember, to leave thereader with a few important issues that can be

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xPreface

immediately applied in practice. We feel thisnew arrangement helps to integrate the chap-ters and allows busy practitioners to read thefull text or to scan the chapters with these mostimportant highlights clearly marked. Updatedreferences and a series of self-study questionsclose each chapter.

We are particularly proud of our list of re-cruited authors. Some have been part of thistextbook since the first edition, some have par-ticipated in at least one earlier edition, andsome are new. Their commitment to education,a clear writing style, and direct experience withneurologic education have made the editorialmanagement of this edition smooth and effi-cient. We have also expanded our Editor teamto four editors, with the long-term plan that

the senior editors will need to pass the batoneventually if this book remains successful andif book publishing remains a viable educationaltool. Editorship requires an agile and harmo-nious team that can work together and at thesame time assume individual responsibility; wefeel we have achieved both goals very comfort-ably with the textbook edition. In an era whenNorth American practice patterns and healthcare may rapidly evolve, we feel that Neurol-ogy for the Non-Neurologist is particularly im-portant as an educational resource.

William J. Weiner, MDChristopher G. Goetz, MD

Steven L. Lewis, MDRobert K. Shin, MD

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AcknowledgmentsWe continue to acknowledge the direction andhelp that Maynard M. Cohen, MD, PhD, pro-vided when the first edition of this book ap-

peared in 1981. We are also indebted to the veryfine support work provided by Cheryl Grant-Johnson, Marilynn Payton, and Janet Gillard.

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1

ROBERT K. SHIN AND NEIL C. PORTER

1 The NeurologicExamination

k e y p o i n t s

• The neurologic examination provides a comprehensiveassessment of the function of the human nervous system.

• When used in conjunction with the history, theneurologic examination can provide information criticalto making a correct diagnosis.

• With practice, the neurologic examination can beperformed efficiently and quickly.

h e n e u r o l o g i cexamination is the foundation of the practiceof neurology and an integral part of the physi-cal examination. Unlike some medical disci-plines that may emphasize ancillary studies,investigations in neurology are guided prima-rily by the information gleaned from the neuro-logic history and examination. Because theneurologic examination is often crucial in es-tablishing the correct diagnosis, all physiciansshould be able to perform and document acomplete evaluation of the nervous system.

At the same time, it is not always practicalto perform a detailed neurologic examinationon every patient. A focused neurologic exami-nation should be influenced by the informationobtained from the interview and guided by theexaminer’s clinical judgment.

■ SPECIAL CLINICAL POINT: Not everypatient requires a detailed neurologicexamination, but physicians should at least be familiar with each component of thecomprehensive neurologic examination.

The neurologic examination is divided into sev-eral parts (Table 1.1). These include assessmentof cognition, cranial nerves, motor function, re-flexes, sensation, and coordination and gait.Each of these parts has multiple componentswith which all physicians should be familiar.

MENTAL STATUS AND COGNITION

The cognitive examination provides an assess-ment of the patient’s general mental status, eval-uating the integrity of the cerebral hemispheres.

TI. CognitionII. Cranial nervesIII. Motor functionIV. Deep tendon reflexes (DTR)V. SensationVI. Coordination and gait

Organization of the NeurologicExamination

TABLE 1.1

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2Chapter 1 The Neurologic Examination■

A comprehensive mental status examinationmay begin with a general assessment of the pa-tient’s appearance, level of consciousness, andmood and affect. Important primary cognitivedomains to be tested include speech and lan-guage, memory, visuospatial processing, and ex-ecutive functioning (including judgment andinsight). Disorders of perception or disorders ofthought form and content should be noted.

■ SPECIAL CLINICAL POINT: Importantprimary cognitive domains include speech andlanguage, memory, visuospatial processing, andexecutive functioning.

Often patients with cognitive problems will tryto hide their deficiencies or may try to avoid di-rectly answering questions. One can minimizeresistance to this testing by reassuring the pa-tient that all of the questions are part of thestandard exam (e.g., “These are questions thatwe ask everybody.”). Mistakes on the patient’spart should be noted silently or corrected gen-tly by the examiner in order to keep the patientat ease.

Appearance and Behavior

The patient’s appearance and general behav-ior are important indicators of his or her general level of function. The well-dressed,well- organized patient is likely functioning ata higher level than the disheveled, unkempt pa-tient. Additionally, a patient’s dress and de-meanor are important indicators of underlyingpsychiatric and psychological disturbances,such as the patient who is inappropriatelydressed for the weather or is clearly respondingto unseen stimuli.

Level of Consciousness

Level of consciousness is a crucial part of themental status examination. One should note anddocument whether the patient is awake, alert,and attentive versus unresponsive or drowsy. Alethargic patient appears drowsy but is easilyaroused. An obtunded patient has a reduced

level of consciousness and cannot easily bearoused. An unconscious patient who cannot befully aroused is stuporous. An unconscious pa-tient with no purposeful response to even nox-ious stimuli is comatose.

Mood and Affect

Mood refers to a person’s persistent emotionalstate, while affect denotes more immediacy.Mood and affect can be assessed by observingthe patient’s body language and behavior aswell as by verbal report. Depression is a state ofpersistently low mood. A brief screen for de-pression includes inquiries about reduced “spir-its,” reduced energy, poor self-attitude, poorappetite, disturbed sleep, anhedonia, thinkingdifficulty, suicidal ideation, and psychomotorretardation. Conversely, mania is a state of per-sistently elevated mood, increased energy, andheightened self-attitude, sometimes in associa-tion with delusions of grandeur, pressuredspeech, and “flight of ideas.” Depression is seenin a number of neurologic disorders includingParkinson disease, Huntington disease, andstrokes affecting the dominant hemisphere;mania may be seen occasionally with cerebrallesions of the nondominant hemisphere.

Speech and Language

Speech refers to the articulation of words,while language deals more with the structureand meaning of the spoken and written word.Both provide the examiner valuable insightinto the patient’s mental state and can be as-sessed easily during the interview. Importantaspects of speech include the amplitude orloudness, volume or amount (paucity vs. over-abundance), and prosody or fluidity. Often pa-tients with end-stage dementia will havepaucity of speech. Patients with Parkinson dis-ease will often have hypophonic or soft speech.Patients with cerebellar disorders may speak in a “choppy” ataxic manner. Speech may beslurred or dysarthric in a number of differentclinical settings.

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Chapter 1 The Neurologic Examination■

3

A patient’s language capabilities can be as-sessed quickly by evaluating spontaneous speechand comparing it to comprehension of spokenand written material. The presence of a languagedisturbance or aphasia should be identified early,as it may preclude an adequate assessment of therest of the mental status examination. An apha-sia may be expressive or receptive. An expressiveor nonfluent aphasia (e.g., Broca aphasia) ischaracterized by difficulty producing speechwith intact comprehension, and typically resultsfrom lesions in the inferior frontal region of thedominant (usually left) hemisphere. In contrast,a receptive or fluent aphasia (e.g., Wernickeaphasia) is characterized by poor comprehensionwithout difficulty producing speech. This mayresult in the production of nonsensical speech(“word salad”) and is typically caused by lesionsof the posterior temporal area of the dominanthemisphere.

Additonal localizing information can begleaned by assessing the patient’s ability to re-peat and write.

Memory

Two components of memory are commonly assessed–working memory (also known as pri-mary memory) and long-term memory (alsoknown as secondary memory).

Working memory is assessed by measuringdigit span (most patients can repeat strings ofapproximately seven digits) or by backwardspelling (“Please spell WORLD backward.”),which are commonly interpreted as tests ofattention.

Long-term memory is typically tested usingdelayed word recall. Patients are given a list ofthree to five words (e.g., “cat, table, apple, pur-ple, and bank”) and asked to repeat them back(registration). After being distracted by othertasks (such as tests of working memory or visu-ospatial processing), the patient is asked to

recall the list of words (retrieval). Clues or cuesmay be given (e.g., “One of the words was ananimal,” or “One of the words began with theletter C.”). Difficulty with this type of delayed

recall can be seen with lesions of the temporallobe or thalami affecting the hippocampi orother structures within the Papez loop. The dis-tinction between “recent long-term memory”(e.g., “What you had for breakfast this morn-ing?”) versus “remote long-term memory” (e.g.,an event from childhood) is somewhat artificial.

The use of the term short-term memory maybe confusing as some use it to refer to workingmemory, while others use it to refer to recentlong-term memory (see Chapter 15, BehavioralNeurology).

Visuospatial Processing

Common tests of visuospatial processing includecopying a complex figure or clock drawing. Pa-tients can be asked to copy a design drawn by theexaminer (e.g., a drawing of a cube, intersectingpentagons, or the façade of a house), or they maybe asked to draw a clock face set to a particulartime (e.g., “twenty after eight”). Patients withparietal dysfunction may neglect to draw half ofthe figure or may have trouble placing the num-bers correctly on the clock face.

Executive Function

The integrity of the frontal lobes may be testedin several ways. Poor performance on tests ofexecutive function, poor judgment and insight,or the presence of frontal release signs may allbe evidence of frontal lobe impairment.

Some simple tests of executive function in-clude assessment of verbal fluency and oraltrail making. To assess verbal fluency, patientsshould be asked to generate a list of wordsfrom a specific category (e.g., “words thatbegin with the letter F” or “all of the animalsyou can think of”) in 1 minute. Although nor-mative values vary based on age and level ofeducation, most patients should be able to gen-erate 10 or more items for each list withoutmuch difficulty. Oral trail making involveshaving the patient sequentially alternate be-tween letters and numbers (“A–1–B–2–C–3–etc.”). Patients with frontal lobe dysfunction

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may perform poorly on these tests while doingsurprisingly well on other components of thecognitive examination.

A person’s judgment relies on the value sys-tem, making an assessment of judgment themost subjective component of the mental sta-tus examination. Clinicians may ask questionssuch as “What would you do if you found astamped envelope lying on the ground?” withthe expected answer being, “Place the envelopein a mailbox.” Such questioning is probablymost helpful in the patient who is demented orcognitively impaired. Insight refers to the pa-tient’s understanding of his or her condition.The patient with Alzheimer disease, for exam-ple, may have little awareness of memory loss,often denying any problems in thinking.

When the frontal lobes are damaged due totrauma, tumor, stroke, or dementia, primitivereflexes may resurface. For example, the pres-ence of a palmar grasp reflex (reflexive grip-ping of a finger or object stroking the palm)may signify a lesion of the contralateral frontallobe. An abnormal glabellar reflex (persistentblinking in response to tapping of the fore-head) can be noted in the setting of frontal lobeinjury, although it may also be present inparkinsonian disorders. Other frontal releasesigns include the palmomental reflex (a twitchof the corner of the mouth when the ipsilateralpalm is stroked), rooting (turning toward thecheek when stroked), and the snout reflex(pursing of the lips when the lips are tappedlightly). The presence or absence of frontal re-lease signs does not, however, correlate wellwith degree of dementia.

Perceptual Disturbances

Patients who are psychotic or delirious oftenreport bizarre sensory experiences such as hal-lucinations and illusions. Hallucinations areperceptions in the absence of stimuli. These canbe elicited by asking the patient if he or she hasseen (or heard) things that “weren’t reallythere” or “that others couldn’t see (or hear).” Illusions are misperceptions, whereby the

patient mistakes an object for something else,such as a coat for an intruder. Both hallucina-tions and illusions can be seen in patients whoare delirious or encephalopathic.

Thought Form and Content

Abnormalities of thought form and content are“psychotic features” associated with delirium,dementia, schizophrenia, and severe affectivedisorders. Abnormalities of thought contentconsist of bizarre beliefs such as delusions, ob-sessions, compulsions, and phobias. Delusionsare fixed, false, idiosyncratic beliefs tena-ciously held by patients. Obsessions are intru-sive, recurring thoughts that disturb patients.Similarly, compulsions are acts that patientsfeel compelled to perform over and over again.Lastly, phobias are irrational fears held by pa-tients. These abnormalities of thought contentcan be uncovered by simply asking the patientif he or she has “any special powers,” or anystrong beliefs or practices that others do notshare. Paranoid delusions can be specificallydetected by asking patients if “anyone is afterthem” or if “anyone is out to get them.”

Abnormalities of thought form consist ofdisordered thinking such as “thought block-ing,” “loosening of associations,” and “flightof ideas.” Thought blocking is evident whenpatients are unable to complete their thoughtswhile speaking. Loosening of associations isseen when patients jump from one subject toanother with little connection. Similarly, flightof ideas is manifested by patients speaking at arapid pace, on any number of subjects, withouteasily identifiable connections. Detecting ab-normalities of thought form involves notingthe manner in which patients volunteer infor-mation or respond to questions. Responsesthat are clear and concise are easily distinguish-able from answers that are difficult to follow.

Mini-Mental Status Examination (MMSE)

The MMSE is a commonly used screen for ab-normalities of cognition. The MMSE is a 30-

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5

point instrument that assesses orientation, lan-guage, recall, concentration, and some visu-ospatial skills. Ten points are awarded forvarying degrees of orientation in time andspace. Three points are given for registration(correctly repeating the names of three ob-jects). Five points are given for concentration,which is tested by having the patient spell“WORLD” backward or sequentially subtract-ing 7 from 100 five times (e.g., 100, 93, 86, 79,72, 65). Three points are given for correctlynaming two objects and repeating the phrase“No ifs, ands, or buts.” Three points are givenfor following a three-step command. Threepoints are given for reading and enacting thesentence “close your eyes,” writing a sentence,and copying a figure composed of two inter-locking pentagons. Finally, three points aregiven for recalling the three objects mentionedfor testing registration.

■ SPECIAL CLINICAL POINT: The MMSEshould not serve as a substitute for the fullmental status evaluation, but it may be helpfulas a screening tool.

Other brief neuropsychological batteries havebeen developed which may be useful in theclinical setting, such as the Montreal CognitiveAssessment (MoCA), which includes measuresof frontal lobe/executive functioning in addi-tion to tests of memory, language, and visu-ospatial processing.

CRANIAL NERVES

There are 12 pairs of cranial nerves, each serv-ing a specific function as illustrated inTable 1.2. A superficial examination of the cra-nial nerves should be incorporated into anyneurologic examination and can be completed

Cranial Nerves and Their FunctionsTABLE 1.2

Cranial Nerve Name of the Cranial Nerve Function

I Olfactory SmellII Optic VisionIII Oculomotor Elevation, depression, and adduction of the eye;

pupillary constrictionIV Trochlear Depression of the adducted eye; intorsion of the

abducted eyeV Trigeminal Sensation of the face and motor control of the muscles of

masticationVI Abducens Abduction of the eyeVII Facial Muscles of facial expression, taste to the anterior two

thirds of the tongueVIII Vestibulocochlear Hearing and balanceIX Glossopharyngeal Taste of posterior one third of the tongue, sensation for

gag reflexX Vagus Gag reflex motor to soft palate, pharynx, larynx;

autonomic fibers to esophagus, stomach, small intestine,heart, trachea; sensation from ear; viscera

XI Spinal accessory Motor control of the sternocleidomastoid and trapezius muscles

XII Hypoglossal Motor control of the tongue

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in just a few minutes. Abnormalities found onthe cursory examination may necessitate amore detailed study of that area.

■ SPECIAL CLINICAL POINT: A systematicexamination of the cranial nerves provides “topto bottom” information about the integrity ofthe brainstem. Remember the “4-4-4” rule: Thefirst four cranial nerves involve the “higher”subcortical structures or midbrain. The secondfour cranial nerves generally localize to thepons. The final four cranial nerves originatefrom the medulla or upper cervical cord.

CN I. The Olfactory Nerve

The olfactory nerve (cranial nerve I) is respon-sible for the sense of smell. CN I is not testedroutinely during the screening neurologic ex-amination, but should be assessed when pa-tients complain of loss of smell. Olfaction isassessed by having the patient identify a fra-grant substance such as coffee or cloves. Asmall vial of the aromatic substance is heldunder one nostril, while the other nostril is oc-cluded. The patient is asked to breathe throughthe unobstructed nostril and identify the scent.The exercise is repeated on the other side witha different aromatic substance. Noxious sub-stances such as ammonia or “smelling salts”should be avoided because of the concomitantstimulation of cranial nerve V, the trigeminalnerve. Although reduced olfaction may be dueto advanced age, pathologic states such as headtrauma, tumors affecting the base of the skull,and certain inflammatory disorders such as sar-coid should also be considered.

CN II. The Optic Nerve

The optic nerve (cranial nerve II) is responsiblefor vision. Evaluation of the optic nerve in-cludes examination of visual acuity, visualfields, the pupillary light reflex, and fundus-copy. Visual acuity is typically tested using awall chart or handheld “near-card.” Each eyeshould be tested separately with contact lensesor glasses in place (if needed).

The pupillary light reflex is checked by hav-ing the patient look into the distance whileswinging a bright light from one eye to theother. Normally, both pupils react equally tolight shone in either eye (the “consensual re-sponse”). A lesion of one optic nerve may resultin a weaker pupillary response from one eyewhen compared to the other. When severe, sucha relative afferent pupillary defect results in aparadoxical dilation of the pupils when light isswung from the “good eye” to the “bad eye.”

Visual fields can be easily tested in the officeor at the bedside by confrontation. The patientshould be asked to fixate on the examiner’snose while covering one eye. The examinershould hold up one, two, or five fingers in eachof the four quadrants of the visual field and askthe patient to count the fingers. One or multi-ple trials can be conducted, depending on theaccuracy of the patient. The other eye shouldbe tested in the same manner.

A visual field defect present only in one eyesuggests a lesion within that eye or of the opticnerve. Visual field defects present in both eyesmay suggest a lesion farther back along the vi-sual pathway. A bitemporal hemianopia (affect-ing the temporal fields of both eyes) implies alesion of the optic chiasm. Quadrantanopias,lesions of the same quadrant of both eyes(upper right, upper left, lower right, or lowerleft), suggest a lesion of the optic radiations. Ahomonymous hemianopia, a field cut involvingthe same side of both eyes (meaning the tempo-ral field of one eye and the nasal field of theother eye), suggests a lesion of the contralateraloptic tract or occipital cortex. With experience,additional visual field defects such as central sco-tomas, macular sparing, or incongruous hemi-anopias can be detected as well (see Chapter 26,Eye Signs in Neurologic Diagnosis).

For many examiners, the funduscopic exam-ination is the most challenging aspect of theneurologic examination. Proficiency with oph-thalmoscopy requires careful instruction andpractice. Items that can be evaluated with a di-rect handheld ophthalmoscope include the opticdisc, the retinal vessels that emanate from the

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disc, the macula, and the peripapillary retina.The optic disc lies slightly nasal to midline and isbest visualized by approaching the patientslightly from the side with the same eye (i.e., usethe right eye to look in a patient’s right eye, andthe left eye to look in a patient’s left eye). Nor-mally, the optic disc has a sharp border, but inthe setting of papilledema or optic neuritis, themargins appear blurred. Optic atrophy due tooptic nerve damage results in a pale disc. Arter-ies and veins generally run together, with veinsappearing thicker than arteries. The forklikebranching of retinal arteries and veins “pointto” the disc. A number of medical conditions,such as diabetes and hypertension, producecharacteristic findings on the funduscopic ex-amination. The macula can be visualized by ask-ing the patient to “look directly at the light.”

CN III. Oculomotor Nerve, CN IV. Trochlear Nerve, and CN VI. Abducens Nerve

The oculomotor nerve (cranial nerve III),trochlear nerve (cranial nerve IV), and abducensnerve (cranial nerve VI) control eye movements.The oculomotor nerve (CN III) supplies the su-perior, inferior, and medial rectus muscles aswell as the inferior oblique muscle. These mus-cles elevate, depress, and adduct the eye. Thetrochlear nerve supplies the superior obliquemuscle. Contraction of this muscle results in de-pression of the adducted eye and intorsion ofthe abducted eye. The abducens nerve suppliesthe lateral rectus muscle. Contraction of thismuscle results in abduction of the eye.

These three cranial nerves are assessed to-gether during testing of eye movements. Thepatient should follow the examiner’s finger orpen vertically and horizontally into the cardi-nal directions of gaze (up, down, left, andright). Normally, the eyes should move to-gether (conjugate gaze). A monocular limita-tion of abduction may suggest a sixth palsy. Amonocular limitation in vertical gaze could beconsistent with a third or fourth nerve palsy.Myasthenia gravis and thyroid eye disease can

be associated with eye movement abnormali-ties. Nystagmus may be noted during the eyemovement examination, which can suggestvestibular or cerebellar dysfunction.

The third nerve also controls elevation ofthe upper eyelid (via the levator palpebrae su-perioris) muscle and pupillary constriction viaparasympathetic fibers to the pupilloconstric-tor and ciliary muscles. A complete lesion ofthe cranial nerve III will result in ptosis and aneye that is abducted and depressed (“down andout”), with a dilated pupil (mydriasis). A lesionof cranial nerve VI will result in esotropia(“crossed eyes”) and an inability to abduct theaffected eye. A lesion of cranial nerve IV mayresult in the patient having a head tilt and headturn away from the affected eye (see Chapter 26,Eye Signs in Neurologic Diagnosis).

CN V. The Trigeminal Nerve

The trigeminal nerve is responsible for sensoryinformation from the skin of the face and ante-rior scalp, providing motor innervation to themuscles of mastication (masseter, temporalis,and pterygoid), and mediating the jaw jerk re-flex. The trigeminal nerve is divided into threebranches, V1 (ophthalmic branch), V2 (maxil-lary branch), and V3 (mandibular branch) (Fig.1.1). V1 innervates the forehead and anteriorscalp down to the lateral corner of the eye; V2innervates the cheek down to the corner of themouth; and V3 innervates the jaw including theunderside of the chin, but excluding the angleof the jaw.

The sensory function of the trigeminal nervecan be tested using a safety pin for pain sensa-tion, a cool tuning fork for temperature sensa-tion, and a fingertip or cotton swab for lighttouch. The corneal reflex also can be used toevaluate CN V, particularly in an unresponsivepatient. To test the corneal reflex, the examinertouches a wisp of cotton to the cornea over theiris, avoiding the pupil or central visual axis.

Jaw strength can be tested by asking the pa-tient to forcibly clench his or her teeth againstthe resistance of the examiner or by forcibly

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opening the jaw against resistance. The jaw jerkreflex is mediated solely by the trigeminal nerveand is elicited by placing one’s index fingeracross the relaxed jaw of the patient and tap-ping that finger with a reflex hammer. A normalresponse is a brisk but slight contraction of themuscles of mastication causing partial jaw clo-sure. An exaggerated response may be a sign ofcerebral pathology (an upper motor neuron signoriginating above the foramen magnum), but anabsent response has little clinical significance.

CN VII. The Facial Nerve

The facial nerve provides innervation to themuscles of facial expression and also suppliestaste to the anterior two thirds of the tongue viathe chorda tympani. Integrity of the facial nervecan be assessed by having the patient performvarious maneuvers such as forcibly closing hisor her eyes, smiling, puffing air into the cheeks,and wrinkling the forehead muscles. Weaknessis indicated by an inability to “bury” the eye-lashes, an asymmetric smile, inability to holdair fully in the cheeks, and reduced foreheadwrinkling. Facial weakness also can be assessedby simple observation. A downturned mouth,

sagging cheek (flattened nasolabial fold), orsagging lower eyelid (widened palpebral fis-sure) are all indicators of facial weakness. Pe-ripheral lesions of the facial nerve produceeyelid retraction and not ptosis, so that the eyeon the affected side appears “larger” than thenormal eye. Facial weakness can occur on the basis of disturbances in the central or pe-ripheral nervous systems. Involvement of thefrontalis muscles (responsible for wrinkling theforehead) can reliably distinguish between thesetwo possibilities. The forehead is spared withcentral lesions such as strokes but is affected byperipheral lesions as in Bell palsy.

The sense of taste may be affected by a pe-ripheral disturbance if the lesion is proximalto the chorda tympani. To test the sense oftaste, the patient is asked to protrude his orher tongue and identify sweet or sour sub-stances, although this is not commonly testedas a part of a routine neurologic examination.

CN VIII. The Vestibulocochlear Nerve

The vestibulocochlear, or acoustic, nerve (cra-nial nerve VIII) is a compound nerve composedof the cochlear nerve, responsible for hearing,

FIGURE 1.1 Distribution of the three divisions of the trigeminal nerve. The sensory portion of thetrigeminal nerve has three divisions: I, ophthalmic; II, maxillary; III, mandibular. Their approximatelocations are illustrated. (From members of the Department of Neurology, Mayo Clinic, and MayoFoundation for Medical Education and Research. Clinical Examinations in Neurology. 6th ed. St. Louis:Mosby Year Book; 1991:270, with permission.)

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and the vestibular nerve, involved in balance.Although a number of techniques can be usedto assess hearing, a simple screen consists ofgently rubbing one’s fingers together near thepatient’s ear to check for gross hearing defects.

Additional methods to test function of cra-nial nerve VIII include the Rinne and Webertests. In the Rinne test, the base of a vibratingtuning fork (256 Hz) is held against the mastoidbone. When the sound disappears, the head ofthe tuning fork then is placed beside the pa-tient’s ear. Normally, air conduction is greaterthan bone conduction. If bone conduction isgreater than air conduction, a blockage of theexternal ear or a defect within the middle earshould be suspected. In the Weber test, a vibrat-ing tuning fork is pressed firmly against the mid-dle of the patient’s forehead. Normally, sound isperceived equally in both ears and the sound ofthe vibration is appreciated as being in the mid-line. With conductive hearing loss, the soundlateralizes to the abnormal ear. In contrast, withsensorineural hearing loss, the sound lateralizesto the opposite ear with the intact nerve.

Dysfunction of the vestibular component ofthe acoustic nerve is suggested by complaintsof vertigo and a unidirectional jerk nystagmuson examination of eye movements. Advancedtesting of vestibular function might include thehead thrust maneuver and testing of dynamicvisual acuity.

CN IX. Glossopharyngeal Nerve and CN X. Vagus Nerve

The glossopharyngeal nerve is responsible forproviding sensation to the pharynx and taste tothe posterior tongue. The vagus nerve performsa number of functions within the body, includ-ing supplying parasympathetic innervation tothe heart and gut and contributing to the nor-mal motor function of the oropharynx.

Cranial nerve IX mediates the sensory limbof the gag reflex, and cranial nerve X mediatesits motor limb. Typically, a gag reflex iselicited by gently stimulating the soft palatewith a cotton swab or tongue blade. Normally,

a gag response is elicited by stimulation of ei-ther side. A unilateral cranial nerve lesion maysuppress the gag reflex on one side. A widerange of variability exists for the normal gagreflex. Some patients will start to gag as soonas they see the tongue blade, while others willhave no gag reflex. In the appropriate clinicalsetting (e.g., the patient with swallowing diffi-culties), an apparently abnormal gag reflexmay assume greater significance. Oftentimesclinicians forgo formal testing of the gag re-flex, assessing simply the motor aspect by hav-ing the patient say “aah.”

Normally, the soft palate and uvula elevatesymmetrically with stimulation of the softpalate or when a subject says “aah.” With aunilateral lesion of the vagus nerve, the uvulaand palate deviate away from the lesion. Withbilateral lesions, no movement may be seen.

CN XI. Spinal Accessory Nerve

The accessory nerve innervates the trapeziusand sternocleidomastoid muscles. It arisesfrom the upper five cervical segments of thespinal cord, ascends through the foramen mag-num, and exits through the jugular foramen.The accessory nerve is tested by having the pa-tient shrug his or her shoulders or turn his orher head against resistance (the examiner’shand pressed against the subject’s jaw). A uni-lateral lesion causes weakness of shouldershrugging on the same side or impaired headturning toward the opposite side.

CN XII. Hypoglossal Nerve

The hypoglossal nerve (cranial nerve XII) pro-vides motor innervation to the tongue. Testingof CN XII includes examination of the bulk ofthe tongue, the ability of the patient to pro-trude the tongue in the midline, and the abilityof the patient to rapidly move the tongue fromside to side. Normally, the tongue should ap-pear symmetrical and the patient should beable to protrude the tongue straight ahead andmove the tongue rapidly from side to side.

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With unilateral lesions of CN XII, the tonguemay appear atrophied with evident fascicula-tions (muscle twitches) on one side. Further-more, on protrusion, the tongue will deviatetoward the weak side.

MOTOR EXAMINATION

The motor examination consists of assessmentof muscle bulk, tone, strength, and dexterity,with notation of any abnormal movements.Muscle bulk simply refers to the normal sizeand contour of the muscle and is assessed bysimple inspection. Muscle wasting or atrophyis a “lower motor neuron sign” seen in disor-ders of the peripheral nervous system such asradiculopathies and neuropathies; muscle hy-pertrophy is rarely seen, but may be noted inspecific disorders (e.g., calf hypertrophy inDuchenne muscular dystrophy).

Muscle tone is defined as the resistance topassive movement. In the arm, one assessesmuscle tone by supporting the patient’s re-laxed upper arm, grasping the patient’s fin-gers, and then quickly flexing, extending,pronating, and supinating the arm at theelbow. Normal tone is negligible, but in-creased tone can be appreciated as marked re-sistance to movement. The increased tone mayhave a “ratchety” quality that is intermittent(i.e., “cogwheel” rigidity of Parkinson disease),a give-way quality reminiscent of one opening apocket or “clasp knife” (i.e., spasticity seen inupper motor neuron lesions), or a more diffuse,persistent quality (i.e., “lead-pipe” rigidity seenwith disorders of the basal ganglia). In the leg,one assesses tone with the patient supine andrelaxed. The examiner grasps the patient’s kneewith two hands and quickly lifts the knee intothe air noting whether the patients heel dragsalong the bed (normal) or comes off the bed (in-dicative of increased tone).

■ SPECIAL CLINICAL POINT: Upper motorneuron signs (increased tone, brisk reflexes,Babinski sign) signify pathology of the centralnervous system (brain or spinal cord). Lower

motor neuron signs (decreased tone, muscleatrophy and fasciculations, depressed reflexes)signify pathology of the peripheral nervoussystem (nerve roots or peripheral nerves). Amix of upper and lower motor neuron signsmay be seen in motor neuron disease (e.g.,amyotrophic lateral sclerosis) or in spinal cordlesions that involve the anterior horn.

Muscle power or strength refers to the forcethat muscles are able to generate. The exam-iner assesses muscle strength through manualmuscle testing. Proper technique dictates thatthe examiner “isolate” the muscle being tested,using two hands to “stabilize” the limb proxi-mal to the joint of interest and apply force tothe limb distal to that joint. One should avoidtesting across multiple joints to guard againstinvolving unwanted muscles. Sufficient forcemust be applied to detect even mild weakness,yet not hurt the patient. Muscles that are com-monly tested in the upper extremities includethe deltoids, biceps, triceps, wrist extensorsand flexors, and finger flexors and extensors.In the lower extremities, the hip flexors, kneeflexors and extensors, and ankle dorsiflexorsand plantarflexors are commonly tested.

Muscle strength is graded on a scale from 0to 5: 0 = absence of movement; 1 = a flicker ofmovement; 2 = movement in the horizontalplane, removing the effect of gravity; 3 = move-ment against gravity; 4 = movement againstsome resistance; and 5 = normal strength(Table 1.3). Various patterns of weakness helpone determine the origin of the disturbance.

0/5 No movement1/5 Flicker of movement2/5 Moves with gravity removed but not

against gravity3/5 Moves against gravity4/5 Movement against resistance5/5 Normal strength

Medical Research Council (MRC)Grading of Muscle Strength

TABLE 1.3

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Weakness of muscle groups on one side of thebody would suggest a cerebral disturbance.Weakness of the proximal muscles suggests amyopathy, while weakness of distal musclessuggests a neuropathic process (see Chapter 17,Neuromuscular Disorders).

Testing for a pronator drift is an easy methodto detect subtle arm weakness. The patient holdsup both arms, extended at the elbows, with thepalms facing upward. When the patient closeshis or her eyes, both arms should stay in place,next to each other. In the case of subtle armweakness, however, the weaker arm will beginto pronate and drop toward the ground. Apronator drift is an extremely sensitive test, es-pecially for subtle weakness of central origin.

To test the speed and dexterity of movement,patients are asked to open and close their handsrapidly, to tap their index finger and thumb to-gether, or to pat their feet on the floor. The ex-aminer is looking for the speed, amplitude, andregularity of these movements. Slowed move-ments suggest a problem within the pyramidaltracts or the extrapyamidal system.

Abnormal movements such as chorea andtremor are observed while the patient is at restand while his or her hands are outstretched.These abnormal movements will be discussed inchapter 13, Hyperkinetic Movement Disorders.

DEEP TENDON REFLEXES (DTRs)

The DTRs, or muscle stretch reflexes, aremonosynaptic reflexes responsible for prevent-ing overstretching of the muscles and hyperex-tension of the corresponding joints (Table 1.4).

The afferent limb of each reflex is composed ofsensory nerves that transmit information fromthe muscle spindles to the anterior horn cellswithin the spinal cord. The efferent limb iscomposed of motor nerves running from thespinal cord back to the original muscle. Al-though a number of DTRs have been de-scribed, only a few are routinely tested in theneurologic examination. These reflexes are thebiceps, brachioradialis, and triceps reflexes inthe upper extremities and the patellar (kneejerks) and Achilles reflexes (ankle jerks) in thelower extremities.

■ SPECIAL CLINICAL POINT: The segmentalrepresentation of the commonly tested deeptendon reflexes can be remembering the “1-to-8” rule: The Achilles tendon reflex or “anklejerk” is mediated by fibers from the S1 and S2nerve roots. The patellar reflex or “knee jerk”is mediated by fibers from the L3 and L4 nerveroots. The biceps reflex is mediated by the C5and C6 nerve roots. The triceps reflex ismediated by the C7 and C8 nerve roots.

The Achilles reflex (ankle jerk) is elicited bystriking the Achilles tendon just proximal tothe heel and monitoring for subsequent plan-tarflexion. The patellar reflex (knee jerk) iselicited by striking the patellar tendon justbelow the kneecap. The biceps reflex is elicitedby having the examiner strike his or her ownfinger that is pressed against the patient’s bi-ceps tendon within the antecubital fossa. Thetriceps reflex is elicited by striking the tricepstendon within the olecranon fossa, just abovethe elbow.

DTRs may be graded numerically (Table 1.5).Absent reflexes are graded as 0, reduced reflexes

S1, S2 Achilles reflex(L2) L3, L4 Patellar reflexC5, C6 Biceps reflex(C6) C7, C8 Triceps reflex

Segmental Innervation of the VariousDeep Tendon Reflexes

TABLE 1.4

1+ Reduced2+ Normal3+ Increased4+ Pathologically increased, clonus

Deep Tendon Reflex GradingTABLE 1.5

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as 1+, normal reflexes as 2+, and brisk reflexesas 3+. When clonus is elicited (rhythmic, oscil-latory movements of the joint), a grade of 4+ isgiven. Unfortunately, the determination of“normal” versus “reduced” versus “brisk” issubjective. To increase reliability, some authorspromote the convention of using 3+ when“spread” is seen, whereby the testing of one re-flex elicits responses in multiple reflex arcs(e.g., striking the biceps tendon elicits a tricepsreflex). Similarly, the grade of 1+ could be re-served for instances in which “augmentation”is necessary (e.g., the patient is asked to “bitedown” while the reflex is being elicited to re-duce the threshold for the response).

Hyperactive reflexes are considered an“upper motor neuron sign” seen in centralnervous system disturbances of the brain orspinal cord. Examples of such disorders in-clude strokes, brain tumors, or spinal cord in-juries. Somewhat brisk reflexes, however, canbe seen in otherwise healthy young people. Re-duced reflexes are seen in disorders of the pe-ripheral nervous system and are considered a“lower motor neuron sign.” Asymmetric de-crease or loss of a particular reflex may be seenwith focal lesions such as radiculopathies, plex-opathies, or mononeuropathies. For example, alesion of the sixth cervical root may lead to ipsi-lateral loss of the biceps and brachioradialis re-flexes, while a femoral neuropathy may result inloss of the knee reflex. Symmetrical loss of re-flexes implies a more generalized process. Forexample, bilaterally decreased or absent DTRsin the legs suggest a peripheral neuropathy, andgeneralize areflexia is often seen with Guillain–Barré syndrome (see Chapter 18, PeripheralNeurologic Disorders).

Assessment of the plantar response is in-cluded under reflex testing. The plantar re-sponse is obtained most commonly by strokingthe lateral sole of the foot, starting at the heel,and then coming across the ball of the foot.This maneuver can be performed with a bluntbut rigid object such as a key, a tongue depres-sor broken lengthwise, or even one’s finger. Thenormal plantar response is flexion of the great

toe with downward curling of the toes. In thesetting of a central or upper motor neuron dis-order, Babinski sign may be noted, in which thegreat toe extends and the toes fan outward.

SENSORY TESTING

The sensory examination is the most subjec-tive portion of the neurologic examination, re-lying heavily on accurate reporting by thepatient. If the patient is confused, demented,aphasic or delirious, the responses may be in-valid and this portion of the examination mayneed to be omitted.

The primary sensory modalities consist oflight touch, pain and temperature sensation, vi-bratory sensation, and proprioception. Morecomplex cortical sensory processing includesstereognosis, graphesthesia, and appreciationof double simultaneous simulation.

The primary sensory modalities are carried ontwo separate sets of nerve fibers. In the periph-eral nervous system, vibratory sensation andproprioception are carried by “large-fiber”nerves, while pain and temperature sensation arecarried by “small-fiber” nerves. This dichotomyis preserved within the spinal cord where vibra-tion and proprioception are conveyed by un-crossed fibers in the dorsal columns, while painand temperature sensation are carried by crossedspinothalamic tracts. The two pathways eventu-ally converge at the thalamus, which then sendsprojections to the primary sensory cortex withinthe parietal lobe. In diabetes and other small-fiber neuropathies, pain and temperature sensa-tion may be more diminished than vibration andproprioception. In large-fiber neuropathies ordorsal column disease, as in vitamin B12 defi-ciency, the opposite pattern of sensory loss isseen with vibration sensation and propriocep-tion being disproportionately affected.

Cortical sensory modalities are the productsof the integrated primary sensory modalities.Cortical sensory loss can be evaluated only in thepresence of intact primary sensory modalities.Disturbances in the cortical sensory modalitiesimply a dysfunction within the parietal lobes.

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The primary sensory modalities should beevaluated in an organized fashion. Pain sensa-tion is most reliably assessed with a disposable,sharp implement such as a safety pin. A quickassessment of side-to-side and proximal versusdistal comparisons usually suffices unless thepatient specifically complains of a region of re-duced sensation. If a particular area of de-creased sensation is identified, careful attentionto its boundaries may suggest a disturbance at

the level of the peripheral nerve, plexus, ornerve root (dermatomal) sensory loss (Fig. 1.2).Temperature sensation can be quickly testedusing a cool tuning fork. As with assessment ofpain, side-to-side and proximal versus distaldifferences should suffice. To test propriocep-tion, the examiner grasps the subject’s distalphalanx (tip of the great toe or index finger) onthe sides of the digit while stabilizing the prox-imal digit. The examiner moves the finger or

FIGURE 1.2 Peripheral distribution of sensory nerves with the dermatomes on the right andcutaneous nerves on the left. (From House EL, Pansky B. A Functional Approach to Neuroanatomy. NewYork: McGraw-Hill; 1960:286, with permission.)

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toe upward or downward, asking the patient tocorrectly identify the direction of movementwithout looking. The examiner assesses the pa-tient’s threshold for detection by initially mov-ing the digit slightly and then progressivelyusing larger movements until the patient canconsistently answer correctly. For vibratorytesting, the examiner sets the base of a vibrat-ing tuning fork against a bony portion of thepatient’s digit or more proximal joint.

Testing of cortical sensory functions (graph-esthesia, stereoagnosia, and double simultane-ous stimulation) can reveal information aboutparietal lobe function, but only when the pri-mary sensory modalities are intact. Graphesthe-sia is the ability to recognize by touch a number“written” on the skin. With the patient’s eyesclosed, the examiner traces numbers on the pa-tient’s palm using a finger or blunt object. Stere-ognosis is the ability to recognize objects bytouch alone. Various items such as safety pins,keys, coins, or pencils are placed in the patient’shand with the patient’s eyes closed. He is al-lowed to move the object around in his hand tofully appreciate the size, shape, and texture. Ifthe hand is paretic, stereognosis still can be eval-uated by moving the object around in the pa-tient’s palm. Double simultaneous stimulation isuseful for detecting hemispatial neglect. Theexaminer alternately touches body parts (e.g.,hand, face, or leg) on one side at a time, then onboth sides simultaneously, asking the patient toidentify which side has been touched. Patientswith neglect may be able to appreciate sensationon both sides of the body when each side istested separately, but will extinguish sensationon one side of the body when both sides aretouched simultaneously.

COORDINATION AND GAIT

Coordinated movements require the integratedworkings of a number of neurologic systemsincluding the sensory pathways, vestibular sys-tem, pyramidal tracts, and extrapyramidalsystem, including the basal bangia and cere-bellum. Incoordination in the setting of intact

motor and sensory testing argues strongly for adisorder in cerebellar function. The cerebellumintegrates proprioceptive information with in-formation from muscles to allow smooth limband truncal movements. Cerebellar dysfunc-tion often results in ataxia. A unilateral lesionwithin the cerebellum produces dysfunction onthe same side of the body.

Tests of coordination include finger-to-noseand heel-to-shin testing, evaluation of rapid al-ternating movements, station, and gait. Thefinger-to-nose and heel-to-shin tests assess forlimb (appendicular) ataxia as opposed to trun-cal ataxia. In finger-to-nose testing, the patientis asked to guide his or her finger back andforth from the examiner’s finger to his or herown nose with eyes open. The patient shouldbe forced to fully extend his or her arm totouch the examiner’s finger so that any tremorat the extreme of arm extension can be seen.Heel-to-shin testing is performed by having thepatient run the heel of one foot along the shin,from the knee to the ankle, of the other leg.

Rapid alternating movements can be testedby asking the patient to pat the front and thenback of his or her hand into the palm of theother hand or onto the thigh in a rapid, rhyth-mic fashion. Because rhythmic movements re-quire an intact cerebellum, difficulty with thistask suggests ipsilateral cerebellar dysfunction.The inability to perform this specific task isknown as dysdiadochokinesia.

Midline cerebellar dysfunction often pro-duces ataxia of the trunk, resulting in difficultieswith standing or walking. To test stance, the pa-tient first is asked to arise from a chair. A patientwith hip weakness may require the use of his orher hands, while an ataxic patient may requirethe assistance of another individual. Next, theexaminer assesses the patient’s stance, notingthe subject’s posture, stability, and foot position.Normally, the patient should stand erect withfeet slightly separated. A patient with Parkinsondisease may exhibit a stooped posture, while apatient with cerebellar disease may have awidened stance and marked truncal instability.The examiner can further assess postural stabil-ity by gently pulling backward or forward on

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the patient’s shoulders, guarding against thepossibility of a fall. Normally, the patient shouldbe able to quickly regain their stance, requiringno more than one or two steps. Patients withtruncal instability, however, may need multiplesteps to avoid falling or have no capacity tocatch themselves.

Although often described as a test of bal-ance, Romberg test is actually an assessment ofproprioception. Patients are asked to standwith their feet together, and then asked to closetheir eyes. Patients may sway slightly, but theyshould not fall over or step to the side to catchtheir balance. Romberg test is positive whenthe patients lose their balance with their eyesclosed, implying dysfunction of the dorsalcolumns or proprioceptive fibers. If a patient isunable to maintain balance with the eyes open(e.g., in the setting of vestibular dysfunction),then Romberg test cannot be performed.

■ SPECIAL CLINICAL POINT: If a patientcannot stand with feet together and eyes open,he or she may have cerebellar or vestibulardysfunction. If a patient can stand with feettogether and eyes open but falls with eyesclosed (a positive Romberg test), then theproblem is likely proprioceptive.

Finally, the patient’s ambulation is analyzed forspeed, stride length, turning, and associatedmovements, with particular attention being paidto any asymmetry. Gait testing can be per-formed in the examination room or the adjacenthallway. Normally, the patient should exhibit asmooth stride with a narrow base and normalsway of the arms. Patients with a cerebellar dis-ease may have an ataxic gait with a wide-basedwobbly, off-balance ambulation that looks“drunk.” Patients with upper motor neuron dis-ease may have gait spasticity, exhibiting stiffnesswhile walking reminiscent of “Frankenstein’smonster.” Patients with weakness of one sidemay have a hemiparetic gait, favoring one side,or perhaps associated with hip hiking or circum-duction of the leg to overcome a unilateral footdrop. A patient with early Parkinson disease ormild unilateral arm weakness may have a de-creased arm swing on one side with ambulation.

Optional tests include assessment of the pa-tient’s heel-walking, toe-walking, and tandemgait. Heel-walking and toe-walking, as theirnames imply, are performed by having patientswalk on their heels and toes, respectively, test-ing the strength of foot dorsiflexion and plan-tarflexion. Tandem gait is assessed by havingpatients walk “heel to toe” as if walking on atightrope. Impairment of tandem gait may beseen with mild ataxia and leg weakness.

THE NEUROLOGIC EXAMINATION IN PEDIATRIC NEUROLOGY

Performing age-appropriate examinations ofinfants and children can be a daunting task,given the amazing developmental changes thatoccur in early childhood. Infants and youngchildren require adaptations of the routineadult neurologic examination including the useof more functional tasks to assess performance.A good working knowledge of normal grossmotor, fine motor, and language development isessential. As with other pediatric disciplines,the child’s parents can be enlisted to assist withexamination. For small children and infants,much of the examination can be performed onthe parent’s lap to ensure the comfort andsafety of the child. Unpleasant tests such as thetesting of pain sensation (i.e., with a pin) shouldbe avoided unless there is a specific need.

■ SPECIAL CLINICAL POINT: The neurologicexamination of children must be tailored to achild’s age, abilities, and temperament. In orderto be most effective, one must establish rapportwith the child, be creative in testing, and makethe examination fun!

Mental Status

The mental status examination often centersaround the child’s behavior with respect to theparents and surroundings. Assessment of re-ceptive and expressive language skills can yieldinsight into the child’s cognitive abilities evenin infancy. Knowledge of normal developmen-tal milestones allows the examiner to relate achild’s abilities to the normal population.

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Cranial Nerves

Most cranial nerves can be tested easily withcreative techniques in children. Visual acuitycan be assessed roughly by holding colorful orbright objects of varying sizes within an in-fant’s field of vision. For example, one canoffer a toddler a small wad of paper withinone’s hand. The examiner can test visual fieldsand eye movements by holding attractive ob-jects in the periphery of the child’s vision andthen having the child follow those objects withhis or her eyes. Visual threat also can be usedto test visual fields in infants older than 4months of age, but this technique may be con-sidered too threatening if not performed in asufficiently playful manner. The funduscopicexamination can be challenging but not impos-sible. The pupillary light reflex can be tested instandard fashion in all age groups. The cornealreflex can be tested in young infants but maybe unacceptably irksome to older children. Al-though not technically proper, a quick puff ofair into the eye is better tolerated than a cottonswab. The examiner can assess facial asymme-try by observing the child’s repertoire of facialexpressions. Observing how children respondto sounds made outside of their field of viewcan be used to assess hearing. As with thecorneal reflex, testing of the gag reflex is welltolerated only by very young infants and olderchildren. On the other hand, most children rel-ish the opportunity to protrude their tongues atan adult.

Motor

Assessment of muscle bulk in children is no dif-ferent than in adults except that young infantsmay have more superficial adipose tissue. Tonecan be assessed easily in older children if theyare at ease or distracted. Assessment of powerin infants usually is restricted to opposing theirvolitional movements. In young children, onemust rely on functional assessment of strength,observing the child perform playful tasks.Older children, however, are usually very coop-erative in testing “how strong they are.”

Deep Tendon Reflexes

Testing of DTRs in children requires no specialaccommodations other than gentleness, withthe major exception being that the ankle jerksare better elicited in infants by grasping the in-fant’s foot and gently tapping on the bottom ofthat foot. Along similar lines, the Babinski re-flex can be elicited with one’s finger in youngerchildren and infants. Remember that an exten-sor plantar response (an upgoing toe) is normalin infants up to 1 year of age.

Sensory

Vibratory sensation can be tested reliably inolder but not younger children. Proprioceptionis tested more reliably in children because theoutcomes are directly observable by the exam-iner. Temperature sensation can be tested witha cool tuning fork. Testing of pin sensationshould be avoided because of the inherentlyuncomfortable nature of the test.

Coordination

Age-appropriate testing of coordination isstraightforward. Infants older than a fewmonths can reach for colorful objects. Toddlerscan be assessed for their ability to walk andreach for things. Older children can be asked torun, jump, and hop or stand on one leg.

Always Remember

• General principles of organization (e.g.,peripheral vs. central, motor vs. sensory, andproximal vs. distal) allow lesion localizationthat aids in the differential diagnosis ofneurologic disorders.

• A focused neurologic examination should beguided by clinical judgment.

• The neurologic examination should be ahelpful tool, not a painful burden to beavoided by nonneurologists.

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