Neurology examination

The Neurologic Exam

byDr. Rajaneesh kumar

Overview

Neuroanatomy History Physical Clinical Scenarios

IntroductionFacilitates CommunicationProvides BaselineDirects Testing Identifies Need For Life-Saving

TherapiesRisk Management

Neuroanatomy Central versus peripheral

symmetrical vs asymmetrical If central, what is the level:

Cerebrum Brain Stem Spinal cord

If peripheral, is it Nerve Muscle NMJ

Neuroanatomy

Central lesions Lesions in the cerebral cortex result in

contralateral deficits of the face and body Lesions at the midbrain result in contralateral

hemiplegia and ipsilateral peripheral paralysis of III and IV

Lesions at the pons result in contralateral hemiplegia and ipsilateral deficits of V, VI, VII, VIII

Lesions at the medulla result in contraleral hemiplegia and ipsilateral deficits of IX, X, XI, XIII

Anatomy of the Spinal Cord

Corticospinal Tracts: motor from cerebral cortex: cross in the lower medulla

Spinothalamic Tracts: pain and temperature: cross 1 or 2 levels above entry

Posterior Column: proprioception and vibration

Spinal Cord : Vascular Supply Single Anterior Paired posterior from vertebral arteries

(Except in cervical cord) Radicular Arteries from aorta:

Varying degrees of contribution Great radicular artery of Adamkiewicz T-10 to L-2

(Major source of blood flow to 50% of anterior cord in 50% of patients)

Anterior perfuses anterior and central cord

UMN vs LMN

UMN increased DTR (after SS) LMN decreased DTR

UMN muscle tone increased LMN tone decreased, atrophy

UMN no fasciculations LMN fasciculations

UMN vs LMN Weakness Myelopathy = Spinal Cord Process = UMN

findings (spasticity, weakness, atrophy, sensory findings, bowel and bladder complaints)

Radiculopathy = Nerve Root Process = LMN findings (Paresthesias, Fasciculations, Weakness, decreased DTR)

Patient may have a radiculopathy with mylopathy below the lesion

The Neuro Exam: History

Neuro complaints may be primary or secondary to other system disease Infection Overdose Metabolic Disorder


History often provides the key since the neuro exam may be normal Subarachnoid Hemorrhage Carbon Monoxide Poisoning Subdural Hematoma Nonconvulsive Seizures


Time of Onset Type of Onset Progression Trauma Associated Symptoms


Factors that make it better/worse Past Symptoms / Events Past Medical History Occupational / Environ Exposures

The Neuro Exam: Physical

Vital SignsHead: Evidence of TraumaNeck: Bruits, RigidityHeart: MurmursAbdomen: Masses / DistentionSkin / Scalp: Lesions /

Tenderness

The Neuro Exam: Physical

Mental StatusCranial NervesMotorSensoryCoordinationReflexes

The Neuro Exam: Initial Approach Posture

Decorticate Decerebrate Facial or body asymmetry

Hemiparesis results in external rotation of the foot of the affected side

Mental Status Exam

GCS Orientation

Speech (dysarthria vs aphasia) Comprehension

Mental Status Exam

Confusion assessment method (CAM)Acute onset / fluctuating course Inattention Disorganized thinking Altered level of consciousness

Mini-mental status examScore affected by education and age <20 = cognitive impairment

Acute Altered Mental Status Intracranial lesionMetabolic disorderToxin Infection Ictal statePostictal state Psychogenic

Cranial Nerve Exam

Focus exam on II - VIII Symmetrical vs asymmetrical

Evaluation of II, III, IV, VI Visual acuity Visual fields Examine the cornea, pupil, fundi Check afferent function Extraocular movements

Accentuated when looking in the direction of the paralyzed muscle

Differentiation can be facilitated by placing a colored glass over one eye

Cranial Nerve II

Visual acuity Visual fields Fundoscopy Swinging flashlight test

III Nerve

Emerges from brainstem next to posterior cerebral artery

May be compressed by herniation Runs in the lateral wall of the cavernous sinus

LR MR MR LR

IO IO SRSR

IR SO SO IR

III Cranial Nerve

Parasympathetics Levator Palpebrae Inferior Obliques, Medial, Inferior, and Superior Rectus

Muscles

LR MR MR LR

IO IO SRSR

IR SO SO IR

III Cranial Nerve ParalysisPtosisDilated PupilParalyzed eye is deviated out and

down; SO and LR control eye

III Cranial Nerve Lesions

Progressive lesions after passage through the dura usually usually causes a ptosis and pupil dilatation first

Lesions in the nucleus cause motor deficits first

Intact pupil indicates a peripheral ischemic lesion

LR MR MR LR

IO IO SRSR

IR SO SO IR

IV Cranial Nerve Superior oblique Causes eye to turn in and down When paralyzed, eye can not turn down when it is rotated in

LR MR MR LR

IO IO SRSR

IR SO SO IR

VI Cranial Nerve Lateral rectus Long course; goes through the cavernous sinus, not within the wall Paralysis impairs abduction

Conjugate Gaze

Controlled by supranuclear connections

Medial longitudinal fasciculus is responsible for coordinating the oculomotor nerves; lesions result in impairment of LR and MR moving in synchrony, ie, contralateral eye does not pass the midline

Multiple sclerosis

Causes of III, VI, VI CN Paralysis

Isolated cases usually due to vascular causes: HTN, DM, Atherosclerosis

Tumors Increased intracranial pressure Colloid cyst of the III ventricle Wernicke-Korsakoff syndrome Myasthenia, Botulism Toxic drug reactions

Cranial Nerve V

Sensory: corneal reflexes Motor: jaw strength and muscle bulk Corneal reflex may be abnormal in cerebellopontine

angle lesions: test in patients with hearing deficits or vertigo

Cranial Nerve VII

Motor Smile Nasolabial fold Forehead has bihemispheric innervation centrally

Taste anterior 2/3

Cranial Nerves VIII - XII

VIII - vestibular function / hearing IX & X - taste / sensation posterior pharynx, bulbar

muscles XI – Sternocleido mastoid, chin to opp. side XII - tongue

Motor Exam Strength

Primary concern: can patient breathe Key test: drift of extremity

Tone Hypertonia: subacute or chronic corticospinal lesion Hypotonia: LMN lesion or acute UMN Rigidity: basal ganglia disease

Motor Exam

BulkWasting correlates with LMN

FasciculationAnterior horn cell lesion

TendernessMetabolic / inflammatory muscle

disease

Motor Exam0 = no movement1 = flicker but no movement2 = movement but can not resist gravity3 = movement against gravity but can not

resist examiner4 = resists examiner but weak5 = normal

Sensory Exam

Pain / Temp - cross at entrance, ascend in spinal thalamic tract

Light touch - ascend in posterior column, cross in the brain stem

Vibration - posterior column, cross in the brain stem

Cortical sensations

Sensory Exam

Dermatomal deficit accompanied with pain suggests peripheral lesion

Central deficits are not dermatomal and usually result in loss of sensation not pain

Thalamic pain syndrome

Sensory Exam

DistributionRight vs left vs bilateralDermatomalDistal versus proximal

Stocking gloveCape like

Pinprick versus light touch

Sensory Exam

Double simultaneous testingEstablish sharp / dullCheck cheek, dorsum of hands, dorsum of

feetTest both sides simultaneously with pin

lateralizes pain, significant sensory deficit initially no lateralization but on repeat 15 sec

later, lateralization suggests subtle deficit

Coordination Requires integration of cerebellar, motor,

and sensory functions Balance requires (2 of 3)

vision vestibular sense proprioception

Falling with eyes open or closed = cerebellar

Falling only with eyes closed = posterior column or vestibular

Reflexes Symmetry / upper vs lower

0 = absent 1 = hyporeflexia 2 = normal 3 = hyperreflexia 4 = clonus (usually indicates organic disease)

Superficial reflexes (corneal, pharyngeal, abdominal, anal, cremasteric, bulbocavernosus)

Pathologic reflexes: babinski

Hysteria (conversion vs malingering) Blindness: opticokinetic test Hand drop on face test for coma Hemianesthesia: if real, patient cannot perform

finger-to nose with eyes closed; vibration remains intact (if bony skeleton intact)

Weakness: elbow extension or flexor test; wrist extensor test

Unilateral leg elevation weakness: thigh abduction test, hoover test

Pitfalls In The Neurologic Exam

Not getting a complete history utilizing family or observers

Not performing a systematic exam Jumping to conclusions before

gathering all the dataMisinterpreting old lesions for new Misinterpreting limitations from pain

as neurologic deficits

PearlsLesions of the cerebral cortex result in

sensory and motor defects confined to the contralateral side of the body

Brain stem and spinal cord lesions result in ipsilateral as well as contralateral defects due to varying patterns of crossover

Pearls

Unilateral pain syndromes without motor deficits suggest possible thalamic pathology

A careful exam of CN II, III, IV, and IV is indicated in patients with headache or suspected processes that cause increased ICP

Testing for pronator drift is the best screen for muscle weakness of central origin

The Neurologic Exam

Case Scenarios

Case Scenario #1

A 46-year-old female with a long history of migraine headaches presented c/o a severe occipital head ache that was different from her past headaches in location and intensity. If an aneurysm is suspected to be causing the patient’s symptoms, which cranial nerve should your exam focus on?

A. III B. VI C. VII D. IV

III NERVEEmerges from brainstem next to posterior

cerebral arteryRuns in the lateral wall of the cavernous sinusMay be compressed:

HerniationAneurysm

Posterior communicating arteryICA in the cavernous sinus (IV, V and VI nerves

also involved)

Case Scenario #2

A 64-year-old male presented C/0 low back pain which has become progressively worse over the past 2 weeks. The pain was primarily in the low back without radiation; C/O nonspecific numbness in the legs. Which nerve root is responsible for plantar flexion and the ankle jerk?

A. L3 B. L4 C. L5 D. S1 E. S2

Lower Extremity Innervation L 3 / L 4 = Patellar reflex L 5 = Big toe extension S 1 = Achilles reflex

Case Scenario #3A 30-year-old female is in an accident hitting her head on the dash. The next day she developed a sudden onset severe right frontal head ache, that persisted. One day later she developed left sided arm weakness that lasted 2 hours. In the ER she had an OD ptosis and OD miosis. Her motor / sensory exam was “WNL”. What is your initial impression? A. Hysteria B. Subarachnoid bleed C. Epidural hematoma D. Carotid artery dissection E. Entrapment syndrome

Pupil Constriction

Disruption of the sympatheticsHorner’sCarotid artery dissectionPontine hemorrhage

ToxinsNarcoticsCholinergics

Case Scenario #4A 50-year-old female c/o a diffuse headache for two months that is constant. There is no past head ache history. She claims that intermittently her vision seems blurred but otherwise denies symptoms. On exam: VA: 20/40. Cranial Nerves: diplopia on far lateral gaze bilaterally. Which of the following is the most likely diagnosis. A. Occipital Lobe Stroke B. Pituitary AdenomaC. Multiple Sclerosis D. Myasthenia GravisE. Intracranial Hypertension

Idiopathic Intracranial Hypertension (Benign Intracranial Hypertension, Pseudotumor Cerebri)

Syndrome Defined By Signs And Symptoms Of High ICP Without Apparent Intracranial Mass

50% Have An Identifiable Underlying Etiology Altered Absorption Of CSF At The Arachnoid Villus Alteration Due To Either:

Elevated Pressure Within The Sagittal Sinus Increased Resistance To Drainage Of CSF Within The

Villus

Physical Findings

PapilledemaVisual disturbance 50 - 80%

Blindness in 10%Decreased visual acuity 30%Transient visual obscuration68%Enlarged blind spotScotomasVI nerve palsy (false localizing) 38%

Case Scenario #5A 20-year-old college student flips his car, hitting head on the dash. He arrives in the ER in full spinal immobilization. On exam he has 2/5 strength in his wrists, 3/5 strength in his deltoids, 5/5 strength in his Leg Extensors. He complains of numbness in his arms but is able to distinguish sharp from dull. DTRs intact. What is your leading diagnosis?A. Central Cord Syndrome B. Anterior Cord SyndromeC. Spinal Epidural Hemorrhage D. Subdural HemorrhageE. Brown - Sequard Syndrome

Central Cord Syndrome

Hyperextension injuries, tumor, syringomyelia Paresis or plegia of arms > legs Posterior column spared

Central Cord Syndrome

sacral sparing Perforating branches of anterior spinal artery at greatest

risk for vascular insult Good prognosis

Case Scenario #6A 23-year-old female presents complaining of feeling generally weak with the sensation that she is dragging her feet when she walks. On exam her sensation is intact; motor strength is 5/5 in all major muscle groups; deep tendon reflexes are 2/2 in the Upper limb, 2/2 at the knees, and and 0/2 at the ankles. What is your major concern?A. Spinal Stenosis B. Conus Medularis C. Guillian Barre D. Polymyalgia Rheumatica E. Myasthenia Gravis

Guillain-Barre

Acute polyneuropathySymmetric ascending weaknessArrflexia (LMN)No meningeal signs, fever,

signs of systemic illnessCSF: increased protein without

pleocytosis

Case Scenario #7A 30-year-old male with AIDS complains of diffuse weakness that is progressive in the Lower limbs associated with paresthesias; there is no back pain. On exam he has 4/5 upper extremity strength, 2/5 lower extremity strength; DTRs are 2/2 in the Upper limbs and 4/2 in the Lower limbs. His plantar reflexes are upgoing bilaterally. Which of the following is the most likely diagnosis?A. Myelopathy B. Neuropathy C. MyopathyD. Neuromuscular Junction Disease E. Radiculopathy

HTLV-1 Associated MyelopathyProgressive lower extremity weakness

(arms more than legs)SpasticityParesthesias are common; sensory

deficits are rareSymmetric upper motor neuron

paraparesisSphincter disturbances

Risk Management: Case #1 A 46-year-old female with a long history of

migraine headaches presented c/o a severe occipital head ache that was different form her past headaches in location and intensity. Neuro exam “WNL”. Patient was treated with Compazine, 10 MG IV, with “Resolution of Headache” and discharged home to “Follow-Up With doctor”.

18 hours later, patient was brought in by EMR comatose

Risk Management: Case #2 A 64-year-old male presented with lower back pain

which had become progressively worse over the past 2 weeks. The pain was primarily in the lower back without radiation, with nonspecific numbness in the legs.

Past h/o: presently being treated for prostatitis. Exam: “Mild Paralumbar Tenderness”, “SLR -”, “Motor /

Sensory Intact”, Knee DTR +2. patient was prescribed Motrin and told to follow-up with his doctor.

Patient developed irreversible renal damage.

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Neurology examination