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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
The Neuro Exam: History
History often provides the key since the neuro exam may be normal Subarachnoid Hemorrhage Carbon Monoxide Poisoning Subdural Hematoma Nonconvulsive Seizures
The Neuro Exam: History
Time of Onset Type of Onset Progression Trauma Associated Symptoms
The Neuro Exam: History
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.