W 6 Neurological Examination

Neurological Examination — Comprehensive Study Notes

  • Objective summary

    • Perform a screening and comprehensive neurological examination
    • Develop and apply a systematic approach to the neurological exam
    • Explain the purpose of performing each component
    • Document normal findings of the neurological exam

  • Major components of the Complete Neurologic Exam

    • Mental Status
    • Cranial Nerves
    • Motor System
    • Sensory System
    • Reflexes

  • Screening Neurologic Examination

    • For screening in patients without neurologic complaints, the exam can be completed in about five minutes or less
    • Use screening results together with patient history to decide whether specific, more specialized components are needed
    • PD Final – Orient to person, place and time; check mental status level and appropriateness of responses

  • Mental Status

    • Concept and framework
    • Assess level of consciousness and orientation first
    • Levels of Consciousness (BOX 9-5)
    • Alertness: patient is awake, eyes open, looks at you, responds fully and appropriately
    • Lethargy: drowsy; opens eyes to loud voice, looks at you, responds to questions, then falls asleep
    • Obtundation: opens eyes with tactile stimulus, looks at you, responds slowly and is somewhat confused
    • Stupor: arouses only after painful stimuli; verbal responses slow or absent; may lapse into unresponsiveness when stimulus ceases
    • Coma: unarousable; eyes closed; no evident response to inner needs or external stimuli
    • Orientation testing (to person, place, and time)
    • PERSON – WHO ARE YOU?
    • PLACE – WHERE ARE YOU?
    • TIME – WHAT DAY IS IT?

  • Mini-Mental Status Examination (MMSE)

    • Purpose and scoring
    • Instructions: Ask the questions in the order listed; score one point for each correct response within each item
    • Maximum score: 30
    • Components and prompts (examples from the transcript)
    • Orientation to time: What is the year? Season? Date? Day of the week? Month?
    • Orientation to place: Where are we now: State? County? Town/city? Hospital? Floor?
    • Immediate recall: examiner names three unrelated objects; patient repeats them (three items; trials may be repeated to learn all)
    • Attention and calculation: Count backward from 100 by sevens (93, 86, 79, 72, 65, …); Stop after five responses
      • Alternative: Spell WORLD backwards
    • Delayed recall: Earlier I told you the names of three things. Can you tell me what those were?
    • Registration: Name three objects again?
    • Language and praxis: Read this and do what it says. (example: "Close your eyes.")
    • Written language: Please copy this picture. (copy a complex figure with all 10 angles and two intersections)
    • Scoring thresholds and interpretation
    • Total possible: 30
    • Cutoffs and interpretation (examples)
      • Single cutoff: <24 indicates abnormal cognition
      • Alternative thresholds by education
      • 8th grade education: <23 abnormal
      • High school education: <23 abnormal
      • College education: <24-30 considered normal; specific breakpoints noted in the material
      • Score interpretations
      • 24-30: No cognitive impairment
      • 18-23: Mild cognitive impairment
      • 0-17: Severe cognitive impairment
      • 21: Abnormal for 8th grade education
      • 23: Abnormal for high school education
      • 25+: Decreased odds of dementia
    • Note: The MMSE items include orientation to time/place, three-object recall, attention/calculation, language, and visuospatial skills (copying a figure)

  • Cranial Nerves (CN I–XII)

    • CN I – Olfactory: Sensory; sense of smell
    • CN II – Optic: Sensory; vision
    • CN III – Oculomotor: Motor; pupillary constriction, eyelid opening, most extraocular movements
    • CN IV – Trochlear: Motor; downward and inward eye movements
    • CN V – Trigeminal: Both; motor (temporal and masseter muscles; lateral jaw movement); sensory (3 divisions: ophthalmic, maxillary, mandibular)
    • CN VI – Abducens: Motor; lateral eye movement
    • CN VII – Facial: Both; motor (facial movements, eyelid/mouth closure); sensory (taste anterior 2/3 of tongue; sensation from ear)
    • CN VIII – Vestibulocochlear (Acoustic): Sensory; hearing and balance
    • CN IX – Glossopharyngeal: Both; motor (pharynx); sensory (posterior ear canal, pharynx, posterior tongue including taste)
    • CN X – Vagus: Both; motor (palate, pharynx, larynx); sensory (pharynx and larynx)
    • CN XI – Accessory (spinal): Motor; movement of SCM and trapezius
    • CN XII – Hypoglossal: Motor; movement of the tongue
    • Mnemonic for CN order
    • On occasion our trusty truck acts funny. Very good vehicle anyhow. Some say marry money, but my brother says big brains matter more.

  • CN exam: summary and components

    • CN II (Optic): test visual acuity with chart at 14 inches; pupillary reaction to light; fundoscopic exam
    • CN III, IV, VI: extraocular movements; pupillary reactions
    • CN V: testing motor (jaw clench) and sensory (three divisions) plus corneal reflex as a specialty exam
    • CN VII: motor facial movements; symmetry; forehead, eyes, smile, pout; assess for Bell Palsy (peripheral CN VII) vs central UMN lesion (lower face weakness with preserved forehead)
    • CN VIII: hearing tests (whisper test) and balance tests
    • CN IX and X: say "ah" and observe soft palate elevation; uvula position; check for palate symmetry
    • CN XI: SCM and trapezius strength via shoulder shrug and head turning against resistance
    • CN XII: tongue movement; look for symmetry, atrophy, deviation; unilateral cortical lesion vs hypoglossal lesion
    • Putting together: map of CN tests per component
    • II: visual acuity, pupillary reaction, fundoscopy
    • III/IV/VI: EOMs, pupillary reaction
    • V: facial sensation (3 divisions) and motor jaw clench; corneal reflex
    • VII: facial movements; taste anterior 2/3 (not typically tested in this exam slide-by-slide)
    • IX/X: palate elevation with "ah"
    • XI: SCM/trapezius function
    • XII: tongue movements
    • Additional CN test mnemonics and worded instructions are provided in the slides for clinical use

  • Putting it together: Cranial Nerve Exam at-a-glance

    • II (Optic): Assess visual acuity individually; pupillary reaction to light; fundoscopic exam
    • III (Oculomotor): Extraocular movements; pupillary reaction to light (direct and consensual)
    • IV (Trochlear): Extraocular movements
    • V (Trigeminal): Light touch of face in three divisions; palpate temporal and masseter muscles during jaw clench
    • VI (Abducens): Extraocular movements
    • VII (Facial): Facial movements; symmetry; facial expressions
    • VIII (Vestibulocochlear): Hearing and balance tests
    • IX (Glossopharyngeal) and X (Vagus): Say "ah"; observe soft palate elevation; uvula midline
    • XI (Accessory): SCM and trapezius strength (shrug and head turn against resistance)
    • XII (Hypoglossal): Tongue movements; symmetry and deviation

  • Motor System: Overview and Pathways

    • Corticospinal (pyramidal) tract
    • Controls voluntary, discrete, skilled movements in the limbs
    • Originates in motor cortex; travels through internal capsule and ventral brainstem; decussates in the medulla to form the pyramids
    • ~75-90 ext{%} of fibers cross to the opposite (contralateral) side in the medulla and continue in the lateral columns of the spinal cord to synapse with lower motor neurons in the anterior horn
    • If damage occurs below the crossover, motor impairment is on the same (ipsilateral) side
    • If upper motor neuron pathways are damaged above the crossover in the medulla, motor impairment is contralateral
    • Upper motor neurons influence movement via lower motor neuron systems; action must be translated by anterior horn cells
    • Lesions in these pathways affect movement or reflex activity
    • The motor cortex is modulated by basal ganglia and cerebellum
    • Basal ganglia: helps maintain muscle tone and regulate movements such as walking
    • Cerebellum: fine-tunes and coordinates movement initiated by motor cortex; coordinates gait and posture; important for speech

  • Upper vs Lower Motor Neuron Lesions

    • Upper Motor Neuron (UMN) lesions
    • Etiology: cerebral stroke, tumor, encephalitis; spinal cord injury; demyelinating diseases (e.g., MS)
    • Signs: increased muscle tone (spasticity), hyperreflexia, + Babinski sign; pronator drift (weakness in supination of the upper extremities); pyramidal weakness with greater involvement of flexors of the LE and extensors of the UE; legs extended/adducted, elbows/wrists flexed
    • Lower Motor Neuron (LMN) lesions
    • Etiology: damage to anterior horn cells, motor roots, peripheral nerves (e.g., spinal muscular atrophy, peripheral neuropathies, myasthenia gravis, radiculopathy)
    • Signs: ipsilateral weakness and paralysis, muscle atrophy and decreased tone, fasciculations, decreased or absent deep tendon reflexes; asymmetry

  • Motor System General Assessment

    • Observe body position and movement at rest and during activity
    • Look for involuntary movements (tremors, tics, chorea, fasciculations)
    • Muscles: assess bulk, tone, and strength
    • Tone: baseline slight residual tension; assess via passive stretch
    • Strength: test actively resisting your movements

  • Muscle Strength: Grading Scale

    • 0 to 5 scale
    • Grade descriptions (wrapped in LaTeX where applicable):
    • 0: No muscular contraction detected
    • 1: A barely detectable flicker or trace of contraction
    • 2: Active movement with gravity eliminated
    • 3: Active movement against gravity
    • 4: Active movement against gravity and some resistance
    • 5: Active movement against full resistance without evident fatigue (normal)
    • Source: Medical Research Council; standard peripheral nerve examination framework

  • Upper Extremity Muscle Strength Tests (examples and nerve roots)

    • Shoulder abduction (C5 – deltoid)
    • Test: push up against resistance; observe strength
    • Elbow flexion (C5, C6 – biceps and brachioradialis)
    • Test: pull against resistance
    • Elbow extension (C6, C7, C8 – triceps)
    • Test: push against resistance
    • Wrist flexion (C7)
    • Test: make a fist and resist upward pressure
    • Wrist extension (C6-C8; radial nerve – extensor carpi radialis longus and brevis)
    • Test: make a fist and resist downward pressure
    • Grip strength (C7-T1)
    • Test: squeeze two fingers as hard as possible and don’t let go
    • Finger abduction (C8, T1; ulnar nerve)
    • Test: spread fingers and try to resist finger adduction
    • Thumb opposition (C8, T1; median nerve)
    • Test: touch tip of little finger with thumb, against resistance
    • Nerve root and peripheral nerve mappings accompany each movement (spiral pattern down the limb)
    • References: detailed figure in the original source (Gelb et al.)

  • Lower Extremity Muscle Strength Tests

    • Hip flexion (L2-L3; iliopsoas; femoral nerve)
    • Hip extension (S1; gluteus maximus; gluteal nerves)
    • Hip adduction (L2-L4; adductors)
    • Hip abduction (L4-L5-S1; gluteus medius/minimus)
    • Knee extension (L3-L4; quadriceps)
    • Knee flexion (L4-L5-S1-S2; hamstrings)
    • Ankle dorsiflexion (L4-L5; tibialis anterior)
    • Ankle plantar flexion (S1; gastrocnemius, soleus)
    • Toe movements (dorsiflexion/plantar flexion via tibialis anterior and gastrocnemius)
    • Note: heel-to-toe walking and toe-heel walking assess distal leg function and corticospinal tract integrity

  • Cerebellar & Coordination (Four key systems)

    • Motor system: strength
    • Cerebellar system: rhythm and steady posture
    • Vestibular system: balance and eye-head-body coordination
    • Sensory system: position sense

  • Rapid alternating movements

    • Observe speed, rhythm, and smoothness of movements
    • Examples: rapidly strike hand on thigh, turn, and strike back; or alternate tapping index finger on distal thumb
    • Alternative: rapid tapping of fingertip to thumb

  • Finger-to-nose test

    • Patient touches examiner’s finger, then their own nose, then back to examiner; watch for accuracy and smoothness
    • Assess direction changes and arm extension; test with eyes open and closed to challenge position sense
    • Perform bilaterally

  • Heel-to-shin test

    • Patient runs heel down the opposite shin from knee to toe; assess smoothness and accuracy; test with eyes closed for position sense

  • Romberg test

    • Stand with feet together; eyes open then closed for 30-60 seconds
    • Normal: minimal sway with eyes open or closed
    • Positive Romberg: unsteadiness with eyes closed (dorsal column/position sense problem)
    • Cerebellar ataxia: difficulty standing with feet together regardless of eyes

  • Pronator drift test

    • Arms extended forward with palms up, eyes closed for 20-30 seconds
    • Pronator drift indicates contralateral corticospinal tract lesion; useful for detecting subtle weakness

  • Gait evaluation

    • Observe posture, balance, arm swing, and leg movements while walking and turning
    • Normal gait: stable base, symmetrical arm swing, smooth turns
    • Ataxia: uncoordinated gait with reeling and instability; cerebellar disease or proprioceptive loss

  • Cerebellar vs Sensory Ataxia signs

    • Cerebellar ataxia: wide-based gait, difficulty with turns, dysmetria, nystagmus, intention tremor
    • Sensory (proprioceptive) ataxia: wide-based gait, compensatory visual guidance, positive Romberg

  • Sensory System: overview of modalities and testing approach

    • Sensations tested: pain and temperature (spinothalamic tract); position and vibration (posterior column); light touch; discriminative sensations
    • Approach: compare symmetric areas; distal to proximal testing for pain/temperature; map dermatomes and nerve distributions
    • References: Bates Atlas figures for dermatomal mapping; map sensory loss or hypersensitivity

  • Light touch testing

    • Use cotton swab to touch skin lightly; patient responds when felt
    • Testing areas (examples from the slide):
    • Deltoid (C4)
    • Proximal forearm (C6; inner and outer forearm; C6, T1)
    • Hand (C6, C8; thumb and little finger)
    • Thigh (L2, L3)
    • Calf (L4, L5)
    • Foot (S1)
    • Terms: anesthesia (absence of touch), hypoesthesia (decreased touch), hyperesthesia (increased touch)

  • Pain testing

    • Use the stick end of a broken cotton swab; ask patient to identify sharp vs dull; compare sides with eyes closed
    • Areas tested: dorsal hand and foot
    • Pain terms: analgesia (absence of pain), hypoalgesia (decreased pain sensitivity), hyperalgesia (increased pain sensitivity)

  • Vibration testing

    • Use a 128 Hz tuning fork on distal joints (DIP of finger and big toe)
    • Patient states what they feel; cease vibration and confirm perception
    • If vibration sense is impaired, test more proximal prominences (wrist, elbow; medial malleolus, shin, patella)

  • Proprioception (joint position sense)

    • Test fingers and big toes bilaterally
    • Grasp a digit and move up or down; ask patient to identify direction with eyes closed
    • If impaired, test more proximal joints

  • Reflexes: Deep Tendon Reflexes (DTRs)

    • Normal process: tap tendon briskly; reflex arc through spinal/brainstem segment
    • Hyperactive reflexes (hyperreflexia): CNS lesions of corticospinal tract; look for UMN signs (weakness, spasticity, Babinski)
    • Hypoactive/absent reflexes: LMN lesions (spinal roots/plexuses/peripheral nerves); look for weakness, atrophy, fasciculations
    • How to perform: relax patient, seat position, hold hammer loosely, strike with brisk, direct movement, use minimal force
    • Grading scale for reflexes (GERM):
    • 4: Very brisk, hyperactive with clonus
    • 3: Brisker than average
    • 2: Average; normal
    • 1: Somewhat diminished; low normal
    • 0: Absent
    • Common reflex tests and how to perform
    • Biceps reflex (C5, C6): place thumb on biceps tendon; strike thumb; observe elbow flexion and biceps contraction
    • Triceps reflex (C6, C7): elbow flexed; strike triceps tendon; observe elbow extension
    • Brachioradialis reflex (C5, C6): forearm partially pronated; strike radius just above the wrist; observe flexion and supination
    • Patellar reflex (L2, L3, L4): knee flexed; tap below patella; observe quadriceps contraction with knee extension; support knees or one knee at a time as needed
    • Achilles reflex (S1): seated with slight dorsiflexion; strike Achilles; observe plantar flexion and relaxation speed
    • Plantar response (L5, S1): stroke lateral sole from heel to ball; observe for toe movement; normal = plantar; abnormal = Babinski (dorsiflexion of big toe)
    • Clonus testing
    • If reflexes seem hyperactive, test for ankle clonus by dorsiflexing the foot and watching for rhythmic oscillations between dorsiflexion and plantar flexion

  • Putting It Together: Case example (brief synthesis)

    • 62-year-old patient with right-sided neck pain for 2 weeks; radiation to right arm with weakness and numbness
    • No fever, chills, night sweats, or bowel/bladder symptoms; right-hand dominant
    • Exam focus: inspect and palpate neck/shoulders/elbows/wrists/hands; ROM testing; strength testing; sensation testing across dermatomes; reflex testing; specialty tests (Spurling’s) and pulses
    • Components to assess: motor strength (shoulder abduction, elbow flexion/extension, wrist flexion/extension, grip), sensation (light touch across dermatomes), reflexes (biceps, triceps, brachioradialis), and vascular pulses

  • Neurological Exam Sample Write-Up (from the slides)

    • Patient is alert and oriented x 3; cooperative; thought process coherent
    • Detailed cognitive testing deferred
    • Cranial nerves II–XII grossly intact
    • Good muscle bulk and tone; strength 5/5 in upper and lower extremities
    • Rapid alternating movements, finger-to-nose, and heel-to-shin intact
    • Gait with normal base; negative Romberg; no pronator drift
    • Sensations in upper and lower extremities intact to light touch and pinprick; vibratory and position senses intact
    • Reflexes: biceps, brachioradialis, patellar and Achilles reflexes 2+ and symmetric; negative Babinski
    • Major components of the Neuro Exam: Mental Status, CN, Motor System, Sensory System, Reflexes

  • References (examples from the slides)

    • Bates’ Guide to Physical Examination and History Taking (13th ed., 2021)
    • Gelb D. The detailed neurologic examination in adults. UpToDate; 2012 update
    • Netter’s Neurology (3rd ed., 2020)

  • Quick recap and study tips

    • Start with Mental Status, then Cranial Nerves, followed by Motor, Sensory, and Reflexes
    • Use the UMN vs LMN sign patterns to localize lesions
    • Practice MMSE items and remember common threshold cutoffs for interpretation
    • Memorize key motor strength tests and their nerve root mappings for rapid bedside assessment
    • Familiarize yourself with the common cerebellar and sensory tests to distinguish coordination, proprioception, and balance issues

  • Endnotes

    • The content above summarizes the lecture slides on neurological examination as of October 15, 2024, including core tests, interpretation, and practical exam tips.