Chapter 12-02: Diagnostics in Neurology

THE NEUROLOGIC EXAM

Mental status

• Orientation: Person, place, time, situation

• Language: Fluency, repetition, naming (high and low frequency items), comprehension (axial [“close eyes, stick out tongue”] and appendicular [“show two fingers, give thumbs up”] commands, complex commands [“take your right thumb, touch your left ear, and stick out your tongue”])

• Attention: Ask patient to spell “WORLD” forward, then backward. Alternatively: Recite months of the year or days of the week backward.

• Memory: Working (digit span forward (normal >5–7 digits), backward) and delayed (remember three words ×5 minutes)

Cranial nerves

• I – Olfactory nerve: Not frequently tested

• II – Optic nerve/III parasympathetic fibers: Visual fields/pupillary constriction (afferent – optic nerve, efferent parasympathetic fibers)

• III, IV, VI – Oculomotor, trochlear, and abducens nerves: Extraocular muscle movements

• V – Trigeminal nerves: Facial sensation, motor for muscles of mastication

• VII – Facial nerve: Facial movement, eyelid closure, lacrimation and salivation, taste in the anterior 2/3 of the tongue

• VIII – Vestibulocochlear nerve: Hearing from the cochlear nerve, balance from the vestibular nerve

• IX, X – Glossopharyngeal and vagus nerve: Palate elevation, gag, cough

Motor

• Bulk and tone: Increased = spasticity, rigidity, or paratonia; decreased = flaccidity

• Screening motor exam: Pronator drift (sign of upper motor neuron weakness; evaluate for finger flexion and/or pronation with arms outstretched and eyes closed), finger taps and toe taps (evaluate for large, symmetric, rapid movements)

• Confrontational strength testing:

  • - Power: Score motor strength in each muscle group from 0 to 5:

    • 0: No contraction

    • 1: Trace movement

    • 2: Full range of motion when gravity is eliminated

    • 3: Full range of motion against gravity

    • 4: Movement against gravity with resistance, but still less than full strength

    • 5: Full/normal strength

  • - Preferential muscle groups to test:

    • Upper extremity: Shoulder abduction (deltoids), flexion and extension at elbow (biceps, triceps, resp), wrist extension, finger extension and abduction

    • Lower extremity: Hip flexion (ilioposas), knee flexion and extension (hamstrings, quads), ankle dorsiflexion (tibialis anterior)

Sensory

• Screening exam: Assess ability to sense light touch

• Small fiber: Pain (safety pin) and temperature (alcohol swab, cold tuning fork)

• Large fiber: Vibration (tuning fork) and proprioception (joint position sense)

Reflexes

• Upper extremity reflexes: Biceps (C5–6), triceps (C7–8)

• Lower extremity reflexes: Patellae (L3–4), Achilles tendon (S1–S2)

• Plantar response: Apply noxious stimulus starting at the lateral aspect of the sole of the foot, moving medially across the ball of the foot. Normal response is flexor (toes down); abnormal response is extensor (large toe goes up and remaining toes fan out = Babinski sign)

Coordination

• Appendicular (limb) ataxia: Finger-nose-finger, heel-knee-shin

• Truncal ataxia: Sitting upright unsupported, gait ataxia

Gait

• Description of gait: Stance (normal, wide, or narrow-based), stride length, foot clearance (shuffling; ...