Neurologic System


image Familiar objects (coins, keys, paper clip)

image Sterile needles

image Cotton wisp

image Tongue blades (one intact and one broken with pointed and rounded edges)

image Cup of water

image Tuning forks, 200 to 400 Hz and 500 to 1000 Hz

image Reflex hammer

image 5.07 monofilament or Waardenberg wheel

image Test tubes of hot and cold water

image Vials of aromatic substances (coffee, orange, peppermint, banana)

image Vials of solutions (glucose, salt, lemon or vinegar, quinine) with applicators

image List of tastes


Assess the neurologic system as the rest of the body is examined. When history and examination findings have not revealed a potential neurologic problem, perform a neurologic screening examination as shown in the box on p. 244, rather than a full neurologic examination. See Chapter 17, Musculoskeletal System, for evaluation of muscle tone and strength, because these findings are important for interpreting neurologic system examination findings. The mental status portion of the neurologic system examination is found in Chapter 2.

Neurologic Screening Examination

This shorter screening examination is commonly used for health visits when no known neurologic problem is apparent.

Cranial Nerves

Cranial nerves II through XII are routinely tested; however, taste and smell are not tested unless some aberration is found.

Proprioception and Cerebellar Function

One test is administered for each of the following: rapid rhythmic alternating movements, accuracy of movements, balance (Romberg test), gait, and heel-toe walking.

Sensory Function

Superficial pain and touch at a distal point in each extremity are tested; vibration and position senses are assessed by testing the great toe.

Deep Tendon Reflexes

All deep tendon reflexes and the plantar reflex are tested, excluding the test for clonus.


The table below summarizes the cranial nerve (CN) examination. When a sensory or motor loss is suspected, be compulsive about determining the extent of the loss.

Procedures for Cranial Nerve Examination

Cranial Nerve (CN) Procedure
CN I (olfactory) Test ability to identify familiar aromatic odors, one naris at a time with eyes closed.
CN II (optic)
Test vision with Snellen chart and Rosenbaum near-vision chart.

Perform ophthalmoscopic examination of fundi.

Test visual fields by confrontation and extinction of vision.
CN III, CN IV, CN VI (oculomotor, trochlear, abducens)
Test extraocular movement.

Inspect eyelids for drooping

Inspect pupil size for equality and direct and consensual response to light and accommodation.
CN V (trigeminal)
Inspect face for muscle atrophy and tremors.

Palpate jaw muscles for tone and strength when patient clenches teeth.

Test superficial pain and touch sensation in each branch.

(Test temperature sensation if there are unexpected findings to pain or touch.)

Test corneal reflex.
CN VII (facial)
Inspect symmetry of facial features with various expressions (e.g., smile, frown, puffed cheeks, wrinkled forehead).

Test ability to identify sweet and salty tastes on each side of tongue.
CN VIII (acoustic)
Test sense of hearing with whisper screening tests or by audiometry.

Compare bone and air conduction of sound.

Test for lateralization of sound.
CN IX (glossopharyngeal)
Test ability to identify sour and bitter tastes.

Test gag reflex and ability to swallow.
CN X (vagus)
Inspect palate and uvula for symmetry with speech sounds and gag reflex.

Observe for swallowing difficulty.

Evaluate quality of guttural speech sounds (presence of nasal or hoarse quality to voice).
CN XI (spinal accessory)
Test trapezius muscle strength (shrug shoulders against resistance).

Test sternocleidomastoid muscle strength (turn head to each side against resistance).
CN XII (hypoglossal)
Inspect tongue in mouth and while protruded for symmetry, tremors, atrophy.

Inspect tongue movement toward nose and chin.

Test tongue strength with index finger when tongue is pressed against cheek.

Evaluate quality of lingual speech sounds (l, t, d, n).

Assess olfactory nerve (CN I)
Ask patient to close eyes. Occlude one naris, hold vial (using least irritating aromatic substances first [e.g., orange or peppermint extract]) under nose, and ask patient to breathe deeply and identify odor. Allow patient to breathe comfortably, then occlude other naris and repeat with different odor. Continue, alternating two or three odors. EXPECTED:Able to perceive and usually identify odor on each side.
UNEXPECTED:Anosmia, loss of smell or inability to discriminate odors.
Assess optic nerve (CN II)
See tests for visual acuity and visual fields in Chapter 7, Eyes.  
Assess oculomotor, trochlear, abducens nerves (CN III, CN IV, CN VI)
See tests for six cardinal points of gaze, pupil size, shape, response to light and accommodation, and opening of upper eyelids in Chapter 7, Eyes. EXPECTED:Equal pupil size, equal and consensual response to light and accommodation, symmetric eye movements in all six cardinal points of gaze.
UNEXPECTED:Absence of lateral gaze. Absence of any expected finding, ptosis.
Assess trigeminal nerve (CN V)

image Facial muscle tone

Ask patient to clench teeth tightly as you palpate muscles over jaw.

EXPECTED:Symmetric tone.
UNEXPECTED:Muscle atrophy, deviation of jaw to one side, or fasciculations.

image Sensation

Ask patient to close eyes and report if sensation to touch is sharp or dull as you touch each side of face at scalp, cheek, and chin areas, alternately using sharp and rounded edges of tongue blade or paper clip in an unpredictable pattern. Ask patient to report when the stimulus is felt as you stroke same six areas with cotton wisp or brush. Finally, test sensation over buccal mucosa with wooden applicator.

EXPECTED:Symmetric discrimination of sensations in each location to all stimuli.
UNEXPECTED:Impaired sensation. If impaired, use test tubes of hot and cold water to evaluate temperature sensation.

Testing sensation over distribution of cranial nerve V.


image Corneal reflex

See test for corneal sensitivity in Chapter 7, Eyes.

EXPECTED:Symmetric blink reflex. May be diminished or absent if patient wears contact lenses.
Assess facial nerve (CN VII)

image Expressions

Assess motor function by asking patient to make the following facial expressions:

Raise eyebrows and wrinkle forehead



Puff out cheeks

Purse lips and blow out

Show teeth

Squeeze eyes shut against resistance
EXPECTED:Facial symmetry.
UNEXPECTED:Tics, unusual facial movements, or asymmetry of expression (flattened nasolabial fold, lower eyelid sagging, side of mouth drooping).

Assessing motor function of cranial nerve VII.


image Speech

Listen to articulation and clarity of speech

UNEXPECTED:Difficulties with enunciating b, m, and p (labial sounds).

image Taste (CN VII and CN IX)

Hold card listing tastes in patient’s view. Ask patient to extend tongue. Apply one of four solutions to lateral side of tongue in appropriate tastebud region. Ask patient to point to taste perceived. Offer patient a sip of water, and repeat with different solution and applicator, testing each side of tongue with each solution.

EXPECTED:Able to identify sweet, salty, sour, bitter taste bilaterally when placed in appropriate tastebud region.

Sites for taste assessment.

Assess acoustic nerve (CN VIII)

image Hearing

See screening tests in Chapter 8, Ears, Nose, and Throat, or use an audiometer to test hearing.

EXPECTED:Adequate hearing bilaterally.

image Balance

See Romberg test, p. 251.

Assess glossopharyngeal nerve (CN IX)

image Taste



image Gag reflex (nasopharyngeal sensation)

See CN X.

Assess vagus nerve (CN X)

image Motor function

Ask patient to say “ah” while observing movement of palate and uvula.

EXPECTED:Soft palate rises with uvula in midline.
UNEXPECTED:Failure of soft palate to rise or uvula deviates from midline.

image Gag reflex (nasopharyngeal sensation) (CN IX and CN X)

Tell patient you will be testing gag reflex. Touch posterior wall of pharynx with applicator while observing palate, pharyngeal muscles, and uvula.

EXPECTED:Upward movement of palate and contraction of pharyngeal muscles, with uvula in midline.
UNEXPECTED:Drooping or absence of arch on either side of soft palate; uvula deviates from midline.

image Swallowing (CN IX and CN X)

Ask patient to swallow water.

EXPECTED:Water easily swallowed.
UNEXPECTED:Retrograde passage of water through nose.
imageSpeech UNEXPECTED:Hoarseness, nasal quality, or difficulty with guttural sounds.
Assess spinal accessory nerve (CN XI)
See Chapter 6, Head and Neck, and Chapter 17, Musculoskeletal System, for evaluations of size, shape, strength of trapezius and sternocleidomastoid muscles. EXPECTED:Symmetric size, shape, and strength.
Assess hypoglossal nerve (CN XII)

image Tongue resting and protruded

Inspect while at rest on floor of mouth and while protruded.

EXPECTED:Tongue midline, symmetric size.
UNEXPECTED:Fasciculations, asymmetry, atrophy, or deviation from midline.

Assessing motor function of cranial nerve XII.


image Tongue movement

Ask patient to move tongue in and out, side to side, curled up toward nose, curled down toward chin.

EXPECTED:Able to perform most tongue movements.

image Tongue strength

Ask patient to push tongue against cheek while you apply resistance with index finger.

EXPECTED:Steady, firm pressure.
imageSpeech UNEXPECTED:Problems with l, t, d, or n (lingual sounds).
Evaluate coordination and fine motor skills
Have patient sit.

image Rapid, rhythmic, alternating movements

Ask patient to pat knees with both hands, alternately patting with palmar and dorsal surfaces of the hands. Alternatively, ask the patient to touch the thumb to each finger of the same hand sequentially from index finger to little finger and back, one hand at a time.

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Mar 25, 2017 | Posted by in PHYSIOLOGY | Comments Off on Neurologic System

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