OSCE: Neurologic Exam

Question 1

How would you test for CN I (Olfactory Nerve)?

Answer 1

• Use familiar and non-irritating odors
• Have patient compress one nostril and sniff through the other
• A person normally perceives odor on each side and can often identify them

Question 2

When can loss of smell happen?

Answer 2

• Sinus conditions
• Head trauma
• Smoking
• Aging
• Use of cocaine
• Parkinson’s disease

Question 3

How would you test for CN II (Optic Nerve)?

Answer 3

• Visual acuity: Snellen eye chart
• Visual fields by confrontation: Wiggling fingers at edge of field asking patient if they see it
• Light Reaction: Shining light into eye checking for direct reaction and consensual reaction in other eye

Question 4

How would you test for CN III, IV, and IV (Oculomotor, Trochlear, and Abducens Nerves)?

Answer 4

• Near Reaction: Patient shift gaze from far object to near one, pupils constrict.
  
  • Tests CN III and acommodation
  • • Cardinal Signs of Gaze: Make the H about 12-18 inches in front of patient’s face
  • 6 eye movement testing CN III, IV, VI
• Check for nystagmus (direction of the quick component)

Question 5

How would you test for CN V (Trigeminal Nerve)?

Answer 5

Motor

• Palpate the temporal and masseter muscles and ask patient to clench their teeth.
• Ask patient to move jaw side to side testing lateral pterygoids.

Sensory

• Test forehead, cheeks, jaw on each side for pain sensation. Patient eyes should be closed.
  
  • Use a broken long-tipped cotton swab occasionally substituting blunt end for point as stimulus.
  • Ask patient if it is sharp or dull & be sure to compare sides.
• If abnormality found, confirm by temperature sensation. Touch skin w/ either hot or cold stimuli and ask patient to report which they feel.

Corneal Reflex

• Use a clean cotton swab to touch the cornea lateral to the iris, blinking of both eyes is the normal reaction to the stimulus.

Question 6

What can corneal reflex tell about cranial nerves?

Answer 6

• CN V lesion: blinking absent in both eyes
• CN VII lesion: blinking is abesent on side of weakness

Question 7

How would you test for CN VII (Facial Nerve)?

Answer 7

Motor

• Raise both eyebrows, frown, close both eyes tight so that you cannot open them
• Test muscular strength by trying to open them, show both upper & lower teeth, smile, puff out both cheeks

Taste

• Anterior ⅔ tongue

Question 8

What is the difference between Bell’s palsy and a central lesion?

Answer 8

• Bell’s Palsy: affects both upper & lower face, loss of taste, and hyperacusis
• Central Lesion: affects mainly lower face

Question 9

How would you test for CN VIII (Vestibulocochlear Nerve)?

Answer 9

• Whisper Test: Check for hearing loss
  
  • ​Stand 2 feet behind patient.
  • Instruct patient to occlude ear not being tested.
  • Exhale a full breath before whispering to ensure a quiet voice.
  • Whisper a combination of three numbers and letters, such as 3-U-1.
  • Use a different combination for the other ear.
  • Abnormal Test: 4/6 numbers or letters are incorrect
• ​Weber and Rinne Test

Question 10

How would you test for CN IX (Glossopharyngeal Nerve)?

Answer 10

• Test gag reflex and motor function with CN X
• Test tasting with CN VII

Question 11

How would you test for CN X (Vagus Nerve)?

Answer 11

• Inspect soft palate & uvula for symmetry
  
  • Fails to rise (bilateral lesion)
  • Deviate to normal side (unliateral lesion)
• Observe for difficulties w/ swallowing
• Test for gag reflex
  
  • If absenct, lesion in CN IX or X (rarely done in office setting)
  • Evaluate for presence of nasal tone & hoarseness of voice (may be presenting sx)

Question 12

How would you test for CN XI (Spinal Accessory Nerve)?

Answer 12

• Look from behind for fasiculations & compare side to side.
• Check for trapezius muscle strength by shrugging shoulders against resistance
  
  • In paralysis, the shoulder droops, & scapula is displaced downward & laterally
• Check SCM muscle strength by turning head to each side against resistance
  
  • Contraction of L SCM turns head to R

Question 13

How would you test for CN XII (Hypoglossal Nerve)?

Answer 13

• Inspect tongue for symmetry, tremors, & atrophy
• Check tongue movement towards nose & chin
• Check tongue strength when pressed against cheek
• Evaluate quality of lingual sounds
• CN XII lesion results in tongue deviation to the weak side

Question 14

How would you test cerebellar function?

Answer 14

• Rapid Alternating Movements
• Finger-to-nose, finger-finger
• Heel-shin

Question 15

Rapid Alternating Movements

Answer 15

• Arms: Strike one hand on thigh, raise hand, turn it over and then strike the back of hand down on same place.
• Urge patient to repeat these movement rapidly. Observe speed, rhythm, smoothness. Repeat w/ other hand. Non-dominate hand often slower.
• Tap the distal joint of thumb w/ tip of index finger as rapidly as possible. Observe same things & non dominate less well again.
• Legs: Tap doc hand as quick as possible w/ ball of each foot in turn. Note any slowness or awkwardness. Feet normally perform less well than hands.

Question 16

Finger-to-nose, Finger-Finger

Answer 16

• Have patient touch doctor’s index finger and then their nose alternating several times.
  
  • Doctor’s finger moves about about so patient has to alter directions and extend arm fully to reach it.
  • Observe accuracy & smoothness of movement & watch for any tremor.
• Now hold finger in one place so patient can touch it with one arm and finger outstretched.
  
  • Ask patient to raise arm overhead & lower it again to touch finger.
  • After several times, ask patient to close eyes & try again.
  • Repeat on other side.

Question 17

Heel to Shin

Answer 17

• Ask patient to place one heel on the opposite knee, & then run it down the shin to big toe.
• Note smoothness & accuracy of movement.
• Repetition w/ pt eye closed tests for position sense.
• Repeat w/ other side.

Question 18

Casual Gait

How do you test for this?

What does a positive test indicate?

Answer 18

Test:

1. Walk across room or hall and back.
2. Doctor observes posture, balance, stance, etc.

Positive Test: Lack of coordination indicates ataxia or cerebellar disease.

Question 19

Tandem Gait

How do you test for this?

What does a positive test indicate?

Answer 19

Test:

1. Walk heel to to toe in a straight line.

Positive Test: Lack of coordination indicates subtle ataxia.

Question 20

Romberg Test

How do you perform this test?

What does this test indicate?

Answer 20

• Patient stands with feet together and eyes open.
• Close both eyes for 30-60 seconds.
  
  • Normal is minimal swaying.

Positive Test:

• Loses balance with eyes open: cerebellar ataxia.
• If patient loses balance with eyes closed: positive Romberg sign.

Question 21

Test for Pronator Drift

How do you perform this test?

What does it indicate?

Answer 21

• Patient closes eyes for 20-30 seconds with both arms held forward, palm up.
• Tap the arms briskly downward. The arms normally return to the horizontal position, requiring muscle strength, coordination and good position strength.

Positive Test:

• One forearm turns inward and down: pronator drift and is specific for corticospinal tract lesion.