Cranial Nerve Assessment

Question 1

Olfactory assessment (CN I)

Answer 1

Function: Identify odor
Assessment: have patient’s close eyes, ask patient to smell one nostril at a time, and choose 2-3 familiar but distinct smelling items

Question 2

Optic assessment (CN II)

Answer 2

Function: contralateral pupil constriction in light
Assessment: ask patient to read the lines on a snellen eye chart or look for contralateral pupil constriction

Question 3

Oculomotor assessment (CN III)

Answer 3

assess ability to elevate both eyelids, ability of eyes to follow a moving target, or use penlight and look for normal ipsilateral pupil constriction

Question 4

Trochlear assessment (CN IV)

Answer 4

eyes converge on object moving towards nose

Question 5

Abducens assessment (CN VI)

Answer 5

eye will have a lateral deviation and assess during the H test

Question 6

Trigeminal assessment (CN V)

Answer 6

test sensation of the skin of the face with the patient’s eyes closed and tell patient to tense their jaw

Question 7

Facial assessment (CN VII)

Answer 7

smile, frown, elevate/depress eyebrows, and puff out cheeks

Question 8

Vestibulocochlear assessment (CN VIII)

Answer 8

with patient’s eyes closed rub the pads of your fingers together and ask for them to indicate when they hear it and separately ask patient to stand unsupported with eyes closed up to 30 seconds

Question 9

Glossopharyngeal assessment (CN IX) and Vagus assessment (CN X)

Answer 9

ask patient to say “ahh” to look for uvula deviation, ask patient to swallow and explain if they have any difficulty, and move tongue depressor towards back of throat to elicit the gag reflex

Question 10

Spinal accessory assessment (CN XI)

Answer 10

shrug shoulders

Question 11

Hypoglossal assessment (CN XII)

Answer 11

ask patient to stick out tongue and observe to any side-to-side deviation

Question 12

When is it a priority to test the cranial nerves

Answer 12

• known or suspected injury to brain, brain stem, or upper cervical spine
• progressive disease affecting the brain or brain stem
• sudden or unexplained change in function
• side to side differences in facial expression
• atrophy in muscles of face or lateral neck

Question 13

When is it pointless to test the cranial nerves

Answer 13

• no observed or reported signs or symptoms

Question 14

What are the hallmark signs of an upper motor neuron lesion

Answer 14

• hyperreflexia
• spasticity
• clonus
• positive babinski
• positive pronator drift

Question 15

What are the hallmark signs of a lower motor neuron lesion

Answer 15

• dermatomes
• myotomes
• hyporeflexia

Question 16

Explain pronator drift test

Answer 16

• hold hands face up for 20-30 secs and if their hands start to pronate then it is a positive sign for an upper motor neuron lesion
• is a result of a deficit within the corticospinal tract

Question 17

Explain babinski test

Answer 17

• firmly stroke the sole of the foot
  Positive test: toes fan out
  Normal test: toes curl inward

Question 18

Explain Hoffman test

Answer 18

• loosely hold the middle finger and flick the fingernail downward
  Positive test: flexion and addiction of the thumb on the same hand

Question 19

When is it a priority to test upper motor neurons

Answer 19

• suspected CNS lesion
• determine extent and severity of known CNS lesion
• determine presentation of CNS condition

Question 20

When is it pointless to test upper motor neurons

Answer 20

• no indication of CNS involvement