Cranial nerves

Question 1

Cranial Nerve I

Answer 1

The Olfactory nerve.

Question 2

How do you assess CN I?

Answer 2

Test sense of smell using familiar scents (e.g., coffee, vanilla) with each nostril separately.

Question 3

Cranial Nerve II

Answer 3

The Optic nerve.

Question 4

How do you assess CN II?

Answer 4

Visual acuity (Snellen chart)
Visual fields (confrontation test)
Inspect optic disc via fundoscopy

Question 5

Cranial Nerve III

Answer 5

The Oculomotor nerve.

Question 6

How do you assess CN III?

Answer 6

Check pupillary reaction to light (PERRLA)
Test extraocular movements (EOMs) for up, down, medial gaze
Check for ptosis

Question 7

Cranial Nerve IV

Answer 7

The Trochlear nerve.

Question 8

How do you assess CN IV?

Answer 8

Test EOMs: look down and inward (superior oblique muscle function)

Question 9

Cranial Nerve V

Answer 9

The Trigeminal nerve.

Question 10

How do you assess CN V?

Answer 10

Sensation to face (light touch to forehead, cheek, jaw)
Motor: palpate muscles of mastication (clench jaw)
Corneal reflex (blink)

Question 11

Cranial Nerve VI

Answer 11

The Abducens nerve.

Question 12

How do you assess CN VI?

Answer 12

Test EOM: lateral eye movement (lateral rectus muscle)

Question 13

Cranial Nerve VII

Answer 13

The Facial nerve.

Question 14

How do you assess CN VII?

Answer 14

Ask patient to: smile, frown, puff cheeks, raise eyebrows, close eyes tightly
Taste on anterior 2/3 of tongue (optional)

Question 15

Cranial Nerve VIII

Answer 15

The Vestibulocochlear nerve.

Question 16

How do you assess CN VIII?

Answer 16

Hearing (whisper test) Rinne and Weber tests (tuning fork)
Balance if needed (Romberg test)

Question 17

Cranial Nerve IX

Answer 17

The Glossopharyngeal nerve.

Question 18

How do you assess CN IX?

Answer 18

Gag reflex
Swallowing assessment
Taste on posterior 1/3 of tongue (rarely tested clinically)

Question 19

Cranial Nerve X

Answer 19

The Vagus nerve.

Question 20

How do you assess CN X?

Answer 20

Listen to voice for hoarseness
Ask patient to say “ah”: observe palate rise symmetrically
Check swallowing Gag reflex (with CN IX)

Question 21

Cranial Nerve XI

Answer 21

The Spinal Accessory nerve.

Question 22

How do you assess CN XI?

Answer 22

Ask patient to shrug shoulders against resistance (trapezius)
Turn head against resistance (sternocleidomastoid)

Question 23

Cranial Nerve XII

Answer 23

The Hypoglossal nerve.

Question 24

How do you assess CN XII?

Answer 24

Ask patient to stick out tongue — look for deviation
Ask them to move tongue side to side
Check speech articulation (“light, tight, dynamite”)