Cranial Nerves And Testing

Question 1

CNI — Olfactory

Answer 1

• Sense of smell

- Identify familiar odors

Question 2

CNII — Optic

Answer 2

• Eye sight
• Test visual fields
• Snellen chart

Question 3

CN III — Oculomotor

Answer 3

• Levator of eyelid
• Superior, medial, and inferior recti
• Inferior oblique muscle of eyeball
• Smooth muscle of eyeball
• Test: Pursuits; upward, downward, medial gaze
• Test: Reaction to light; pupil constriction

Question 4

CNIV — Trochlear

Answer 4

• Superior oblique muscle of eyeball
• Test: Downward and inward gaze
• Test: Visual fields in lower quadrant

Question 5

CNV — Trigeminal

Answer 5

• Skin of face
• Mucous membrane of nose
• Sinuses
• Mouth
• Anterior tongue
• Test: Clench teeth
• Test: Face sensation
• Test: Corneal reflex
• Test: Perform mandibular protrusion, retrusion, and lateral deviation

Question 6

CNVI — Abducens

Answer 6

• Lateral rectus muscle of eyeball

- Test: Lateral gaze

Question 7

CNVII — Facial

Answer 7

• Facial expression
• Anterior taste of tongue
• Lacrimal, submandibular, and sublingual glands (tears and salivation)
• Test: Puff out cheeks, whistle, close eyes tight, smile showing teeth
• Test: Identify familiar tastes (sweet, sour, salty)

Question 8

CNVIII — Vestibulocochlear

Answer 8

• Hearing and balance
• Test: Hear watch ticking
• Test: Balance and coordination tests

Question 9

CNIX — Glossopharyngeal

Answer 9

• Touch, pain, and taste of posterior tongue
• Touch and pain of pharynx
• Pharynx muscles
• Parotid gland
• Test: Gag reflex
• Test: Ability to swallow
• Test: Taste on posterior portion of tongue

Question 10

CN X — Vagus

Answer 10

• Touch and pain of pharynx, larynx, bronchi
• Taste of tongue and epiglottis
• Muscles of palate, pharynx, larynx
• Thoracic and abdominal viscera
• Test: Gag reflex
• Test: Ability to swallow
• Test: Say “Ahh”

Question 11

CN XI — Accessory

Answer 11

• SCM and traps

- Test: Resisted Shoulder shrug

Question 12

CN XII — Hypoglossal

Answer 12

• Muscles of tongue

- Test: Tongue protrusion (will deviate to injured side)

Question 13

A positive test while testing the trochlear nerve is. Indicated by inability to depress the eyes or …

Answer 13

Complaints of diplopia

Question 14

While testing CN VIII — Vestibulocochlear, a positive test is indicated by an inability to hear the ticking sound of a watch what distance away?

Answer 14

18-24 inches away OR significant bilateral difference

Question 15

Alternatively, CN VIII — Vestibulocochlear can be tested using…

Answer 15

Weber and Rinne, which require a 512 Hz tuning fork