Cranial Nerves (Deficits)

Question 1

What happens if CN 1 is damaged?

Answer 1

Unilateral anosmia

Question 2

What happens if CN 2 is damaged?

Answer 2

Macular blindess and Marcus Gunn pupil

Question 3

What happens if CN 3 is damaged?

Answer 3

Ptosis, dilated pupil, eye deviated down and out

Question 4

What happens if CN 4 is damaged?

Answer 4

Vertical diplopia; can’t move eye down and in

Question 5

What happens if CN 5 is damaged?

Answer 5

Facial numbness, loss of corneal blink, and weakness of muscles of mastication

Question 6

What happens if CN 6 is damaged?

Answer 6

Horizontal diplopia, eye deviated inward

Question 7

What happens if CN 7 is damaged?

Answer 7

Facial weakness, eye closure weakness, hyperacusis, and loss of taste to anterior 2/3 of tongue

Question 8

What happens if CN 8 is damaged?

Answer 8

Vestibular: Imbalance, vertigo, nystagmus

Cochlear: Hearing loss, tinnitus

Question 9

What happens if CN9 is damaged?

Answer 9

Dysphagia, loss of gag reflex

Question 10

What happens if CN 10 is damaged?

Answer 10

Dysphagia and dystonia (due to vocal cord paralysis)

Question 11

What happens if CN 11 is damaged?

Answer 11

Weakness of shoulder elevation and head rotation

Question 12

What happens if CN 12 is damaged?

Answer 12

Dysarthria; weakness and atrophy of half of the tongue, tongue deviates toward weak side