NEURO - Cranial Nerve Lesions

Question 1

CN V motor lesion

Answer 1

Jaw deviates *toward side of lesion due to unopposed force from the opposite pterygoid muscle.

Question 2

CN X lesion

Answer 2

Uvula deviates *away from side of lesion.

Weak side collapses and uvula points *away.

Question 3

CN XI lesion

Answer 3

Weakness turning head to contralateral side of lesion (SCM).
Shoulder droop on side of lesion (trapezius).

The left SCM contracts to help turn the head to the right.

Question 4

CN XII lesion

Answer 4

LMN lesion.

Tongue deviates *toward side of lesion (“lick your wounds”) due to weakened tongue
muscles on affected side.

Question 5

CN VI

Answer 5

innervates the Lateral Rectus

Medially directed eye that cannot abduct

Question 6

CN IV

Answer 6

innervates the Superior Oblique

Eye moves upward, particularly with contralateral gaze and head tilt *toward the side of the lesion

Question 7

CN III

Answer 7

innervates the All Others
(Superior Rectus, Medial rectus, Inferior rectus, Inferior Oblique)

Eye looks down and out, ptosis, pupillary dilation, *Loss of accommodation