1j Motor 1&2 Motor Cortex 4

Question 1

What type of input on from Corticonuclear Fibers project to CN V motor nuclei?

Answer 1

Bilateral influence (so unilateral loss is minor)

Question 2

What happens with a lesion of Corticonuclear Fiber input to CN V motor nuclei?

Answer 2

minor loss because there is bilateral influence, may see exaggeration of Jaw Jerk Reflex

Question 3

What happens with a lesion of CN V Motor nuclei or nerve?

Answer 3

atrophy of IPSILATERAL muscles of mastication & jaw DEVIATION upon opening to IPSILATERAL side

Question 4

What type of corticonuclear input goes to CN VII motor nuclei?

Answer 4

bilateral input to upper face, ONLY CONTRALATERAL to lower face

Question 5

What are the patients capabilities of facial movement upon lesion of corticonuclear input of one side to CN VII motor nucleus?

Answer 5

patient can still move forehead (bilateral input to upper face), but lower facial muscles of CONTRALATERAL side do not respond

Question 6

How does Bell’s Palsy (lesion of facial n.) present?

Answer 6

LMN damage - paralysis of both upper and lower face muscles, etc.

Question 7

What is the origin of the corticonuclear cells giving input to CN XII N. relative to the Hypoglossal Nucleus receiving input?

Answer 7

CONTRALATERAL side

Question 8

How does a corticonuclear to Hypoglossal Nucleus lesion vs Hypoglossal N. lesion compare?

Answer 8

deviate to side of weakness; corticonuclear lesion would be contralateral weakness and nerve lesion would be ipsilateral to weakness

Question 9

What is the motor function of the Nucleus Ambiguus?

Answer 9

soft palate, pharynx, larynx (uvula)

Question 10

What UMN input from corticonuclear neurons goes to Nucleus Ambiguus?

Answer 10

bilateral input

Question 11

How does a presentation of lesion of corticonuclear neuron to Nucleus Ambiguus differ from lesion of Nucleus Ambiguus?

Answer 11

uvula will deviate AWAY from side of WEAKNESS. cortonuclear input is bilateral, but contralateral weakness can be seen, so uvula will deviate toward side of UMN lesion. nucleus ambiguus lesion is ipsilateral to weakness, so uvula will deviate away from lesion.

Question 12

What side of the body shows weakness relative to corticonuclear lesion to CN XI nucleus?

Answer 12

Ipsilateral corticonuclear input to Spinal Accessory

Question 13

What can’t a patient with a corticonuclear lesion to CN XI do?

Answer 13

cannot shrug shoulder of ipsilateral side (trapezius) or turn head away from side of lesion (sternocleidomastoid)

Question 14

Which Cranial Nerve Motor Neurons show contralateral deficits when their UMN is lesioned?

Answer 14

VII (lower face) & XII