Neuroscience Week 3: Common Cranial and Facial nerve Lesions

Question 1

CN V AKA

Answer 1

Trigeminal Nerve

Question 2

CN V motor lesion

Answer 2

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

Question 3

CN X AKA

Answer 3

Vagus Nerve

Question 4

CN X Lesion

Answer 4

Uvula deviates away from side of lesion

Weakside collapses and uvula points away

A lesion in the vagus nerve (CNX) causes the uvulA to deviate Away from the side of the lesion (uvula to the right, lesion on left side of brain).

Question 5

CN XI AKA

Answer 5

Spinal Accessory Nerve

Question 6

CN XI Lesion

Answer 6

Weakness turning the head to contralateral side of lesion (SCM)

Shoulder droop on side of lesion (trapezius)

The left SCM contracts to help turn the head right

Question 7

CN XII AKA

Answer 7

Hypoglossal Nerve

Question 8

CN XII Lesion

Answer 8

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

Question 9

The most common cause of peripheral facial palsy

Answer 9

Bell Palsy

Question 10

Bell Palsy Etiology

Answer 10

Usually develops after HSV reactivation

Question 11

Bell Palsy Treatment

Answer 11

Corticosteroids +/- acyclovir

Question 12

Bell Palsy Prognosis

Answer 12

Most patients gradually recover function, but aberrant regeneration can occur

Question 13

Causes of peripheral facial palsy

6 listed

Answer 13

• Bell Palsy (most common)
• Lyme Disease
• Herpes Zoster (Ramsay-Hunt Syndrome)
• Sarcoidosis
• Tumors (e.g. parotid gland)
• Diabetes Mellitus

Question 14

UMN Lesion location in peripheral facial palsy

Answer 14

Motor cortex

or

connection from motor cortex to facial nucleus in pons

Question 15

UMN Lesion peripheral facial palsy Affected side

Answer 15

Contralateral

Question 16

UMN Lesion in peripheral facial palsy Muscles involved

Answer 16

Lower muscles of facial expression

Question 17

UMN Lesion in peripheral facial palsy Forehead involved

Answer 17

Spared due to bilateral UMN innervation

Question 18

UMN Lesion in peripheral facial palsy Other symptoms

Answer 18

None

Question 19

LMN Lesion in peripheral facial palsy Lesion Location

Answer 19

Facial nucleus

or

anywhere along CN VII

Question 20

LMN Lesion in peripheral facial palsy Affected Side

Answer 20

Ipsilateral

Question 21

LMN Lesion in peripheral facial palsy Muscles involved

Answer 21

Upper and lower muscles of facial expression

Question 22

LMN Lesion in peripheral facial palsy Forehead involved

Answer 22

Affected

Question 23

LMN Lesion in peripheral facial palsy Other Symptoms

Answer 23

• Incomplete eye closure (dry eyes, corneal ulceration)
• hyperacusis
• loss of taste sensation to anterior tongue

Question 24

Facial palsy UMN vs LMN diagram

Answer 24