Cranial Nerve Lesions

Question 1

Lesions of which cranial nerves results in a non-functioning eye?

Answer 1

3, 4 and 6

Question 2

What does a lesion of CN3 (oculomotor) cause?

Answer 2

Ptosis
Down and out eye
Fixed dilated pupil (Edinger Westphal nuclei dysfunction)

Question 3

What does a lesion of CN 4 (trochlear) cause?

Answer 3

Diplopia (double vision) looking down

Question 4

What is a cause of CN4 lesion?

Answer 4

Trauma

Question 5

What does a lesion of CN6 cause?

Answer 5

Adducted eye, sign of raised ICP

Question 6

What does a lesion of CN 5 (trigeminal) cause?

Answer 6

Jaw deviates towards the affected side
Loss of corneal reflex
Trigeminal neuralgia

Question 7

What is the corneal reflex?

Answer 7

Involuntary blinking by touching the cornea with a sterile cotton applicator

Question 8

What does a lesion of CN 7 cause?

Answer 8

Facial droop with no forehead sparing

Question 9

What can cause a lesion of CN 7?

Answer 9

Bell’s palsy (virus causes nerve inflammation)
Parotid inflammation (salivary gland)

Question 10

What does a lesion of CN 8 cause?

Answer 10

Hearing loss
Loss of balance

Question 11

What can cause a lesion of CN 8?

Answer 11

Changes to skull eg Paget’s disease
Compression
Middle ear disease

Question 12

What does a lesion of CN 9 and 10 cause?

Answer 12

Impaired gag reflex
Issues with swallowing, respiring and voice

Question 13

What can cause a lesion CN 9 and 10?

Answer 13

Jugular foramen lesion

Question 14

What does a lesion of CN 11 cause?

Answer 14

Can’t shrug shoulders
Can’t turn head against resistance

Question 15

What does a lesion of CN 12 cause?

Answer 15

Tongue deviation towards side of lesion

Question 16

What are 3 causes of brainstem pathology (CN 3-12)?

Answer 16

Trauma
MS
Tumours