Cranial Nerve Vivas

Question 1

Features of Horners syndrome

Answer 1

Miosis (small pupil)
Ptosis
Anhidrosis (loss of sweating one side)

Question 2

What is seen in congenital Horners?

Answer 2

Heterochromia: difference in iris colour

Question 3

What characterises Horners caused by central lesions? List 5 causes

Answer 3

Anhidrosis of FACE, ARM + TRUNK
Stroke
Syringomyelia
MS
Tumour
Encephalitis

Question 4

What characterises Horners caused by pre-ganglionic lesions? List 4 causes

Answer 4

Anhidrosis of FACE
Pancoast’s tumour
Thyroidectomy
Trauma
Cervical rib

Question 5

What characterises Horners caused by post-ganglionic lesions? List 4 causes

Answer 5

NO anhidrosis
Carotid artery dissection
Carotid aneurysm
Cavernous sinus thrombosis
Cluster headache

Question 6

Ix for Horners syndrome

Answer 6

CT head: ?CVA
CT angiography: ? Carotid artery dissection
CXR: ? Pancoast tumour

Question 7

Third nerve palsy

Answer 7

Eye deviated down + out
Ptosis

Question 8

Surgical third nerve palsy

Answer 8

Eye deviated down + out
Ptosis
Mydriasis

Question 9

Medical causes of third nerve palsy

Answer 9

DM
GCA
SLE
MS

Question 10

Surgical causes of third nerve palsy

Answer 10

Posterior communicating artery aneurysm
Cavernous sinus thrombosis
Tumour

Question 11

What causes mydriasis in surgical CNIII palsy?

Answer 11

Compression of external parasympathetic fibres

Question 12

What is strabismus?

Answer 12

misalignment of the visual axes, eyes do not properly align with each other when looking at an object

Question 13

Most common cause of CN IV palsy

Answer 13

Trauma

Question 14

UMN facial nerve palsy

Answer 14

Stroke

Question 15

LMN facial nerve palsy

Answer 15

Bells palsy

Question 16

What is Bells palsy?

Answer 16

Acute, unilateral, idiopathic, facial nerve paralysis
Peaks at 20-40y

Question 17

Other than unilateral facial paralysis, list 4 S/S of Bells palsy

Answer 17

Post-auricular pain (may precede paralysis)
Altered taste
Dry eyes
Hyperacusis

Question 18

Mx of Bells palsy

Answer 18

<72h: Prednisolone PO
Artificial tears
Eye lubricants
Microporous tape for sleep

Question 19

Describe follow up in Bells palsy

Answer 19

If no improvement after 3w, refer urgently to ENT
If long standing (months) weakness: refer to plastics

Question 20

2 causes of bilateral ptosis

Answer 20

Myasthenia gravis
Myotonic dystrophy

Question 21

Describe Argyll Robertson Pupils (ARP)

Answer 21

Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)

Small, irregular pupils
No response to light but there is a response to accommodate

Question 22

Name 2 causes of Argyll Robertson Pupils

Answer 22

DM
Syphilis

Question 23

What is Myasthenia Gravis?

Answer 23

AI disorder characterised by muscle fatiguability
Abs to ACh receptors

Question 24

S/S of myasthenia gravis

Answer 24

Extraocular muscle weakness: diplopia
Proximal muscle weakness: face, neck, limb girdle
Ptosis
Dysphagia

Question 25

3 associations to myasthenia gravis

Answer 25

Thymoma (CT thorax)
AI disorders: Thyroid, RhA, SLE
Thymic hyperplasia

Question 26

Ix for myasthenia gravis

Answer 26

SINGLE FIBRE EMG
CT thorax
CK normal
Abs to ACh receptors

Question 27

Mx of myasthenia gravis

Answer 27

Pyridostigmine
Later: Prednisolone/ Azathioprine/ MM
Thymectomy

Question 28

Mx of myasthenic crisis

Answer 28

Plasmapheresis
IVIG

Question 29

4 drugs that exacerbate myasthenia gravis

Answer 29

B-blockers
Lithium
Phenytoin
Abx: Gentamicin, Macrolides

Question 30

Tool to measure resp function in GBS and MG

Answer 30

FVC

Question 31

5 causes of sudden visual loss

Answer 31

CRAO
Retinal detachment
Vitreous haemorrhage
GCA
Optic neuritis

Question 32

4 causes of gradual visual loss

Answer 32

Diabetic retinopathy
Cataract
Glaucoma (open angle)
Dry age-related macular degeneration (AMD)