Unilateral vision loss

Question 1

What nucleus connects the optic tracts to the optic radiations?

• Where is it found?
• What other nucleus is involved in the auditory pathway?

Answer 1

Lateral geniculate nucleus, found in the thalamus

Medial geniculate nucleus - auditory

Question 2

Ptosis:

a) Congenital causes
b) Acquired causes

Answer 2

a) Myotonic dystrophy, Chronic progressive external
ophthalmoplegia, Myasthenia, Kearns-Sayre syndrome

b) Horner’s, Bell’s, CN III palsy, CVA, Thyroid eye disease, MS

Question 3

RAPD

Answer 3

RAPD is diagnosed by observing paradoxical dilatation when light is directly shone in the affected pupil after being shown in the healthy pupil (due to reduced intensity of signal relayed from diseased optic nerve that is interpreted as reduced light - hence, mydriasis)

Question 4

NMO antibodies

Answer 4

Anti-AQP-4 or NMO-IgG

Question 5

Diagnosis of MS

a) Clinical
b) Imaging
c) Other

Answer 5

a) Dissemination in time and space
(2 discrete episodes consistent with demyelination)

b) MRI scan - White matter lesions in:
- Corpus callosum
- Periventricular areas

c) - Exclude differentials - neuropathy screen, anti-NMO antibodies, etc.
- LP - oligoclonal bands (only if not present in serum) and elevated protein
- NCS - eg. visually-evoked potentials

Question 6

Internuclear ophthalmoplegia

a) Features
b) Cause

Answer 6

a) - Ipsilateral eye - failed ADDuction
- Contralateral eye - nystagmus

b) Due to disease of the MLF, commonly in MS

Question 7

Management of MS.

Answer 7

Patient education and self-management.

• Disease course (relapsing-remitting, secondary-progressive, etc.)
• DVLA notification
• Awareness that infections and vaccinations may trigger relapse

MDT management.

• PT/OT
• SALT
• Neurologist
• Psychological

Symptomatic.

• Spasticity - baclofen, cannabis extract spray
• Urge incontinence/OAB - oxybutynin
• Pain - analgesia, neuropathic drugs
• Depression - SSRI
• Erectile dysfunction - sildenafil

Acute flare-up.

• Oral pred/ IV methylpred for relapses
• Should be given within 24 hours of onset
• Reduce duration of relapse

Disease-modifying therapy.

• SC/IM beta-interferon (women should not conceive for 12 months after stopping therapy)
• SC Glatiramer
• Oral dimethyl fumarate
• Teriflunamide
• Alemtuzumab