visual loss

Question 1

what are the signs of optic neuritis?

Answer 1

decreased acuity with scotoma, painful eye movement, worse when hot (uhthoff’s), pupillary afferent defect and colour blindness

Question 2

What are the causes of optic neuritis?

Answer 2

MS, GBS, arteritis, autoimmune problems, B12 deficiency, diabetes, infection and sarcoidosis

Question 3

What in the pahtophysiology of optic neuritis

Answer 3

inflammation of CN 2

Question 4

Differentials for unilateral visual loss?

Answer 4

• Vascular—> amaurosis fugax, retinal vein occlusion, GCA, anterior ischaemic optic neuropathy
• retinal detachment
• glaucoma

Question 5

How do we diagnose MS

Answer 5

McDonald criteria
Two or more attacks; disseminated in space AND time

space can be represented by T2 lesion on MRI in 2/4 CNS regions (periventricular, juxtacortical, infratentorial, spinal cord), CSF monoclonal bands or attack on different cns site

time represented by another attack - cliically reported or seen on MRI

Question 6

How can MS present?

Answer 6

optic neuritis, pyramidal weakness, sensory disturbance, cerebellar symptoms. GU dysfunction, electric shocks down the spine (Lhermitte’s), Uhthoff’s, fatigue and cognitive impairment, trigemina neuralgia

Question 7

How do we manage MS?

Answer 7

methylprednisolone, (acute attacks) beta-interferon if 2+ relapses a year, baclofen for spasticity and oxybutynin for urge incontinence, catheter

Question 8

What are the different types of MS?

Answer 8

relapsing-remitting: short duration (days/months), may be symptom free for a hwile (months or years)
Secondary progressive: relapsing remitting stops remitting to the previous state the patient was in
Primary progressive: steady increase in disability without attacks
Progressive relapsing: gets worse with flare ups present

Question 9

Investigations for MS?

Answer 9

MRI brain and spine for white matter lesions in the periventricular region
LP for oligoclonal bands
blds for differentials- FBC, TSH, metabolites, B12

Question 10

4 most common presentations of MS?

Answer 10

Optic neuritis

Transverse myelitis — focal inflammation within the spinal cord.
This manifests as sensory symptoms such as paraesthesia, or motor symptoms such as weakness, below the level of the inflammation that typically develop over hours or days. Some people describe a tight band sensation around the trunk at the level of the inflammation, or a shock like sensation radiating down the spine induced by neck flexion (Lhermitte’s phenomena).
There may be urinary symptoms such as urgency, frequency, or retention.
Examination may reveal focal muscle weakness and reduced sensation below the affected spinal level. Muscle tone is initially reduced.
Symptoms and signs may be symmetrical or asymmetrical, and tend to reflect a partial myelitis that only affects a part of the spinal cord. Therefore, symptoms and signs similar to a full spinal cord transection are rare.

Cerebellar related symptoms
These can manifest with such symptoms and signs as ataxia, vertigo, clumsiness, and dysmetria (as demonstrated by abnormalities with finger-to-nose testing and walking heel to toe).

Brainstem syndromes — these may result in:
Ataxia.
Eye movement abnormalities that can cause diplopia, oscillopsia (a sensation of movement of the vision), nystagmus, and internuclear ophthalmoplegia (inability to adduct one eye and nystagmus in the abducting eye on oculomotor examination).
Bulbar muscle problems resulting in dysarthria or dysphagia.