Neuro-ophthalmology - Conditions

Question 1

What are the common signs of optic nerve dysfunction?

Answer 1

Decrease in visual acuity
Dyschromatopsia - visual colour impairment
Visual field defects
Diminished contract sensitivity
Relative afferent pupillary defect (RAPD)

Question 2

What can cause optic neuritis?

Answer 2

Demyelinating diseases e.g. MS

Infections

Question 3

Clinical features of MS

Answer 3

Sensory loss - numbness
Spinal cord symptoms - muscle cramping & weakness
Autonomic features - bladder, bowel & sexual dysfunction
Cerebellar - tremor + dysartyhria + ataxia (Charcot’s triad)
L’hermitte sign - electrical shock on neck flexion
Uhthoff phenomenon - worsening of symptoms due to increase in temp e.g. hot shower
Optic neuritis - USUALLY IS THE PRESENTING COMPLAINT
Nystagmus

Question 4

Ix Optic neuritis and what you will see if you do the investigations in an affected pt

Answer 4

MRI - demyelinating plaques

Lumbar puncture - Oligoclonal bands

Question 5

Tx Optic neuritis

Answer 5

IV methylprednisolone + Oral prednisolone

Question 6

Aetiology of Anterior Ischaemic Optic Neuropathy (AION)

Answer 6

Damage to the optic nerve as a result of ischaemia

Question 7

Cause of NON-arteritic AION

Answer 7

Occlusion of short posterior ciliary artery due to:
Hypertension
Diabetes 
Sleep apnoea
Optic disc anomaly

Question 8

Cause of arteritic AION

Answer 8

Giant cell arteritis - this occludes the short posterior ciliary artery

Question 9

What is the difference in vision loss between arteritic and non-arteritic AION ?

Answer 9

Arteritic = painful
Non-arteritic = painless

Question 10

What happens to the optic disc in arteritic/non-arteritic AION?

Answer 10

Arteritic - Chalky-white diffuse swollen disc

Non-arteritic - disc swelling

Question 11

Ix of arteritic AION

Answer 11

ESR, CRP, temporal artery biopsy

Question 12

Tx of arteritic/non-arteritic AION

Answer 12

Arteritic - high dose systemic steroid IV methylprednisolone or oral prednisolone + aspirin

Non-arteritic - treat cause

Question 13

Aetiology of papilloedema

Answer 13

Optic disc swelling secondary to elevated intracranial pressure

Question 14

Clinical features of papilloedema

Answer 14

Elevated ICP symptoms - headache, N&V
Transient visual loss
Enlarged blind spot
Optic disc signs - hyperaemia and blurred margins of optic disc (early)
Swelling and elevation of the whole optic disc with peripaillary splinter haemorrhages (late)

Question 15

Aetiology of Horner’s syndrome

Answer 15

lesion in the sympathetic pathway

Question 16

3 classic symptoms of Horner’s syndrome

Answer 16

Ptosis
Miosis
Ipsilateral anhidrosis

Question 17

Causes of Horner’s syndrome

Answer 17

Stroke
Pancoast tumour
Carotid artery dissection
Cluster headache

Question 18

Ix Horner’s syndrome

Answer 18

Give apraclonidine - a receptor-1 agonist causing little pupillary dilation in horner’s pupil but will significantly dilate the unaffected eye

CT/MRI used to confirm any tumours or artery dissection

Question 19

What is Adie’s Pupil?

Answer 19

Loss of postganglionic parasympathetic innervation to the iris sphincter and ciliary muscle
Unilateral
Occurring in young females

Question 20

Clinical features of Adie’s pupil

Answer 20

Anisocoria (affected pupil is larger)
Blurring on near vision
Light reflex absent & Near reflex is slow

Question 21

Ix Adie’s pupil

Answer 21

Slit lamp

0.125% topical pilocarpine in both eyes - adie’s pupil constricts while normal pupil doesn’t

Question 22

What is Argyll Robertson pupil?

Answer 22

Bilateral irregular small pupils

Both pupils don’t react to light - they do constrict normally on accomadation

Question 23

Pilocarpine does cause constriction of pupils. T/F?

Answer 23

F. It does NOT. (opposite of adie’s)

Question 24

Clinical feature of 3rd nerve palsy

Answer 24

Ptosis
Down and out eye
Ophthalmoplegia (only abduction of eye is fully normal)
Dilated pupil and accommodation abnormality

Question 25

What medical issues could cause 3rd nerve palsy?

Answer 25

Diabetes and Hypertension

Question 26

Clinical features of 4th nerve palsy?

Answer 26

Vertical diplopia - worse walking downstairs or looking down Hypertropia Depression of eye limited Head tilt

Question 27

Clinical features of 6th nerve palsy?

Answer 27

Horizontal double vision - worse on looking at distant targets Esotropia in primary position Abduction is limited

Question 28

Cause of 6th nerve palsy

Answer 28

Diabetes Hypertension Increased ICP

Question 29

What is myasthenia gravis

Answer 29

Autoimmune disease of acetylecholine receptors at post-synaptic neuromuscular junctions F>M Affects voluntary muscles Occular problems are usually the presenting complaint

Question 30

Clinical features of myasthenia gravis

Answer 30

Ptosis - bilateral Lid twitch Diplopia Weakness of muscles of facial expression

Question 31

Ix Myasthenia

Answer 31

Ice test - ptosis improves after 2 mins Antibodies - Anti-ACh receptor antibody and anti-muscle specific kinase (MUSK) antibody Electromyography and muscle biopsy Imaging of thorax - can reveal thymoma which is associated with myasthenia (tumour)

Question 32

Tx Myasthenia Gravis

Answer 32

Pyridostigmine (anticholinesterase), steroids & immunomodulators Surgery if thymoma present

Question 33

Is neurofibromatosis autosomal dominant or recessive?

Answer 33

Dom

Question 34

Clinical features of neurofibromatosis?

Answer 34

Neurofibromas Café au lait spots Axillary freckling Ophthalmic features: - Optic nerve glioma - Bilateral lisch nodules (harmless, don't affect vision) - Plexiform neurofibromas of the eyelid - 'bag of worm' sensation

Question 35

NF 2 is more common than NF 1? T/F

Answer 35

F. NF1 is more common

Question 36

What is in the cavernous sinus and at what location within the sinus?

Answer 36

Lateral wall contains CN 3,4,5 (V1 ,V2) | Internal carotid artery & CN6 pass THROUGH the cavernous sinus

Question 37

Clinical features and the reasoning behind them

Answer 37

Ptosis & ophthalmoplegia (paralysis of the muscles within or surrounding the eye) - due to compression of CN 3,4,6 Loss of corneal reflex - due to V1 Maxillary sensory loss - due to V2 Horner's syndrome - due to involvement of internal carotid ocular sympathetics Proptosis & periorbital swelling - due to increased venous pressure in the veins draining the orbit

Question 38

Causes of cavernous sinus syndrome?

Answer 38

``` Infections Tumours Cavernous sinus thrombosis Internal carotid aneurysm Carotid-cavernous fistula ```