Neuro-ophthalmology

Question 1

What happens if an eye is covered in diplopia?

Answer 1

In binocular diplopia - disappears with one eye covered

In monocular diplopia - persists

Question 2

Are the images the same in diplopia?

Answer 2

In binocular diplopia - both images are similar

In monocular diplopia - one is a ‘ghost’

Question 3

What are the features of raised ICP?

Answer 3

Generalised headache
Worse lying supine
N+V
Diplopia, visual obscurations
Precipitated / ophthalmic symptoms exacerbated by valsalva manoeuvres (coughing / straining), bending forwards

Question 4

What are the features of temporal arteritis?

Answer 4

Often diffuse headache
Scalp tenderness
Jaw claudication
Maybe systemically unwell
Transient or persistent diplopia
Bilateral visual loss (often transient initially)

Question 5

How do colours appear in optic nerve disease?

Answer 5

Reds appear washed out

Question 6

Which nerves are involved in the parasympathetic pupillary light reflex?

Answer 6

Afferent pathway = optic nerve to brain

Efferent pathway = brain to oculomotor nerve

Question 7

What is anisocoria?

Answer 7

Difference in right and left pupil size

Question 8

What is the Argyll-Robertson pupil?

Answer 8

Bilateral small pupils - brisk response to accommodation, no response to direct light

Question 9

What is Adie’s syndrome?

Answer 9

Dilated pupil with slow response to accommodation, but even slower to direct light

Question 10

What does RAPD test for?

Answer 10

Unilateral or asymmetric optic nerve disease

Question 11

What are the signs of Horner’s syndrome?

Answer 11

Affected pupil is smaller (miosis)
Delayed dilation in the dark
Mild upper lid ptosis
Lower lid higher
Anhidrosis of face

Question 12

What causes Horner’s syndrome?

Answer 12

Damage / interruption in function of sympathetic nerve fibres (course = hypothalamus –> upper spinal cord near carotid artery –> face)
Birth trauma to neck and shoulder, brainstem stroke
Injury / clot / dissection of carotid artery
Tumours - neuroblastoma, Pancoast tumour

Question 13

What does it mean if anisocoria is the same in the light and dark?

Answer 13

Likely to be a physiological cause

Question 14

What does it mean if anisocoria is greater in the light?

Answer 14

Caused by a defect in parasympathetic nervous system

Larger pupil is abnormal

Question 15

What does it mean if anisocoria is greater in the dark?

Answer 15

Caused by a defect in sympathetic nervous system

Smaller pupil is abnormal

Question 16

What roles do the parasympathetic and sympathetic nervous systems have in the pupils?

Answer 16

Sympathetic = fight or flight = stress = pupil dilation
Parasympathetic = rest and digest = pupil constriction

Question 17

How does the eye appear in IIIrd nerve palsy?

Answer 17

Upper lid ptosis
Dilated pupil with no response to light
Eye is deviated down and out
NB may not involve pupil eg in vasculopaths, in surgical cases eg aneurysm pupil is always involved

Question 18

How does the eye appear in IVth nerve palsy?

Answer 18

Eye is elevated in affected eye
Head tilt to opposite side of lesion (unilateral cases)
Chin depression (bilateral cases)
Common causes = trauma, microvascular pathology, decompensation of old lesion

Question 19

What are signs of VIth nerve palsy?

Answer 19

Diplopia (especially when looking to the side, lateral rectus cannot abduct eye)
Headaches
Pain around the eye
Commonly seen in vasculopaths, GCA
Raised ICP causes bilateral palsy

Question 20

Why are headaches + optic nerve swelling a red flag?

Answer 20

Could be secondary to raised ICP - space-occupying lesion, requires urgent neuroimaging
Could be secondary to GCA - neuroimaging not required, immediate steroids and temporal biopsy

Question 21

Why are IIIrd nerve palsies concerning?

Answer 21

If it involves the pupil could be due to intracranial aneurysm

Question 22

How should you approach cranial nerve palsies?

Answer 22

If multiple - cavernous sinus could be a cause, refer for neuroimaging
In patients >50, check inflammatory markers