Neuro-ophthalmology Flashcards
What happens if an eye is covered in diplopia?
In binocular diplopia - disappears with one eye covered
In monocular diplopia - persists
Are the images the same in diplopia?
In binocular diplopia - both images are similar
In monocular diplopia - one is a ‘ghost’
What are the features of raised ICP?
Generalised headache Worse lying supine N+V Diplopia, visual obscurations Precipitated / ophthalmic symptoms exacerbated by valsalva manoeuvres (coughing / straining), bending forwards
What are the features of temporal arteritis?
Often diffuse headache Scalp tenderness Jaw claudication Maybe systemically unwell Transient or persistent diplopia Bilateral visual loss (often transient initially)
How do colours appear in optic nerve disease?
Reds appear washed out
Which nerves are involved in the parasympathetic pupillary light reflex?
Afferent pathway = optic nerve to brain
Efferent pathway = brain to oculomotor nerve
What is anisocoria?
Difference in right and left pupil size
What is the Argyll-Robertson pupil?
Bilateral small pupils - brisk response to accommodation, no response to direct light
What is Adie’s syndrome?
Dilated pupil with slow response to accommodation, but even slower to direct light
What does RAPD test for?
Unilateral or asymmetric optic nerve disease
What are the signs of Horner’s syndrome?
Affected pupil is smaller (miosis) Delayed dilation in the dark Mild upper lid ptosis Lower lid higher Anhidrosis of face
What causes Horner’s syndrome?
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
What does it mean if anisocoria is the same in the light and dark?
Likely to be a physiological cause
What does it mean if anisocoria is greater in the light?
Caused by a defect in parasympathetic nervous system
Larger pupil is abnormal
What does it mean if anisocoria is greater in the dark?
Caused by a defect in sympathetic nervous system
Smaller pupil is abnormal
What roles do the parasympathetic and sympathetic nervous systems have in the pupils?
Sympathetic = fight or flight = stress = pupil dilation Parasympathetic = rest and digest = pupil constriction
How does the eye appear in IIIrd nerve palsy?
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
How does the eye appear in IVth nerve palsy?
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
What are signs of VIth nerve palsy?
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
Why are headaches + optic nerve swelling a red flag?
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
Why are IIIrd nerve palsies concerning?
If it involves the pupil could be due to intracranial aneurysm
How should you approach cranial nerve palsies?
If multiple - cavernous sinus could be a cause, refer for neuroimaging
In patients >50, check inflammatory markers
