Pupils

Question 1

causes of CNIII palsy

Answer 1

Brain stem:
tumour
cva
demyelination

Posterior communicating artery aneurysm
Extra-dural haematoma

Cavernous sinus:
Carotid cavernous fistula
Tumour
Inflammation

Orbit
Trauma
inflammationtumour

Vascular III palsy
diabetes/BP increase

Question 2

Most common CNIII cause? how can you spot it?

Answer 2

Vascular CNIII palsy. This is pupil sparing (pupillary fibres have extensive innervation beyond CNIII)
It’s usually self-limiting
it’s related to microangiopathy, where vasa vasorum, vaso navorum (blood supply to arteries and nerves are afected.

Question 3

Causes of H.S?

Answer 3

1st order neuron pathology
CNS disease: MS, syphilis, tum,our
Cervial region: syringomyelia, tumour, injury

2nd order:
Cervical rib, pancoast tumour
aneurysm
Lympadeonpathy
apical TB
Neck tumour

3rd order
ICA aneurysm
migraine
idiopathic

Question 4

Signs of an ICA aneurysm?

Answer 4

Horners
neck pain

urgent angiogram! carotid bruits?

Question 5

Why test for an RAPD? Explain an RAPD

Answer 5

If there is visual loss, it might be due to glaucoma or damage to the optic nerve
To test for an RAPD would be to test for optic nerve pathology
In the healthy eye illumination causes both the healthy and unhealthy eye to constrict
1,2,3
The illumination of the pathological eye does not illicit direct constriction, as it should. However a consensual reflex is illicited

Question 6

ddx for an RAPD

Answer 6

ischaemic optic nerve
optic neuritis 
CMV, Herpes infecting the retina
Trauma to optic nerve, or radiation
Retinal detachment
Tumour
Severe mac degen
Glaucoma causing optic nerve damage

Question 7

What about for an Adie Pupil and an Argyll-Robertson pupil?

Answer 7

Adie-pupil: tonic constriction with sluggish or no direct or consensual response
Argyll-Robertson: (tertiary syphilis) as above but accommodation is ok!