8: Eye in neurological disease Flashcards
What are the cardinal features of neurological eye disease?
Problems with eye movement - e.g diplopia
Visual field defects - test visual acuity and fields
What causes neurological eye disease?
VASCULAR DISEASE!!!
Space occupying tumours
Trauma
Demyelinating diseases
Inflammation
Infection
Which scan is used to check the brain for vascular disease and space occupying lesions?
MRI head
Which mnemonic tells you the cranial nerve supplies to the extraocular muscles?
LR6 SO4 AO3
Apart from elevation and depression, what do the oblique muscles do?
Superior oblique causes INTORSION
Inferior oblique causes EXTORSION
Which cranial nerve palsy produces a medial manifest squint?
CN VI palsy
What symptom does CN VI palsy produce?
Diplopia
Patients with a CN VI palsy poorly (abduct / adduct) the affected eye.
abduct
What most commonly causes a CN VI nerve palsy?
Raised ICP secondary to a vascular problem
CN VI is compressed by raised ICP producing a palsy.
What sign is seen in the eye?
Medial manifest squint
Papilloedema
What symptoms does a CN IV palsy cause?
Diplopia when looking DOWN (impaired depression)
Compensatory HEAD TILT due to intorsion
In CN IV palsy, which direction does the affected eye look in the central position?
Upwards
Why do patients with a CN IV palsy tilt their heads?
Superior oblique normally intorts the eye
So head tilt to compensate for that not working
What is the most common cause of a CN IV palsy?
Congenital defcts
What are common causes for any nerve palsy?
Microvascular
Tumour
Trauma
What two muscles apart from the extraocular ones does a CN III palsy affect?
LPS
Sphincter papillae
What position does the eye sit in due to CN III palsy?
Why?
DOWN AND OUT
Only lateral rectus and superior oblique are working
What is the most common cause of CN III palsy?
Microvascular problems
If a CN III palsy is painful what do you need to strongly suspect?
Aneurysm
Life-threatening CN III palsies are caused by ___.
aneurysm
6th raised icp
4th congenital, trauma
3rd aneurysm
What is an example of a demyelinating disorder which causes visual loss?
MS
Lesions before the optic chiasm cause which kind of visual field loss?
Lesions at the optic chiasm?
Lesions after?
Monocular vision loss
Bitemporal hemianopia
Loads of symmetrical visual losses e.g homonymous hemianopia. quadrantanopias etc.
What is ischaemic optic neuropathy?
Optic nerve damage due to vascular causes
What are the symptoms of optic neuritis?
Progressive unilateral visual loss
Pain on eye movement
Loss of colour vision
Scotoma (loss of central vision)
Is optic neuritis reversible?
Yes, gradually
What does a pale disc indicate?
Optic atrophy
What causes bitemporal hemianopia?
Almost always pituitary tumours
Is visual loss due to compression irreversible?
Not always
Which compressions give you homonymous visual field losses?
Those AFTER optic chiasm
What is the most common cause of visual field defects which should be eliminated along with space occupying tumours?
Vascular disease
