Neurology of Eye Disease Flashcards
What feature of neuro-ophthalmic disease is present if a patient has double vision?
Eye movement defect
How is the cause of a neuro-opthalmic defect identified?
Full medical and neurological examination
Bloods
MRI
Lumbar Puncture if suspected MS
What can potentially cause an eye movement defect?
IIIrd Nerve
IVth Nerve
VIth Nerve
Inter-nuclear (in nucleus of the cranial nerve)
Supra-nuclear (in the frontal lobe, signal is broken before reaching nucleus)
A palsy of CN VI removes the ability to move the eye in which direction?
Laterally (temporally)
Due to Lateral Rectus dysfunction
What other pathologies would cause the lateral rectus to malfunction?
Myositis Impingement (due to petrous tip of temporal bone which CN VI passes over)
What sign is often seen on fundoscopy if there is a CN VI palsy?
Papilloedema
What movements is the superior oblique responsible for?
Down and IN
adduction
If there is a IV nerve palsy, how does the eye normally appear to sit?
Eye cant move down in adduction
=> sits a bit higher than usual when looking straight ahead
How do patients compensate the work of CN IV?
They tilt their head to move their eye inwards for them
What can cause a IV nerve palsy
Congenital decompensated
Microvascular
Tumour
Bilateral – closed head trauma
What causes a palsy of CN VI?
Microvascular
Raised Intracranial pressure
Tumour
Congenital
Name all the eye muscles that are supplied by CN III
Medial rectus muscle Inferior rectus Superior rectus Inferior oblique Sphincter pupillae Levator palpebrae superioris
How does the eye appear if the CN III is paralysed
Down and OUT
What are the main causes of a CN III palsy
Microvascular Tumour Aneurysm MS Congenital
Why is CN IV most susceptible to compromise on head trauma?
Longest CN with a course from the posterior brain to anterior eye
An aneurysm of what artery can cause impingement of CN III?
Posterior communicating artery
If the pupil is spared in a suspected CN III palsy, what is thought to be the cause?
Microvascular cause
What has occurred if pupil involvement is seen in a CN III palsy?
Superficial periphery of optic nerve = damaged by aneurysm
What is meant by the term Inter-nuclear Ophthalmoplegia?
Both eyes need to move in the same direction at the same time and speed
What can cause Inter-nuclear Ophthalmoplegia?
Multiple sclerosis
Vascular
Lots of small print
Plaques on an MRI is a sign of what disease process?
Demyelination in Multiple Sclerosis (MS)
What can cause visual field defects?
Vascular disease
Space occupying lesion
Demyelination (MS)
Trauma - including surgical
How does optic neuritis usually present?
Progressive visual loss (unilateral) Pain behind eye, especially on movement Colour desaturation Central scotoma Gradual recovery over weeks - months
Patients with what other condition usually develop optic neuritis?
MS
