The Eye in Neurological Disease Flashcards
What are the cardinal features of neuro-ophthalmic disease?
Eye movement defects = double vision
Visual defects = visual acuity, field loss
What are the possible aetiologies of neuro-ophthalmic disease?
Vascular disease, tumours, trauma, demyelination, infection, inflammation, congenital abnormalities
What are some investigations done for neuro-ophthalmic disease?
Full medical and neurological examination, blood tests. MRI
What are causes of ocular motility defects?
CN III, CN IV, CN VI, internuclear, supranuclear
What muscle is affected by CN VI palsy?
Lateral rectus = loss of abduction
What are some causes of CN VI palsy?
Microvascular, raised intracranial pressure, tumour, congenital
What may be a sign of CN VI palsy?
Papilloedema
What muscle is affected by CN IV palsy?
Superior oblique = loss of intorsion and depression in adduction (also loss of weak abduction)
What may be a sign of CN IV palsy?
Loss of incyclotorsion during head tilt
What are the causes of CN IV palsy?
Congenital decompensation, microvascular, tumour, closed head trauma (if bilateral)
What is a sign of CN III palsy?
Eye faces down and out
What muscles may be affected by CN III palsy?
Medial rectus, inferior rectus, superior rectus, sphincter pupillae, levator palpebrae superioris, inferior oblique
If the CN III palsy is painful, what is the likely cause?
An aneurysm
What are the causes of CN III palsy?
Microvascular, trauma, aneurysm, MS, congenital
What are the causes of internuclear ophthalmoplegia?
MS, vascular, repeated eye strain from reading small print
What is impacted in the eye affected by internuclear ophthalmoplegia?
Eye has impaired adduction
What ensures that both eyes work together at the same time?
Internuclear pathway
What happens when a patient with internuclear ophthalmoplegia is asked to look contralaterally (with regards to the affected eye)?
Affected eye adducts minimally (or not at all)
Contralateral eye abducts with nystagmus
What structures in the optic pathway may be affected to cause visual field defects?
Optic nerve, optic chiasm, optic tracts/radiations, visual cortex in occipital lobe
What are some causes of visual field defects?
Vascular disease (CVA), space occupying lesions, demyelination (MS), trauma
What are some pathologies that may affect the optic nerve?
Ischaemic optic neuropathy, tumours (rare), optic neuritis
What are some tumours that may affect the optic nerve?
Meningioma, glioma, haemangioma
What are the features of optic neuritis?
Progressive unilateral visual loss, pain behind the eye (especially on movement), colour desaturation, central scrotoma
How long does it take to recover from optic neuritis?
Gradual recovery over weeks to months = may lead to optic atrophy
What are some pathologies that affect the optic chiasm?
Craniopharyngioma, meningioma, pituitary tumour
What defect is caused by optic chiasm pathology?
Bitemporal field defect
What defect is caused by optic nerve pathology?
Defects are complete or abide by the horizontal
Can visual defects caused by a pituitary tumour be reversed?
Yes = commonly resolve after tumour is decompressed or removed
What are some pathologies that impact the optic tracts/radiations?
Tumours, demyelination, vascular anomalies
What defect is caused by optic tracts/radiations pathology?
Homonomous defects, macula involved, incongruous, quadrantanopia
What are some pathologies that can affect the occipital visual cortex?
Vascular disease (CVA), demyelination
What defects are caused by occipital visual cortex pathologies?
Homonomous defect, macula spared, congruous
