Neurological Conditions and the Eye Flashcards
what is the most common problem that affects the brain tissue?
vascular disease
what pathologies/processes can cause neural issues?
- vascular
- tumours
- trauma
- demyelination
- inflammation/infection
- congenital abnormalities
what nerves can be damaged that would cause ocular motility defects?
CN III, IV and VI
what is the most common nerve palsy? (in terms of the nerves that supply ocular mobility)
VIth nerve palsy
what muscle does CN VI supply?
the lateral rectus
what is the lateral rectus muscle responsible for?
abduction
what can be seen in the eye of someone with a VIth nerve palsy?
convergent squint. affected eye is facing inwards as the lateral rectus is not working to pull it out
4 most common causes (in order) of VIth nerve palsy?
- microvascular
- raised ICP
- tumour
- congenital
if there is raised ICP, what is the VIth nerve compressed against?
the petrous part of temporal bone
second most common nerve palsy?
IVth nerve palsy - trochlear nerve
3 most common causes of IVth nerve palsy?
- congenital
- microvascular
- tumour
what is the most common cause of bilateral IVth nerve palsy?
closed head trauma
what muscle does the IVth nerve supply?
superior oblique muscle
what is a clinical sign of a IVth nerve palsy?
eyeball cannot look down and in
what would you suspect in a child who sits with their head tilted to see better?
a IVth nerve palsy
what is the least common nerve palsy?
IIIth nerve palsy - occulomotor nerve
what muscles does the oculomotor nerve supply?
- medial, inferior and superior rectus
- inferior oblique
- sphincter pupillae
- levator palpebrae superioris
what is the occular position in a 3rd nerve palsy?
down and out
what might you notice in the pupil in a 3rd nerve palsy?
dilated pupil
5 most common causes of IIIrd nerve palsy?
- microvascular
- tumour
- aneurysm
- MS
- congenital
what would a painful 3rd nerve palsy indicate?
an aneurysm
what are the causes of inter-nuclear Ophthalmoplegia?
- MS
- vascular
- etc etc
what happens in inter-nuclear ophthalmoplegia?
the 2 eyes no longer work together so when one looks left, the other will not do this at the same rate and speed
what nerve is involved in inter-nucleus ophthalmoplegia?
medial longitudinal fasciculus
at what areas on the optic pathway can be affected to cause a visual field defect?
- optic nerve
- optic chiasm
- optic tracts
- optic radiations
- cortex
what happens in optic neuritis in relation to visual loss?
progressive visual loss unilaterally
what can a patient with optic neuritis present with?
pain behind the eye, loss of some colour vision
what makes the pain worse in optic neuritis?
eye movement
what is a gap in visual field called?
a scotoma
in what age group does optic neuritis commonly affect?
young people/ young adults
does optic neuritis recover?
yes
over how long does optic neuritis recover?
over weeks-months
what often happens the optic nerve after optic neuritis?
optic atrophy
what can affect the optic chiasm causing visual defects?
- pituitary tumour
- craniopharyngioma
- meningioma
what age group does craniopharyngioma affect?
children
if something compresses the optic chiasm, what type of visual field loss is there?
bi-temporal field defect
what type of visual defect occurs when a problem is affecting the optic tracts or radiations?
homonomous defects
is the macula spared when the problem is affecting the optic tracts and radiations?
no
is there macular sparing when there is damage to the occipital cortex?
yes
what type of defect arises in when there is damage to the occipital cortex?
homonmous defect
what is a ring enhancing lesion in the brain and what can cause them?
long held abscess- eg in TB, parasitic abscess, chronic bacterial abscess
