Systemic Disease Flashcards
how do eye movement defects generally present?
double vision
how do visual defects usually present?
loss of visual acuity
visual field loss
what is the most common cause of a neuro-ophthalmic defect?
vascular disease
what ocular muscle is innervated by CN VI?
lateral rectus
what happens to the eye in a sixth nerve palsy?
cannot abduct
turned in eye
what are four causes of a sixth nerve palsy?
microvascular
raised ICP
tumours
congenital
what needs to be checked when a patient presents with a sixth nerve palsy?
check if they have papilloedema to rule out raised ICP as a cause
what ocular muscle is controlled by CN IV?
the superior oblique
what happens to the eye in a fourth nerve palsy?
eye can’t undergo intorsion and depression in adduction
how to patients with fourth nerve palsy often present?
vertical squint
head tilt to compensate for loss of intorsion
what can cause a bilateral fourth nerve palsy?
blunt trauma to the head
how does bilateral fourth nerve palsy present?
torsion of the eyes
depression of the chin with the eyes looking up
what are four causes of a fourth nerve palsy?
congenital
microvascular
tumour
head trauma
what ocular muscles are innervated by CN III?
all other extra ocular muscles
what happens to the eye in third nerve palsy?
eye faces down and out
what are four causes of third nerve palsy?
microvascular
compression
MS
congenital
what is the medial longitudinal fascicles?
a pathway between the nuclei of CN III and CN VI
what are the main causes of inter nuclear ophthalmoplegia?
multiple sclerosis
vascular
many others
what type of visual defect is caused by a problem with the optic nerve?
either complete or horizontal
what type of visual defect is caused by a problem with the optic chasm?
bitemporal hemianopia
what type of visual defect is caused by a problem with the optic tracts and optic radiations?
homonymous defects
macula won’t be spared
what type of visual defect is caused by a problem with the cortex?
homonymous defect with macular sparing
