week 2 systemic disease the eye:neurological condition Flashcards
what are features of neuro-ophthalmic disease?
Eye movement defects – double vision
Visual defects - visual acuity, field loss
aetiology of neuro-ophthalmic disease
Vascular disease Tumours (primary and secondary) - SOLs Trauma Demyelination Inflammation/infection Congenital abnormalities depends on age, other clinical findings and site of lesion
how to investigate neuro-ophthalmic disease?
- Full medical and neurological examination
- Blood tests
- Imaging - MRI scanning
Secondary prevention of vascular disease is important to reduce further morbidity
6th CN palsy symptoms
right LR palsy, cannot look to right creating double vision
causes of 6th nerve palsy
microvascular (main cause)
Raised Intracranial pressure
Tumour
Congenital (mainly in kids)
why does raised ICP cause 6th nerve palsy? what is seen on examination?
as in ICP, the brainstem moves downwards, meaning CN6 is stretched over the PETROUS TIP
papilloedema
Superior oblique function?
Intorsion
Depression in adduction
Abduction (weak)
symptoms of CN4 palsy?
head tilted to the right
what is CN4 due to?
congenital decompensated (mainly) Microvascular Tumour Bilateral – closed head trauma
what causes bilateral 4th nerve palsy
blunt head trauma
signs of bilateral CN4 palsy?
Torsion
Chin depressed
3rd nerve palsy sign
down and out eye
what does the 3rd CN effect?
Medial rectus muscle Inferior rectus Superior rectus Inferior oblique Sphincter pupillae Levator palpebrae superioris
causes of 3rd nerve palsy?
Microvascular Tumour Aneurysm MS Congenital
severly painful (back of head), ptosis, large undiluted pupil, 3rd nerve palsy?
aneurysm - refer to storke unit
which artery is most usually aneurysm in 3rd nerve palsy?
posterior communicating artery
tumour and vascular are causes of all 3 nerve palsy’s affecting the eye. which causes are specific to each?
3rd - aneurysm
4th - congenital, trauma
6th - inc ICP
causes of visual field defect?
Vascular disease - CVA
Space occupying lesion (SOL)
Demyelination (MS)
Trauma - including surgical
describe the visual pathway defect sites?
optic nerve chiasm optic tracts optic radiations cortex
problems affecting the optic nerve
Ischaemic Optic Neuropathy
Optic neuritis – commonly MS
Tumours (Meningioma, Glioma, Haemangioma)
how do optic nerve defects present?
complete or abide the horizontal
what is optic neuritis?
Progressive visual loss (unilateral)
symptoms of optic neuritis
unilateral (mostly) Pain behind eye, especially on movement Colour desaturation Central scotoma Gradual recovery over weeks - months
complication of optic neuritis
optic atrophy - vision will not recovery fully
pathology affects optic chasm giving bitemporal hemianopia
Pituitary tumour
Craniopharyngioma
Meningioma
what occurs once pituitary tumour is removed to visual field defect?
commonly reversed after the tumour is decompressed or removed
pathology in the optic facts and radiations
- Tumours (primary or secondary)
- Demyelination
- Vascular anomalies
when is the macula spared? why?
lesion in the occipital lobe, blood supply to macula different
what causes a superior quadrantanopia?
temporal lobe (Meyer’s loop)
what causes a inferior quadrantanopia?
parietal lobe (Baum’s loop)
pathology of the occipital cortex?
- Vascular disease (CVA)
- Demyelination
(macula sparing)
what to do to test optic nerve?
visual acuity, colour (red), pupil reflex, visual fields, Fundoscopy.
4 parts of optic nerve route?
intraocular infraorbital intracanicular (though sphenoid bone) intracranial
what are the 3 C’s to look for for optic disc?
cup, contour, colour (pink/orange but not pale =atrophy)
how is cup to nerve ratio measured?
height of optic nerve ratio against cup height.
check other eye to compare
when might you not see any cup in patient?
long sighted
what causes an increases blind spot?
papilloedema
optic neuritis
