Systemic Disease and the Eye - Neurological Conditions

Question 1

what are the 2 cardinal features of neuro-ophthalmic disease?

Answer 1

eye movement defects (double vision)
visual defects (visual acuity, field loss)

Question 2

name 6 underlying causes of neuro-ophthalmic disease

Answer 2

vascular disease (most common)
tumours (primary and secondary)
trauma
demyelination
inflammation/infection
congenital abnormalities

Question 3

important aspects of investigation in neuro-ophthalmic disease?

Answer 3

full medical and neurological examination
blood tests
imaging - MRI = gold standard

Question 4

what 3 cranial nerves control movement of the eye?

Answer 4

CN III
CN IV
CN VI

Question 5

defects in which 2 parts of the nerve pathway can cause eye mobility defects?

Answer 5

inter-nuclear

supra-nuclear

Question 6

which muscle is controlled by CN VI and what does it do?

Answer 6

lateral rectus

abducts the eye (pulls it laterally/temporally)

Question 7

name 4 causes of CN VI palsy

Answer 7

microvascular
raised intracranial pressure
tumour
congenital

Question 8

how can pressure inside the skull affect CN VI?

Answer 8

CN VI wraps around petrous tip which can impinge the nerve if swollen

Question 9

definition of papilloedema?

Answer 9

swollen optic nerve/disc in context of raised intracranial pressure

Question 10

what muscle is controlled by CN IV and what does it do?

Answer 10

superior oblique
keeps eye depressed in orbit in adduction 
stabilises eye while head moves
weak abduction
intorsion

Question 11

how might CN IV palsy affect posture?

Answer 11

patients can compensate with a head tilt

Question 12

how might CN IV palsy present?

Answer 12

problems in depression of eye (most obvious when looking down and medially)
affected eye sits higher
images which are horizontally next to each other may appear vertical as one eye is seeing higher than the other

Question 13

head tilt to the right compensates for CN IV palsy in which eye?

Answer 13

left

Question 14

4 causes of CN IV palsy?

Answer 14

congenital decompensated
microvascular
tumour
bilateral - closed head trauma (susceptible to head trauma as its the longest cranial nerve in terms op ophthalmology)

Question 15

what muscles are supplied by CN III?

Answer 15

medial rectus
inferior rectus]superior rectus
inferior oblique
sphincter pupillae
levator palpebrae superioris

Question 16

position of eye with CN III palsy?

Answer 16

looking down and out

lid is often drooping

Question 17

why does a down and out eye position occur in CN III palsy?

Answer 17

lateral rectus and superior oblique not innervated by CN III so their actions are unopposed
lateral rectus = looking out
superior oblique = looking down

Question 18

5 causes of CN III palsy?

Answer 18

microvascular
tumour
aneurysm
MS
congenital

Question 19

most likely cause of a painful CN III palsy?

Answer 19

aneurysm

Question 20

pupil sparing CN III palsy?

Answer 20

microvascular as outside nerve fibres not affected

Question 21

pupil involving CN III palsy?

Answer 21

probably aneurysm

always do imaging

Question 22

where is the issue in inter-nuclear ophthalmoplegia?

Answer 22

grey matter pathways in the brainstem

Question 23

what is the function of inter-nuclear pathways?

Answer 23

allows the eyes to work together

e. g to look left
- left eye looks left
- right eye looks left
- at the same time and same speed

Question 24

what happens in inter-nuclear ophthalmoplegia?

Answer 24

still have ability to look tot he left, but when you do so, the affected eye flickers (nystagmus) as the muscle doesn’t work to move the eye left but the fibres are still firing telling the eye to move which causes it to flicker in that direction

Question 25

sign of demyelination disease (e.g MS) on MRI?

Answer 25

plaques

Question 26

2 causes of internuclear ophthalmoplegia?

Answer 26

MS

vascular

Question 27

name 5 sites where a problem can occur in visual field defects?

Answer 27

optic nerve
chiasm
optic tract
optic radiations
cortex

Question 28

4 causes of problems in visual field pathway?

Answer 28

vascular disease (CVA)
space occupying lesion (SOL)
demyelination (MS)
trauma (including surgical)

Question 29

how can you distinguish whether a visual field defect is occurring at the optic tract or occipital cortex?

Answer 29

macula will be spared if at occipital cortex

Question 30

what can cause a defect at the optic nerve?

Answer 30

ischaemic optic neuropathy
optic neuritis (commonly MS)
tumours 
- meningioma
- glioma
- haemangioma

Question 31

what are the features of optic neuritis?

Answer 31

progressive visual loss (unilateral)
pain behind eye, especially on movement
colour desaturation
central scotoma
gradual recovery over weeks - months

Question 32

how does visual loss due to optic nerve differ to that due to eye or brain problems?

Answer 32

optic nerve = either complete vision loss or visual field is divided horizontally
other causes = vertical division

Question 33

what can optic neuritis progress to?

Answer 33

optic atrophy

Question 34

name 3 pathologies of optic chiasm?

Answer 34

pituitary tumour
craniopharyngioma
maningioma

Question 35

what is the prognosis of pituitary tumour in terms of vision?

Answer 35

commonly reversed after tumour is decompressed or removed

Question 36

name 3 pathologies of the optic tracts and optic radiations

Answer 36

tumours
demyelination
vascular anomalies (including strokes)

Question 37

general features of optic tract/radiation defects?

Answer 37

homonomous defects
macula not spared
quadrantanopia
incongruous

Question 38

name 2 pathologies of occipital cortex?

Answer 38

vascular disease (CVA)
demyelination

Question 39

name 3 general features of a defect in the occipital cortex?

Answer 39

homonomous defect
macular sparing
congruous