neuroopthalmology

Question 1

what are the muscles of thee upper lid ?

Answer 1

superior tarsal
levator palpebral superiors

Question 2

what is the main retractor of the lower lid ?

Answer 2

the inferior rectus

Question 3

what is the nerve supply of the inferior rectus and the levator muscles ?

Answer 3

occulomotor

Question 4

what is lagopthalmus ?

Answer 4

failure to close the eyes due to facial paralysis

Question 5

what is the most common complication of the cornea that happens as a consequence of lagopthalmos ?

Answer 5

exposure keratitis

Question 6

what are the different causes of ptosis ?

Answer 6

congenital
paralytic
neuromuscular
involutional
mechanical

Question 7

what is the etiology of myasthenia gravis ?

Answer 7

formation of auto antibodies against acetylcholine receptors in the neuromuscular junction

Question 8

what are the clinical tests that can bee used to help in the diagnosis of myasthenia gravis ?

Answer 8

increased ptosis with upwards gaze
improved ptosis with icee packs to the lids
IV injection of edrophonium causes rapid improvement of ptosis

Question 9

what is the mediical therpay for myasthenia gravis ?

Answer 9

pyridostigmine
oral steriods

Question 10

what is the surgical therapy associated with myasthenia gravis ?

Answer 10

removal of the thymus gland

Question 11

what are the causes of paralytic strabismus ?

Answer 11

lesions of the motor nerve nucleus
lesions of the nerve trunk
lesions of the muscles

Question 12

what is paralytic strabismus ?

Answer 12

strabismus caused by the affection of the extra occular muscles

Question 13

what is the nerve supply of the extra occular muscles ?

Answer 13

CN3 supplies sphincter pupillae and ciliary muscles
supplies the medial , superior and inferior rectus, inferior and superior oblique
CN4 supplies the superior oblique
CN6 supplies the lateral rectus

all extra occular muscles ar supplied by the occulomottor nerve except for the lateral rectus and supeerrior oblique

Question 14

what are thee compensatory mechanisms for diplopia ?

Answer 14

1. suppression - more common in children and easier with them due to high brain plasticity
2. abnormal head posture

Question 15

suppression as a compensatory mechanism for diplopia increases the risk for ?

Answer 15

Amblyopia ( lazy eye)

Question 16

what is the clinical picture of 3rd CN palsy ?

Answer 16

the eye will bee looking downwards and outwards
pupils will be dilated and fixed
lid ptosis
accommodation is completely lost
complete ptosis ? no diplopia

Question 17

what is the most common cause of isolated CN3 palsy ?

Answer 17

posterior communicating artery aneurysm

Question 18

what is the clinical picture of CN4 palsy ?

Answer 18

the head would be tilted away from the lesion to reduce the diplopia
affected eye is deviated upwards
ipsilateral hypertropia

Question 19

what is the function of the superior oblique muscle ?

Answer 19

depression
intorsion

Question 20

what is the clinical picture of CN6 palsy ?

Answer 20

• Limitation of abduction with esotropia

Question 21

what are the causes of CN6 palsy ?

Answer 21

any increase in intracranial pressure
microvascular disease due to HTN or DM

Question 22

what are the causes of CN6 palsy in children ?

Answer 22

secondary to severe otitis media
trauma
post viral disease

Question 23

where is the lesion if RAPD is positive ?

Answer 23

asymmetrical lesion that exists before the lateral geniculate body

Question 24

what is the presentation in RAPD ?

Answer 24

shine light in normal eye causes constriction in both pupils
shine light in diseased eye then both pupils dilate

Question 25

lesion of the visual field at the optic nerve ?

Answer 25

left or right anopia

Question 26

lesiion of the visual field at the optic chiasm ?

Answer 26

bitemporal hemianopia

Question 27

lesion of the visual field after the optic chiasm ?

Answer 27

homonymous hemianopia ( right or left )

Question 28

lesion of the visual field in the optic tract ?

Answer 28

quandrantopias

Question 29

when should diseease of the optic nerve be suspected ?

Answer 29

vision loss over hours or days
visual field loss
color vision loss
headache or pain
pain upon eye movement

Question 30

what is papilledema ?

Answer 30

passive non inflammatory swelling of the optic nerve head (optic disc)

Question 31

case of bilateral papiloedema differential diagnosis ?

Answer 31

intracranial space occupying lesion until proven otherwise

Question 32

what systemic diseases may be associated with papilledema ?

Answer 32

malignant hypertension
polycythemia
anemia

Question 33

what are thee symptoms of early papilledema ?

Answer 33

may bee asymptomatic
amaurosis
headache , vomiting due to increased ICP
may experience diplopia due to CN6 affection

Question 33

what are the symptoms of early papiloedema ?

Answer 33

may bee asymptomatic
amaurosis
headache , vomiting due to increased ICP
may experience diplopia due to CN6 affection

Question 34

what is the presentation of IIH ?

Answer 34

idiopathic intracranial hypertension is a diagnosis of exclusion , common in young females who are obese and other causes of inc ICP have been excluded
always present with papilloedmea

Question 35

what is the differential diagnosis of IHH ?

Answer 35

sleep apnea

Question 36

what is the presentation of a late case of papiloedema ?

Answer 36

gradual painless loss of vision
due to secondary optic atrophy

Question 37

what are the investigations required for cases of papilledema ?

Answer 37

CT scan
MRI
MRV
lumabr puncture

Question 38

what are the complications of papilledema ?

Answer 38

post papilledema optic atrophy
the optic disc becomes flat and greyish in colour with ill defined borders
obscured lamina cribrosa

Question 39

what is the treatment for papilledema ?

Answer 39

treatment of the cause
decrease ICP pressure
carbonic anhydrase drops
weight loss
surgery is indicated

Question 40

what surgery is performed in cases of papiloedema ?

Answer 40

optic nerve sheath fenestration
CSF shunting procedures

Question 41

what is the difference between papillitis and retrobulbar optic neuritis ?

Answer 41

papillitis - inflammation of the optic nerve head
retrobulbar optic neuritis - inflammation of thee optic nerve along with the orbital part of the nerve

Question 42

what is the etiology of optic neuritis ?

Answer 42

infective disease
demyelinating disease
inflammatory conditions
Uveitis and retinitis may cause secondary papillitis

Question 43

what are the signs associated with optic neuritis ?

Answer 43

pain on ocular movement
RAPD can be detected
fundus examination is normal