Eye movement in health and disease

Question 1

what muscle controls adduction of the eye and which cranial nerve

Answer 1

medial rectus

CN3

Question 2

what muscle controls abduction of the eye and what CN

Answer 2

lateral rectus

CN6

Question 3

what muscles control elevation of the eye and CN

Answer 3

inferior oblique

superior rectus

Question 4

what muscles control depression of the eye and cranial nerves

Answer 4

superior oblique - CN4

inferior rectus CN3

Question 5

what muscles control intorsion( nasal rotation) of eye

Answer 5

superior oblique CN4

Question 6

what muscle control extorsion (temporal rotation) of the eye?

Answer 6

inferior oblique CN3

Question 7

rectus muscle pull towards themselves and the obliqeu muscles

Answer 7

pull away from themselves e.g. superior obliqeu pulls inf

LR6, SO4, 3

Question 8

convergence means both eyes must point medial to see near objects
if this dosent work what happens

Answer 8

inability to alternate between distant and near objects

Question 9

conjugation is eyes must move together

if this dosent happen what happens

Answer 9

double vision - diplopia

Question 10

accommodation is when the lens must be shaped to focus light coming from the viewed objects if this dosent work what happens

Answer 10

short or near sightedness

Question 11

the centres fro conjugate gaze is found int h mid Brain and cranial nerve eye nuclei found in pons or midbrain so people with lesions here what will happens

Answer 11

won’t be Able to move their eyes with coordination or focus on near of far objects

6th uncle pons
3/4 in midbrain

Question 12

vergence

Answer 12

eyes move in opposite directions to focus on near and far.objects

Question 13

if the oculomotor nerve is injured what will the present with

Answer 13

Down and out appearance

Down to SO
and out due to LR
those are still working

elevation won’t work - SR an IO
depression and adduction IR and MR respectively

Question 14

if the trochlear nerve is injured what will happen

Answer 14

Head tilt

depression and intorsion will not work - SO

Question 15

if abducens nerve is injured what happens

Answer 15

move medially due to MR and no LR

abduction lost

Question 16

Levator palpebrae superioris
Ciliary muscle
Pupillary sphincter

controlled by what nerve

Answer 16

oculomotor

Question 17

Levator palpebrae superioris fucntion and if damaged

Answer 17

eye lid elevation

ptosis

Question 18

ciliary muscle normally and If injured

Answer 18

Changes lens shape

focusing, accommodation

Question 19

Pupillary sphincter

Answer 19

constricts the pupil

mydriasis

Question 20

pupil dilator muscle is controlled by what never

Answer 20

trigeminal

Question 21

CN palsies

Answer 21

Ischaemia (strokes)
Compression (tumour, abscess, aneurysm) 
Trauma (concussion, whiplash) 
Microvascular damage (diabetes) 
Migraines (e.g. ophthalmoplegic migraines)
Raised intracranial pressure
Congenital

Question 22

A 55-year-old man with a history of hypertension and diabetes presents on a Friday night to the emergency department. He was found by an ambulance crew wandering in the road. He looks dishevelled, and is slurring his words and staggering around the department. You also note his eyes are jerking horizontally when he is looking at you. You put him in a bed with some IV fluids running to let him “sleep it off”, but 10 hours later he is still looking and acting the same way.

Where is the lesion likely to be?

Middle cerebral artery
Anterior cerebral artery
Superior cerebellar artery
Posterior communicating artery

Answer 22

sup cerebellar artery

Cerebellar signs: DANISH

Dysdiadochokinesia
Ataxia
Nystagmus
Intention tremor
Slurred speech (or scanning dysarthria)
Hypotonia

Question 23

A 38-year-old man presents to his GP with double vision. He has a history of poorly controlled HIV, and reports headaches and fevers over the past few weeks. When you examine him, you note he is holding his head so it is pointing up and to his left, he reports this makes the double vision better.

You send him to hospital where a CT-scan confirms a brain abscess, later confirmed to be caused by cryptococcus.

What nerve was affected which led to the diplopia?

Right oculomotor
Left oculomotor
Right trochlear
Left trochlear

Answer 23

Patient is moving their head up and left so that both eyes are pointing down and to the right when looking at an object, as this is the only way the right eye can point.

Question 24

A 45-year-old woman with a history of MS presents to A+E complaining of vision changes that have occurred over the previous 2 days. She reports that she has double vision when she tries to look to the right, but not when she looks to the left. She has no other eye movement signs or symptoms.

What nerve was affected which led to the diplopia?

Right oculomotor
Left oculomotor
Right trochlear
Right Abducens

Answer 24

double vision sign of right abducens

Patient cannot look right due to failure of the right lateral rectus muscle. When she looks left, her eyes point together so no diplopia. LR is innervated by CN VI.

Question 25

A 23-year-old man presents to his GP with a sensation like the room is spinning. He reports this has happened over the last 2 days and he has been feeling fluey with it, with myalgia and general fatigue and malaise. He looks ataxic when mobilising, and you note nystagmus on examination. What is the most likely diagnosis?

Answer 25

viral labyrintitis

Question 26

viral labyrintitis

Answer 26

Inflammation of the inner ear Normally due to a viral infection (30% will have a cold before symptoms arise) Causes nystagmus, vertigo, hearing loss/tinnitus, and viral symptoms Can take 2 months to fully recover No specific treatment unless bacterial or other cause Strokes don’t affect the young and don’t cause viral symptoms. Infection of the labyrinths causes failure of postural sensation, which leads to vertigo and nystagmus (failure vestibulo-ocular reflex), and viral symptoms

Question 27

68-year-old man with a history of hypertension, diabetes, and MI, presents to hospital with drooping of the right side of his face, as well as weakness in his left arm and leg. He also reports visual changes that he struggles to quantify. Full visual field testing reveals the following defect: Where is the lesion? defect of upper right quadrant of both eyes gone

Answer 27

left temporal lobe damage

Question 28

A 32-year-old woman with a history of lupus presents to A+E with loss of vision. She says her vision has been getting worse for the last few days, and she is now almost completely blind in both eyes. She also reports worsening weakness in her arms and legs on both sides. On examination she can see the difference between light and dark only, with normal eye movement and fundoscopic findings shown below. She also has reduced sensation and power bilaterally below the level of C8. An MRI of her spine is shown below. What is the pathogenesis of this condition?

Answer 28

anti-aquaporin 4 antibodies

Question 29

neuromyelitis optica NMO

Answer 29

RARE condition (10 per 100,000) Caused by anti-aquaporin 4 antibodies Presents with optic neuritis (like MS) and transverse myelitis (inflammation of a section of the spinal cord, usually >3 vertebral bodies in height) ON is more severe and can be bilateral (Unlike MS) Can be relapsing and remitting or monophasic You don’t get brain lesions, unlike in MS

Question 30

myopia

Answer 30

short sighted

Question 31

signals from the bottom of the eye correlate to parietal lobe and signals from the top of the eye correlate with the temporal lobe visual fields. Therefore a lesion in the parietal lobe cause what

Answer 31

inf quantanopia temporal casue superior quadrantopia superior radiation fibres go into temporal lobe which are the ones that look wider inferior radiation fibres go to parietal lobe and are closer to mid line of diagram PITS optic nerve - optic chiasm - optic tract - lateral geniculate nucleus - optic radiations all optic fibres must go through the LGN

Question 32

if the upper bank of the calcimine fissure is injured it presents with what

Answer 32

contralateral inferior quadranopia - parietal

Question 33

if the lower bank of the calcimine fissure is injured it causes

Answer 33

contralateral superior quadraopia - same as temporal

Question 34

is the posterior cerebral artery is occluded the whole of the calcimine fissure is injured so complete loss of one side but with what

Answer 34

a central sparing

Question 35

PPRF - parapontine reticular formation

Answer 35

6th cranial nearby same side however 3rd cranial nerve on the other side as through the medial longitudinal fasciutlus

Question 36

1 and half syndrome is most commonly caused by MS and is characterised by what where is the lesion

Answer 36

a lateral gaze palsy on looking toward the side of the lesion ( only LR left) and INO looking in the other direction location of the lesion is the paramedic pontine reticular formation or VI nerve nucleus