Eye and Neurology

Question 1

Describe the difference between Optic disc swelling and papilloedema?

Answer 1

Optic disc swelling is a descriptive term and can describe disc swelling secondary to any cause
Papilloedema describes bilateral optic disc swelling secondary to raised ICP.

Question 2

Why can raised ICP cause raised IOP?

Answer 2

Raised ICP is transmitted along the subarachnoid space which is continuous with the subarachnoid space surrounding the optic nerve.

Question 3

Until proven otherwise all patients with bilateral disc swelling should be suspected of….

Answer 3

Raised ICP due to space occupying lesion until proven otherwise

Question 4

3 causes of raised ICP and papilloedema?

Answer 4

BRAIN: space occupying lesion
BLOOD: Malignant hypertension
CSF: Idiopathic Intracranial hypertension (problem with CSF circulation/ drainage/ production)

Question 5

Presentation of papilloedema?

Answer 5

Produces few symptoms. Symptoms are usually due to the underlying cause.
If chronic disc swelling when the swelling subsides the disc becomes atrophic and pale and loss of visual function and blindness can occur.

Question 6

Describe the difference between monocular and binocular double vision, what does this tell you?

Answer 6

Monocular: cover one eye and still double
Binocular: goes away when cover eye > NEUROLOGICAL PROBLEM

Question 7

Lesions posterior to the optic chiasm produce what kind of field defects?

Answer 7

Homonymous field defect (involvement of the same side in both eyes as information from the two visual hemifields is separated beyond this point.

Question 8

Lesions damaging the optic chiasm cause?

Answer 8

Bitemporal defects

Question 9

Common causes of cranial 6 nerve palsy?

Answer 9

Increased ICP, Infiltration of nerve sheath by tumours, microvascular ischaemia (can occur in diabetics)

Question 10

What muscle is effected in cranial nerve 6 palsy?

Answer 10

Lateral rectus muscle

Question 11

Presentation of cranial nerve 6 palsy?

Answer 11

Cannot abduct the eye and have medial deviation of the eye. Horizontal diplopia more commonly when looking far away or in direction of the affected eye.

Question 12

Causes of cranial nerve 4 palsy?

Answer 12

Congenital, head trauma

Question 13

What muscle is effected in cranial nerve 4 palsy?

Answer 13

Superior oblique muscle

Question 14

Presentation of cranial nerve 4 palsy?

Answer 14

Problems moving eye inferomedially
Torsional diplopia (2 objects at an angle)
When asked to gaze to the right eye moves superior as well as medial
Patient often tilts their head to correct the double vision

Question 15

Causes of cranial nerve 3 palsy?

Answer 15

Aneurysm, infarction (diabetes and atheroma), tumour, MS (autoimmune condition attacking the nervous system)

Question 16

What muscles are effected in cranial nerve 3 palsy?

Answer 16

Medial rectus, superior rectus, inferior rectus, inferior oblique, LPS and sphincter pupillae

Question 17

Presentation of cranial nerve 3 palsy?

Answer 17

Can only abduct and depress the eye slightly > DOWN and OUT appearance
Ptosis of eyelid due to paralysed LPS and dilated pupil (may be sparing)

Question 18

What can sparing or involvement of the pupil in cranial nerve 3 palsy suggest?

Answer 18

No sparing of the pupil suggests a compressive session as parasympathetics run on the outside of the nerve
Sparing of the pupils may indicate a microvascular problem (infarction in diabetes) as this would effect the middle of the nerve.

Question 19

Painful 3rd nerve palsy effecting the pupil?

Answer 19

Aneurysm

Question 20

Optic nerve lesions will cause what visual field defect?

Answer 20

Unilateral visual loss

Right optic nerve causes right vision loss and vice versa

Question 21

Causes of optic nerve related vision loss?

Answer 21

Optic neuritis in MS, trauma, compression, ischaemia optic neuropathy, infection, papilloedema.

Question 22

Describe presentation of optic neuritis?

Answer 22

Unilateral progressive visual loss, pain behind the eye especially with movement, disc may appear normal

Question 23

Course of optic neuritis?

Answer 23

usually gradually recovers with no treatment

Question 24

Optic chiasm lesions cause what type of visual field defect?

Answer 24

Bitemporal hemianopia

Question 25

Causes of bitemporal hemianopia?

Answer 25

Pituitary tumours, meningioma, carniopharyngioma

Question 26

What type of visual field defect do optic tract lesions cause? Why?

Answer 26

Homonymous (effects same side) hemianopia

Once you are past optic chiasm right brain is taking all left and left all right

Question 27

What type of visual field defect does occipital cortex problems cause?

Answer 27

Homonymous hemianopia often with macular sparing as information from the macula takes up such a large area

Question 28

Causes of occipital cortex visual problems?

Answer 28

Stroke and demyelination

Question 29

What could cause an inferior quadrantopia? Why?

Answer 29

Parietal lobe lesion

parietal takes lower field so lesion causes loss of inferior quadrant on other side

Question 30

What causes homonymous hemianopia with macular sparing?

Answer 30

Occipital cortex problem

Question 31

What causes homonymous hemianopia?

Answer 31

Optic tract lesions

Occipital cortex problem (may however be macular sparing)

Question 32

What could cause a superior quadrantopia? Why?

Answer 32

temporal lobe lesion

temporal takes upper field so lesion causes loss of superior quadrant on other side

Question 33

Commonest cause of horizontal diplopia?

Answer 33

Vascular issue with CN6