Neuro & the eye

Question 1

Define what ophthalmoplegia is

Answer 1

• Paralysis of the muscles within or surrounding the eye.
• It can affect one or more of the six muscles that hold the eye in place and control its movement.

Question 2

What are the causes of intra-nuclear ophthalmoplegia ?

Answer 2

• Multiple sclerosis
• Vascular disease
• Mass

Question 3

What is the underlying cause of intra-nuclear ophthalmoplegia?

Answer 3

It is due to a lesion in the medial longitudinal fasciculus, which connects the IIIrd, IVth and VIth cranial nuclei

Question 4

What are the clinical features suggestive of intra-nuclear ophthalmoplegia ?

Answer 4

• Horizontal disconjugate (not paired in action or joined together) eye movement
• Impaired adduction of the eye on the same side as the lesion
• Horizontal nystagmus of the abducting eye on the contralateral side

Question 5

What is the potential problem shown in the pic ?

Answer 5

Horners syndrome - can see the constricted pupil & ptosis (compare how much of the iris you can see on the right side compared to the left)

Question 6

Visual loss, headache & hormonal disturbance should raise the suspicion of what?

Answer 6

Pituitary tumours

Question 7

What are the main parts of the optic pathways which can be affected by pathology resulting in visual field defects ?

Answer 7

• Optic nerve
• Chiasm
• Optic tracts
• Optic radiations
• Cortex

Question 8

What are the main pathologies which can affect the optic nerve resulting in a visual field defect & specifically what visual field defect is seen?

Answer 8

• Ischaemic Optic Neuropathy
• Optic neuritis – commonly MS
• Tumours (rare) - Meningioma, Glioma, Haemangioma

Visual field defect at the optic tract is Ipsilateral (same side as pathology) monocular vision loss

Question 9

What are the main pathologies which can affect the optic chiasm resulting in a visual field defect & specifically what visual field defect is seen?

Answer 9

• Pituitary tumour
• Craniopharyngioma
• Meningioma

Visual field defect seen is a bitemporal heminopia

Question 10

What pathologies cause visual field defects affecting the optic tracts & radiations ?

Answer 10

• Tumours (primary or secondary)
• Demyelination
• Vascular anomalies

Question 11

If pathology affects the optic tract what visual field defect will it result in ?

Answer 11

A contralateral homonymous heminopia (no macula sparing)

Question 12

If pathology affects the upper optic radiation in the parietal lobe what visual field defect will it result in ?

Answer 12

Contralateral homonymous inferior quadrantanopia (no macula sparing)

Question 13

If pathology affecting the lower optic radiations in the temporal lobe what visual field defect would arise ?

Answer 13

Contralateral homonymous superior quadrantanopia (no macula sparing)

Question 14

What pathologies affect the visual cortex resulting in visual field defects here & what specific visual field defect do they result in ?

Answer 14

• Vascular disease (CVA)
• Demyelination

Visual field defect = contralateral homonymous heminopia + macula sparing

Question 15

Appreciate this:

• Learn to write out the visual defect pathway
• Also temporal side is the peripheral (outer) half of vision but the fibres come from the inner half of the eye