Neurological Causes of Visual Loss

Question 1

What are common neurological causes of visual loss?

Answer 1

Optic neuritis, anterior ischaemic optic neuropathy (AION), stroke, pituitary tumours, and papilloedema.

Question 2

What is optic neuritis?

Answer 2

Inflammation of the optic nerve causing visual loss, pain with eye movement, and sometimes colour desaturation.

Question 3

What are the symptoms of anterior ischaemic optic neuropathy (AION)?

Answer 3

Sudden, painless monocular vision loss, often with an afferent pupillary defect and disc swelling.

Question 4

What is papilloedema?

Answer 4

Swelling of the optic disc due to raised intracranial pressure, often causing transient visual obscurations.

Question 5

What are common visual symptoms of a stroke?

Answer 5

Homonymous hemianopia, visual neglect, or cortical blindness.

Question 6

What is the pathophysiology of optic neuritis?

Answer 6

Inflammation causes demyelination of the optic nerve, disrupting signal transmission to the brain.

Question 7

What are the risk factors for anterior ischaemic optic neuropathy (AION)?

Answer 7

Hypertension, diabetes, atherosclerosis, and giant cell arteritis.

Question 8

What is the main cause of papilloedema?

Answer 8

Increased intracranial pressure due to conditions such as a brain tumour, hydrocephalus, or idiopathic intracranial hypertension.

Question 9

What are the visual field changes in optic neuritis?

Answer 9

Central scotoma (central visual field defect).

Question 10

What are the visual field changes in a stroke?

Answer 10

Homonymous hemianopia (loss of the same side of the visual field in both eyes).

Question 11

What is a pituitary tumour’s effect on vision?

Answer 11

Bitemporal hemianopia due to compression of the optic chiasm.

Question 12

What is the role of MRI in optic neuritis?

Answer 12

To assess for optic nerve inflammation and rule out multiple sclerosis.

Question 13

What is the treatment for optic neuritis?

Answer 13

High-dose intravenous corticosteroids can be used to hasten recovery, especially in severe cases.

Question 14

What are the clinical signs of papilloedema on fundoscopy?

Answer 14

Blurred optic disc margins, elevated optic disc, and venous congestion.

Question 15

What is the differential diagnosis for visual loss with a neurological cause?

Answer 15

Optic neuritis, stroke, multiple sclerosis, brain tumours, and papilloedema.

Question 16

What is the afferent pupillary defect (APD), and when is it seen?

Answer 16

A relative APD is seen in conditions like optic neuritis and AION, where one optic nerve is impaired.

Question 17

What is the management of anterior ischaemic optic neuropathy (AION)?

Answer 17

Treat underlying conditions such as hypertension or diabetes and investigate for giant cell arteritis if suspected.

Question 18

What is the role of visual field testing in neurological vision loss?

Answer 18

To identify specific field defects that indicate the site of the lesion, such as hemianopia or scotomas.

Question 19

What systemic conditions are associated with optic neuritis?

Answer 19

Multiple sclerosis and other autoimmune conditions.

Question 20

What is cortical blindness?

Answer 20

Bilateral visual loss due to damage to the visual cortex, with preserved pupillary reflexes.

Question 21

How does idiopathic intracranial hypertension (IIH) affect vision?

Answer 21

Causes papilloedema, leading to transient visual obscurations and potential permanent vision loss if untreated.

Question 22

What are the symptoms of bitemporal hemianopia?

Answer 22

Loss of peripheral vision in both eyes, typically caused by optic chiasm compression from a pituitary tumour.

Question 23

Why is urgent treatment important in giant cell arteritis-related AION?

Answer 23

Delay in treatment can lead to permanent vision loss in both eyes and systemic complications.

Question 24

What investigations are needed for papilloedema?

Answer 24

Brain imaging (CT/MRI) and lumbar puncture to assess intracranial pressure.

Question 25

What is the prognosis for optic neuritis?

Answer 25

Vision usually improves within weeks to months, but recurrent episodes may occur in multiple sclerosis.