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Flashcards in Nerve Palsies Deck (21)
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1

Abduction issues are often as a result of an issue with which muscle and which nerve?

Lateral rectus

Abducens nerve

2

For which reasons may the abducens nerve fail to fucntion correctly?

  1. Microvascular causes
  2. Raised ICP
  3. Tumour
  4. Congenital

3

Why does raised ICP cause the abducens nerve to often fail?

It is compressed onto the petrous tip of the temporal bone

4

How will a fourth nerve palsy present?

Reduced depression in adduction

 

5

With which nerve palsy will a head tilt often be seen and why?

Trochlear

Attempted correction of double vision

6

What are the causes for a 4th nerve palsy?

  1. Congenital (most common)
  2. Microvascular
  3. Tumour
  4. Trauma

7

How does a 3rd nerve palsy present?

Eye down and out

8

What are the causes for a 3rd nerve palsy?

  1. Microvascular
  2. Tumour
  3. Aneurysm (often life threatening)
  4. Multiple sclerosis
  5. Congenital

9

Which vessel is often affected by aneurysm in a 3rd nerve palsy?

Posterior communicating artery

10

The following clinical signs are indicative of what?

  1. Pain in the back of the head
  2. Large pupil
  3. Ptosis

Posterior communicating artery aneurysm

(causing a third nerve palsy)

11

What causes homonymous hemionopia?

Damage to temporal nerve fibres from one eye and nasal fibres from the other eye

(this happens after the optic chiasm)

12

What can can cause optic nerve defects?

  1. Ischaemic optic neuropathy
  2. Optic neuritis
  3. Tumours

13

What is internuclear ophthalmoplegia?

The affected eye cannot abduct

The other eye abducts but with nystagmus

 

14

What can cause internuclear ophthalmoplegia?

  1. MS
  2. Vascular causes
  3. Many others

15

How quickly is vision lost with optic neuritis?

Gradually

16

What may be the cause for an visual field defect originating at the optic chiasm?

  1. Pituitary tumour
  2. Craniopharyngioma
  3. Meningioma

17

Which type of defect will a optic chiasm problem induce?

Bi-temporal field defect

18

What are the main causes for visual field defects originating in the optic tracts and radiations?

  1. Tumours
  2. Demyelination
  3. Vascular abnormalities

19

Which type of visual field defects are associated with the optic tracts and radiations?

Homonomous defects

(sometimes quadrantanopia)

20

What are the main causes for a visual field defect originating in the occipital cortex?

  1. Vascular disease
  2. Demyelination

 

21

How do visual field defects originating in the occipital cortex differ from those which originate in the optic tract/radiations?

Macula is spared