Diplopia

Question 1

What is a typical presentation of CN 3 palsy?

Answer 1

Down and out appearance
Ptosis
Mydriasis

Question 2

What muscle does CN 6 innervate? Which movement does this muscle produce?

Answer 2

Lateral rectus

Responsible for lateral movement of the eyeball

Question 3

Which muscles does CN 3 innervate?

Answer 3

Superior rectus, inferior rectus, inferior oblique, medial rectus
Levator palpebrae superioris
Also responsible for pupil constriction

Question 4

Which muscle does CN4 innervate?

Answer 4

Superior oblique

Question 5

With 4th nerve palsy, in which direction is the diplopia worse?

Answer 5

Downgaze (vertical diplopia)

Question 6

How do people with CN4 palsy compensate?

Answer 6

Head tilt opposite to the affected SO muscle

Question 7

How does the affected eye in CN4 palsy present?

Answer 7

Hypertropic - involved eye is higher

Question 8

How does CN6 palsy present?

Answer 8

Unable to abduct the eye fully on the affected side

Question 9

What are some causes of CN3 palsy

Answer 9

Vascular - e.g. diabetes, heart disease (PCA)
Infection
Trauma
MS
MG
Tumour

Question 10

What is a common traumatic deformity that can cause double vision?

Answer 10

Orbital blowout fracture

Question 11

In an orbital blowout fracture which parts are commonly affected?

Answer 11

Orbital floor and/or medial orbital wall

Question 12

Signs and symptoms of orbital blowout fracture?

Answer 12

Pain
Enophthalmos
Limitation of eye movement
Hypoesthesia (loss of sensation) along T2 nerve distribution
Vertical diplopia
Subcutaneous emphysema (gas/air under the skin)

Question 13

Treatment of third nerve palsy

Answer 13

Possible spontaneous recovery in 6 months
Removing pressure from nerve (tumour/aneurysm)
Patching
Prism lenses