Cyclic Oculomotor Spasm

Question 1

What age does Cyclic Oculomotor Spasm tend to present?

Answer 1

In infancy/before the age of 2 with 90% of cases presenting before the age of 1 but there are acquired cases in adults described in the literature

Question 2

Is Cyclic Oculomotor Spasm progressive?

Answer 2

It’s rare and non-progressive

Question 3

What causes Cyclic Oculomotor Spasm?

Answer 3

Muscles innervated by the III cranial nerve undergo alternating rhythmic spasm and paralysis

• brief spasms of III nerve function alternates with complete or Partial III nerve palsy

Question 4

What does a cycle look like in Cyclic Oculomotor Spasm?

Answer 4

Cycle can consist of periods of ptosis and mydriasis alternating with eyelid retraction with miosis (Yazici, 2000).

Question 5

What are the two phases of Cyclic Oculomotor Spasm?

Answer 5

Paretic & Spastic Phase

Question 6

How long does the paretic phase of cyclic oculomotor spasm last and what are the symptoms?

Answer 6

Lasts 1-3 mins

III nerve palsy - ptosis, dilated pupil (mydriasis), reduced accommodation, exotropia/hypotropia

Question 7

How long does the spastic phase of cyclic oculomotor spasm last and what are the symptoms?

Answer 7

Lasts 30 -100 seconds
Every 2-3 minutes – lasts 30 – 100 secs

Ptotic lid elevates, pupil constricts (miosis), esotropia or orthophoria

Question 8

See slide 7 for images

Question 9

What is the aetiology of Cyclic Oculomotor Spasm?

Answer 9

It’s not fully understood but is likely due to a combination of central and peripheral nerve damage.

Also though to be due to a possible lesion in the supraclinoid portion of the ICA (internal carotid artery).

Question 10

What is the Supraclinoid portion of the ICA?

Answer 10

A segment of artery between the ophthalmic and posterior communicating arteries

Question 11

What are some congenital aetiologies for Cyclic Oculomotor Spasm?

Answer 11

• Injury: to CNIII at birth or in infancy
• Infection

Question 12

What are some acquired aetiologies for Cyclic Oculomotor Spasm?

Answer 12

• Intracranial lesions / Aneurysm compression on the IIIrd nerve
• Irradiation of the skull base to treat intracranial tumours

Question 13

What is the treatment for Cyclic Oculomotor Spasm?

Answer 13

There’s no effective treatment

• Medication such as carbamazepine and baclofen been unsuccessful
• Levator muscle transposition has been shown to stop cyclic eyelid movements in a limited case series (Manners et al 1996)
• If palsy becomes constant may consider ocular realignment surgery