3rd Nerve Palsy

Question 1

What are the 7 syndromes

Answer 1

• nuclear palsy
• fasicular lesion
• uncal herniation syndrome
• posterior communications artery
• pupil sparing 3rd nerve palsy
• cavernous sinus syndrome/superior orbital fissure syndrome
• orbital syndrome

Question 2

What is a nuclear palsy

Answer 2

• nuclear 3rd requires paresis of the contralateral SR
• nuclear 3rd has bilateral ptosis

Question 3

4 syndromes associated with fasicular lesion

Answer 3

Benediks syndrome
- possible tremour

• dorsal lesion has palsy on the same side

Nothnagels syndrome
- lesion of superior cerebellar peduncle
- ipsilateral 3rd nerve palsy
- ipsilateral cerebellar ataxia

Webers syndrome
- dorsal lesion in cerebral peduncle
- ipsilateral 3rd and contralateral hemiplegia

Claude’s syndrome
- features of benedikts and nothnagels

Question 4

What is uncal herniation syndrome

Answer 4

• 3rd nerve rests on tentorium cerebelli
• a tumour above this causes downward displacement and compresses the nerve
• dilated and fixed pupil, sign of space occupying lesion

Question 5

Features of posterior communicating artery lesion

Answer 5

• circle of Willis, can balloon due to aneurysm
• can press on nerve causing palsy affecting pupil and lids
• severe headache

Question 6

Pupil sparing 3rd nerve palsy

Answer 6

• pupilomotor fibres travel in outer layers of the nerve
• closer to nutrient supply
• 80% of ischemic 3rd nerve palsies have pupil sparing
• 95% of compressive palsies do not have pupil sparing

Question 7

What is cavernous sinus syndrome/superior orbital fissure syndrome

Answer 7

• idiopathic granulomatous inflammation
• may cause painful ophthalmoplegia involves 4th, 3rd and 6th nerve
• tolosa-hunt syndrome

Question 8

What is orbital syndrome

Answer 8

• unilateral palsy
• isolated palsy
• compression or vascular
• all unilateral palsy is orbital
• myasthenia gravis can mimik

Question 9

Aetiologies

Answer 9

• ischemic
• tumours
• inflammatory conditions
• metabolic disorders
• ophthalmoplegic migraine
• trauma
• dental anaesthesia

Question 10

Congenital 3rd features

Answer 10

• less common
• most unilateral
• ptosis and paresis
• miosed pupils
• absent or incomplete nerve nucleus

Question 11

Management of congenital

Answer 11

• surgery of ptotic lid
• squint surgery
• poor prognosis
• prevention of stimulus deprivation amblyopia by ptosis

Question 12

Management of acquired

Answer 12

• aetiology
• may have incomplete recovery
• review every 3/4 weeks
• fresnel prisms
• may require surgery

Question 13

Surgery for 3rd nerve palsy

Answer 13

• large recession of LR up to 12mm, with large resection of MR
• SO tenectomy can reduce hypotropia
• transposition of vertical can reduce hypotropia
• nasal transposition of SO
• resection of vertical recti on opposite eye if vertical strabismus
• resect horizontal recti if persistent horizontal deviation
• ptosis is corrected after ocular alignment and sling procedure is best

Question 14

Posterior communicating artery vs carotid artery

Answer 14

• carotid artery wont have pupil dilation if sympathetic fibres are affected