Ophthalmoplegia

Question 1

What signs and symptoms would you expect with a 3rd nerve palsy?

Answer 1

• Complete ptosis (LPS)
• Down and out in primary position
• +/- dilated non-reactive pupil
• Diplopia maximal on adduction and elevation

Question 2

What signs and symptoms would you expect with a 4th nerve palsy?

Answer 2

• Slight head tilt: Ocular torticollis
• Appear normal in rest position
• Failure to depress eye in adduction
• Diplopia maximal in down and in
• Ask if the patient has trouble walking down stairs
• Rare station

Question 3

What signs and symptoms would you expect with a 6th nerve palsy?

Answer 3

• Appear normal in resting position
• Failure to abduct
• Diplopia maximal in abduction
• Commonly a false localising sign of raised ICP: contralateral lesion

Question 4

What are some causes for isolated nerve palsies?

Answer 4

• Central:
  
  • MS
  • Vascular
  • SOL
• Peripheral:
  
  • DM (mononeuritis)
  • Compression
  • Trauma

Question 5

How would you investigate someone with an isolated nerve palsy?

Answer 5

• Urine dip: glucose
• Bloods: Glucose + HbA1c
• Imaging: MRI brain

Question 6

What is the definition of ophthalmoplegia?

Answer 6

Paralysis of the muscles within or surrounding the eye

Question 7

What is internuclear ophthalmoplegia?

Answer 7

A condition characterised by the failure of ipsilateral adduction

Question 8

What are the signs and symptoms of internuclear ophthalmoplegia?

Answer 8

• Failure of ipsilateral adduction (characteristic)
• Nystagmus in the contralateral abducting eye (may be absent)
• May be bilateral
• Convergence preserved
• Patient may complain of diplopia on looking to the contralateral direction
• Adduction becomes normal when the contralateral (abducting) eye is covered

Question 9

What are the causes of internuclear ophthalmoplegia?

Answer 9

Demyelination: MS (most common)

Infarct: Ischaemia or haemorrhage

Syringomyelia

Iatrogenic: Phenytoin toxicity

NB: MG may cause a pseudo-internuclear ophthalmoplegia

Question 10

What is the cause of internuclear ophthalmoplegia?

Answer 10

Lesion in the ipsilateral medial longitudinal fasciculus (i.e. the lesion is ipsilateral to the side that cannot adduct)

Question 11

What is a complex ophthalmoplegia?

Answer 11

Ophthalmoplegia that does not fit a single pattern- diagnosis of exclusion

Question 12

What are some causes of a complex ophthalmoplegia?

Answer 12

• DM (mononeuritis multiplex)
• MS
• MG
• Thyrotoxicosis

Question 13

How would you investigate a patient with a complex ophthalmoplegia?

Answer 13

• Bedside: Urine dip
• Bloods:
  
  • DM: Glucose, HbA1c
  • TFT: Reduced TSH
  • MG: Anti-AChR antibodies
• Imaging:
  
  • MRi brain- plaques in periventricular white matter