Opthalmoplegia

Question 1

H test: Movement of superior oblique

Answer 1

Looking medially and inferiorly

Question 2

H test: Movement of inferior rectus

Answer 2

Looking laterally and inferiorly

Question 3

Elements of an ophthalmoplegia examination

Answer 3

Inspect the eye: Ptosis, alignment, pupil sizes
Ask patient to tell you if they get double vision
Use H test:
Ophthalmoplegia
Diplopia (do cover test)
Nystagmus
Saccades: vertical and horizontal

Question 4

Determining which eye is affected in diplopia

Answer 4

Outer image disappears when affected eye is covered

Question 5

Features of 3rd nerve palsy

Answer 5

Complete ptosis
Down and out in rest position
± dilated, non-reactive pupil
Diplopia maximal when looking supero-medially (opposite of resting pupil position)

Question 6

Features of 4th nerve palsy

Answer 6

Slight head tilt: ocular torticollis
Appear normal in rest position
Failure to depress eye in adduction (i.e. cannot look infero-medially)
Diplopia maximal down and in
Ask if patient has trouble walking down stairs

Question 7

Features of 6th nerve palsy

Answer 7

Appear normal in resting position
Failure to abduct
Diplopia maximal in abduction
Commonly a sign of raised ICP (‘false localising sign’)

Question 8

Causes of simple ocular palsies (CN3 or CN4 or CN6)

Answer 8

CNS: MS, vascular, SOL
PNS: DM (mononeuritis), compression, trauma

Question 9

Investigations for simple ocular palsies

Answer 9

Urine dip: glucose
Bloods: glucose and HbA1c
imaging: MRI brain

Question 10

Internuclear ophthalmoplegia signs on examination

Answer 10

Failure of ipsilateral adduction
Nystagmus in the contralateral abducting eye
May be bilateral
Convergence preserved

Question 11

Neruophysiology of internuclear ophthalmoplegia

Answer 11

To maintain convergent gaze, median longitudinal fasciculus (MLF) yokes together the nuclei of CN3 and CN6.
Pontine centre for lateral gaze initiates movement and outputs to CN3 nucleus and CN6 nucleus via MLF. Failure of adduction is ipsilateral to MLF lesion.

Question 12

Causes of internuclear opthalmoplegia

Answer 12

Multiple sclerosis
Infarct
Syringomyelia
Phenytoin toxicity

Question 13

Diagnosing complex ophthalmoplegia

Answer 13

Dx of exclusion

Ophthalmoplegia doesn’t fit a single pattern

Question 14

Causes of complex ophthalmoplegia

Answer 14

DM (mononeuritis multiplex)
MS
Myasthenia gravis
Thyrotoxicosis

Question 15

investigations for complex ophthalmoplegia

Answer 15

Urine dip: glucose
Bloods: DM (glucose + HbA1c), TFT (low TSH), MG (anti-AChR antibodies)
MRI brain: plaques in periventricular white matter