Opthalmoplegia Flashcards Preview

Alasdair - Neurology > Opthalmoplegia > Flashcards

Flashcards in Opthalmoplegia Deck (15):
1

H test: Movement of superior oblique

Looking medially and inferiorly

2

H test: Movement of inferior rectus

Looking laterally and inferiorly

3

Elements of an ophthalmoplegia examination

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

4

Determining which eye is affected in diplopia

Outer image disappears when affected eye is covered

5

Features of 3rd nerve palsy

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

6

Features of 4th nerve palsy

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

7

Features of 6th nerve palsy

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

8

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

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

9

Investigations for simple ocular palsies

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

10

Internuclear ophthalmoplegia signs on examination

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

11

Neruophysiology of internuclear ophthalmoplegia

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.

12

Causes of internuclear opthalmoplegia

Multiple sclerosis
Infarct
Syringomyelia
Phenytoin toxicity

13

Diagnosing complex ophthalmoplegia

Dx of exclusion
Ophthalmoplegia doesn't fit a single pattern

14

Causes of complex ophthalmoplegia

DM (mononeuritis multiplex)
MS
Myasthenia gravis
Thyrotoxicosis

15

investigations for complex ophthalmoplegia

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