horizontal jerky nystagmus

Last reviewed 04/2022

Jerky horizontal nystagmus occurs when the oscillations are in a horizontal direction.

Causes include:

  • vestibular lesion:
    • nystagmus away from the side of the lesion
  • cerebellar lesion:
    • unilateral cerebellar disease causes nystagmus to the side of the lesion
  • toxic causes e.g. phenytoin and alcohol
  • internuclear ophthalmoplegia:
    • in this case, nystagmus is greater in the abducting eye with failure of adduction on the affected side
    • due to a lesion in the medial longitudinal fasciculus
  • Wernicke's encephalopathy

The commonest cause of unilateral nystagmus is multiple sclerosis.

The commonest cause of bilateral nystagmus is vascular disease.