• Nystagmus = involuntary eye movement
  • The semicircular canals of the vestibules and the extraocular muscles of the eye function together physiologically to help control gaze when the head is in motion
  • Nystagmus is an aberration in this stabilization of the ocular muscles when the head is in motion

Clinical Features

  • Rapid, uncontrolled, rhythmic oscillation of the eye
  • May be horizontal, vertical, and/or rotary

Differential Diagnosis

Congenital Nystagmus

Acquired Nystagmus


  • Differentiate monocular vs. binocular
    • Monocular suggests medial pontine stroke or medial longitudinal fasciculus damage
    • Look for contralateral internuclear opthalmoplegia (INO)
  • Differentiate between central versus peripheral lesions[1]
Central Peripheral
Pure vertical, pendular, or rotaryHorizontal
Fast beat towards lesionsFast beat away from lesion
Not relieved by gaze fixationRelieved by gaze fixation
Cerebellar signsNo cerebellar signs

Optokinetic Drum Test

  • Optokinetic reflex develops ~6 months of age
  • Slow pursuit of eyes towards direction of vertical bar movement with quick saccade towards the opposite side to find the next bar to fixate on
  • Abnormal in congenital nystagmus
  • In parietal or parietal-occipital lesions, optokinetic nystagmus is impaired when the drum is rotated towards side of lesion

"H in space" Test

  • Trace H in space

Caloric Reflex Test (also known as Vestibular Caloric Stimulation)

  • The best clinical test for the Vestibulo-Optic reflex
  • Water irrigated into the external auditory canal will exaggerate nystagmus if present
  • Temperature of the irrigated water will control the direction.
    • Cold water will exaggerate a nystagmus to move contralaterally
    • Warm water will exaggerate a nystagmus to move ipsilaterally

COWS: Cold Opposite, Warm Same.


Stabilize patient and manage primary cause of illness.


See Also


  1. Bardorf CM et al. Acquired Nystagmus Clinical Presentation. Updated My 13, 2016. http://emedicine.medscape.com/article/1199177-clinical?src=refgatesrc1#b4.
This article is issued from Wikem. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.