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Upbeat nystagmus and its causes

Upgaze nystagmus is a  Central vestibular disorders -Pitch plane disorder

  • Nystagmus with fast phase upwards in primary position it  worsens on upward gaze

Where is the site of lesion?

  • The site of lesion is Tegmentum of the pontomesencephalic region (either the SCP orVTT) 

SCP - superior cerebellar peduncle or VTT - vestibulotegmental tract.

  • Pontomedullary junction (NPH)

What are the causes of Upbeat nystagmus ?

  • CVD, MS.
  • Cerebellar degeneration.
  • Wernicke's encephalopathy
  • Encephalitis