Downbeat nystagmus with a pseudocycloid waveform: improvement with base-out prisms

Ann Neurol. 1983 Jun;13(6):621-4. doi: 10.1002/ana.410130607.


Downbeat nystagmus in primary position and oscillopsia resulted from nutritional deficiency during prolonged intravenous therapy of a patient with hyperemesis gravidarum. Wide bandwidth infrared oculography demonstrated a pseudocycloid nystagmus waveform with an increasing-velocity exponential slow phase. Because the oscillopsia decreased and the nystagmus was damped with convergence, visual acuity improved with the addition of base-out prisms to each spectacle lens.

MeSH terms

  • Adult
  • Eye Movements
  • Eyeglasses
  • Female
  • Follow-Up Studies
  • Humans
  • Hyperemesis Gravidarum / complications*
  • Nystagmus, Pathologic / diagnosis
  • Nystagmus, Pathologic / etiology*
  • Nystagmus, Pathologic / therapy
  • Pregnancy
  • Pregnancy Trimester, First
  • Visual Acuity
  • Wernicke Encephalopathy / complications*