title: Downbeat nystagmus with a pseudocycloid waveform: improvement with base-out prisms.
abstract: 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: D000328:Adult; D005133:Eye Movements; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006939:Hyperemesis Gravidarum / Q000150:complications*; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014792:Visual Acuity; D014899:Wernicke Encephalopathy / Q000150:complications*