Spontaneous nystagmus direction does not indicate laterality.

There have been conflicting statements made in the literature on electronystagmograms (ENG) concerning the direction of beating of spontaneous nystagmus in the presence of a damaged labyrinth. This report presents a retrospective examination of 1,220 ENGs done at Stanford over the past four years with regard to the direction of spontaneous nystagmus and the side of the diseased labyrinth. The diseased labyrinth is indicated by a hypoactive caloric response. The study showed that one cannot predict the side of the labyrinthine lesion from the direction of beating of the spontaneous nystagmus.