Abstract

Direct current electronystagmographic recordings of spontaneous nystagmus in light, in darkness, and with eye closure have been carried out on (a) 33 patients with acoustic neurinomata pressing on the brain stem, and (b) 10 patients with lesions involving the brain stem at a high level. Patterns of response characteristics of each group have been identified in 21 out of 28 cases of group a, the spontaneous nystagmus present in light was abolished by eye closure and inhibited in darkness, nystagmus being absent in the remaining five; in group b the greater proportion (70-80%) of patients presented with spontaneous nystagmus in light which was abolished by both eye closure and darkness.