Convergence nystagmus, with notes on a single case of divergence nystagmus.

Convergence nystagmus, as defined in this paper, is a rhythmic oscillation in which a slow abduction of the eyes in respect to each other is followed by a quick, and presumably corrective, movement of adduction. It must be an unusual finding, since it has been so little discussed in the literature. The only description of specific cases appears to be that of Furtado (1956), who reported two instances. 1 Kestenbaum (1946) referred to it in connection with nystagmus retractorius in the para-aqueductal syndrome 2 ; Walsh (1957) referred to it with spasms of convergence accompanying pinealomas, 3 and incidental allusions to it may be found in papers dealing with other entities. 4 As Furtado points out, however, it has not been considered a clear-cut entity. The present report is based on the observation of six patients with convergence nystagmus (and one with divergence nystagmus) studied with the particular aim of localizing