Vertical nystagmus in infants with congenital ocular abnormalities.
In a series of 131 patients with congenital nystagmus, nine patients initially presented with vertical nystagmus associated with congenital ocular abnormalities. Four patients initially presented with upbeating nystagmus. All four of these patients had Leber's amaurosis. The upbeating nystagmus became horizontally directed in three of the four patients prior to one year of age. The other patient is now eight years old and upbeating nystagmus persists. CT scanning reveals cerebellar vermis hypoplasia in this patient. Five patients with albinism in this series presented initially with seesaw nystagmus. In two cases this resolved to one year of age, but in the other three cases, it is still intermittently seen in children ranging in age from two and a half to five years old. Vertically directed nystagmus may be associated with some ocular abnormalities in infancy and is not always a sign of isolated neurologic disorders.