Hereditary Congenital Conjugate Circumductory Nystagmus in Mother and Daughter

Abstract

A mother and a daughter showed similar spontaneous conjugate circumductory nystagmus. There was appreciable influence only of horizontal, not of vertical gaze positions. In the mother there was no conjugate null region without nystagmus and the waveform did not become jerky. Optokinetic nystagmus, horizontal or vertical, could not be elicited and the same was true of the vestibulo-ocular reflex, although there were sensations of self-rotation during vestibular stimulation. Oscillopsia was reported only during head movements. This particular type of pendu-lar nystagmus, in which the vertical and horizontal pendular components are (90°) out of phase so that the apex of the cornea describes a circular or ellipsoidal trajectory, has not been described and recorded before in a hereditary congenital variety.

Key Words:

• pendular nystagmus
• saccadic oscillations
• optokinetic nystagmus
• vestibulo-ocular reflex
• autosomal dominant inheritance