Cyclic oculomotor paralysis

Abstract

Cyclic oculomotor paralysis is a rare, benign motility disorder. Because the onset is usually before the age of two, it is often mistaken for a congenital third nerve paralysis. The correct diagnosis can be reached easily, however, by observation over a five minute period. The cyclic changes that occur are pathognomonic. The paralytic phase, during which the eyelid is ptotic, the pupil dilated and unresponsive to light, and the globe down and out, is succeeded by a spastic phase heralded by twitching movements of the lid. The marked twitching of the lid in our patient produced a striking, intermittent artifact in the electroencephalogram.