Oculomotor paresis with cyclic spasms. A critical review of the literature and a new case.

Oculomotor paresis with cyclic spasms is a rare syndrome, usually noticeable at birth or developing during the first year of life. On a background of oculomotor paresis, spastic movements occur at regular intervals: about every second minute the lid is raised, the globe wanders toward midline, the pupil contracts, and accomodation increases. These spasms last from 10 to 30 seconds, and then give way again to paresis. Since this phenomenon was first described, opinions were divided about its mechanism and about the site of the responsible defect. Based on a quantitative analysis of a new case, and of all previously published reports, a new theory is proposed which can account for all features of the syndrome.