[Direction-changing spontaneous nystagmus with simultaneous change in pupil diameter and eyelid interspace. Oculopupillomotor syndrome in blindness due to dysgenesis mesodermalis iridis et corneae Rieger].

Case report on a 47-year-old man who got blind during the last 10 years because of dysgenesis mesodermalis iridis et corneae Rieger. The patient showed an oculopupillomotor syndrome consisting of direction-changing spontaneous nystagmus and simultaneous changes of pupil diameter and eyelid interspace. The specific modification of direction, form, frequency, and amplitude of nystagmus under central influences such as emotional excitement, change of gaze, eye closure, head tilt, and other vestibular stimuli was registered electronystagmographically and is described in this paper. The unique oculomotor disturbance is compared pathogenetically with periodic oculomotor phenomena such as periodic alternating nystagmus, other types of direction-changing nystagmus, and uninhibited oculomotoricity of the blind. Loss of cerebellar inhibition mechanisms in the central pathogenesis of this syndrome is discussed hypothetically.