Ｏｃｕｌｏｐａｌａｔａｌ ｍｙｏｃｌｏｎｕｓの２症例

Abstract

We describe here two patients with oculopalatal myoclonus (OPM) after brainstem hemorrhage.The first patient, a 56-year-old hypertensive woman, had regular, persistent, vertical pendular oscillations (frequency 2.2Hz, amplitude 3-13 degrees) and palatal myoclonus which was purely vertical at the same frequency of ocular oscillation. The first case represented the midline form of OPM.The second patient, a 60-year-old man had regular, persistent jerky nystagmoid horizontal oscillations (frequency 1.3Hz, amplitude 2-4 degrees), palatal myoclonus which jerked obliquely to the left, and myoclonus of the upper lip and larynx. The second case represented the lateral form of OPM.The term myoclonus has been applied to a variety of involuntary, short-term, shocklike contractions of one or more muscles. In this meaning, “ocular myoclonus” is misleading, because it is a regular, rhythmic ocular oscillation which is persistent. Therefore, “ocular myoclonus” has frequently been confused with opsoclonus, which is a chaotic, rapid, involuntary ocular oscillation. We suggest that “rhythmic ocular myoclonus” or OPM is appropriate instead of the term “ocular myoclonus”.