Glossary of Sleep-related terms


A brief and involuntary contraction of one or several muscles which displaces a segment of a limb, a whole limb, or even the entire body in a jerk-like movement. It may be normal as in the bilateral myoclonus of falling asleep ("nocturnal starts") or the fragmentary myoclonus ("twitching") or REM sleep, or pathological, as in various forms of epileptic myoclonus (the "startle disease") or fragmentary myoclonus of various degenerative brain diseases.4