Definitions for "Myoclonus"
These are brief, "jumping", jerking movements. Some myoclonus is normal (during or just before sleep, for example). However it can be a feature of certain diseases, especially, but not only, CJD.
Muscle contractions in the form of "jerks" or twitches. In sleep-related (nocturnal) myoclonus, the jerks are primarily of the flexor groups in the lower extremities and have a characteristic frequency of 20-40 seconds.
rapid, brief, shock-like muscle jerks.