How is myoclonus distinguished from chorea and tics?
Myoclonus is defined as a brief, sudden, shock-like jerk that may be caused not only by active muscle contractions (positive myoclonus) but also by lapses of muscle contraction (negative myoclonus).
Many of the individual movements of chorea are myoclonic, but, unlike myoclonus, they are continuous, occurring in a constant flow.
Tics may resemble myoclonus, but they are usually preceded by premonitory feelings, and patients usually have some degree of control over them.
