A seizure that is characterized by shock-like contractions involving a muscle or group of muscles.
Myoclonic seizures, formerly called minor motor seizures, are characterized by brief, involuntary muscle contractions and may affect one or many muscles bilaterally, although not necessarily symmetrically. A hand may suddenly fling out, a shoulder may shrug, a foot may kick, or the entire body mayjerk. It can occur as a single event or as a series of jerks. The abrupt jerking may affect the legs, causing the child to fall, or it may cause the child to drop or spill what he or she is holding. Myoclonic seizures should not be confused with tics, tremors, chorea, or startle responses. Tics can usually be suppressed—at least temporarily—by an effort of will, whereas myoclonus cannot; and myoclonus does not have the characteristic continuous flow of movements as in chorea or the smooth to-and-from movements of tremors.