Rapid and uncontrollable jerking or spasm of one or more muscles either at rest or during movement. Myoclonus may be associated with a muscular or nervous disorder. It also occurs in healthy people, such as when the limbs twitch before sleep.
A brief, twitching muscular contraction which may involve only a single muscle or many muscles (see MUSCLE). It may be too slight to cause movement of the affected limb, or so violent as to throw the victim to the ?oor. The cause is not known, but in some cases may be a form of EPILEPSY. A single myoclonic jerk in the upper limbs occasionally occurs in minor motor epilepsy (petit mal). The myoclonic jerks which many people experience on falling asleep are a perfectly normal phenomenon.
n. a sudden spasm of the muscles. Occasional myoclonic jerks occur between seizures in patients with idiopathic *epilepsy, and myoclonus is a major feature of some progressive neurological illnesses with extensive degeneration of the brain cells (including the *spongiform encephalopathies). Myoclonic jerks on falling asleep (nocturnal myoclonus) occur in normal individuals. —myoclonic adj.
rhythmical contraction of the palatal muscles. There are two forms, ordinary and essential. Ordinary palatal myoclonus is idiopathic and can result in *pulsatile tinnitus. Essential palatal myoclonus has no link to pulsatile tinnitus but may be associated with lesions of the brainstem.... palatal myoclonus
Health Encyclopedia