The term myoclonus is used clinically to describe a wide variety of suddenly appearing involuntary movements or jerks not otherwise readily classified.1-18 These myoclonic movements may be generalized, segmental, or even limited to one muscle or muscle group. They vary in force and complexity from mere muscular twitches to coordinated movements sufficiently violent to displace one or more limbs, or throw the subject to the ground. They may be isolated, intermittent, and of short duration, as in the myoclonus accompanying certain epileptic states. On the other hand, they may continue repetitively over prolonged periods of time. The movements, when widespread, frequently appear synchronously throughout many parts of the body, or present first in one region before bursting forth successively in others. In some instances the explosive outbursts seem to follow a definite rhythm; in others they are rather irregular in time. It seems evident, therefore, that clinical patterns implied
LUTTRELL CN, BANG FB, LUXENBERG K. Newcastle Disease Encephalomyelitis in Cats: II. Physiological Studies on Rhythmic Myoclonus. AMA Arch NeurPsych. 1959;81(3):285–291. doi:10.1001/archneurpsyc.1959.02340150017002
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