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myoclonus vs. clonus

[mahy-ok-luh-nuhs] / maɪˈɒk lə nəs /

noun

Pathology.
  1. an abrupt spasm or twitch of a muscle or group of muscles, occurring in some neurological diseases.

[kloh-nuhs] / ˈkloʊ nəs /

noun

Pathology.

plural

clonuses
  1. a rapid succession of flexions and extensions of a group of muscles, usually signifying an affection of the brain or spinal cord.