Myoclonus
A condition of abnormal contraction of muscles or portions of muscles.
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One or a series of shock-like contractions of a group of muscles, of variable regularity, synchrony, and symmetry, generally due to a central nervous system lesion. [myo- + G. klonos, tumult]
- benign m. of infancy SYN: benign infantile m..
- benign infantile m. a seizure disorder of infancy in which myoclonic movements occur in the neck, trunk, and extremities; the EEG is normal, and seizures do not persist beyond 2 years of age. SYN: benign m. of infancy.
- m. multiplex an ill-defined disorder marked by rapid and widespread muscle contractions. SYN: paramyoclonus multiplex, polyclonia, polymyoclonus.
- nocturnal m. frequently repeated muscular jerks occurring at the moment of dropping off to sleep.
- palatal m. rhythmic contractions of the soft palate, the facial muscles, and the diaphragm, related to lesions of the olivocerebellar pathways. SEE ALSO: palatal nystagmus.
- stimulus sensitive m. m. induced by a variety of stimuli, e.g., talking, calculation, loud noises, tapping, etc.

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my·oc·lo·nus .mī-'äk-lə-nəs n irregular involuntary contraction of a muscle usu. resulting from functional disorder of controlling motor neurons also a condition characterized by myoclonus

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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 encephalopathy). Myoclonic jerks on falling asleep (nocturnal myoclonus) occur in normal individuals.
myoclonic adj.

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my·oc·lo·nus (mi-okґlo-nəs) [myo- + clonus] shocklike contractions of a portion of a muscle, an entire muscle, or a group of muscles, restricted to one area of the body or appearing synchronously or asynchronously in several areas. It may be part of a disease process (e.g., epileptic or post-anoxic myoclonus) or be a normal physiological response (e.g., nocturnal myoclonus). myoclonic adj

Medical dictionary. 2011.

Look at other dictionaries:

  • Myoclonus — Classification and external resources ICD 10 G25.3 ICD 9 333.2 …   Wikipedia

  • myoclonus — [mī äk′lə nəs] n. [ MYO + CLONUS] involuntary twitching or spasm of a muscle or muscles myoclonic [mī΄ō klän′ik] adj …   English World dictionary

  • myoclonus — 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… …   The new mediacal dictionary

  • myoclonus — noun Etymology: New Latin Date: 1883 irregular involuntary contraction of a muscle usually resulting from functional disorder of controlling motor neurons; also a condition characterized by myoclonus • myoclonic adjective …   New Collegiate Dictionary

  • myoclonus — /muy ok leuh neuhs/, n. Pathol. an abrupt spasm or twitch of a muscle or group of muscles, occurring in some neurological diseases. [1880 85; MYO + CLONUS] * * * …   Universalium

  • myoclonus — noun The brief, involuntary twitching of a muscle or group of muscles …   Wiktionary

  • myoclonus — n. muscular spasms (Pathology) …   English contemporary dictionary

  • myoclonus — [ˌmʌɪə(ʊ) kləʊnəs] noun Medicine spasmodic jerky contraction of groups of muscles. Derivatives myoclonic adjective …   English new terms dictionary

  • myoclonus — my·oc·lo·nus …   English syllables

  • myoclonus — my•oc•lo•nus [[t]maɪˈɒk lə nəs[/t]] n. pat an abrupt spasm or twitch of a muscle or muscles, occurring in some neurological diseases • Etymology: 1880–85 my•o•clon•ic ˌmaɪ əˈklɒn ɪk adj …   From formal English to slang

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