Clonus

Clonus

Clonus (from the Greek for "violent, confused motion") is a series of involuntary muscular contractions and relaxations. Clonus is a sign of certain neurological conditions, and is particularly associated with upper motor neuron lesions such as in stroke, multiple sclerosis, spinal cord damage and hepatic encephalopathy. Unlike the small, spontaneous twitching known as fasciculations (usually caused by lower motor neuron pathology), clonus causes large motions that are usually initiated by a reflex.

Clonus is most common in the ankles, where it is tested by rapidly flexing the foot upward (dorsiflexion). It can also be tested in the knees by rapidly pushing the patella (knee cap), towards the toes. Only sustained clonus (5 beats or more) is considered abnormal.

Clonus appearing after ingesting potent serotonergic drugs strongly predicts imminent serotonin toxicity (serotonin syndrome).

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  • Clonus — (del latin clonus y este del Griego klonós, que refiere a movimiento violento, confuso) es un término médico usado para describir uno de los signos de ciertas alteraciones neurológica que consiste en la aparición involuntaria de contracciones… …   Wikipedia Español

  • clonus — [ klɔnys ] n. m. • 1862; du gr. klonos « agitation » ♦ Méd. Contraction rythmique déclenchée par la traction brusque de certains muscles, traduisant une exagération des réflexes. Clonus de la rotule, du pied, de la main. ● clonus nom masculin… …   Encyclopédie Universelle

  • clonus — clónus s. n. Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  CLÓNUS s.n. (med.) Serie de convulsii (1), denotând existenţa unei leziuni a centrilor nervoşi motori superiori; clonie. [< fr. clonus, cf. gr. klonos – agitaţie]. Trimis …   Dicționar Român

  • clonus — m. neurol. Serie de contracciones rítmicas e involuntarias de un músculo estriado o conjunto de ellos provocada por la extensión pasiva y brusca de sus tendones; es un consecuencia de una lesión de la vía piramidal, pero también se observa en el… …   Diccionario médico

  • Clonus — Clo nus, n. [NL., fr. Gr. klo nos violent, confused motion.] (Med.) A series of muscular contractions due to sudden stretching of the muscle, a sign of certain neuropathies. [Webster 1913 Suppl.] …   The Collaborative International Dictionary of English

  • Clonus — vgl. Klonus …   Das Wörterbuch medizinischer Fachausdrücke

  • clonus — (n.) violent muscular spasms, 1817, from Modern Latin, from Gk. klonos turmoil, violent motion, confusion, tumult, from PIE *kel to drive, set in motion …   Etymology dictionary

  • clonus — [klō′nəs] n. [ModL < Gr klonos, turmoil < kelomai, to start, impel < IE base * kel > HOLD1, < L celer, swift] a series of muscle spasms induced by sudden stretching or certain nervous diseases: see TONUS …   English World dictionary

  • Clonus — 1Clo|nus der; , se <über nlat. clonus aus gr. klo̅n »Schössling, Zweig«> svw. ↑Klon. Clonus 2 2Clo|nus der; , se <zu 1↑Clonus> ohne natürliche Zeugung aus lebenden Zellen entwickelter künstlicher Mensch …   Das große Fremdwörterbuch

  • Clonus — Un clonus est une série de contractions rapides et réflexes apparaissant suite à l’étirement brusque de certains muscles. Le clonus est le témoin d’une lésion du faisceau pyramidal. Portail de la médecine Catégorie : Signe cli …   Wikipédia en Français

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