A debilitating medical condition in which a person suddenly feels weak and collapses at moments of strong emotion such as laughter, anger, fear or surprise. In so collapsing, people with cataplexy may injure themselves. Laughter and other emotions trigger a reflex in persons that can bring many of the muscles of the body to the point of collapse. The phenomenon can be measured by sending electric signals through the muscles and gauging their response. In cataplexy, what is known as the H-reflex, a neurological pathway that causes muscle contractions, virtually disappears. Cataplexy often affects people who have narcolepsy, a disorder in which there is great difficulty remaining awake during the daytime. The word "cataplexy" comes from the Greek "kata" meaning "down" + "plexis" meaning a stroke or seizure = a falling-down seizure.
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A transient attack of extreme generalized weakness, often precipitated by an emotional response, such as surprise, fear, or anger; one component of the narcolepsy quadrad. [cata- + G. plexis, a blow, stroke]

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cat·a·plexy 'kat-ə-.plek-sē n, pl -plex·ies -sēz a sudden loss of muscle control with retention of clear consciousness that follows a strong emotional stimulus (as elation, surprise, or anger) and is a characteristic symptom of narcolepsy

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a sudden onset of muscle weakness that may be precipitated by excitement or emotion. There may be total loss of muscle tone, resulting in collapse, or simply jaw dropping or head nodding. It occurs in 60-90% of patients with narcolepsy.

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cat·a·plexy (katґə-plek″se) a condition in which there are abrupt attacks of muscular weakness and hypotonia triggered by an emotional stimulus such as mirth, anger, fear, or surprise. It is often associated with narcolepsy.

Medical dictionary. 2011.

Look at other dictionaries:

  • Cataplexy — Cat a*plex y, n. [Gr. ? amazement: cf. {Apoplexy}.] (Med.) A morbid condition caused by an overwhelming shock or extreme fear and marked by rigidity of the muscles. {Cat a*plec tic}, a. [Webster 1913 Suppl.] …   The Collaborative International Dictionary of English

  • cataplexy — (n.) the state of an animal when it is feigning death, 1883, from Ger. kataplexie, from Gk. kataplexis stupefaction, amazement, consternation, from kataplessein to strike down (with fear, etc.), from kata down (see CATA (Cf. cata )) + plessein to …   Etymology dictionary

  • Cataplexy — Infobox Disease Name = PAGENAME Caption = DiseasesDB = 16311 ICD10 = ICD10|G|47|4|g|40 ICD9 = ICD9|347 ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = MeshID = D002385 Cataplexy is a medical condition which often affects people who… …   Wikipedia

  • cataplexy — noun (plural cataplexies) Etymology: German Kataplexie, from Greek kataplēxis, from kataplēssein to strike down, terrify, from kata + plēssein to strike more at plaint Date: 1883 sudden loss of muscle power following a strong emotional stimulus …   New Collegiate Dictionary

  • cataplexy — n. [Gr. kata, down; plessein, to strike] Feigning death; see catalepsy …   Dictionary of invertebrate zoology

  • cataplexy — cataplectic, /kat euh plek tik/, adj. /kat euh plek see/, n. Pathol. a condition characterized by sudden, brief attacks of muscle weakness sometimes causing the body to fall helplessly, that is usually triggered by strong emotion: often… …   Universalium

  • cataplexy — noun /ˈkætəplɛksi/ An abrupt loss of muscle tone, sometimes associated with narcolepsy …   Wiktionary

  • cataplexy — n. paralysis, shock …   English contemporary dictionary

  • cataplexy — [ katəˌplɛksi] noun a medical condition in which strong emotion or laughter causes a person to suffer sudden physical collapse though remaining conscious. Derivatives cataplectic adjective Origin C19: from Gk kataplēxis stupefaction , from… …   English new terms dictionary

  • cataplexy — cat·a·plexy …   English syllables