cat·​a·​plexy ˈka-tə-ˌplek-sē How to pronounce cataplexy (audio)
plural cataplexies ˈka-tə-ˌplek-sēz How to pronounce cataplexy (audio)
: sudden loss of muscle power following a strong emotional stimulus

Examples of cataplexy in a Sentence

Recent Examples on the Web In addition to sleep disturbance, most people with Type 1 narcolepsy experience sudden, temporary loss of muscle control or paralysis, called cataplexy. Tribune News Service, Hartford Courant, 15 Jan. 2024 How is cataplexy treated? Sarah Fielding,, 6 Dec. 2021 People with cataplexy, a rare condition tied to narcolepsy, may suddenly lose all their muscle strength and collapse during a fit of laughter. Elizabeth Preston, Discover Magazine, 29 Aug. 2014 Not all narcoleptics experience cataplexy, but those who do may lose all strength in their muscles during moments of strong emotion. Elizabeth Preston, Discover Magazine, 30 Aug. 2011 But this view ignores narcolepsy's most ridiculous symptom, called cataplexy. Elizabeth Preston, Discover Magazine, 30 Aug. 2011 According to the Mayo Clinic, the frequency of cataplexy varies tremendously case by case. Sarah Fielding,, 3 Dec. 2021 Symptoms such as hallucinations, sleep paralysis, and cataplexy may follow, says Manjamalai Sivaraman, MD, FAASM, a sleep medicine specialist and neurologist at the University of Missouri. Sarah Fielding,, 8 Dec. 2021 Excessive daytime sleepiness and cataplexy can improve after several weeks of regularly taking sodium oxybate. Sarah Fielding,, 6 Dec. 2021

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cataplexy.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


German Kataplexie, from Greek kataplēxis, from kataplēssein to strike down, terrify, from kata- + plēssein to strike — more at plaint

First Known Use

1883, in the meaning defined above

Time Traveler
The first known use of cataplexy was in 1883

Dictionary Entries Near cataplexy

Cite this Entry

“Cataplexy.” Dictionary, Merriam-Webster, Accessed 14 Jul. 2024.

Medical Definition


cat·​a·​plexy ˈkat-ə-ˌplek-sē How to pronounce cataplexy (audio)
plural cataplexies -sēz How to pronounce cataplexy (audio)
: 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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