Cataplexy is best described as what?

• A. Cataplexy is a sleep paralysis
• B. Cataplexy is daytime confusion
• C. Nightly hallucinations
• D. Cataplexy is sudden loss of muscle tone often triggered by emotion

Answer: (D)

Cataplexy is a sudden loss of voluntary muscle tone that occurs while you are awake, often triggered by strong emotions such as laughter or anger. This brief collapse can range from a limp facial expression to a full collapse, but you remain fully conscious. It is a hallmark feature of narcolepsy type 1, reflecting intrusion of REM sleep–related muscle atonia into wakefulness. Sleep paralysis, by contrast, happens at the transition between sleep and wake and involves being unable to move despite being awake, often with a sense of pressure or fear. Nightly or hypnagogic/hypnopompic hallucinations are vivid dream-like experiences at sleep onset or wakefulness. Therefore, the description that matches cataplexy is the sudden loss of muscle tone often triggered by emotion.