You searched for: “cataplexy
cataplexy (s) (noun), cataplexies (pl)
1. 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: When such collapsing results, people with cataplexy may seriously injure themselves.

Sometimes, laughter and other emotions trigger a reflex of cataplexy in people which can bring many of the muscles of the body to the point of collapse.

The phenomenon of cataplexy can be measured by sending electric signals through the muscles and gauging their responses. In cataplexy, what is known as the H-reflex, a neurological pathway that causes muscle contractions, virtually disappears.

Cataplexy often happens to people who have narcolepsy, a disorder in which there is great difficulty stayin awake during the daytime.

2. Etymology: from Greek kata, "down" + plexis,"a stroke, a seizure," or "a falling-down seizure".