ABSTRACT
Cataplexy, is a sudden drop of antigravity-muscle tone triggered most often by positive emotional factors (such as laughter, winning a game, responding with a witty remark) (1). Cataplexy is pathognomonic for narcolepsy, and it occurs almost exclusively in idiopathic narcolepsy and in rare cases of symptomatic narcolepsy (i.e., narcolepsy associated with other neurological conditions such as a brain tumor or stroke). Approximately sixty percent of narcoleptic subjects diagnosed by the current International Classification of Sleep Disorders (ICSD) Diagnostic Criteria develop cataplexy.
