Cataplexy is usually triggered by emotions. A survey (Anic-Labat, 1998) of 300 narcoleptics indicated that laughter, feelings of amusement, or being "tickled by oneself, repartee, or a joke" induced cataplexy in 93% of the patients. Other emotions found to trigger cataplexy include anger (90% of patients), excitement and elation (82%), surprise (61%), athletic activities with an emotional content, such as winning or hitting a good shot (60%), elation (59%), "response to a call for action" (38%), sexual intercourse (37%), and embarrassment (36%). Surprisingly, driving an automobile was reported to trigger cataplexy in less than 1 % of the patients. Sleepiness and tiredness was cited as a trigger in 50% of the patients, and 36% of the patients said that in some attacks they could not identify the immediate trigger. A given individual usually reports several different triggers over time.
A self-administered questionnaire was validated on 983 subjects who consulted a sleep disorder center (Anic-Labat, 1998). This questionnaire included 51 cataplexy-related items. Responses to the items were composed between subjects with clear-cut cataplexy (n = 63) and all other patients (n = 920). Nonnar-coleptic subjects were found to experience muscle weakness with various intense emotions (1.8-18%) or athletic activities (26.2-28.8%). Factor analysis and Receiver Operating Characteristics Curve Analysis were used to determine the most predictive items for clear-cut cataplexy. Cataplexy was best differentiated from other forms of muscle weakness when triggered by three typical situations: when hearing or telling a joke, while laughing, and when angry.
Was this article helpful?