Cataplexy [kat-uh-plek-see] is a sudden and transient episode of loss of muscle tone, often triggered by emotions. It is a rare disease (prevalence of fewer than 5 per 10,000 in the community), but affects roughly 70% of people who have narcolepsy. Cataplexy can also be present as a side effect of SSRI Discontinuation Syndrome. The term cataplexy originates from the Greek ‘kata’ (‘downwards’), and ‘plexis’ (‘hitting’). Cataplexy manifests itself as muscular weakness which may range from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or a total collapse. Usually the speech is slurred, vision is impaired (double vision, inability to focus), but hearing and awareness remain normal.
These attacks are triggered by strong emotions such as exhilaration, anger, fear, surprise, orgasm, awe, embarrassment, and laughter. A person’s efforts to stave off cataplectic attacks by avoiding these emotions may greatly diminish their quality of life, and they may become severely restricted emotionally if diagnosis and treatment is not begun as soon as possible. Cataplexy may be partial or complete, affecting a range of muscle groups, from those controlling facial features to (less commonly) those controlling the entire body.