Narcolepsy

IT is useful to divide the clinical problems associated with sleep into three general categories: the insomnias, the hypersomnias, and the episodic or intermittent sleep disorders. In this general classification the term hypersomnia refers to any condition involving excessive sleep and sleepiness or falling asleep. The hypersomniac process in narcolepsy is characterized by attacks of sleep often in circumstances that ordinarily are not at all conducive to sleepiness. It is this aspect that makes narcolepsy one of the most dramatic of the sleep disorders and that, together with a relatively high prevalence, has made it the most extensively studied. In . . .