Narcolepsy and excessive daytime sleepiness

TL;DR: An update on the biology, diagnosis, and management of narcolepsy—an important, yet often misdiagnosed, cause of sleepiness that has seen exciting recent advances is provided.

Abstract: Excessive daytime sleepiness is common,1 yet opportunities to learn about sleep medicine in medical school are rare; a survey in 1998 indicated that undergraduate courses devoted a median of five minutes to sleep and its disorders2 In this review we provide an update on the biology, diagnosis, and management of narcolepsy—an important, yet often misdiagnosed, cause of sleepiness that has seen exciting recent advances We also briefly outline the other principal causes of daytime sleepiness and aim to equip the general reader with a practical approach to the assessment of patients who complain of excessive daytime sleepiness This paper is based on a literature search conducted to produce evidence based guidelines on the diagnosis and management of narcolepsy in adults and children3 We searched Medline, Embase, the Cochrane Collaboration, and two specialist sleep literature resources for abstracts with the key word “narcolepsy” We read the full text of relevant papers and hand searched these for other relevant material A multidisciplinary working party prepared the guidelines, and a group of 10 independent experts later reviewed them These guidelines can be downloaded from the news section of http://wwwsleepingorguk/ (accessed July 2004) Narcolepsy is a chronic neurological disorder affecting sleep regulation and causing excessive sleepiness and, in most cases, cataplexy (brief attacks of weakness on emotional arousal)3 4 The excessive sleepiness of narcolepsy comprises both a background feeling of sleepiness present much of the time and a strong, sometime irresistible, urge to sleep recurring at intervals through the day This desire is heightened by conducive, monotonous circumstances, but naps at inappropriate times—such as during meals—are characteristic The naps of narcolepsy usually last from minutes to an hour and occur a few times each day Cataplexy refers to partial or generalised, almost invariably bilateral, loss of skeletal muscle tone and …