Oliveira, Marcio M, Conti, Cristiane, Prado, Gilmar F

This is an updated version of the original Cochrane review, published in Issue 2, 2009.Kleine-Levin syndrome (KLS) is a rare disorder that mainly affects adolescent men. It is characterised by recurrent episodes of hypersomnia, usually accompanied by hyperphagia, cognitive and mood disturbances, abnormal behavior such as hypersexuality and signs of dysautonomia.In 1990 the diagnostic criteria for Kleine-Levin syndrome were modified in the International Classification of Sleep Disorders, where KLS was defined as a syndrome composed of recurring episodes of undue sleepiness lasting some days, which may or may not be associated with hyperphagia and abnormal behavior.The cause of Kleine-Levin syndrome remains unknown, and several treatment strategies have been used. Some medications have been reported to provide benefit in the treatment of patients with KLS, but because of the rarity of the condition, no long-term follow-up therapies have yet been described.