Kleine-Levin syndrome (KLS) is a rare sleep disorder mainly affecting teenage boys in which the main features are intermittent hypersomnolence, behavioral and cognitive disturbances, hyperphagia, and in some cases hyper sexuality. Etiology is unknown, and there is no specific clinical or imaging test for this syndrome even though the illness has well-defined clinical features. Also, there is no effective treatment for KLS. KLS is self-limited, so the prognosis for these patients is not so bad. This study presents our case report and comprehensive workout that led to diagnosis which is primarily clinical. Our patient is a 20-year-old man referred to our clinic because of sleeping problems. At the age of 14, he presented with complaints of the excessive duration of sleep, increased appetite, excessive daytime sleepiness, loss of interest in social activities during attendance of high school and hallucinations. The excessive diagnostic procedure does not find pathological. Kleine-Levin syndrome (KLS) is a rare sleep disorder of unknown etiology which diagnosis is clinical and diagnostic workup is mainly to exclude other similar conditions. There is no specific therapy, but the disease is self-limited and with good prognosis.
Keywords: Hyper sexuality; Hypersomnia; Kleine-Levin syndrome; Megaphagia; Periodic.