Kleine-Levin syndrome

Overview
Kleine-Levin Syndrome, or KLS, is a rare disorder characterized by the need for excessive amounts of sleep (hypersomnia), (e.g. up to 20 hours a day); excessive food intake (compulsive hyperphagia); and an abnormally uninhibited sexual drive. Adolescent males are the predominant victims of the disorder.

Presentation
Individual sufferers may often become irritable, lethargic, and/or apathetic. KLS patients may appear disoriented and report hallucinations. Symptoms are cyclical; with days to weeks (even up to months) of suffering interspersed by weeks or months (even up to years) symptom-free. Although resolution of the disorder may occur for some in later life, this is not universal.

Causes
While some researchers speculate of a hereditary predisposition; others believe the condition may be the result of an autoimmune disorder. Both proposals need not be mutually exclusive with the result being a malfunction of the portion of the brain that helps to regulate functions such as sleep, appetite, and body temperature (hypothalamus).

Similarities between KLS and Klüver-Bucy syndrome (another rare condition characterized by hyperphagia, hypersexuality, and emotional blunting) may warrant further attention.

Treatment
There is no definitive treatment for Kleine-Levin syndrome. Stimulants, including amphetamines, methylphenidate, imipramine and modafinil, administered orally, are used to treat sleepiness. Because of similarities between Kleine-Levin syndrome and certain mood disorders, lithium and carbamazepine may be prescribed. Responses to treatment have often been limited. This disorder needs to be differentiated from cyclic re-occurrence of sleepiness during the premenstrual period in teenage girls that may be controlled with hormonal contraception.

Eponym
It is named for Willi Kleine and Max Levin.