Kleine-Levin syndrome is a rare self-limited disorder which usually affects adolescent males and is characterized by episodic hypersomnia, increased appetite, and behavioral/psychiatric disturbances. Individuals are normal between the attacks.

The case of an adolescent boy is presented who suffered from recurrent sleepiness, hyperphagia, and behavioral disturbances such as rocking, punching and pacing, and was originally misdiagnosed as suffering from encephalitis. Before the diagnosis of Kleine-Levin was given, the patient underwent unnecessary investigations and treatment which, in turn, complicated his clinical condition both physically as well as psychologically. In the course of five years he had four such episodes which appeared to have progressively milder manifestations. Between episodes he was normal.

It is important that the diagnosis is suspected early, especially in adolescent males who present with recurrent episodes of somnolence, increased appetite, and abnormal behavior, since it most often represents a benign and self-limited entity and does not warrant extensive investigations or treatment. It is also important to distinguish this syndrome from more serious organic and psychiatric diseases with more serious prognoses. The differential diagnosis of this syndrome is discussed and a review of the literature is presented including evidence and hypotheses regarding its pathophysiology.

The Kleine–Levin syndrome (KLS) is characterized by periodic, sudden-onset episodes of hypersomnia, compulsive hyperphagia, and behavioral–emotional symptoms, lasting from a few days to a few weeks, with complete remission in the intercritical periods. We report on efficacy of lithium treatment in a highly recurring form of the disorder in a 17-year-old male adolescent. The decreasing severity of the disorder paralleled the progressive increase of lithium dosage, up to 0.9 mEq l–1. Implications regarding the pharmacological treatment of this neglected disorder are discussed.

A 27 year-old man initially considered as a schizophrenic patient was later diagnosed as having Kleine-Levin syndrome.

The Kleine-Levin Syndrome (KLS) a rare disorder comprising of periodic bouts of hypersomnia and megaphagia is reviewed. The syndrome chiefly affects males. The four accepted female cases in the literature are reviewed and a new female case described. This patient had an IQ in the normal range, unlike the other three female cases where the IQ was measured. She showed an abnormal Cortisol rhythm during both a well and an unwell phase replicating the findings of other workers in some KLS patients. This patient showed normal dexamethasone suppression, a test not previously reported on in KLS. The patient also smoked excessively during the bouts, an occurrence not previously remarked on in this disorder.