Kleine-levin syndrome and idiopathic hypersomnia: spectrum disorders.

Kleine-Levin syndrome (KLS) and idiopathic hypersomnia (IH) are primary sleep disorders of unknown etiologies, which often run a chronic course. The common core symptoms of these syndromes are hypersomnolence and sleep drunkenness, with periodic hypersomnolence and hyperphagia being the prominent symptoms of KLS. Psychiatric manifestations are common to both and include irritability, depression, apathy, inattention and poor concentration. Both disorders are diagnosed clinically and no specific laboratory investigation is available to confirm the diagnosis. We present a case highlighting the overlapping of the symptoms of KLS and IH, producing a complex clinical picture.