[Kleine-Levin syndrome--diagnostic and therapeutic problems].

An overview of the literature is given and an attempt is made to describe the diagnostic problems associated with this etiologically unclear disorder. The only successful therapy to date is treatment with lithium. A case study is presented of a 14-year-old boy with typical symptoms. Within a period of 12 months the boy had 6 episodes characterized by hypersomnia and hyperphagia, each lasting between 8 and 14 days. The symptom-free intervals lasted from 10 days to 8 months. Extensive medical and neurological evaluation including single-photon emission-computed tomography (SPECT) showed no abnormalities, and no criteria for another psychiatric disorder were met. After the sixth episode we considered treating the patient with lithium, but this option was rejected by his family. The patient has remained asymptomatic (36-month follow-up). A possible relationship to endogenous psychotic disorders and the role of neurotransmitter metabolism are discussed. Computer-assisted analysis of electroencephalographic activity revealed high signal complexity, which we believe suggests a primary cortical regulatory defect.