Kleine-Levin syndrome (KLS) is an episodic hypersomnia with cognitive disturbances such as confusion, apathy, and derealization. Hyperphagia and hypersexuality occur in around 50% of cases. No evidence-based treatments have been established for KLS. Many drugs have been tried, most often with little success. Here, a case with a striking response to lithium is presented.
Keywords: Kleine–Levin syndrome; cognitive disorders; hypersomnia; hypothalamus; lithium.