The Use of Lorazepam for Acute Episodes in a Patient with Kleine-Levin Syndrome: A Longitudinal Case Report

Kleine-Levin Syndrome (KLS) is a rare, neurological disorder characterized by episodes of hypersomnia, cognitive impairment, and behavioral abnormalities. The etiology of KLS remains unclear, and treatment responses are highly variable. This report describes a 22-year longitudinal experience with a 40-year-old male diagnosed with KLS at 15 years of age. Treatment trials of all standard KLS medications (lithium, valproic acid, selective serotonin reuptake inhibitors, modafinil) yielded no benefit in attenuating or preventing episodes. Following the onset of overlapping an acute KLS exacerbation and catatonia-like symptoms, the patient’s episode was shortened after a trial of intravenous (IV) lorazepam. This response was consistently reproduced, with episodes resolving after approximately 5–7 days of IV lorazepam administration. Notably, the frequency of episodes increased after the patient contracted COVID-19 despite the continued efficacy of IV lorazepam in reducing episode duration. This case highlights the potential utility of IV lorazepam in terminating acute KLS episodes. While short-term outcomes were favorable, the observed increase in episode frequency underscores the need to assess the risks of chronic benzodiazepine exposure, including receptor downregulation and tolerance. These findings support the use of lorazepam in acute KLS management but emphasize caution regarding long-term reliance and encourage further mechanistic and therapeutic research into episodic hypersomnia and benzodiazepine responsiveness. Psychopharmacology Bulletin. 2026;56(1):162–169.