Résumé
CSF hypocretin-1 measurements were performed during a period of hypersomnia and during an asymptomatic interval in a 14-year-old girl affected with severe Kleine–Levin syndrome. A twofold decrease in hypocretin-1 was evidenced during the period of hypersomnia in comparison with the asymptomatic interval. Together with previous data, this result is in favour of recurrent dysfunction at the hypothalamic level in Kleine–Levin syndrome.