Obstructive Sleep Apnea Comorbid with Late-Onset Kleine–Levin Syndrome: A Rare Condition

Obstructive sleep apnea (OSA) co-occurring with Kleine–Levin Syndrome (KLS) is a rare condition. We present the case of a middle-aged woman who presented with short lasting episodes of hypersomnia, anorexia, irritability, crying and symptoms of derealization. She was given antidepressants considering depression earlier with which she was not responding. After ruling out other potential causes for the same, diagnosis of KLS was made. Oxcarbazepine 450 mg/day led to resolution of symptoms. However, daytime sleepiness and fatigue persisted. Polysomnography suggested the presence of severe OSA which resolved with use of CPAP. Addition of CPAP to oxcarbazepine resolved symptoms completely.