This chapter discusses the case of an 11-year-old Asian-American girl who was admitted for treating sleep disturbances, excessive daytime sleepiness (EDS) and paroxysmal weakness in the sleep center. It presents the clinical history, examination, follow-up, treatment, diagnosis, and the results of the procedures performed on the patient. Nocturnal video-polysomnography (PSG) followed by a multiple sleep latency test (MSLT) were ordered. She went into REM sleep, without going into any other sleep stages at the beginning of the MSLT in three of the five naps. The diagnosis was narcolepsy with cataplexy. Sodium oxybate was administered and titrated twice nightly, which helped further decrease her cataplexy to once or twice daily. Cataplexy may take the form of prolonged waxing and waning, with partial or complete muscle atonia, called status cataplecticus. Schizophreniamay be co-morbid or an intrinsicmanifestation of narcolepsy. Obesity is frequently observed in association with narcolepsy, contributing to sleepiness.