A Case of Late Onset Type1 Narcolepsy Complicated by Sleep Apnea Syndrome in which Cataplexy Improved with CPAP Treatment.

A 73-year-old woman experienced sudden drowsiness and sleep attacks for 10 years, as well as a loss of strength in her legs when laughing. Polysomnography (PSG) showed an apnea-hypopnea index (AHI) of 87.0, indicating severe obstructive sleep apnea (OSA). The Multiple Sleep Latency test showed three sleep-onset rapid eye movement periods, and symptoms of sleep attacks and cataplexy were observed, leading to a diagnosis of narcolepsy. After Continuous Positive Airway Pressure treatment, the AHI decreased to 21.0, and cataplexy occurred only once a month. Late-onset narcolepsy is a rare condition. We herein report a case of late-onset Type1 narcolepsy complicated by OSA.