Parasomnia as an Initial Presentation of Narcolepsy

ABSTRACT

Narcolepsy is characterized by excessive daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucinations. Only a few studies have focused on non-rapid eye movement (NREM) and REM parasomnias in narcolepsy. We report a narcolepsy without cataplexy patient presenting parasomnia as an initial symptom. A 18-year-old boy was admitted to hospital for abnormal behavior of sitting up during sleep over 2 years. He had a symptom of lethargy without cataplexy and subjective excessive daytime sleepiness, but his family found him often asleep during daytime. He underwent 3 times of polysomnography (PSG) including 1 multiple sleep latency test (MSLT) after the last PSG. The last PSG showed 1 episode of abrupt sitting. Three sleep REM onset period was observed in MSLT which was not detect in PSG. Parasomnia as an initial symptom of narcolepsy is a rare clinical entity. The MSLT may be useful in the evaluation of patients with parasomnia and unexplained hypersomnia.