A Case of Narcolepsy by Excessive Daytime Sleepiness

주간졸음증 환자로부터 기면증 1예 보고

We report a case of narcolepsy. A 25-year-old man has had excessive daytime sleepiness of about 10 years durations. He awakens daily feeling exhausted and continually falls asleep during the day while engaged in such situation like reading and watching television. He has exhibited cataplexy, a sudden loss of muscular tone, brought on by emotion, usually laughter. Polysomnogram revealed increased sleep stage 1, 2 and decreased deep sleep. Multiple sleep latency test (MSLT) showed that sleep latency was 1.33 minutes and there were 3 noted sleep onset rapid eye movement (SOREM) on 5 trials. The epworth sleepiness scale (ESS) was 17/24. Typing of HLA haplotype that was positive for the $DQB1^{\ast}0602$ allele, and hypocretin-1 (orexin A) could not be detected in cerebrospinal fluid (CSF). Brain MRI showed normal image. We diagnosed his case as narcolepsy based on history of cataplexy, and three occurances of SOREM, and positive of HLA haplotype.