Abstract
All-night polygraphy was performed twice on one subject (a 23-year-old female) who received clinical examination under suspicion of cerebro-organic disease, suspected due to the subject's frequent, sudden and continuous lapses into a state of sleep. The result and some discussion are reported here. The subject twice fell into REM-stage sleep immediately after sleep by both records, and, thereafter, irregular occurrences were observed in the REM-stage, in which, awakening on the way was also observed. While, slow-wave sleep (4th stage) was not observed, and the incidence of REM-stage and REM-density showed higher levels than the mean values. These EEG findings were characteristic of narcolepsy, thereby, diagnosis was easily established. Narcolepsy shows 4 major symptoms, namely, sleep attack, cataplexy, sleep paralysis and hypnagogic hallucinations. This subject rarely had isolated sleep attacks, and, in fact, the occurrence of this is reported to take place in only 5 % of all narcoleptic cases. A narcoleptic whose only major symptom is sleep attack does not show REM sleep at the onset stage. This sleep-onset process is reported to show a similar process to that of the sleep-onset time in normal subjects, while, in the present case, it is interesting to have observed sleep-onset REM.
