A case of subwakefulness syndrome.

We report a patient, a 30-year-old male Japanese-Brazilian migrant construction worker, suffering from excessive daytime sleepiness for at least 6 months. Electroencephalogram recordings during his waking states showed that 10-Hz and 60-microV alpha activity was present prominently in the occipital regions. From the multiple sleep latency test, it was found that stages 1-2 NREM sleep episodes appeared repetitively without any REM episodes, and that the mean sleep latency was 10.2 min. These findings support the diagnosis that this patient suffers from subwakefulness syndrome.