Abstract
The patient was a 24-year old male office worker. He used to late hours. When he was 23 years old, he tended to have hypersomnia and his wake up time was delayed, so he was often late for and absent from work. In July 1992,he consulted our hospital and was admitted. He was diagnosed as having delayed sleep phase syndrome (DSPS) by sleep log, polysomnography test, multiple sleep latency test (MSLT) and measurement of rectal temperature. After admission, we made his schedule free for 10 days to observe his sleep-wake schedule. Then he adapted his schedule to the time table of our hospital in order to fix sleep-wake pattern, while we treated him with VB12 for a week. Furthermore, he received timed exposure of the bright light for a week. After these treatments, we carried out polysomnography test, MSLT and measurement of rectal temperature again, his wake up time and bedtime were fixed at 7 a. m. and 10 p. m. respectively and sleep phase was advanced. After discharge, he stayed at dormitory to stable his sleep-wake schedule. He successfully maintained his regular schedule, although during the weekends, his sleep-wake schedule tended to delay temporarily. We considered that a change of life style induced by overtime work, single life and so on made it difiicult to synchronize circadian rhythm and consequently he developed DSPS.
