[Sodium gamma-hydroxybutyrate in the treatment of essential hypersomnia].

Five non-narcoleptic hypersomniac patients were given GHB (3.10 to 4.5 g per os) at night. Four patients reported a persistent improvement of their daytime sleepiness as a result of this treatment. Nocturnal polygraphic recordings were performed in all patients before and after GHB. The durations of sleep and of waking times were reduced after GHB while there was an increase of stages 3 and 4 during the first third of the night. It is possible that the increase in delta wave sleep early in the night is responsible for a re-establishment of a normal distribution of subsequent sleep stages and thus produces a more recuperative sleep.