[Age and insomnia: the number and length of waking periods (author's transl)].

The role and importance of the number of awakenings and their duration in relation to increasing intervening wakefulness were investigated. The data were collected from a group of 38 subjects suffering from chronic primary insomnia, aged 17-70 years, polygraphically recorded; the analysis was made on the second night. With age, the total quantity of intervening wakefulness increases more quickly than the total number of awakenings. The amount of wakefulness due to awakenings lasting greater than or equal to 3 min increases with age. Older insomniacs wake up somewhat more often but, above all, they go back to sleep less quickly. Our hypothesis is that in old patients insomnia is linked to an increase in stability of wakefulness.