[Density and dynamic of frontal sharp waves (encoches pointues frontales) during sleep in new-borns and infants (author's transl)].

Frontal sharp waves (encoches pointues frontales) identified by Monod (1960) were studied in 110 neonates and infants. Three pattern were described: typical, related and degraded. They were recorded in all subjects, the reason why the frequency of each pattern varied was discussed. Pathological states did not increase the occurrence of those frontal sharp waves since most of them were recorded in children either normal or suffering from a minor pathology. Incidence of maturation seemed to be probable since the highest proportion of frontal sharp waves occurred in infants whose gestational and legal age were respectively greater than 43 weeks and between 20 and 40 days at the time of investigation. Typical and degraded forms were predominant in transitional period towards quiet sleep; they were less numerous during falling asleep in active sleep and totally absent during active sleep following quiet sleep. This could suggest that the two states of active sleep are different in nature.