[An all-night electroencephalographic study on grand mal epilepsy in childhood. A longitudinal study on the incidence of epileptic discharges with treatment and the comparison between all-night electroencephalography and standard sleep activated electroencephalography].

In order to quantify changes in epileptic discharges during the course of phenobarbital (PB) therapy, 8 children with generalized tonic-clonic seizure (GTC) corresponding to sleep epilepsy as defined by Janz were given PB, and their all-night EEGs were obtained by means of a polygraph with simultaneous measurement of the blood concentration of PB. EEGs were recorded before the treatment commenced and 3 days, 14 days, one month, 6 months, one year, 1.5 and 2 years after the beginning of the treatment. For each child, the number of epileptic discharges during sleep was determined. The incidence of epileptic discharges (total number of epileptic discharges during sleep divided by total sleep time) was calculated, and changes during the course of the treatment were examined. In addition, the findings (pattern of epileptic discharges) obtained through standard short-time EEG recordings were compared with those obtained through all-night EEG recordings in terms of the incidence of epileptic discharges during the first S1-S2 after the subject had fallen asleep and the incidence of epileptic discharges during all stage of S1 and S2 while asleep. There were two different patterns of changes in the incidence of epileptic discharges. In 5 of the 8 children, the incidence was decreased at the initial stages of treatment, but it began to increase about one month later, returning to the baseline level (re-increased type). In the remaining 3 children, the incidence decreased favorably after the beginning of treatment, reaching nil within one year (simple decrease type). The incidence of epileptic discharges was found to be decreased in all 8 children after 3 days of treatment, when the blood PB concentration had not reached the effective level. Standard EEG and all-night EEG revealed similar patterns of epileptic discharges.