Reduced NREM sleep instability in benign childhood epilepsy with centro-temporal spikes

To analyze sleep architecture and NREM sleep instability by means of the cyclic alternating pattern (CAP) in children with benign epilepsy with rolandic spikes (BERS).

Ten children with BERS, drug free at the time of the study and 10 age-matched normal controls were included in this study. Sleep was visually scored for sleep architecture and CAP using standard criteria.

Sleep architecture in BERS showed only few significant differences vs. controls with a reduction of total sleep time, sleep efficiency, and REM sleep percentage. CAP analysis revealed several significant differences: reduced total CAP rate, mainly in sleep stage 2, and reduced EEG slow oscillations and arousals during stages N1 and N2.

Sleep architecture is not importantly affected in BERS but CAP analysis reveals a decrease of NREM instability, mainly in sleep stage 2. Since there is a spindle-related spike activation in BERS, we speculate that the decrease of CAP and of EEG slow oscillations and arousals might be linked with the inhibitory action of spindling activity and spikes on arousals.

CAP analysis discloses sleep structure abnormalities in children with BERS not shown by the classical sleep scoring. Spike activity and CAP A1 subtypes seem to be mutually exclusive probably because centro-temporal spikes disturb the physiological synchronization mechanisms needed for the generation of slow-wave components of CAP.