Temporal relationship of generalized epileptiform discharges to spindle frequency activity in childhood absence epilepsy

Objective: The hypothesis that the two main synchronizing mechanisms (spindle and delta oscillations) acting during non-rapid eye movement sleep show opposite relationship with the distribution of generalized epileptiform discharges (GEDs) during sleep was evaluated. Methods: We studied the temporal relationship between the distribution of sleep GEDs and the dynamics of Sigma Activity (SA, 12–16 Hz) and Delta Activity (DA, 0.5–4.5 Hz) in 5 children affected by childhood absence epilepsy. Results: Using correlation techniques, we found a high and positive correlation between GEDs and SA, while DA resulted negatively correlated with GEDs. Conclusion: Sleep generalized spike-and-slow-waves seems to be produced when spindle synchronizing mechanisms are active while DA production seem to exert an inhibiting role. Such a feature seems to be common to other childhood partial and undetermined epileptic syndromes