Localization of sleep spindles, k-complexes, and vertex waves with subdural electrodes in children.

PURPOSE To describe for the first time in children the localization of sleep spindles, K-complexes, and vertex waves using subdural electrodes. METHODS We enrolled children who underwent presurgical evaluation of refractory epilepsy with subdural grid electrodes. We analyzed electroencephalogram data from subdural electrodes and simultaneous recording with Cz scalp electrode. Sleep spindles, K-complexes, and vertex waves were identified and localized based on their morphology on the subdural electrodes. RESULTS Sixteen patients (9 boys; age range, 3-18 years) were enrolled in the study. The inter-rater reliability on identification and localization of maximal amplitude was high with an intraclass correlation coefficient of 0.85 for vertex waves, 0.94 for sleep spindles, and 0.91 for K-complexes. Sleep spindles presented maximum amplitude around the perirolandic area with a field extending to the frontal regions. K-complexes presented maximum amplitude around the perirolandic area with a field extending to the frontal regions. Vertex waves presented maximum amplitude around the perirolandic areas. CONCLUSIONS In our series of pediatric patients, sleep spindles, K-complexes, and vertex waves were localized around the perirolandic area.