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.