1-A-D-10. A study on spike focus-dependence of high-frequency oscillations in benign childhood partial epilepsy

Abstract

We analyzed spike-associated high-frequency oscillations (HFOs) and their relationship to spike foci in electroencephalograms (EEGs) of patients with benign epilepsy with centrotemporal spikes (BECTS) and Panayiotopoulos syndrome (PS). In 35 patients with BECTS and 29 with PS, focal spikes in scalp sleep EEGs were firstly classified into clusterings according to their characteristics including shapes and distributions. In each patient, the maximum of three spike clusters were investigated through time–frequency and single-dipole analyses to explore relationships between presence or absence of spike-associated HFOs and the distribution of estimated spike sources. A total of 159 spike clusters was analyzed (96 in BECTS and 63 in PS). HFOs were detected in 73 spike clusters (76.0%) in BECTS and 37 (58.7%) in PS with a statistically significant difference ( p = 0.024 by Fisher’s exact test). In BECTS, the spike sources had a close relationship with HFOs and were largely uniform irrespective of presence or absence of HFOs. In contrast in PS, the spikes tended to be dispersed and the rate of association with HFOs was significantly higher in occipito-parietal spikes (29/39) than the others (8/24; p = 0.002) suggesting that occipito-parietal spikes with a close link to HFOs were indicated to have a particular meaning in the epileptogenesis.