title: Using ictal high-frequency oscillations (80-500Hz) to localize seizure onset zones in childhood absence epilepsy: a MEG study.
abstract: This study aimed to use ictal high-frequency oscillations (HFOs) ranging from 80Hz to 500Hz to locate seizure onset zones in childhood absence epilepsy (CAE) using non-invasive magnetoencephalography (MEG). Ten drug-naïve children with CAE were studied using a 275-channel MEG system. MEG data were digitized at a sampling rate of 6000Hz. HFO spectral power in real-time spectrograms was assessed using Morlet continuous wavelet transform. Magnetic sources were volumetrically localized through dynamic magnetic source imaging with a slide window. HFOs were identified in all patients. The total time of fast ripples (250-500Hz) was greater than that of ripples (80-250Hz) during absence seizures. The rate of fast ripples was associated with seizure frequency. HFO duration was significantly longer when co-occurring with spikes than when occurring independently, and the maximum frequency of HFOs co-occurring with spikes was higher than that of HFOs occurring independently. HFOs were predominantly localized in the medial prefrontal cortex (MPFC), whereas spikes were widespread to a variety of regions during the absence seizures. Compared with spikes, HFOs appeared to be more focal. The findings indicate that HFOs in the MPFC have a primary function in initializing epileptic activity in CAE.
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China. Electronic address: Ailiangmiao1986@163.com.
authors.forename: Ailiang
authors.initials: A
authors.lastname: Miao
authors.affiliation: MEG Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45220, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Huaiting
authors.initials: H
authors.lastname: Ge
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Liu
authors.affiliation: MEG Center, Nanjing Brain Hospital, Nanjing, Jiangsu 210029, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.affiliation: MEG Center, Nanjing Brain Hospital, Nanjing, Jiangsu 210029, China.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Neurology, Nanjing Children's Hospital, Nanjing, Jiangsu 210029, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Neurology, Nanjing Children's Hospital, Nanjing, Jiangsu 210029, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China. Electronic address: lidou2005@126.com.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Wang
mesh_terms: D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D004832:Epilepsy, Absence / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D012640:Seizures / Q000503:physiopathology*
keywords: Childhood absence epilepsy; Dynamic magnetic source imaging; High-frequency oscillations; Magnetoencephalography; Morlet continuous wavelet transform