Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
MEG Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45220, USA.
Neurosci Lett. 2014 Apr 30;566:21-6. doi: 10.1016/j.neulet.2014.02.038. Epub 2014 Feb 26.
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.
本研究旨在使用 80Hz 至 500Hz 的发作期高频振荡（HFO），通过非侵入性脑磁图（MEG）定位儿童失神癫痫（CAE）的发作起始区。使用 275 通道 MEG 系统对 10 名未用药的 CAE 儿童进行研究。MEG 数据以 6000Hz 的采样率数字化。使用 Morlet 连续小波变换实时频谱图评估 HFO 谱功率。通过动态磁源成像的滑动窗口对磁源进行容积定位。所有患者均识别出 HFO。失神发作期间快锐波（250-500Hz）的总时间大于锐波（80-250Hz）的总时间。快锐波的频率与癫痫发作频率有关。与棘波同时发生的 HFO 持续时间明显长于独立发生的 HFO，与独立发生的 HFO 相比，与棘波同时发生的 HFO 的最大频率更高。HFO 主要定位于内侧前额叶皮质（MPFC），而棘波在失神发作期间广泛分布于多种区域。与棘波相比，HFO 似乎更局限。研究结果表明，MPFC 中的 HFO 在 CAE 中初始癫痫活动中起主要作用。
