Department of Neurosurgery, University of Utah, Salt Lake City, 84132, USA.
Department of Neurology, Columbia University, New York, 10032, USA.
Sci Rep. 2020 Nov 5;10(1):19166. doi: 10.1038/s41598-020-76138-7.
High frequency oscillations (HFOs) are bursts of neural activity in the range of 80 Hz or higher, recorded from intracranial electrodes during epileptiform discharges. HFOs are a proposed biomarker of epileptic brain tissue and may also be useful for seizure forecasting. Despite such clinical utility of HFOs, the spatial context and neuronal activity underlying these local field potential (LFP) events remains unclear. We sought to further understand the neuronal correlates of ictal high frequency LFPs using multielectrode array recordings in the human neocortex and mesial temporal lobe during rhythmic onset seizures. These multiscale recordings capture single cell, multiunit, and LFP activity from the human brain. We compare features of multiunit firing and high frequency LFP from microelectrodes and macroelectrodes during ictal discharges in both the seizure core and penumbra (spatial seizure domains defined by multiunit activity patterns). We report differences in spectral features, unit-local field potential coupling, and information theoretic characteristics of high frequency LFP before and after local seizure invasion. Furthermore, we tie these time-domain differences to spatial domains of seizures, showing that penumbral discharges are more broadly distributed and less useful for seizure localization. These results describe the neuronal and synaptic correlates of two types of pathological HFOs in humans and have important implications for clinical interpretation of rhythmic onset seizures.
高频振荡（HFOs）是指在癫痫样放电期间，从颅内电极记录到的 80Hz 或更高频率的神经活动爆发。HFOs 是癫痫性脑组织的一个潜在生物标志物，也可能对预测癫痫发作有用。尽管 HFOs 具有如此的临床应用价值，但这些局部场电位（LFP）事件的空间背景和神经元活动仍不清楚。我们试图通过在有节律性起始性癫痫发作期间，在人类新皮质和内侧颞叶的多电极阵列记录中，进一步了解发作期高频 LFPs 的神经元相关性。这些多尺度记录从人类大脑中捕获单细胞、多单位和 LFP 活动。我们比较了微电极和宏电极在癫痫核心区和半影区（多单位活动模式定义的空间癫痫域）中癫痫发作期间的多单位放电和高频 LFP 的特征。我们报告了高频 LFP 在局部癫痫入侵前后的频谱特征、单位局部场电位耦合和信息论特征的差异。此外，我们将这些时域差异与癫痫发作的空间域联系起来，表明半影放电分布更广泛，对癫痫定位的帮助不大。这些结果描述了人类两种类型病理性 HFOs 的神经元和突触相关性，对有节律性起始性癫痫发作的临床解释具有重要意义。
