Laboratoire Traitement du Signal et de l'Image (LTSI-U1099), Université de Rennes 1, INSERM, 35000 Rennes, France.
J Neural Eng. 2021 Apr 26;18(4). doi: 10.1088/1741-2552/abf774.
Fast ripples (FRs) have received considerable attention in the last decade since they represent an electrophysiological biomarker of the epileptogenic zone (EZ). However, the real dynamics underlying the occurrence, amplitude, and time-frequency content of FRs generation during epileptogenesis are still not well understood. This work aims at characterizing and explaining the evolution of these features.Intracortical electroencephalographic signals recorded in a kainate mouse model of temporal lobe epilepsy were processed in order to compute specific FR features. Then realistic physiologically based computational modeling was employed to explore the different elements that can explain the mechanisms of epileptogenesis and simulate the recorded FR in the early and late latent period.Results indicated that continuous changes of FR features are mainly portrayed by the epileptic (pathological) tissue size and synaptic properties. Furthermore, the microelectrodes characteristics were found to dramatically affect the observability and spectral/temporal content of FRs. Consequently, FRs evolution seems to mirror the continuous pathophysiological mechanism changes that occur during epileptogenesis as long as the microelectrode properties are taken into account.Our study suggests that FRs can account for the pathophysiological changes which might explain the EZ generation and evolution and can contribute in the treatment plan of pharmaco-resistant epilepsies.
快涟漪（FRs）在过去十年中受到了相当多的关注，因为它们代表了致痫区（EZ）的一种电生理生物标志物。然而，在癫痫发生过程中 FRs 产生的发生、幅度和时频内容的真正动态仍然不太清楚。这项工作旨在对这些特征的演变进行特征描述和解释。在颞叶癫痫的海人酸小鼠模型中记录的皮质内脑电图信号被处理，以便计算特定的 FR 特征。然后，采用现实的基于生理学的计算模型来探索可以解释癫痫发生机制并模拟早期和晚期潜伏期记录的 FR 的不同元素。结果表明，FR 特征的连续变化主要由癫痫（病理）组织大小和突触特性来描绘。此外，发现微电极特性会极大地影响 FRs 的可观察性和频谱/时频内容。因此，只要考虑到微电极特性，FRs 的演变似乎就反映了在癫痫发生过程中发生的连续病理生理机制变化。我们的研究表明，FRs 可以解释可能导致 EZ 产生和演变的病理生理变化，并有助于制定抗药性癫痫的治疗计划。
