Institut de Neurosciences des Systemes INS UMR1106, AMU, INSERM, Marseille, France.
PLoS Comput Biol. 2024 Mar 6;20(3):e1011903. doi: 10.1371/journal.pcbi.1011903. eCollection 2024 Mar.
The Epileptor is a phenomenological model for seizure activity that is used in a personalized large-scale brain modeling framework, the Virtual Epileptic Patient, with the aim of improving surgery outcomes for drug-resistant epileptic patients. Transitions between interictal and ictal states are modeled as bifurcations, enabling the definition of seizure classes in terms of onset/offset bifurcations. This establishes a taxonomy of seizures grounded in their essential underlying dynamics and the Epileptor replicates the activity of the most common class, as observed in patients with focal epilepsy, which is characterized by square-wave bursting properties. The Epileptor also encodes an additional mechanism to account for interictal spikes and spike and wave discharges. Here we use insights from a more generic model for square-wave bursting, based on the Unfolding Theory approach, to guide the bifurcation analysis of the Epileptor and gain a deeper understanding of the model and the role of its parameters. We show how the Epileptor's parameters can be modified to produce activities for other seizures classes of the taxonomy, as observed in patients, so that the large-scale brain models could be further personalized. Some of these classes have already been described in the literature in the Epileptor, others, predicted by the generic model, are new. Finally, we unveil how the interaction with the additional mechanism for spike and wave discharges alters the bifurcation structure of the main burster.
《癫痫发作器》是一种癫痫发作活动的现象学模型,用于个性化的大规模脑建模框架《虚拟癫痫患者》中,旨在提高耐药性癫痫患者的手术效果。发作和间歇状态之间的转变被建模为分岔,从而可以根据起始/结束分岔来定义癫痫发作类型。这在其基本潜在动力学的基础上建立了癫痫发作的分类法,并且《癫痫发作器》复制了最常见的癫痫发作类型的活动,如局灶性癫痫患者中观察到的那样,其特征是方波爆发特性。《癫痫发作器》还编码了一种额外的机制来解释间歇期棘波和棘波和尖波放电。在这里,我们使用基于展开理论方法的更通用的方波爆发模型的见解来指导《癫痫发作器》的分岔分析,并深入了解该模型及其参数的作用。我们展示了如何修改《癫痫发作器》的参数以产生分类法中其他癫痫发作类型的活动,这些活动如患者中观察到的那样,以便进一步个性化大规模脑模型。其中一些类型已经在《癫痫发作器》的文献中进行了描述,而其他的则是由通用模型预测的新类型。最后,我们揭示了与棘波和尖波放电的附加机制的相互作用如何改变主爆发器的分岔结构。