The Role of Excitability and Network Structure in the Emergence of Focal and Generalized Seizures
The Role of Excitability and Network Structure in the Emergence of Focal and Generalized Seizures
复制标题
DOI：
10.3389/fneur.2020.00074
复制
发表时间：
2020-02-11
影响因子：
3.4
通讯作者：
Terry, John R.
中科院分区：
文献类型：
--
作者：
Lopes, Marinho A.;Junges, Leandro;Terry, John R.
癫痫发作通常分为局灶性或全身性。传统上认为，局灶性癫痫发作意味着局部脑异常，而全身性癫痫发作涉及广泛的脑病变。然而，最近的证据表明，大规模的大脑网络参与了局灶性癫痫发作的产生，全身性癫痫发作可能起源于局部脑区。在这里，我们研究网络结构和组织异质性如何支持局灶性和广泛发作动力学的出现。癫痫发作出现在大脑网络的数学建模，使负责局灶性和全身性癫痫发作的特点澄清。我们认为，神经质量网络动态的癫痫发作生成的范例合成网络，我们测量整个网络的致敏性的方差。致痫性被定义为癫痫发作活动中网络节点的参与，其方差用于量化癫痫发作模式在整个网络中是局灶性的还是广泛的。我们解决了网络结构和不同的兴奋性分布在整个网络上的影响的致发作的方差。我们发现，这种变化取决于网络结构和兴奋性分布。高方差，即，局部癫痫发作活动，在网络中观察到高度异质性的连接或兴奋性的分布。然而，网络的结构和兴奋性都是异质的，这取决于结构和兴奋性之间的相互作用，可以成为全身性癫痫发作的基础。因此，我们的研究结果意味着，出现局灶性和全身性癫痫发作是由网络结构和兴奋性分布之间的相互作用。
Epileptic seizures are generally classified as either focal or generalized. It had been traditionally assumed that focal seizures imply localized brain abnormalities, whereas generalized seizures involve widespread brain pathologies. However, recent evidence suggests that large-scale brain networks are involved in the generation of focal seizures, and generalized seizures can originate in localized brain regions. Herein we study how network structure and tissue heterogeneities underpin the emergence of focal and widespread seizure dynamics. Mathematical modeling of seizure emergence in brain networks enables the clarification of the characteristics responsible for focal and generalized seizures. We consider neural mass network dynamics of seizure generation in exemplar synthetic networks and we measure the variance in ictogenicity across the network. Ictogenicity is defined as the involvement of network nodes in seizure activity, and its variance is used to quantify whether seizure patterns are focal or widespread across the network. We address both the influence of network structure and different excitability distributions across the network on the ictogenic variance. We find that this variance depends on both network structure and excitability distribution. High variance, i.e., localized seizure activity, is observed in networks highly heterogeneous with regard to the distribution of connections or excitabilities. However, networks that are both heterogeneous in their structure and excitability can underlie the emergence of generalized seizures, depending on the interplay between structure and excitability. Thus, our results imply that the emergence of focal and generalized seizures is underpinned by an interplay between network structure and excitability distribution.