Coben Robert, Mohammad-Rezazadeh Iman
NeuroRehabilitation & Neuropsychological Services , Massapequa Park, NY , USA ; Integrated Neuroscience Services , Fayetteville, AR , USA.
Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at University of California Los Angeles , Los Angeles, CA , USA.
Front Hum Neurosci. 2015 Jul 14;9:194. doi: 10.3389/fnhum.2015.00194. eCollection 2015.
Epilepsy is a chronic neurological disorder characterized by repeated seizures or excessive electrical discharges in a group of brain cells. Prevalence rates include about 50 million people worldwide and 10% of all people have at least one seizure at one time in their lives. Connectivity models of epilepsy serve to provide a deeper understanding of the processes that control and regulate seizure activity. These models have received initial support and have included measures of EEG, MEG, and MRI connectivity. Preliminary findings have shown regions of increased connectivity in the immediate regions surrounding the seizure foci and associated low connectivity in nearby regions and pathways. There is also early evidence to suggest that these patterns change during ictal events and that these changes may even by related to the occurrence or triggering of seizure events. We present data showing how Granger causality can be used with EEG data to measure connectivity across brain regions involved in ictal events and their resolution. We have provided two case examples as a demonstration of how to obtain and interpret such data. EEG data of ictal events are processed, converted to independent components and their dipole localizations, and these are used to measure causality and connectivity between these locations. Both examples have shown hypercoupling near the seizure foci and low causality across nearby and associated neuronal pathways. This technique also allows us to track how these measures change over time and during the ictal and post-ictal periods. Areas for further research into this technique, its application to epilepsy, and the formation of more effective therapeutic interventions are recommended.
癫痫是一种慢性神经系统疾病,其特征为反复癫痫发作或一组脑细胞中出现过度放电。全球患病率约为5000万人,10%的人一生中至少有过一次癫痫发作。癫痫的连接性模型有助于更深入地了解控制和调节癫痫活动的过程。这些模型已获得初步支持,包括脑电图(EEG)、脑磁图(MEG)和磁共振成像(MRI)连接性测量。初步研究结果显示,癫痫病灶周围直接区域的连接性增加,而附近区域和神经通路的连接性较低。也有早期证据表明,这些模式在发作期会发生变化,甚至可能与癫痫发作事件的发生或触发有关。我们展示的数据表明,格兰杰因果关系可如何与脑电图数据一起用于测量参与发作期事件及其缓解过程的脑区之间的连接性。我们提供了两个案例作为如何获取和解释此类数据的示范。对发作期事件的脑电图数据进行处理,转换为独立成分及其偶极定位,并用这些来测量这些位置之间的因果关系和连接性。两个案例均显示癫痫病灶附近存在超耦合,而附近及相关神经通路的因果关系较低。该技术还使我们能够追踪这些测量值如何随时间以及在发作期和发作后期发生变化。建议对该技术、其在癫痫治疗中的应用以及形成更有效的治疗干预措施进行进一步研究。