基于电生理的颞叶癫痫脑网络机制研究

发布时间：2018-08-25 19:31

【摘要】：颞叶癫痫(TLE)是一种在成年人中最常见的难治性癫痫。近年来,应用复杂网络分析方法,研究大脑区域间的连接变化和神经疾病的发作机制,已成为脑科学研究的热点。新近的研究表明,颞叶癫痫的发作和传播过程中伴随多个脑区的活动和功能连接的异常,这说明基于复杂网络的TLE机制研究,对于我们进一步理解颞叶癫痫的神经机制具有重要的意义。然而,目前TLE相关脑区在癫痫发作过程中所扮演的关键角色仍不清楚。本学位论文基于氯化锂-匹鲁卡品颞叶癫痫大鼠模型的多通道颅内脑电信号,探究不同频段下脑区间的功能连接和大脑拓扑结构随颞叶癫痫发作过程的变化。本学位论文主要研究内容及结果如下:1.对EEG信号进行时频分析和功率谱分析,发现TLE发作的主要节律是Delta(1-4 Hz)、Theta(4-8 Hz)和Alpha(8-12 Hz)频段。利用信息熵分析节点复杂度变化,发现局部脑区(背内侧丘脑、海马CA1区、前额叶皮质、前扣带皮质和第一运动皮层)在TLE发作前期先于其他脑区出现复杂度的显著性升高。2.对脑区间的相干值分析,发现大发作时期脑区间的耦合性在Delta、Theta和Alpha频段均出现显著性增强,在发作前期和发作后期皮层与皮层下结构间的耦合性在各频段下均出现显著性增强。3.在Delta、Theta和Alpha频段,利用独立有效相干算法分析脑区间的因果流向变化,发现局部皮层与皮层下结构间因果流向随着颞叶癫痫发作的动态变化过程,这一变化过程可能对颞叶癫痫的发作与传播起着重要的作用。4.对因果网络使用图论方法分析,发现在TLE发作过程中,因果网络的全局效率、局部效率和聚类系数都高于基线状态,并且这些网络属性在发作前期出现显著性升高,随后开始逐渐下降,同时因果网络在发作过程中呈现较强的“小世界”属性。综上所述,我们的研究结果表明,Delta、Theta和Alpha频段可能是TLE发作的关键节律,并且不同的发作状态有不同的节律特性;局部皮层与皮层下结构间相互的因果作用在TLE的发作与传播中起着重要的作用;TLE发作时,因果网络倾向于更加规则化,脑区间的交互效率增强。这些发现,使我们对TLE具体的产生发展机制有了更进一步的认识。
[Abstract]:Temporal lobe epilepsy (TLE) is one of the most common refractory epilepsy in adults. In recent years, using the complex network analysis method to study the changes of the connections between brain regions and the attack mechanism of neural diseases has become a hot spot in brain science. Recent studies have shown that the seizure and spread of temporal lobe epilepsy are accompanied by abnormalities in activity and functional connections in multiple brain regions, suggesting that TLE mechanisms based on complex networks are studied. It is of great significance for us to further understand the neural mechanism of temporal lobe epilepsy. However, the key role of TLE-related brain regions in epileptic seizures remains unclear. Based on the multichannel intracranial EEG of the rat model of lithium-Pilucapine temporal lobe epilepsy, the functional connections of the brain and the changes of the brain topological structure with the seizure process of the temporal lobe were investigated in different frequency bands. The main contents and results of this dissertation are as follows: 1. By time-frequency analysis and power spectrum analysis of EEG signal, it was found that the main rhythm of TLE attack was Delta (1-4 Hz) Theta (4-8 Hz) and Alpha (8-12 Hz). Using information entropy to analyze the changes of node complexity, it was found that the local brain regions (dorsal medial thalamus, hippocampal CA1 region, prefrontal cortex, anterior cingulate cortex and first motor cortex) had a significant increase in complexity before the onset of TLE. The results of coherence analysis showed that the coupling of cerebral regions was significantly enhanced in Delta,Theta and Alpha bands, and the coupling between cortical and subcortical structures in preictal and late seizures was significantly enhanced in each frequency range. In the band of Delta,Theta and Alpha, the independent effective coherence algorithm was used to analyze the causal direction of brain region. The dynamic change process of causal direction between local cortex and subcortical structure with temporal lobe seizure was found. This process may play an important role in the onset and spread of temporal lobe epilepsy. It is found that the global efficiency, local efficiency and clustering coefficient of the causal network are higher than the baseline state during the onset of TLE, and the attributes of these networks are significantly increased in the early stage of the attack. Then it began to decline, and the causal network showed a strong "small world" attribute during the attack. In conclusion, our results indicate that the Alpha and Theta bands may be the key rhythms of TLE attacks, and different seizure states have different rhythmic characteristics. The causal interaction between local cortex and subcortical structure plays an important role in the onset and transmission of TLE. These findings make us have a further understanding of the specific mechanism of TLE production and development.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R742.1

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