颞叶癫痫大鼠电生理默认模式网络研究

发布时间：2018-03-18 10:40

本文选题：颞叶癫痫　切入点：默认模式网络　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：癫痫是对人类健康造成严重危害的神经系统疾病,有超过30%的癫痫病人经过手术治疗后,仍然持续性地发作癫痫,其原因仍不明确。神经影像学的证据表明,癫痫是大脑神经网络病态改变的结果,而不仅仅是由单一脑区引起。因此,识别出癫痫患者的大脑网络特征,对临床癫痫发作的预测以及术前核心脑区的定位具有重要意义。新近基于功能磁共振(Functional Magnetic Resonance Imaging,fMRI)的研究发现,啮齿类动物大脑存在与人和非人类灵长类相似的默认模式网络。但癫痫发作过程中,大脑神经放电出现特征性的病理改变,其网络机制还没有进行深入系统的研究。因此,本文通过多通道颅内电生理记录,对颞叶癫痫动物模型在癫痫发作过程中默认模式网络的动态变化过程进行探讨。本研究结果发现:1.正常大鼠电生理默认模式网络分为相对独立的前部网络和后部网络两个模块,与在fMRI中的发现一致。2.在癫痫发作过程中,脑网络聚类系数以及最短路径长度出现显著性变化,且在不同频段有明显差异。所有频段的脑网络属性参数在癫痫发作开始及大发作阶段网络传输效率不断增加,在发作后期网络传输效率迅速下降。delta频段脑网络传输效率最高峰出现在癫痫发作开始时,而alpha及beta频段脑网络传输效率最高峰出现在癫痫大发作时。3.在癫痫发作过程中,大脑默认模式网络小世界属性有显著性改变,脑网络在癫痫发作早期向随机网络方向偏移,在大发作时最接近随机网络,而在癫痫后期迅速向规则网络方向偏移。4.在癫痫发作过程中,大脑网络拓扑结构出现显著性改变,表现为默认模式网络前后部系统连接在癫痫发作开始及大发作过程中逐渐增强,在癫痫发作后期前后部系统连接迅速下降。且不同频段的网络拓扑图在癫痫过程中的变化有显著差异,theta频段在发作前表现全脑连接增强,delta频段在发作开始时连接增强,而alpha和beta频段在大发作时出现连接增强。本研究结果表明,在癫痫发作过程中,脑网络属性、小世界属性以及网络拓扑结构都出现了特征性改变,表现为发作前、发作开始及大发作大脑网络传输效率增高且全脑连接增强,而发作后期网络传输效率迅速下降且全脑连接减弱。此外,EEG不同频段成分在癫痫发作过程中承担着不同角色,theta及delta频段在发作前及发作开始时表现出显著的网络传输效率增强及全脑连接增强,可能参与癫痫发作的启动;而alpha和beta频段在大发作时表现出显著的网络效率增加及全脑连接增强,可能与癫痫活动在全脑的扩散有关。
[Abstract]:Epilepsy is a nervous system disease that causes serious harm to human health. More than 30% epileptic patients are still suffering from persistent seizures after surgical treatment, the causes of which are still unclear. Epilepsy is the result of pathological changes in the neural network of the brain, not just a single brain region. It is important for the prediction of clinical seizures and the localization of the core brain area before operation. There are default pattern networks in rodent brains similar to human and non-human primates. However, during epileptic seizures, there are characteristic pathological changes in brain discharges, and the network mechanism has not been studied systematically. In this paper, multichannel intracranial electrophysiological records were used. The dynamic changes of the default pattern network in temporal lobe epileptic animal model were studied. The results showed that the default pattern network of electrophysiology in normal rats was divided into two modules: the anterior network and the posterior network. In accordance with the findings in fMRI, the clustering coefficients of brain network and the shortest path length were significantly changed during epileptic seizures. And there are obvious differences in different frequency bands. The transmission efficiency of brain network attribute parameters of all frequency bands increases continuously at the beginning of epileptic seizure and the stage of seizure. The peak of brain network transmission efficiency occurred at the beginning of epileptic seizure, while the peak of brain network transmission efficiency in alpha and beta band appeared at the time of seizure. The brain's default network network has a significant change in small-world properties. The brain network shifts to a random network in the early stages of seizures, and is closest to a random network during a large seizure. In the later period of epilepsy, the brain network topology changed significantly during epileptic seizures. In default mode, the system connection between the front and back parts of the network is gradually enhanced during the onset of the seizure and the onset of the seizure. Before and after the onset of epilepsy, the connections of the system decreased rapidly, and there were significant differences in the changes of the network topology in the different frequency bands during the epileptic process. The whole brain junction enhancement and delta band were observed before the onset of the seizure, and the delta band was enhanced at the beginning of the seizure, and there were significant differences in the changes of the network topograms during the course of epilepsy. The results of this study show that the brain network properties, small-world attributes and network topology have characteristic changes during epileptic seizures. The transmission efficiency of the brain network and the whole brain connection were increased at the beginning of the attack and the onset of the attack. However, the network transmission efficiency decreased rapidly and the whole brain connection was weakened in the later stage of seizure. In addition, the different components of delta played different roles in the seizure process. The delta and theta showed significant network before and at the beginning of the seizure. Enhanced transmission efficiency and global connectivity, The alpha and beta bands may be involved in the initiation of epileptic seizures, while the alpha and beta bands show a significant increase in the network efficiency and the global brain connection, which may be related to the spread of epileptic activity in the whole brain.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R742.1

【相似文献】