Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Neurosci Lett. 2019 Aug 24;708:134351. doi: 10.1016/j.neulet.2019.134351. Epub 2019 Jun 24.
Numerous neuroimaging studies have reported aberrant functional activities of the default mode network (DMN) in temporal lobe epilepsy (TLE). However, the alteration on topological organization within the DMN has not been clearly illuminated. In this study, we aimed to investigate the topological abnormalities within the DMN from a larger-scale perspective. Twenty three patients with TLE and 23 age, gender, and education matched healthy controls (HCs) were recruited in this study. All participants underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scanning and completed the Attention Network Test (ANT) for executive function assessment. Specific subregions in the DMN were extracted for network construction according to the automated anatomical labelling atlas. Network properties, including global properties, nodal properties and edge analyses, were assessed using graph theory. Correlation analyses were performed between significantly different topological properties and clinical factors in patients. The ANT tests showed that executive function was impaired in the patients with TLE compared with the HCs. Furthermore, the TLE group showed decreased nodal strength in the left medial orbital superior frontal gyrus and increased nodal strength in the right inferior parietal gyrus in the DMN. Significantly increased functional connectivities between subregions in the DMN were primarily located in the bilateral superior frontal gyrus, inferior parietal gyrus, precuneus, and posterior cingulate gyrus. Moreover, the degree centrality of the right inferior parietal gyrus was positively correlated with disease duration. In conclusion, this study indicated that there existed a disrupted topological reorganization within the DMN in patients with TLE, which may further contribute to executive deficits and, to some extent, play a compensatory role.
大量神经影像学研究报告颞叶癫痫（TLE）患者默认模式网络（DMN）的功能活动异常。然而，DMN 内的拓扑组织改变尚未得到清晰阐明。在这项研究中，我们旨在从更大的角度研究 DMN 内的拓扑异常。本研究纳入了 23 例 TLE 患者和 23 名年龄、性别和教育程度匹配的健康对照者（HCs）。所有参与者均接受静息态功能磁共振成像（rs-fMRI）扫描，并完成注意力网络测试（ANT）进行执行功能评估。根据自动解剖学标记图谱提取 DMN 中的特定亚区进行网络构建。使用图论评估网络属性，包括全局属性、节点属性和边缘分析。在患者中，对差异显著的拓扑属性与临床因素进行相关性分析。ANT 测试表明，与 HCs 相比，TLE 患者的执行功能受损。此外，TLE 组 DMN 中左侧内侧眶额上回的节点强度降低，右侧顶下小叶的节点强度增加。DMN 中各亚区之间的功能连接明显增加，主要位于双侧额上回、顶下小叶、楔前叶和后扣带回。此外，右侧顶下小叶的节点度与病程呈正相关。总之，这项研究表明 TLE 患者的 DMN 内存在拓扑重组织紊乱，这可能进一步导致执行功能缺陷，并在一定程度上发挥代偿作用。
