From Université Lille, INSERM, CHU Lille, U1171-Degenerative and Vascular Cognitive Disorders, Lille, France.
Neurology. 2018 May 22;90(21):e1879-e1888. doi: 10.1212/WNL.0000000000005553. Epub 2018 Apr 20.
To study the association between poststroke cognitive impairment and defining a specific resting functional marker.
The resting-state functional connectivity 6 months after an ischemic stroke in 56 patients was investigated. Twenty-nine of the patients who had an impairment of one or several cognitive domains were compared to 27 without any cognitive deficit. We studied the whole-brain connectivity using 2 complementary approaches: graph theory to study the functional network organization and network-based statistics to explore connectivity between brain regions. We assessed the potential cortical atrophy using voxel-based morphometry analysis.
The overall topological organization of the functional network was not altered in cognitively impaired stroke patients, who had the same mean node degree, average clustering coefficient, and global efficiency as cognitively healthy stroke patients. Network-based statistics analysis showed that poststroke cognitive impairment was associated with dysfunction of a whole-brain network composed of 167 regions and 178 connections, and functional disconnections between superior, middle, and inferior frontal gyri and the superior and inferior temporal gyri. These regions had connections that were specifically and positively correlated with cognitive domain scores. No intergroup differences in overall gray matter thickness and ischemic infarct topography were observed. To assess the effect of prestroke white matter hyperintensities on connectivity, we included the initial Fazekas scale in the regression model for a second network-based analysis. The resulting network was associated with the same key alterations but had fewer connections.
The observed functional network alterations suggest that the appearance of a cognitive impairment following stroke may be associated with a particular functional alteration, shared specifically between cognitive domains.
研究卒中后认知障碍与特定静息功能标志物之间的关系。
研究了 56 例缺血性卒中后 6 个月的静息状态功能连接。将 29 例存在 1 个或多个认知域受损的患者与 27 例无认知缺陷的患者进行比较。我们使用 2 种互补的方法研究了全脑连接：图论用于研究功能网络组织，网络统计用于探索脑区之间的连接。我们使用基于体素的形态计量学分析评估潜在的皮质萎缩。
认知障碍卒中患者的功能网络整体拓扑组织未改变，其节点度、平均聚类系数和全局效率与认知健康卒中患者相同。基于网络的统计学分析显示，卒中后认知障碍与由 167 个区域和 178 个连接组成的全脑网络功能障碍有关，并且额叶上、中、下回与颞叶上、下回之间存在功能连接中断。这些区域的连接与认知域评分具有特异性和正相关性。两组间的总灰质厚度和缺血性梗死部位无差异。为了评估卒中前白质高信号对连接的影响，我们将初始 Fazekas 量表纳入基于网络的回归模型进行第二次分析。得到的网络与相同的关键改变有关，但连接较少。
观察到的功能网络改变表明，卒中后认知障碍的出现可能与特定的功能改变有关，这种改变在认知域之间具有特异性。
