阿尔茨海默病患者默认网络社团结构的分析

研究表明,默认网络(DMN)的功能失调与阿尔茨海默病有关。为进一步发现阿尔茨海默病患者大脑默认网络存在的异常连接结构,使用最小生成树方法构建无偏的脑网络,采用树层次聚类方法分析早期轻度认知障碍组(EMCI)、晚期轻度认知障碍组(LMCI)、阿尔茨海默病患者(AD)和健康对照者(NC) DMN社团结构的变化,并且对4种被试大脑网络中回直肌-眶部额上回、楔前叶-后扣带回的连接以及颞上回中心性进行差异分析。结果显示:DMN在NC和EMCI中分成5个社团,在LMCI中分成7个社团,但是在AD分成9个社团; LMCI和AD在回直肌-眶部额上回的连接存在显著差异(P=0. 048),LMCI和EMCI在楔前叶-后扣带回的连接存在显著差异(P=0. 042),LMCI和NC在楔前叶-后扣带回的连接存在显著差异(P=0. 016);颞上回介数中心性在AD组与LMCI组(P=0. 028)、LMCI组与NC组(P=0. 001)、EMCI组与NC组(P=0. 048)都存在显著差异。阿尔茨海默病患者随着病情的进展,DMN的结构逐渐分散,脑区之间的连接以及中心性发生变化,这些脑区主要包括海马、海马旁回、楔...

Analysis of Default Mode Network Community Structure in Patients with Alzheimer′s Disease

Studies have shown that dysfunctions of the default mode network (DMN) are associated with Alzheimer′s disease. In this work, in order to further find out the abnormal connective structure of default mode network in patients with Alzheimer′s disease, an unbiased brain network was constructed by using the minimum spanning tree method and tree hierarchical clustering method was used to analyze community structure of DMN in patients with early mild cognitive impairment (EMCI), lately mild cognitive impairment (LMCI), Alzheimer′s disease (AD) and normal controls (NC). In addition, the difference between gyrus rectus and superior frontal gyrus of orbital part, and precuneus and posterior cingulate gyrus was analyzed. At the same time, the centrality of superior temporal gyrus was analyzed. The results showed that DMN was divided into 5 clusters in NC and EMCI, and it was divided into 7 clusters in the LMCI, but it was divided into 9 clusters in AD. There was significant difference between LMCI and AD in the connection between gyrus rectus and superior frontal gyrus of orbital part (P=0.048), LMCI and EMCI in the connection between precuneus and posterior cingulate gyrus (P=0.042). There was a significant difference between LMCI and NC in the connection between precuneus and posterior cingulate gyrus (P=0.016). There was a significant difference in betweenness of superior temporal gyrus between AD and LMCI (P=0.028), LMCI and NC (P=0.001), EMCI and NC (P=0.048). The results showed that with the progress of the disease, the structure of DMN was gradually dispersed, the connection between the brain regions and the centrality were changed. These brain regions mainly include hippocampus, parahippocampal gyrus, precuneus, posterior cingulate gyrus, superior frontal gyrus of orbital part, middle frontal gyrus of orbital part, gyrus rectus and superior temporal gyrus.