阿尔茨海默患者大脑功能网络的中央节点性改变

Changes of betweenness centrality in brain functional network of patients with Alzheimer's disease

目的网络的中央节点性是时网络中某节点重要性的评估指标,反映了该节点的信息传递能力。本研究基于静息态fMR1数据,采用图论方法探讨阿尔茨海默病(Alzhemier's disease,AD)对大脑功能网络中央节点性的影响。方法采集33例AD患者和20例正常老年人的静息态BOLD-fMR1数据,应用SPM5和DPARSF软件进行预处理,提取大脑90个区域的平均时间序列构建相关矩阵,以网络代价Cost为阚值,计算Cost=0.2时两组受试者90个脑区的中央节点性值,用双样本t检验分析AD组90个脑区的中央节点性值与正常人是否存在显著差异。结果阿尔茨海默病患者右扣带回后部(近枕下回)、右舌回和右豆状核壳的中央节点性值较正常人显著降低,右枕中回、左缘上回和左颞极颞上回的中央节点性值较正常人显著增高。结论 AD患者扣带回后部及豆状核等脑区的信息传递能力降低。脑内可能存在代偿机制,以代偿这些重要脑区的功能减低。

Objective To investigate the changes of betweenness centralities in brain functional network of patients with Alzheimer＇s disease （AD） by resting state functional magnetic resonance imaging （fMRI）. Methods Thirty three patients with Alzheimer＇s disease and 20 normal elderly subjects were included in this study. Resting BOLD-fMRI data were collected and preprocessed by SPM5 and DPARSF software package. Average time course of each 90 brain areas were extracted to construct correlation matrix. Betweenness centralities of the 90 areas in two groups were calculated at the threshold of network Cost = 0. 2. Two sample t-test was used to examine the differences of these 90 areas between AD patients and normal elderly subjects. Results Compared to normal elderly subjects the betweenness centralities values in AD patients were significantly decreased at right posterior cingulate （near inferior occipital gyrus）, right lingual gyrus and right lenticular nucleus＇ putamen, while the values were increased at the right middle occipital gyrus, left supramarginal gyrus and lefttemporal pole of superior temporal gyms. Conclusion AD patients shows decreased information transfer efficiency in posterior cingulated, right lingual gyms and lenticular nucleus＇ putamen, while that in right middle occipital gyms, left supramarginal gyms and left temporal pole of superior temporal gyms are compensatory increased, indicating that these 6 areas should be focused on in the diagnosis and treatment of Alzheimer＇s disease.