轻度认知功能障碍对大脑功能网络效率的影响

The Brain Functional Network Efficiency in Patients with Mild Cognitive Impairment

目的:从网络效率的角度来检验轻度认知功能障碍(MCI)患者大脑功能网络的小世界特性,并探讨MCI对大脑功能网络效率的影响。方法:共采集13名MCI患者和17名正常老年人(NC)的大脑静息态BOLDf MRI数据,对数据进行预处理并构建大脑功能网络。针对每个网络生成100个与之具有相同节点和边数的规则网络和随机网络,计算各网络的全局效率(Eglobal)、局部效率(Elocal)和网络收益(Earn)。通过双样本t检验比较MCI患者与正常老年人大脑功能网络效率的差异。结果:两组受试者大脑网络均符合Eglobal(Greg)<Eglobal(G)<Eglobal(Grand)和Elocal(Grand)<Elocal(G)<Elocal(Greg),且MCI组Eglobal和Earn均高于NC组(0.16≤Sparsity≤0.28,P<0.05),Elocal低于NC组。两组Earn均为正值。结论:MCI患者和正常老年人的大脑功能网络都具有经济有效的小世界特性,但MCI患者大脑网络效率发生了异常,提示MCI患者大脑信息传递能力受损。

Purpose： To explore the small-world property of brain functional networks in patients with mild cognitive impairment （MCI） from the perspective of network efficiencies. Methods： Thirteen MCI pa- tients and 17 healthy elders （NC） were included in this study. Resting-state Bold-fMRI data were acquired and preprocessed. Brain functional network of each subject was then constructed. One hundred correspond- ing regular networks and random networks, which had the same node size and edge number with each brain functional network, were generated. Global efficiency, local efficiency and network earning were calculated and compared by two samples t test between the two groups. Results： Eglobat（Grg） 〈 Egtobal（G） 〈 Eglobal（Grand） and Elocal（Grand） 〈 Elocal（G） 〈 Elocal（G^g） were satisfied in both groups. Global efficiency and network earning were higher in MCI group, especially at the threshold of 0.16≤ Sparsity≤0.28 （P〈0.05）. The local efficiency of MCI was decreased. The network earning of both groups were positive. Conclusion： The brain func- tional networks of MCI patients and normal elders have economic and efficient small-world property. The network efficiencies of MCI patients＇ brains were changed, indicating the losses of information transfer capability of MCI patients＇ brain.