轻度认知障碍人群局部一致性与全脑功能连接探讨

Regional homogeneity and whole brain functional connectivity in subjects with mild cognitive impairment

目的通过联合应用局部一致性(ReHo)与全脑功能连接(FC)对轻度认知障碍(MCI)患者进行研究,探讨静息态下MCI的机制。方法对24例MCI患者以及30例年龄、性别、民族相匹配的健康对照组进行静息态功能磁共振扫描(RSfMRI)扫描,采用DPARSFA2.3和SPM8软件分析筛选MCI患者的异常脑区,分析以后扣带回/楔前叶为种子点行全脑FC分析与ReHo分析。结果与健康对照组相比,MCI组左侧额中回、左侧中央前回、左侧中央后回左侧中央沟盖、左侧岛盖额下回ReHo值升高(Voxel水平,Alphasim校正,P<0.05),右侧颞上回、右侧颞中回、中央后回颞极ReHo值减低(Voxel水平,Alphasim校正,P<0.05);后扣带回/楔前叶与右侧梭状回、右侧丘脑、右侧舌回、右侧海马旁回FC增强(Voxel水平,Alphasim校正,P<0.05),与左侧颞中回、左侧角回、左侧颞上回.左侧枕中回FC降低(Voxel水平,Alphasim校正,P<0.05)。结论默认网络异常可能与MCI发病有关,后扣带回/楔前叶连接异常可能有助于发现对MCI敏感性较高的影像学.证据。

Objective To investigate regional homogeneity(ReHo)and whole brain functional connectivity(FC)in patients with mild cognitive impairment(MCI),and to explore the mechanisms of MCI in the resting state.Methods Resting-state functional magnetic resonance imaging(RS-fMRI) was performed on 24 patients with MCI and 30 age,gender and nationality-matched normal controls.Abnormal brain areas in the MCI group were screened and analyzed by using the DPARSFAZ.3 and SPM8 software programs.Whole brain FC analysis was performed with the posterior cingulate cortex(PCC)I precuneus as the seed points.Results Compared with the control group,MCI subjects displayed higher ReHo values in the frontal-middle-Left,precentral-Left,postcentral-Left,rolandic-opercular-Left,and frontal-inferior-opercular-Left and lower Re Ho values in the temporal-superior-right,temporal-middle-right,postcentral-right,and temporal-pole-superior-right(Voxel level,Alphasim correction,P<0.05).Whole brain FC analysis showed greater functional connectivity of PCC/precuneus with fusiform-right,thalamus-right,lingual-right and parahippocampalright in subjects with MCI,and less functional connectivity of the PCC/precuneus with temporalmiddle-Left,angular-Left,temporal-superior-Left and occipital-middle-Left in subjects with MCI(Voxel level,Alphasim correction,P<0.05).Conclusions Abnormalities of the default mode network may be associated with the onset of MCI,and abnormalities in posterior cingulate/precuneus connectivity may be helpful in finding imaging evidence with high sensitivity to MCI.