第一临床医学院知识库

目的: 探讨阿尔茨海默症（Alzheimer's disease，AD）患者静息状态下局部自发脑功能活动与两侧大脑半球解剖结构等位体素之间功能连接改变。 方法: 纳入经我院神经内科确诊为AD的患者24例，招募正常老年对照24例，受试者均行3.0T（Siemens，Skyra）静息态血氧水平依赖磁共振（Blood oxygenation level dependent-Resting state magnetic resonance,BOLD-Rs-MR）扫描，对所有受试者扫描图像资料分别行局部一致性（Regional homogeneity，ReHo）和体素镜像同伦连接（Voxel-mirrored homotopic connectivity,VMHC）分析，通过统计学分析ReHo异常脑区并运用VMHC分析该异常区域两半球每对镜像体素之间功能连接状态。

结果: 1. 相比健康对照组（healthy control，HC），AD患者双侧额内侧上回、眶额中回、眶额下回、眶额内侧回、前-中扣带回、尾状核，右侧海马、岛回、杏仁核、额中回和左侧颞上回、颞下回ReHo增高，双侧枕中回、枕上回、距状皮层、楔前叶、后扣带回、中央前-后回、角回、额下回岛盖部，左侧顶下小叶、额中回、辅助运动区及右侧额上回ReHo减低；同时，AD较健康对照VMHC增高的脑区分布于双侧嗅回、额内侧上回、眶额中上回、眶额内侧回、前扣带回、尾状核及岛回，双侧距状叶、颞中回及枕中回VMHC减低。2.分析ReHo异常脑区的分布，AD较健康对照ReHo增高脑区分布于右侧额中回、海马、杏仁核、岛回及左侧颞下回、颞上回者，VMHC分析未发现该区域出现异常。然而，对于两半球额内侧上回、眶额回、前扣带回和尾状核ReHo均增高的脑区，均减低的脑区距状皮层、颞中回及枕中回，VMHC显示该区域半球间功能连接异常。3.分析ReHo统计学结果，对于AD较健康对照两半球相同脑区ReHo均异常者，右侧半球ReHo增高脑区的体素簇集及t峰值较左侧相对增大，左侧半球ReHo减低脑区，其体素簇集及t峰值较右侧相对增大。

结论: 1. AD患者较健康对照组ReHo值及VMHC值存在明显差异的脑区与临床记忆、认知障碍功能区有关。2.相比健康对照，AD者两半球间功能连接改变与局部脑活动协同性可能有关。3.AD与健康对照者相比较，两半球解剖对称区域ReHo均发生改变者，其左右半球ReHo存在明显差异脑区的活动程度不对称，也许与右侧优势半球有关。

Objective To investigate the changes of local spontaneous brain activity and functional connec tivity between the voxels of equal position in terms of anatomical structure in both sides of the cereb- ral hemisphere of resting state in patients with Alzheimer' s disease（AD）. Methods Including AD 24 patients diagnosed by the department of neurology and recruiting normal elderly control subjects 24 cases, who all undergo 3.0 T blood oxygenation level dependent resting-state Magnetic Resonance (BOLD-Rs-MR)scanning, the datas of all subjects have been given ReHo and VMHC analysis, through stati-stical analysis found that ReHo abnormal functional regions，then using VMHC analyze functional connectivity condition  between  each pair of mirrored voxels in abnormal areas within the bilateral hemisphere.

Results 1.Compared with healthy controls, the ReHo value of AD group in bilateral superior medial frontal gyrus,middle-inferior orbitofrontal gyrus, the medial orbitofrontal, anterior-middle cingulate  cortex, caudate nucleus,right hippocampus,right insular, right amygdala, right middle frontal gyrus and left superior-inferior temporal gyrus increased,decreased areas in bilateral middle occipital gyrus,superior occipital gyrus,calcarine,precuneus, posterior cingulate gyrus, precentral-postcentral gyrus,angular gyrus, inferior frontal operculum gyrus, left inferior parietal lobule,left middle frontal gyrus,left supplementary motor area and right superior frontal gyrus;at the same time，compared to healthy controls，the VMHC values of the bilateral olfactory gyrus,superior medial frontal gyrus, middle-inferior orbitofrontal gyrus,medial orbitofrontal gyrus, anterior cingulate gyrus and insular gyrus were higher,but the bilateral calcarine cortex, middle temporal gyrus and middle occipital gyrus were lower in AD group. 2.Analyzing the distribution of abnormal brain regions of ReHo,compared with HC group,the brain regions with higher ReHo value in AD patients located in the right middle frontal gyrus, right hippocampus, right amygdala, right island back and left inferior-superior temporal gyrus, there were no abnormalities of the VMHC analysis found in these areas. However, for the brain regions of bilateral cerebral hemisphere with incresed ReHo value which included medial frontal gyrus, orbital frontal gyrus, anterior cingulate gyrus and caudate nucleus, the reduced brain areas of bilateral cerebral hemisphere mainly located in the calcarine, mid-temporal gyrus and mid-occipital gyrus, the VMHC demonsrated abnormal functional connectivity between bilateral hemispheres in these regions. 3.Analyzing ReHo statistics results showed that for same brain regions with abnormal ReHo values in both sides of hemispheres in AD patients compared with healthy controls.The voxel-clusters and t-peak intensity in brain areas with ReHo higher of right hemisphere relatively have increased compared to left hemisphere,but the voxel-clusters and t-peak intensity in brain areas with ReHo lower of left hemisphere relatively have increased compared to right hemis-phere.

Conclusion 1.Significant difference brain regions of ReHo and VMHC value between healthy control group and AD patients associated with brain functional areas of clinical memory and cognitive impairment. 2.Compared to healthy controls,the alterations of function connectivity in bilateral hemisphere maybe connect with local spontaneous brain activity homogeneity in AD patients. 3.AD compared with healthy controls, for the anatomical symmetry regions with changed ReHo in the both sides of hemispheres,which the degree of activity in brain areas with ReHo value having significant difference in both groups between left-right hemispheres were asymmetry,which may be related to the right dominant hemisphere.