Hippocampus Subregions Functional Connectivity Study Of Rs-fMRI In The Aging With Hypertension And Mild Cognition Impairment

Objective:To investigate the functional connectivity between bilateral hippocampus subregions and the whole brain in elderly hypertensive patients with mild cognitive impairment,10 subregions of bilateral hippocampus were selected as regions of interest,and the study would be proceeded by using rs-f MRI.Methods:A total of 66 volunteers aged between 60 and 80 years were recruited.All subjects had 6 years of education and were right-handed.All the volunteers were divided into three groups: hypertension with cognitive dysfunction group(H-MCI group,n=20),hypertension with normal cognitive function group(H-CN group,n=25),and age,gender,years of education and other matched healthy volunteers with normal blood pressure and cognitive function(NC group,n=21).All volunteers underwent magnetic resonance scanning with T2 WI,T2FLAIR,3D-T1 WI and EPI sequence,and then DPARSF software was used to preprocess magnetic resonance data with 3D-T1 WI and EPI sequence.According to SPM Anatomy Toolbox,a total of 10 bilateral hippocampal subregions(bilateral CA1,CA2,CA3,DG,SUB)were extracted as ROI.The functional connections(FC values)between the 10 ROIs and other brain voxels were calculated,and the functional connections among the three groups were analyzed by ANOVA with SPM,and the results were tested after the fact(double-sample t test).Results:1.A total of 10 subregions of bilateral hippocampus were used as ROIs,and a univariate analysis of variance was conducted for the volunteers in the three groups.The brain regions with statistically significant differences in functional connectivity of bilateral hippocampus subregions were: bilateral superior frontal gyrus,right middle frontal gyrus,left caudate nucleus,left parhippocampal gyrus,and right posterior cerebellar lobe;2.H-MCI,H-CN and NC groups were subjected to post hoc test in pairs.2.1 Post hoc test was conducted between the H-MCI and H-CN groups,and the results showed that the brain regions with reduced functional connectivity included:left superior frontal gyrus.Functional connectivity was increased in the right superior frontal gyrus and the right middle frontal gyrus.2.2 Post hoc test was conducted between the H-MCI and NC groups,and the results showed that the brain regions with reduced functional connectivity included: the right posterior lobe of the cerebellum;Functional connectivity was increased in the right superior frontal gyrus and the right middle frontal gyrus.2.3 Post hoc test was conducted between the H-CN and NC groups.The results showed that the brain regions with reduced functional connectivity included: right superior frontal gyrus,right middle frontal gyrus,and right posterior cerebellar lobe;The areas with increased functional connectivity were: the left superior frontal gyrus;Conclusion:1.In the elderly,hypertension impairs the resting state functional connectivity between the hippocampus and several brain regions,and further affects cognitive function;Some hippocampal subregions have enhanced functional connectivity,which may be a compensation for cognitive decline.2.In the elderly with hypertension and cognitive dysfunction,the functional connectivity of resting state between bilateral hippocampus and related brain regions are not uniform,and different subregions have their own characteristics.