A Voxel-based Morphometry (VBM) Analysis Of Gray Matter In Alzheimer’s Disease Based On Brainstem Morphological Changes

Objective:To investigate the morphological changes of gray matter in patients with Alzheimer’s disease with different degree of brainstem atrophy to explore the relationship between brainstem and gray matter in Alzheimer’s disease.Methods:The study data were from the ADNI database,included brain MRI data from the initial examination and two years follow-up,including 31 patients with Alzheimer’s disease,32 patients with mild cognitive impairment,and 34 normal elderly people.The ITK-SNAP software was used to perform interactive brainstem segmentation of brain MRI of all subjects and the volume of brainstem was calculated for each subject when examined twice.According to the extent of brainstem atrophy,patients in the Alzheimer group and the mild cognitive impairment group were divided into the brainstem atrophy(BA)group and the brainstem spared(BS)group.After all the MR images were registered,standardized,and smoothed using SPM software,gray matter voxel-based morphometry(VBM)analysis was performed on different groups of data.At the same time,the volume of gray matter,brainstem volume,deep brain nucleus(caudate nucleus,putamen)volume,hippocampal volume,age,sex,MMSE scores were analyzed statistically.Reasult: First examination and after follow-up,the three groups of MRI-based brainstem volume,gray matter volume,and deep brain nucleus volume(caudal nucleus,putamen nucleus)were compared,AD group <MCI group<NC group,The difference was statistically significant(P<0.05).During the follow-up period,the indexes of AD group and MCI group were significantly decreased(P<0.05),while there was no significant change in NC group(P>0.05).Pearson correlation analysis results suggest that there is a positive correlation between the brainstem and deep brain nuclei volume(caudal nucleus,putamen)changes in Alzheimer’s disease patients(r=0.653,0.596,P<0.05).In the VBM analysis of AD group and MCI group,BA group compared with BS group found in the frontal lobe,parietal lobe brain and other areas of gray matter atrophy,and as the course of progress,The second examination showed a gradual increase in the degree of morphological differences in gray matter,and patients in the AD group showed more distinct areas and levels than those in the MCI group.Conclusion: As age increases,the brainstem and deep brain nucleus volume of Alzheimer’s disease continue to decrease and there is a positive correlation between them.Using VBM technology can clearly understand the specific areas and extent of gray matter atrophy in Alzheimer’s patients,at the same time,through the differences in the extent of brainstem atrophy,the post-grouping of patients can be used to determine whether brainstem and gray matter have interaction and influence in Alzheimer’s disease.It will help to further understand the pathogenesis and leading factors of Alzheimer’s disease and provide assistance for seeking neuroimaging evidence for the early diagnosis of Alzheimer’s disease.