AUTHOR=Dong Haoyang , Guo Lining , Yang Hailei , Zhu Wenshuang , Liu Fang , Xie Yingying , Zhang Yu , Xue Kaizhong , Li Qiang , Liang Meng , Zhang Nan , Qin Wen 

TITLE=Association between gray matter atrophy, cerebral hypoperfusion, and cognitive impairment in Alzheimer’s disease

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 15 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2023.1129051

DOI=10.3389/fnagi.2023.1129051

ISSN=1663-4365

ABSTRACT=Background: Alzheimer's disease (AD) is one of the most severe neurodegenerative diseases leading to dementia in the elderly. Cerebral atrophy and hypoperfusion are two important pathophysiological characteristics. However, it is still unknown about the causal pathways between regional gray matter atrophy, cerebral hypoperfusion, and cognitive impairment in AD patients. Method: Forty-two qualified AD patients and forty-nine healthy controls (HC) were recruited in this study. First, we explored voxel-wise inter-group differences in gray matter volume (GMV) and arterial spin labeling (ASL) -derived cerebral blood flow (CBF). Then we explored the voxel-wise associations between GMV and Mini-Mental State Examination (MMSE) score, GMV and CBF, and CBF and MMSE to identify brain targets contributing to cognitive impairment in AD patients. Finally, a mediation analysis was applied to test the causal pathways among atrophied GMV, hypoperfusion, and cognitive impairment in AD. Results: Voxel-wise permutation test identified that the left middle temporal gyrus (MTG) had both decreased GMV and CBF in the AD. Moreover, the GMV of this region was positively correlated with MMSE and CBF, and CBF of this region was also positively correlated with MMSE in AD (P < 0.05, corrected). Finally, mediation analysis revealed that gray matter atrophy of left MTG drives cognitive impairment of AD via the mediation of CBF (proportion of mediation = 44.01%, β= 0.210, 95% confidence interval by bias-corrected and accelerated bootstrap: 0.028 to 0.480). Conclusion: Our findings indicated that left MTG is an important target linking gray matter atrophy, hypoperfusion, and cognitive impairment for AD. Our study provides new insight into the precision treatment of AD.