Association between gray matter atrophy, cerebral hypoperfusion, and cognitive impairment in Alzheimer's disease

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

doi:10.3389/fnagi.2023.1129051

Association between gray matter atrophy, cerebral hypoperfusion, and cognitive impairment in Alzheimer's disease

Front Aging Neurosci. 2023 Apr 6:15:1129051. doi: 10.3389/fnagi.2023.1129051. eCollection 2023.

Authors

Haoyang Dong¹, Lining Guo¹, Hailei Yang¹, Wenshuang Zhu¹, Fang Liu², Yingying Xie¹, Yu Zhang¹, Kaizhong Xue¹, Qiang Li³, Meng Liang⁴, Nan Zhang², Wen Qin¹

Affiliations

¹ Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, China.
² Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China.
³ Technical College for the Deaf, Tianjin University of Technology, Tianjin, China.
⁴ School of Medical Imaging, Tianjin Medical University, Tianjin, China.

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 area-specific causal pathways between regional gray matter atrophy, cerebral hypoperfusion, and cognitive impairment in AD patients.

Method: Forty-two qualified AD patients and 49 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 its 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 = 55.82%, β = 0.242, 95% confidence interval by bias-corrected and accelerated bootstrap: 0.082 to 0.530).

Conclusion: Our findings indicated suggested that left MTG is an important hub linking gray matter atrophy, hypoperfusion, and cognitive impairment for AD, and might be a potential treatment target for AD.

Keywords: Alzheimer’s disease; arterial spin labeling; cognitive impairment; gray matter atrophy; hypoperfusion; magnetic resonance imaging; pathway analysis.