Gray Matter Atrophy in Amnestic Mild Cognitive Impairment: A Voxel-Based Meta-Analysis
Jinhuan Zhang1,2, Yongfeng Liu3, Kai Lan1
1The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China.
Abstract:
Background: Voxel-based morphometry (VBM) has been widely used to investigate structural alterations in amnesia mild cognitive impairment (aMCI). However, inconsistent results have hindered our understanding of the exact neuropathology related to aMCI. Objectives: Our aim was to systematically review the literature reporting VBM on aMCI to elucidate consistent gray matter alterations, their functional characterization, and corresponding co-activation patterns. Methods: The PubMed, Web of Science, and EMBASE databases were searched for VBM studies on aMCI published from inception up to June 2020. Peak coordinates were extracted from clusters that showed significant gray matter differences between aMCI patients and healthy controls (HC). Meta-analysis was performed using seed-based d mapping with the permutation of subject images (SDM-PSI), a newly improved meta-analytic method. Functional characterization and task-based co-activation patterns using the BrainMap database were performed on significant clusters to explore their functional roles. Finally, VBM was performed based on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset to further support the findings. Results: A total of 31 studies with 681 aMCI patients and 837 HC were included in this systematic review. The aMCI group showed significant gray matter atrophy in the left amygdala and right hippocampus, which was consistent with results from the ADNI dataset. Functional characterization revealed that these regions were mainly associated with emotion, cognition, and perception. Further, meta-regression analysis demonstrated that gray matter atrophy in the left inferior frontal gyrus and the left angular gyrus was significantly associated with cognitive impairment in the aMCI group. Conclusions: The findings of gray matter atrophy in the left amygdala and right hippocampus are highly consistent and robust, and not only offer a better understanding of the underlying neuropathology but also provide accurate potential biomarkers for aMCI.
Insights
Gray matter atrophy in the left amygdala and right hippocampus is consistently observed in amnesia mild cognitive impairment (aMCI). These findings offer robust biomarkers for understanding aMCI neuropathology.
Area of Science:
- Neuroimaging
- Neurology
- Cognitive Science
Background:
- Voxel-based morphometry (VBM) studies on amnesia mild cognitive impairment (aMCI) yield inconsistent results regarding structural brain alterations.
- Understanding consistent neuropathological changes in aMCI is crucial for diagnosis and treatment.
Approach:
- Systematic literature review of VBM studies on aMCI up to June 2020, including 31 studies with 681 patients and 837 healthy controls.
- Meta-analysis using seed-based d mapping with permutation of subject images (SDM-PSI) to identify consistent gray matter differences.
- Functional characterization and meta-regression using the BrainMap database and Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset to explore functional roles and cognitive associations.
Key Points:
- Meta-analysis revealed significant gray matter atrophy in the left amygdala and right hippocampus in aMCI patients compared to healthy controls.
- These atrophic regions are functionally associated with emotion, cognition, and perception.
- Gray matter loss in the left inferior frontal gyrus and left angular gyrus correlated with cognitive impairment severity in aMCI.
Conclusions:
- Consistent gray matter atrophy in the left amygdala and right hippocampus serves as a robust indicator of aMCI neuropathology.
- These findings provide valuable insights into the underlying brain changes associated with aMCI.
- Identified atrophic regions represent potential reliable biomarkers for early detection and monitoring of aMCI.
