Default-mode network activity distinguishes amnestic type mild cognitive impairment from healthy aging: a combined
Feng Bai1, Zhijun Zhang, Hui Yu
1School of Clinical Medicine, Southeast University, Nanjing 210009, China.
Abstract:
Resting-state functional magnetic resonance imaging (MRI), have revealed coactivation in a distributed network that characterizes the default-mode in the human brain. However, details from resting-state imaging in amnestic type mild cognitive impairment (aMCI) is poorly understand. Regional homogeneity, which characterizes low-frequency blood oxygenation level dependent fluctuation, after statistically controlling for the regional atrophy and age in resting-state, were examined and compared between the two groups. When regional atrophy was controlled, decreased regional homogeneity in posterior cingulate cortex and precuneus still remained significant in aMCI patients. In addition the aMCI subjects displayed several regions of increased homogeneity, typically in right inferior parietal lobule, right fusiform gyrus and bilateral putamen. The impairment of posterior cingulate and precuneus could be an important marker to distinguish aMCI from healthy aging in the resting-state. Moreover, the increased regional homogeneity changes would be consistent with compensation for damage to the medial temporal regions and limbic structures, perhaps by recruitment of alternative regions.
Insights
Resting-state brain imaging reveals reduced activity in the posterior cingulate and precuneus in amnestic mild cognitive impairment (aMCI). These changes may serve as key markers distinguishing aMCI from healthy aging.
Area of Science:
- Neuroimaging
- Cognitive Neuroscience
- Neurology
Background:
- Resting-state functional MRI identifies the brain's default-mode network.
- Understanding default-mode network alterations in amnestic mild cognitive impairment (aMCI) is crucial.
Purpose of the Study:
- To investigate regional homogeneity (ReHo) differences in the resting-state brain of aMCI patients compared to healthy controls.
- To identify potential neuroimaging markers for distinguishing aMCI.
Main Methods:
- Resting-state functional MRI was used to assess low-frequency BOLD signal fluctuations.
- Regional homogeneity was analyzed, controlling for regional atrophy and age.
- Comparisons were made between aMCI patients and healthy aging individuals.
Main Results:
- Decreased ReHo was observed in the posterior cingulate cortex and precuneus in aMCI patients, even after controlling for atrophy and age.
- Increased ReHo was found in the right inferior parietal lobule, right fusiform gyrus, and bilateral putamen in aMCI subjects.
- These findings suggest distinct patterns of brain activity in aMCI.
Conclusions:
- Impaired posterior cingulate and precuneus activity may be a significant resting-state marker for differentiating aMCI from healthy aging.
- Increased ReHo in other regions might reflect compensatory mechanisms for medial temporal and limbic damage in aMCI.
More Related Videos
08:43Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment
Published on: August 7, 2017
09:01A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance
Published on: May 7, 2014