Impairment and compensation coexist in amnestic MCI default mode network
Zhigang Qi, Xia Wu, Zhiqun Wang, Nang Zhang, Huiqing Dong, Li Yao, Kuncheng Li
NeuroImage December 17, 2009 DOI: 10.1016/j.neuroimage.2009.12.025 via OpenAlex
Summary
AI-generated from the abstractPeople with amnestic mild cognitive impairment (aMCI), a transitional stage between healthy aging and Alzheimer's disease, show altered brain activity in the default mode network (DMN) compared to healthy older adults. Using resting-state fMRI, 14 healthy elderly participants showed increased activity in DMN regions including the bilateral precuneus/posterior cingulate cortex, right inferior parietal lobule, and left fusiform gyrus, with a trend toward increased right medial temporal lobe activity. The 14 aMCI patients showed increased activity in the left prefrontal cortex, inferior parietal lobule, and middle temporal gyrus, which may reflect compensatory processes. These abnormal DMN activity patterns could serve as an imaging biomarker for diagnosing and monitoring aMCI.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 28 |
| Population | 14 amnestic MCI patients and 14 healthy elderly |
| Citations | 328 |
| Key finding | Compared to healthy elderly, aMCI patients show decreased DMN activity in posterior regions but increased frontal-parietal activity, possibly reflecting compensation. |
Abstract
Mild cognitive impairment (MCI) is the transitional, heterogeneous continuum from healthy elderly to Alzheimer's disease (AD). Previous studies have shown that brain functional activity in the default mode network (DMN) is impaired in AD patients. However, altering DMN activity patterns in MCI patients remains largely unclear. The present study utilized resting-state functional magnetic resonance imaging (fMRI) and an independent component analysis (ICA) approach to investigate DMN activity in 14 amnestic MCI (aMCI) patients and 14 healthy elderly. Compared to the aMCI patients, the healthy elderly exhibited increased functional activity in the DMN regions, including the bilateral precuneus/posterior cingulate cortex, right inferior parietal lobule, and left fusiform gyrus, as well as a trend towards increased right medial temporal lobe activity. The aMCI patients exhibited increased activity in the left prefrontal cortex, inferior parietal lobule, and middle temporal gyrus compared to the healthy elderly. Increased frontal-parietal activity may indicate compensatory processes in the aMCI patients. These findings suggest that abnormal DMN activity could be useful as an imaging-based biomarker for the diagnosis and monitoring of aMCI patients.