Altered default-mode network activation in mild cognitive impairment compared with healthy aging

Area of Science:

• Neuroscience
• Gerontology

Background:

• Global population aging drives increased prevalence of Alzheimer's disease (AD) and mild cognitive impairment (MCI).
• Early identification of individuals at risk is essential for disease management and preserving quality of life.

Purpose of the Study:

• To identify and compare the default-mode network (DMN) in healthy elderly individuals and patients with MCI.
• To investigate hippocampal and lateral temporal involvement within the DMN in these groups.

Main Methods:

• Utilized independent component analysis (ICA) and statistical parametric mapping (SPM).
• Compared DMN functional activation between MCI patients and age/education-matched healthy elderly controls.

Main Results:

• MCI patients exhibited reduced DMN cortical activation, particularly in the retrosplenial cortex/posterior cingulate cortex, left hippocampus, and frontal areas.
• Increased activation was noted in MCI patients within the medial prefrontal cortex and bilateral middle temporal/angular cortex.
• Lateral temporal regions showed slightly increased DMN activation in MCI patients compared to controls, more pronounced on the right.

Conclusions:

• Findings suggest alterations in DMN resting-state networks in early MCI.
• Discussed in the context of early pathological changes in AD and MCI and compensatory mechanisms.
• Highlights potential for DMN analysis as a biomarker for early detection and disease monitoring.