Increased functional connectivity and brain atrophy in elderly with subjective memory complaints

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Gerontology

Background:

• Subjective memory complaints (SMC) are prevalent in the elderly.
• Neuropsychological tests often fail to detect subtle memory changes.
• Neuroimaging reveals structural brain differences in individuals with SMC.

Purpose of the Study:

• To investigate resting-state functional connectivity and brain structure in elderly individuals reporting SMC.
• To determine if neuroimaging can objectively differentiate individuals with SMC.

Main Methods:

• Analyzed magnetic resonance imaging (MRI) data from 25 elderly with SMC and 29 controls.
• Employed voxel-based morphometry and subcortical volume measurements for structural analysis.
• Utilized dual regression to assess resting-state functional connectivity across eight networks.

Main Results:

• Elderly with SMC exhibited reduced gray matter volume in regions including the hippocampus and anterior cingulate cortex (ACC).
• Increased functional connectivity was observed in the default mode network and medial visual network in the SMC group.
• Significant group differences were identified using two-sample t-tests (p<0.05, Family-Wise Error corrected).

Conclusions:

• This study is the first to demonstrate both reduced brain volume and increased functional connectivity in elderly with SMC.
• Findings suggest that subjective memory complaints correlate with objective alterations in brain structure and function.
• Functional and structural neuroimaging are valuable tools for assessing brain integrity in individuals experiencing SMC.