White-Matter Hyperintensity Load and Differences in Resting-State Network Connectivity Based on Mild Cognitive...

Area of Science:

• Neuroscience
• Radiology
• Cognitive Science

Background:

• Mild cognitive impairment (MCI) is categorized into amnesic (aMCI) and non-amnesic (naMCI) subtypes based on memory deficits.
• Understanding the underlying neurofunctional mechanisms, particularly resting-state brain networks, is crucial for differentiating MCI subtypes.
• The impact of white-matter hyperintensities (WMHs) on these networks in aMCI versus naMCI remains unclear.

Purpose of the Study:

• To investigate the interaction between MCI subtypes (aMCI vs. naMCI) and white-matter hyperintensity (WMH) burden on large-scale brain networks.
• To determine if WMH load differentially affects functional connectivity in aMCI and naMCI patients.
• To explore the neurofunctional basis of MCI heterogeneity.

Main Methods:

• A cohort of 123 MCI patients underwent MRI, including T1-weighted, FLAIR, and resting-state fMRI.
• White-matter hyperintensities (WMHs) were quantified using the Lesion Segmentation Toolbox.
• Resting-state fMRI data were analyzed using independent component analysis to identify key brain networks (salience, frontoparietal).

Main Results:

• A significant interaction between MCI subtype and WMH burden was observed in the salience and left frontoparietal networks.
• Low WMH burden was associated with stronger salience network connectivity in aMCI patients (right insula).
• Low WMH burden was linked to stronger left frontoparietal network connectivity in naMCI patients (left mediotemporal lobe).

Conclusions:

• The association between white-matter hyperintensity burden and resting-state network connectivity varies significantly between aMCI and naMCI.
• These findings suggest that clinical profiles of MCI reflect underlying mechanistic interactions.
• Understanding these interactions may be vital for improved diagnostic and prognostic assessments in MCI.