Higher white matter hyperintensity lesion load is associated with reduced long-range functional connectivity

Area of Science:

• Neurology
• Neuroimaging
• Cognitive Neuroscience

Background:

• Cerebral small vessel disease (CSVD) is prevalent in older adults, a key risk factor for cognitive decline and stroke.
• CSVD affects global brain integrity, disrupting neuronal networks and functional connectivity.
• White matter hyperintensities (WMH) are a common neuroimaging hallmark of CSVD.

Purpose of the Study:

• To investigate early neuronal network alterations in individuals with CSVD and varying WMH loads.
• To explore the relationship between WMH, brain oscillations, functional connectivity, and cognitive function in individuals without clinical cognitive impairment.

Main Methods:

• Utilized high-resolution resting-state electroencephalography (EEG) with source reconstruction.
• Analyzed data from 35 participants with diverse WMH severity but no overt cognitive impairment.
• Performed whole-brain functional connectivity analysis and cognitive testing.

Main Results:

• Increased global theta power correlated with higher WMH load, independent of age.
• Disrupted long-range functional connectivity in the alpha band was observed in participants with higher WMH loads, particularly in frontal regions.
• Executive function deficits correlated with increased WMH lesion load, despite no global cognitive impairment.

Conclusions:

• Oscillatory brain changes and disrupted functional connectivity are associated with WMH load in individuals without clinical cognitive impairment.
• These neuronal network alterations may precede clinically significant cognitive decline, serving as potential early biomarkers for CSVD.
• WMH significantly impact neuronal network integrity, highlighting the subclinical effects of CSVD.