White matter hyperintensities-related cortical changes and correlation with mild behavioral impairment

Area of Science:

• Neuroimaging
• Neurology
• Gerontology

Background:

• White matter hyperintensities (WMH) are common in aging brains and associated with cognitive decline.
• Mild behavioral impairment (MBI) is increasingly recognized as a precursor to dementia.
• Understanding the relationship between WMH, brain structure changes, and MBI is crucial for early intervention.

Purpose of the Study:

• To investigate changes in cortical thickness and gray matter volume (GMV) in brain regions affected by WMH.
• To explore the association between these structural changes and MBI.
• To determine if WMH mediate MBI through alterations in GMV and cortical thickness.

Main Methods:

• Voxel-based morphology (VBM) and surface-based morphology (SBM) analyses were applied to 3T MRI scans of 60 patients.
• Patients were categorized into lower WMH (LWMH) and higher WMH (HWMH) groups.
• Mild Behavioral Impairment Checklist (MBI-C) scores were assessed, and analyses adjusted for age, gender, education, and total intracranial volume.

Main Results:

• The HWMH group exhibited higher MBI-C scores.
• VBM revealed decreased GMV in the left anterior insula (AIns) and thalamus proper in the HWMH group.
• SBM indicated reduced cortical thickness in the right posterior cingulate cortex (rPCC) and other frontal/cerebellar regions in the HWMH group. GMV in the left AIns and thalamus proper, and rPCC thickness, negatively correlated with MBI-C scores.

Conclusions:

• MBI in patients with WMH is associated with gray matter and cortical atrophy.
• WMH may partially mediate MBI by causing gray matter and cortical atrophy in specific brain regions.
• These findings provide novel insights into the link between WMH and dementia pathology.