Loss of white matter integrity mediates the association between cortical cerebral microinfarcts and cognitive

Jiannan Huang1, Megan Oh1, Caroline Robert2

  • 1Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.

Insights

Cortical cerebral microinfarcts (CMIs) are linked to white matter (WM) damage and cognitive decline. Mean diffusivity (MD) changes partially explain the association between CMIs and global cognition over time.

Area of Science:

  • Neurology
  • Neuroimaging
  • Cognitive Science

Background:

  • Cortical cerebral microinfarcts (CMIs) are increasingly recognized as a significant factor in cognitive impairment.
  • Previous cross-sectional studies suggest a link between CMIs, white matter (WM) integrity, and cognitive decline, necessitating longitudinal investigation.

Purpose of the Study:

  • To determine the association between cortical CMIs and WM integrity using diffusion-tensor imaging (DTI) measures.
  • To investigate if DTI measures mediate the relationship between cortical CMIs and cognitive decline over time.

Main Methods:

  • Cortical CMIs were assessed using 3T MRI and graded.
  • Diffusion-tensor imaging (DTI) measures, including mean diffusivity (MD) and fractional anisotropy (FA), were derived from histogram analysis.
  • Cognitive function was evaluated using a neuropsychological test battery, and linear mixed-effect models analyzed longitudinal changes.

Main Results:

  • The presence of cortical CMIs at baseline correlated with longitudinal changes in MD and FA histogram parameters.
  • Cortical CMIs were associated with declines in global cognition and executive function.
  • Mean diffusivity (MD) median was found to mediate the cross-sectional association between cortical CMIs and global cognition.

Conclusions:

  • Cortical CMIs are associated with microstructural white matter changes and cognitive decline.
  • The findings suggest that white matter integrity, particularly MD, may play a mediating role in the relationship between CMIs and cognitive impairment.
  • Further research is needed to elucidate the causal relationship between CMIs, WM integrity, and cognitive decline.