Approved Research

The association of intra-white matter hyperintensities (WMH) heterogeneity with cognitive decline in cerebral small vessel disease

Lay summary

White matter hyperintensities (WMH) are one of the Magnetic Resonance Imaging (MRI) markers used to quantify damage caused by cerebral small vessel disease (CSVD). WMH contribute to the disconnection of specific fiber tracts, leading to brain damage that disrupts the connectivity of the brain's white matter network, thereby affecting effective communication within the entire brain network and causing cognitive decline. Historically, several studies have addressed the burden of WMH based on volume, establishing certain correlations between WMH volume in Subcortical vascular cognitive impairment (SVCI) patients and cognitive outcomes. However, in clinical practice, the relationship between the extent of WMH burden and cognitive function decline is not always linear. This discrepancy implies that relying solely on volumetric changes of WMH over time may not comprehensively delineate its association with cognitive impairment.

Therefore, in this 36-months research project, we would like to explore the association of white matter hyperintensities (WMH) heterogeneity with cognitive decline in a more diverse population using UK Biobank.

Both diffusion- and perfusion-weighted MRI have been established as effective tools for detecting microstructural and CBF heterogeneous changes. In this study, we hypothesized that habitat analysis based on diffusion- and perfusion-weighted MRI, together with structural connectivity analysis, could serve as a valuable tool for predicting the growth of WMH and the related cognitive decline at baseline. Furthermore, we posited that a spatial habitat analysis would facilitate the identification of regions in the normal-appearing white matter (NAWM) that later progressed into WMH (referred to as "the growing WMH") by analyzing similar diffusion- and perfusion-environments.

Our study aimed to predict the growth of WMH and explored the association between  WMH heterogeneity and cognitive decline in cerebral small vessel disease by performing a multi-parametric MRI-based habitat analysis. Thus providing radiological evidence for early intervention in patients with cerebral small vessel disease, and thereby reducing the burden of dementia worldwide.