Topological relationships between perivascular spaces and progression of white matter hyperintensities: a pilot study in a sample of the Lothian Birth Cohort 1936

Abstract

AbstractEnlarged perivascular spaces (PVS) and white matter hyperintensities (WMH) are features of cerebral small vessel disease which can be seen in brain magnetic resonance imaging (MRI). Given the associations and proposed mechanistic link between PVS and WMH, they are hypothesised to also have topological proximity. However, this, and the influence of their spatial proximity on WMH progression are unknown. We analysed longitudinal MRI data from 29/32 participants (mean age at baseline = 71.9 years) in a longitudinal study of cognitive ageing, from three waves of data collection at 3-year intervals, alongside semi-automatic segmentation masks for PVS and WMH, to assess relationships. The majority of deep WMH clusters were found adjacent to or enclosing PVS (Wave – 1: 77%; 2: 76%; 3: 69%), especially in frontal, parietal and temporal regions. Of the WMH clusters in the deep white matter that increased between waves, most increased around PVS (Waves – 1-2: 73%; 2-3: 72%). Formal statistical comparisons of severity of each if these two SVD markers yielded no associations between deep WMH progression and PVS proximity. These findings may suggest deep WMH clusters preferentially form and grow around PVS, possibly reflecting the consequences of impaired interstitial fluid drainage via PVS. The utility of these relationships as predictors of WMH progression remains unclear.