Objective: We observed obvious WMH shrinkage one year after minor stroke in several participants in a longitudinal study, therefore assessed factors associated with WMH change in the whole cohort.
Methods: We recruited participants with minor ischemic stroke, performed clinical assessments and brain MRI. At one year, we assessed recurrent cerebrovascular events, dependency and repeated MRI. We assessed change in WMH volume from baseline to one year (normalised to intracranial volume, %ICV) and associations with baseline variables, clinical outcomes and imaging parameters using multivariable analysis of co-variance, model of changes and multinomial logistic regression.
Results: Amongst 190 participants, mean age 65.3 (range 34·3-96·9) years, 112 (59%) males, WMH decreased in 71 participants by one year. At baseline, participants whose WMH decreased had similar WMH volumes but higher blood pressure (p=0·0064) to participants whose WMH increased. At one year, participants with WMH decrease (expressed as %ICV) had larger reductions in blood pressure (β=0·0053, 95%CI 0·00099-0·0097 fewer WMH per mmHg decrease, p=0·017) and in mean diffusivity in normal-appearing white matter (β=0.075, 95%CI 0.0025-0.15 fewer WMH per unit mean diffusivity decrease, p=0.043) than participants with WMH increase; those with WMH increase experienced more recurrent cerebrovascular events (32%, vs 16% with WMH decrease, β=0·27, 95%CI 0·047-0·50, more WMH per event, p=0.018).
Conclusions: Some WMH may regress after minor stroke, with potentially better cerebrovascular and brain tissue outcomes. The role of risk factor control requires verification. Interstitial fluid alterations may account for some WMH reversibility, offering potential intervention targets.