The aim of this study is to describe the cognitive associations, characteristics, burden and of cerebral small vessel disease (CSVD) in Canadians living in precarious housing. The participants involved received susceptibility-weighted imaging 3T magnetic resonance imaging sequences and T1, T2-fluid-attenuated inversion recovery; along with cognitive, comprehensive clinical, laboratory assessments. The burden of CSVD was characterized using a modified Small Vessel Disease (mSVD) score. The median age of the 228 participants (of which 77% were male) was 44.7 years. In 188 participants with good quality MRI sequences, mSVD scores were 0 (68%), 1 (27%), and 2 (6%).

 Overall, 32% of them had an mSVD ≥1; this proportion remained the same when participants with missing sequences were added to the study. The most prevalent feature was lacunes 7%, cerebral microbleed 8%, and white matter hyperintensities 24%. Higher diastolic blood pressure, older age, and a history of injection drug use had significant independent associations with an mSVD score of ≥1 in multivariable analysis. The mSVD score ≥1 was associated with lower performance on decision-making, sustained attention, and verbal memory tests, leading to a 4-5% variance in each individual cognitive domain.

In conclusion, the 32% prevalence of CVSD in this cohort study was higher than expected for age and was associated with significantly lower cognitive performance.