Supplementary Material for: Perivascular Space Progression in Patients with Cerebral Amyloid Angiopathy

Introduction: Dilated perivascular spaces (PVS) are associated with small vessel disease in the aging population. We sought to investigate the incidence and dynamic evolution of MRI-detectable PVS progression in patients with cerebral amyloid angiopathy (CAA). Methods: Patients with symptomatic CAA who underwent baseline and follow-up MRI scans >2 years apart were included. The severity of both basal ganglia (BG) and centrum semiovale (CSO) PVS were rated. Multivariable logistic regression was used to determine the risk factors for PVS progression. Results: We included 90 patients with CAA (mean age 72.6 years, SD 8.0 years), of which 53 (58.9%) had intracerebral hemorrhage (ICH) at baseline. During a median follow-up of 4.8 years (IQR 3.6 - 6.6 years), PVS progression was observed in 24 patients (26.7%) at follow-up MRI. After adjusting for age, hypertension and time between baseline and follow-up MRI, cerebral microbleed (CMB) progression (OR 4.12, 95% CI 1.31 - 12.95; p=0.015) and presence of ICH at baseline (OR 8.61, 95% CI: 2.09 - 35.52; p=0.003) were independent predictors of PVS progression. In multivariable regression analysis, presence of ICH (OR 8.78, 95% CI 1.74 - 44.35; p=0.009) and hypertension (OR 5.73, 95% CI 1.25 – 26.29; p=0.025) were associated with BG-PVS progression. However, only CMB progression (OR 10.17, 95% CI 1.84 - 56.35; p=0.008) was associated with CSO-PVS progression. Conclusion: PVS progression occurs in a subset of CAA patients reimaged after a median of 4.8 years and is associated with CMB progression. PVS progression might be a useful neuroimaging marker for visualizing CAA-related vascular changes.