Prognostic relevance of cortical superficial siderosis in cerebral amyloid angiopathy

Objective: To investigate the prognostic relevance of cortical superficial siderosis (cSS) in patients with cerebral amyloid angiopathy (CAA). Methods: 302 patients fulfilling the modified Boston criteria for probable or possible CAA were enrolled into a prospective, multicenter cohort study and followed for 12 months. cSS was assessed on T2*/SWI MRI. The predefined primary composite endpoint was incident stroke or death in patients with cSS compared to those without. Secondary analyses included cerebrovascular events and functional outcome measured by the modified Rankin scale (mRS). Multiple regression analysis was performed to adjust for possible confounders.1 Results: cSS prevalence was 40%. The primary endpoint occurred more frequently in patients with cSS (22%, 27/121) compared to those without (8%, 15/181, p=0.001). Rates of CAA-related incident intracranial hemorrhage were 17% (cSS) and 4% (no cSS, p=0.0003). The proportion of patients being functionally independent (mRS 0-2) 1...