sDWI and iDWI lesions in cerebral amyloid angiopathy had distinct topographical distributions and risk factor profiles, suggesting potentially different underlying mechanisms, with cerebral ischemia not uncommon in CAA.
Symptomatic DWI lesions predominantly involved deep regions while incidental DWI lesions were mainly located in cortical-juxtacortical regions in CAA patients.
The 3-year cumulative incidence of iDWI lesions (25.74%) was substantially higher than that of sDWI lesions (9.45%) in probable CAA patients.
The number of traditional vascular risk factors and lacunes were independent predictors for symptomatic DWI lesions in CAA.
Lacunes, disseminated cortical superficial siderosis, and lobar cerebral microbleed grade were independent predictors for incidental DWI lesions in CAA.
Cerebral ischemia was not uncommon in CAA, with sDWI and iDWI lesions having distinct topographical distributions and risk factor profiles suggesting potentially different underlying mechanisms.
Cerebral amyloid angiopathy (CAA) is a brain disease where abnormal protein deposits in blood vessel walls increase the risk of bleeding in the brain. While CAA has traditionally been considered a hemorrhagic (bleeding) disease, this study investigated whether ischemic strokes and stroke-like episodes — where blood flow is temporarily blocked rather than bleeding occurring — are also common in CAA patients. Researchers tracked 185 CAA patients over several years, recording both symptomatic DWI lesions (sDWI, which caused noticeable symptoms like a stroke) and incidental DWI lesions (iDWI, which were silent and only detected on brain scans). The study found that these two types of lesions occurred in different parts of the brain and had different risk factors, suggesting they arise from different disease processes. Symptomatic lesions tended to occur in deeper brain regions and were associated with traditional cardiovascular risk factors (like high blood pressure, diabetes, and smoking) and lacunes (small cavities from old strokes), pointing toward general blood vessel disease. In contrast, silent incidental lesions were more often found in the outer cortical layers of the brain and were associated with CAA-specific imaging markers — namely, cortical superficial siderosis (iron deposits on the brain surface) and a higher burden of lobar microbleeds — suggesting these lesions are more directly driven by CAA pathology itself. Over three years, about 1 in 4 patients developed silent ischemic lesions and about 1 in 11 developed symptomatic ones. This research suggests that ischemic brain injury is a meaningful and underappreciated part of CAA, not just hemorrhage. Because sDWI and iDWI lesions appear to have distinct causes, they may require different treatment approaches. The findings also support using DWI lesions as imaging markers to track disease activity in future CAA research and clinical trials, potentially helping researchers better understand how the disease progresses and how to measure the effects of new treatments.
Sha Y, Wu J, Zhou Y, Liu Z, Han F, Yao M, et al.. (2026). Distinct characteristics and risk factors of symptomatic and incidental DWI lesions in cerebral amyloid angiopathy.. Journal of neurology. https://doi.org/10.1007/s00415-026-14107-2