Cortical superficial siderosis and acute convexity subarachnoid hemorrhage in cerebral amyloid angiopathy.

Background Acute convexity subarachnoid hemorrhage (cSAH) and cortical superficial siderosis (cSS) are neuroimaging markers of cerebral amyloid angiopathy (CAA) that may arise through similar mechanisms. We sought to compare the prevalence of cSS between patients with CAA presenting with acute cSAH versus lobar intracerebral hemorrhage (ICH), and to explore the physiopathology of cSS by examining neuroimaging associations. Methods We retrospectively analyzed data from 116 consecutive patients with probable CAA (mean age, 77.4 ± 7.3 years) presenting with acute cSAH (n = 45) or acute lobar ICH (n = 71). MRI scans were analyzed for cSS and other imaging markers. We compared the two groups’ clinical and imaging data and explored the associations between cSAH and cSS. Results Patients with cSAH presented mostly with transient focal neurological episodes. Prevalence of cSS was higher among cSAH patients than among ICH patients (88.9% vs. 57.7%; p < 0.001). In multivariable logistic regression analysis, focal (OR: 6.73; 95% CI: 1.75–25.81; p = 0.005) and disseminated (OR: 11.68; 95% CI: 3.55–38.35; p < 0.001) cSS were independently associated with acute cSAH, whereas older age (OR: 0.93; 95% CI: 0.87–0.99; p = 0.025) and chronic lobar ICH count (OR: 0.45; 95% CI: 0.25–0.80; p = 0.007) were associated with acute lobar ICH. Conclusions Among patients with CAA, cSS is independently associated with acute cSAH. These findings suggest that cSAH may be involved in the pathogenesis of the cSS observed in CAA. Longitudinal studies are warranted to assess this potential causal relationship. This article is protected by copyright. All rights reserved.