Abstract WMP93: Cortical Superficial Siderosis in Cerebral Amyloid Angiopathy: Higher Prevalence Among Convexity Subarachnoid Hemorrhage Than Among Intracerebral Hemorrhage

Abstract

Introduction: Cerebral amyloid angiopathy (CAA) is a major cause of both lobar intracerebral hemorrhage (ICH) and cerebral microbleeds (CMB), especially in the elderly. Recently, acute convexity subarachnoid hemorrhage (cSAH) and cortical superficial siderosis (cSS) has been identified as markers of CAA. Although the clinical feature and the increased risk of future lobar ICH of cSS is well established, little is known about the specific pattern of CAA-related cSAH. Hypothesis: We hypothesized that clinical and imaging characteristics of CAA-related cSAH differ from CAA-related lobar ICH. Methods: We retrospectively analyzed clinical and MRI data of a monocentric cohort of 45 consecutive patients with an acute cSAH related to probable CAA and a comparison group of 70 consecutive patients presenting with an acute lobar ICH meeting Boston criteria for probable CAA. Results: cSAH patients were younger than ICH patients (mean age +/-SD: 75 +/-7 vs 78 +/-7; p=0.046). Transient focal neurological episodes (TFNE) were common among cSAH patients (84.4% vs 0%; p<0.001). Persistent focal neurological deficits were frequent among ICH patients (15.6% vs 98.6%; p<0.001). Prevalence of cSS was significantly higher among cSAH patients than among ICH patients (88.9% vs 60%; p<0.001) especially disseminated (66.7% vs 37.1%; p=0.002) and bilateral cSS (48.9% vs 28.6%; p=0.027). Number of lobar macrobleeds (median number [IQR]: 0 [0-1] vs 1[1-2]; p=0.07) and lobar CMB (median number [IQR]: 3 [1-6] vs 6 [2-14.75]; p=0.405) did not differ between the two groups. Conclusions: In CAA, patients presenting with cSAH are characterized by a younger age, TFNE as presenting symptoms and a higher prevalence of cSS than those presenting with Lobar ICH. These findings suggest that restricted hemorrhage into the subarachnoid space may play a crucial role in cSS physiopathology.