Cerebellar Superficial Siderosis in Cerebral Amyloid Angiopathy on 1.5T T2*-Weighted Imaging.

BACKGROUND: Cerebellar superficial siderosis (SS) has been recently reported to be present in about 10% of both hereditary and sporadic cerebral amyloid angiopathy (CAA) on 3T MRI using primarily susceptibility-weighted imaging. OBJECTIVES: Our aim was to assess cerebellar SS in sporadic CAA patients using 1.5T T2*-weighted MRI and to evaluate possible underlying mechanisms. METHOD: We retrospectively screened MRI scans of sporadic probable CAA patients initially presenting with intracerebral hemorrhage-, acute subarachnoid hemorrhage- or cortical SS-related symptoms between September 2009 and January 2022 registered in our stroke database. Patients with familial CAA were excluded. On 1.5T T2*-weighted MRI, cerebellar SS (including kappa statistics for interobserver agreement) was assessed together with typical CAA hemorrhagic features and with the presence of supratentorial macrobleed and cortical SS adjacent to the tentorium cerebelli (TC) and TC hemosiderosis. RESULTS: We screened 151 patients and finally included 111 CAA patients (median age 77) with cerebellar SS observed in 6 (5%) patients. Cerebellar SS presence was associated with a higher number of supratentorial macrobleeds (median n = 3 vs. n = 1, p = 0.0012), presence of supratentorial macrobleed adjacent to the TC (p = 0.002), and TC hemosiderosis (p = 0.005). CONCLUSIONS: Cerebellar SS in CAA patients can be identified on 1.5T T2*-weighted imaging. Associated MRI characteristics suggest contamination from supratentorial macrobleeds.

Brain hemorrhage on 24h-CT and functional outcome in stroke patients with cerebral amyloid angiopathy features on pre-thrombolysis MRI treated with intravenous thrombolysis: A case series.

BACKGROUND AND OBJECTIVES: In stroke patients treated with intravenous thrombolysis (IVT), presence and high number of strictly lobar cerebral microbleeds (compatible with cerebral amyloid angiopathy, CAA) seems to be associated with increased risk of hemorrhagic transformation, symptomatic hemorrhagic transformation, remote hemorrhage, and poor functional outcome. Some of these CAA patients with cerebral microbleeds also have chronic lobar intracerebral hemorrhage. Few data are available on IVT-treated CAA patients showing cortical superficial siderosis. There are no reports studying factors associated with brain hemorrhagic complication or functional outcome in IVT-treated CAA patients. We present a case series study of IVT-treated stroke patients with CAA features on pre-IVT MRI in whom we have evaluated brain hemorrhagic complications on 24 h-CT and functional outcome after IVT. MATERIAL AND METHODS: In our stroke center, IVT decision in patients with CAA MRI features is at the physician's discretion. We retrospectively screened our stroke database between January 2015 and July 2022 for pre-IVT imaging of 959 consecutive IVT-treated stroke patients without ongoing anticoagulation therapy for probable CAA MRI features defined by modified Boston criteria. After exclusion of 119 patients with missing MRI (n = 47), MRI showing motion artefacts (n = 49) or with alternative chronic brain hemorrhage cause on MRI (n = 23), 15 IVT-treated patients with probable CAA on pre-IVT MRI were identified. In these 15 patients, clinical, biological and MRI characteristics were compared between patients with vs. without post-IVT hemorrhage and between patients with poor (MRS 3-6) vs. good (MRS 0-2) functional outcome at discharge. RESULTS: Two patients showed brain hemorrhage on 24 h-CT and both died after 40 and 31 days respectively. The remaining patients had no brain hemorrhage and showed very good outcome except one. Atrial fibrillation (p = 0.029) and Fazekas scale (p = 0.029) were associated with brain hemorrhage whereas atrial fibrillation (p = 0.0022), NIHSS (p = 0.027), blood glucose level (p = 0.024), CRP (p = 0.022) and DWI ASPECT (p = 0.016) were associated with poor outcome. DISCUSSION: Consequences of IVT in CAA patients can be dramatic. Larger studies are needed to compare IVT risks and outcome between CAA and non-CAA patients, also including CAA patients with chronic intracerebral hemorrhage or cortical superficial siderosis. In addition, future studies should try to identify clinical, biological and radiological features at high risk for brain hemorrhage and poor outcome in order to assess the risk-benefit ratio for IVT in CAA. CLINICAL TRIAL REGISTRATION-URL: http://www. CLINICALTRIALS: gov. Unique identifier: NCT05565144.