Epidemiologic, Clinical, and Radiologic Study of Cerebral Amyloid Angiopathy–Related Inflammation in Northern Ireland

Cerebral amyloid angiopathy-related inflammation (CAAri) can present with acute or subacute encephalopathy, focal neurologic deficits, or seizures. In a population study, we describe epidemiologic, clinical, and radiologic features of patients with CAAri. Using multiple sources, a cohort of patients diagnosed with CAAri in Northern Ireland was recruited over 12 years. Standardized incidence and prevalence data, clinical presentation, radiologic findings, treatment, and outcome were recorded. Twenty-five patients (12 women, 13 men) presented with CAAri (mean age 69.8 (SD 9.7) years). The age-standardized incidence of CAAri was 0.128 (95% CI 0.078-0.179)/100,000/y, and the point prevalence of CAAri was 0.904 (0.461-1.346)/100,000. Patients presented with subacute cognitive decline or behavioral change, focal deficits, headache, seizures, and falls. MRI contrast enhancement occurred in 5 of 17 (29%), and 19 of 25 (76%) had over 50 cerebral microbleeds. Nineteen patients (76%) were treated with steroid therapy ± other immunotherapies. Neuroimaging improvement occurred in most patients, but 7 patients (28%) had clinical progression. The median survival was 81 (95% CI 43.5-118.5) months. CAAri is rare and has a broad spectrum of presentations. Most patients with CAAri survive more than 6 years. Further research is required to identify the most appropriate immunotherapy regimen for patients with CAAri.