Incidence and risk factors associated with seizures in cerebral amyloid angiopathy

Background and purpose: Cerebral amyloid angiopathy (CAA) is a common cause of intracranial hemorrhage (ICH), which is a risk factor for seizures. The incidence and risk factors of seizures associated with a heterogeneous cohort of CAA patients have not been studied. Methods: We conducted a retrospective study of patients with CAA treated at Mayo Clinic Florida between 1 January 2015 and 1 January 2021. CAA was defined using the modified Boston criteria version 2.0. We analyzed electrophysiological and clinical features, and comorbidities including lobar ICH, nontraumatic cortical/convexity subarachnoid hemorrhage (cSAH), superficial siderosis, and inflammation (CAA with inflammation [CAA-ri]). Cognition and mortality were secondary outcomes. Univariate and multivariate analyses were performed to determine risk of seizures relative to clinical presentation. Results: Two hundred eighty-four patients with CAA were identified, with median follow-up of 35.7 months (interquartile range = 13.5–61.3 months). Fifty-six patients (19.7%) had seizures; in 21 (37.5%) patients, seizures were the index feature leading to CAA diagnosis. Seizures were more frequent in females (p = 0.032) and patients with lobar ICH (p = 0.002), cSAH (p = 0.030), superficial siderosis (p < 0.001), and CAA-ri (p = 0.005), and less common in patients with microhemorrhage (p = 0.006). After controlling for age and sex, lobar ICH (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.1–4.2), CAA-ri (OR = 3.8, 95% CI = 1.4–10.3), and superficial siderosis (OR = 3.7, 95% CI = 1.9–7.0) were independently associated with higher odds of incident seizures. Conclusions: Seizures are common in patients with CAA and are independently associated with lobar ICH, CAA-ri, and superficial siderosis. Our results may be applied to optimize clinical monitoring and management for patients with CAA.