Prevalence and risk factors of seizures in cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is caused by the progressive deposition of β-amyloid in the walls of small to medium-sized cerebral vessels. While seizures are a known manifestation of CAA and CAA-specific risk factors have been evaluated, less is known about other risk factors in patients with CAA. We aim to fill this gap by determining the prevalence of seizures in CAA and identifying factors associated with an increased seizure risk in a large multicenter cohort.

We identified consecutive patients with CAA who were evaluated at Mayo Clinic sites in Minnesota, Florida, and Arizona between 2015 and 2024 using the ICD-10 code I68.0. Data on demographics and comorbidities were compared between those with and without seizures using the chi-square test for categorical variables and independent samples t-test for continuous variables. Odds ratios (OR) were estimated after adjusting for age, sex, and race in multivariable logistic regression.

We included 1,914 patients with CAA with a mean age of 75.4 ± 8.6 years, of whom 52.3 % were female and 87.5 % were white. Seizures were observed in 347 patients (18.1 %). Individuals with seizures were significantly younger (mean age 67.7 ± 9.1 vs. 77.2 ± 7.5 years, p < 0.001). In multivariable logistic regression, alcohol use (OR 1.92, 95 % CI 1.03-3.56, p = 0.04), diabetes mellitus (OR 2.14, 95 % CI 1.13-4.06, p = 0.02), hypertension (OR 1.79, 95 % CI 1.33 - 2.41, p < 0.001), liver disease (OR 1.75, 95 % CI 1.14-2.69, p = 0.01), and ischemic stroke (OR 1.33, 95 % CI 1.01-1.74, p = 0.04) were independently associated with an increased risk of seizures.

Seizures affect nearly one in five patients with CAA. Hypertension, diabetes, alcohol use, liver disease, and ischemic stroke were independently associated with higher odds of a seizure diagnosis after adjustment for age, sex, and race. These comorbidities are potentially modifiable, but whether their management reduces seizure incidence requires prospective, imaging-informed studies.