To compare baseline characteristics, vascular risk factors, radiological findings between patients with CAA-RI and noninflammatory CAA.

CAA-related inflammation (CAA-ri) is an increasingly recognized inflammatory variant of cerebral amyloid angiopathy (CAA). While prior reports describe clinical and radiographic features of CAA-RI, few studies have directly compared its clinical and imaging profile to that of noninflammatory CAA.

We retrospectively reviewed 378 patients diagnosed with probable or definite CAA at a single center between 2015 and 2024. Patients were categorized as inflammatory (CAA-ri/ABRA) or non-inflammatory CAA. Clinical variables, comorbidities, laboratory results, and MRI markers of small-vessel disease were compared using chi-square and t-tests

Among 378 patients with CAA (mean age 78 ± 6 years; 49.6% female), 58 (15.3%) had inflammatory CAA. Compared with noninflammatory CAA, the inflammatory group had lower rates of hypercholesterolemia (29.3% vs 44.1%, p = 0.036) and higher prevalence of atrial fibrillation (5.2% vs 1.1%, p = 0.001) and alcohol use (81.4% vs 66.0%, p = 0.045). Serum blood glucose was significantly lower (106 ± 20 vs 119 ± 39 mg/dL, p = 0.023).
On MRI, inflammatory CAA demonstrated a greater lobar microbleed burden (p = 0.049) and more extensive cortical superficial siderosis (p = 0.013). Rates of epilepsy (25.9% vs 20.3%), ischemic or hemorrhagic stroke, and small-vessel disease burden were comparable. Mortality was lower among inflammatory cases (8.6% vs 19.7%, p = 0.043).

Inflammatory CAA displays distinct clinical, metabolic, and imaging profiles compared to noninflammatory CAA, including lower cholesterol and glucose levels, higher atrial fibrillation and alcohol use, greater hemorrhagic lesion burden, and lower mortality. These findings underscore the importance of integrating clinical features with radiographic and metabolic markers to enable earlier recognition of the inflammatory subtype and guide personalized treatment strategies, ultimately improving patient outcomes.