Early vs Delayed Steroid Treatment in Cerebral Amyloid Angiopathy–Related Inflammation

BACKGROUND AND OBJECTIVES: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a potentially reversible inflammatory syndrome for which corticosteroid administration constitutes the cornerstone of management. However, evidence that early steroid treatment improves clinical and radiologic outcomes remains limited. This study aimed to determine whether early steroid initiation is associated with improved clinical and radiologic outcomes compared with delayed treatment in CAA-ri and to further investigate 12-month all-cause mortality and CAA-ri recurrence. METHODS: This retrospective cohort study included patients admitted up to May 31, 2025, from 3 Italian academic referral centers, with a maximum follow-up of 12 months. Eligible patients had probable CAA-ri per diagnostic criteria, comparable baseline, and follow-up MRI studies and underwent modified Rankin Scale (mRS) evaluations within 12 months. Early steroid therapy was defined as initiation within 6 weeks of CAA-ri symptom onset. Patients were compared with those who initiated steroids beyond 6 weeks. The primary outcomes were functional status and vasogenic edema severity at follow-up, assessed with the mRS and the 3-point Amyloid-related Imaging Abnormalities-Edema scale, respectively; secondary outcomes were 12-month all-cause mortality and CAA-ri recurrence. Inverse-probability weighting from a propensity-score model was used. Primary outcomes were analyzed with weighted ordinal logistic regression, and secondary outcomes with weighted Cox proportional hazards models with robust variance. RESULTS: = 0.001). No differences were found for 12-month recurrence (hazard ratio [HR], 1.25; 95% CI 0.31-5.07). Regarding mortality, a higher risk was suggested in the ES group (HR, 4.10; 95% CI 1.10-15.32), although not supported by complementary survival analyses. DISCUSSION: Early steroid therapy was associated with more favorable functional and radiologic outcomes. Findings on mortality and recurrence were inconclusive, reflecting limited statistical power. These results suggest an association between early steroid initiation and short-term outcomes, while longer-term trajectories warrant further investigation.