Comparative Outcomes of Arteriovenous Malformations in Eloquent versus Non-Eloquent Brain Regions: A Multicenter Study With Propensity-Score Weighting

Introduction: Arteriovenous malformations (AVMs) are complex vascular anomalies with a high risk of hemorrhage and neurological deficits, especially when located in eloquent brain regions. The eloquence of AVM location is a critical factor in treatment planning, influencing both the risk of complications and long-term functional outcomes. This study aims to compare outcomes between eloquent and non-eloquent AVMs.

Methods: This multicenter, retrospective study utilized data from the Multicenter International Study for Treatment of Brain AVMs (MISTA) consortium. Patients with eloquent and non-eloquent AVMs were compared on baseline characteristics, angiographic outcomes, and functional outcomes using the modified Rankin Scale (mRS). Propensity score weighting (IPTW) was applied to adjust for confounding variables. Outcomes were analyzed across treatment types, with subgroup analyses conducted to assess differential impacts by modality.

Results: The study included 1,013 patients, with 498 (49.2%) AVMs located in eloquent regions and 515 (50.8%) in non-eloquent regions. In unadjusted analysis, eloquent AVMs had lower complete obliteration rates (67.6% vs. 79.5%, OR: 0.53, 95% CI: 0.39–0.72, p < 0.001) and higher complication rates (24.5% vs. 19.0%, OR: 1.38, 95% CI: 1.02–1.86, p = 0.03) compared to non-eloquent AVMs. After IPTW adjustment, eloquent AVMs continued to show significantly lower odds of complete obliteration (OR: 0.45, 95% CI: 0.28–0.72, p = 0.001) and higher odds of general complications (OR: 1.59, 95% CI: 1.02–2.47, p = 0.04) and symptomatic complications (OR: 1.64, 95% CI: 1.00–2.69, p = 0.04). Subgroup analysis indicated that embolization alone was linked to an elevated risk of complications, while surgery and radiosurgery showed comparable outcomes.

Conclusion : AVMs in eloquent brain areas present higher risks of complications and lower obliteration rates, emphasizing the need for cautious, individualized treatment planning. While embolization alone increased the risk of complications, surgery and radiosurgery showed comparable outcomes, suggesting that less invasive options like radiosurgery may be preferable for eloquent AVMs when feasible. These findings highlight the importance of location in AVM management and support further research to refine strategies for AVMs in critical brain areas.