Cerebellar Arteriovenous Malformations: Clinical Feature, Risk of Hemorrhage and Predictors of Posthemorrhage Outcome

Abstract

We aimed to summarize the clinical presentation, risk of hemorrhage, and predictors of posthemorrhage outcome in patients with cerebellar arteriovenous malformations (AVMs). We searched our AVM database at Beijing Tiantan Hospital and identified 225 patients with cerebellar AVMs between the year 2000 and 2015. The clinical presentation and hemorrhage risk were analyzed in all patients. Further analysis of predictors for immediate posthemorrhage outcome was performed in patients with ruptured AVMs. Posthemorrhage modified Rankin Scale (mRS) scores were dichotomized into nonsevere outcome (mRS ≤3) and severe outcome (mRS >3). Univariate and multivariate logistic regression analyses were applied to test the risk factors of hemorrhage and predictors of severe outcome. Of the 225 patients, 197 (88%) presented with hemorrhage. Patients with initial hemorrhage were much younger than those with unruptured AVMs (univariate: P= 0.003; multivariate: P= 0.002). Single arterial supply (odds ratio [OR], 2.846; 95% confidence interval [CI], 1.022-7.922) and exclusively deep venous drainage (OR, 3.361; 95% CI, 1.045-10.813) were the other 2 independent risk factors for hemorrhagic presentation. Regarding the neurologic outcome immediately after hemorrhagic presentation, we used 3 models of multivariate logistic regression. Severe neurologic outcome (mRS >3) was associated with eloquent or deep AVM location, associated aneurysm, and the presence of intraventricular hemorrhage (all P < 0.05). Cerebellar AVMs have an aggressive nature of hemorrhage. Younger age, single feeding artery, and exclusively deep venous drainage were independent risk factors for hemorrhagic presentation. Eloquent location, associated aneurysm, and presence of intraventricular hemorrhage may predict severe immediate posthemorrhage outcome.