Clinical and morphological determinants of focal neurological deficits in patients with unruptured brain arteriovenous malformation

Objective: Some patients with brain arteriovenous malformation (BAVM) present with focal neurological deficits (FNDs) unrelated to clinically discernable seizure activity or hemorrhage. The aim of this study is to determine demographic and morphological AVM characteristics associated with FNDs. Methods: The 735 patients of the prospective Columbia AVM Databank were analyzed. Univariate and multivariate statistical models were used to test the association of demographic (age, gender), and morphological characteristics (BAVM size, anatomic location, arterial supply, venous drainage pattern, venous ectasia) with the occurrence of FNDs at the time of initial BAVM diagnosis. Results: Fifty-three patients (7%, mean age 40 +/- 16 years, 70% women) presented with FNDs. The multivariate logistic regression model revealed an independent association of FNDs with increasing age (OR 1.03; 95%-CI 1.00-1.05), female gender (OR 2.14: 95%-CI 1.15-3.97), deep brain location (OR 2.46; 95%-CI 1.24-4.88), brainstem location (OR 5.62; 95%-CI 1.65-19.23), and venous ectasia (OR 1.91; 95%-CI 1.01-3.64). No association was found for BAVM size, lobar location, arterial supply and venous drainage pattern. Interpretation: Focal neurologic deficits unrelated to seizures or hemorrhage are a rare initial presentation of BAVMs. The predominance of FNDs among brainstem and deeply located BAVMs and the lack of a significant association of BAVM size with FNDs indicate selective white matter pathway-specific vulnerability, the association with patient age a time dependent effect The higher frequency of FNDs among women suggests gender-specificity of brain tissue vulnerability. (C) 2009 Elsevier B.V. All rights reserved.