Abstract
BACKGROUND AND PURPOSE: The Val66Met polymorphism of brain-derived neurotrophic factor is associated with decreased brain-derived neurotrophic factor secretion and poor outcome after acute neurological injury. We hypothesized that the Met allele is associated with worsening of functional outcome after brain arteriovenous malformation resection.
METHODS: Three hundred forty-one surgically treated patients with brain arteriovenous malformation with outcome data were genotyped for Val66Met. Outcome was change in modified Rankin Scale preoperatively versus postoperatively, dichotomized into poor (change >0) or good outcome (change ≤0). Likelihood ratio tests for interactions and logistic regression analysis were performed.
RESULTS: A significant interaction (P=0.03) of Val66Met genotype and hemorrhagic presentation existed; thus, ruptured and unruptured patients were considered separately. The Met allele was associated with increased risk of poor outcome among patients presenting unruptured (OR, 2.15; 95% CI, 1.02-4.55; P=0.045) but not ruptured (OR, 0.54; 95% CI, 0.19-1.53; P=0.25), adjusting for covariates.
CONCLUSIONS: The Val66Met polymorphism is associated with worsened surgical outcome in patients with unruptured brain arteriovenous malformation, a group that currently has no good risk predictors. Further studies replicating these findings are needed.