Thrombophilia differences in cerebral venous sinus and lower extremity deep venous thrombosis.

Objective: To characterize differences in the prevalence of thrombophilic variables in a large cohort of patients with cerebral venous sinus thrombosis (CVST) and lower extremity deep vein thrombosis (DVT).

Methods: An inception cohort of individuals was identified with first lifetime incident CVST between 1995 and 2005 for whom comprehensive thrombophilia testing was available. To test the hypothesis that thrombophilia prevalence differs with respect to thrombus location, test results were compared to a randomly selected group of patients with lower extremity DVT with comprehensive thrombophilia testing.

Results: During this time period, 163 patients with CVST were identified who underwent comprehensive thrombophilia testing. Thrombophilia results were abnormal in 29% including anticardiolipin antibodies (17%), heterozygous factor V Leiden (10%), and heterozygous prothrombin G20210A mutation (n = 14/122; 11%). The prothrombin mutation was more than twice as common in patients with CVST (p = 0.04). Activated protein C resistance, factor V Leiden, and protein C deficiency were more common in patients with DVT (p < 0.05 for each comparison). The anticardiolipin antibodies in patients with CVST were primarily low titer IgM isotype.

Conclusion: The prevalence of selected thrombophilia factors differs comparing patients with cerebral venous sinus thrombosis and deep vein thrombosis. These differences may offer insights into mechanisms governing the geographic distribution of venous thrombosis.