Background: Thrombophilia could be one of the causes of venous thromboembolism at the unusual sites such as cerebral
venous sinus thrombosis (CVST). In addition, it is generally accepted that CVST is one of the etiologies of dural arteriovenous fistulas (DAVFs).
Objective: The present study aimed to examine the prevalence of CVST in DAVF patients and to identify the associations between thrombophilia and DAVFs.
Material and Method: This is a cross sectional pilot study included 30 patients with DAVFs. All patients underwent cerebral angiography and were examined for thrombophilic factors potentially relevant to venous sinus thrombosis. The prevalence of thrombophilic abnormalities were compared between patients with and without CVST.
Results: CVST was diagnosed in 21 out of 30 patients (70%) patients with DAVFs. There are 11 out of 30 patients (36.7%)
who had low protein S level. Six out of 28 patients (21.4%) had low antithrombin III level. Four patients (13.3%) had positive
lupus anticoagulant. There was no patient with low level of protein C or positive anticardiolipin antibodies. There was no
statistical difference in the prevalence of thrombophilic abnormalities between the patients with and without CVST.
Conclusion: This pilot study reported the prevalence of CVST in DAVFs in Thai population. It provides the information that DAVFs seemed to correlate with thrombophilia, whether the patients had CVST or not.

Keywords: Thrombophilia, Dural arteriovenous fistulas, Cerebral venous sinus thrombosis, Cerebral angiography