Dural arteriovenous fistulas are abnormal connections between an artery and the tough covering over the brain or spinal cord (dura) and a draining vein. Abnormal passageways between arteries and veins (arteriovenous fistulas) may occur in the brain, spinal cord or other areas of your body. An unusually heavy blood flow also can lead to aneurysms or ruptures in the veins. This condition can be caused by head trauma, infection, surgery or blood clots in the brain, called thrombosis, or may be a congenital or birth defect. The symptoms of dural arteriovenous fistulae (DAVF) can vary widely, depending on the location of the fistulae. Some of the common symptoms include: Headaches, Ringing in ears and stroke like symptoms. Treatment for dural arteriovenous fistulae (DAVF) depends on the blood vessels involved. Endovascular techniques, which are minimally invasive procedures that are performed through the blood vessels, have been developed to safely treat DAVFs. Some fistulas can't be completely blocked with embolization and may require surgery to disconnect or close them. All AVMs are present at birth, but they are not always clinically evident. Stimuli during puberty or pregnancy or following minor trauma can precipitate clinical features of the malformation. AVMs occur with equal frequency among males and females.