Abnormal connection of the brain's arteries and veins (dural arteriovenous fistula)

An abnormal connection between arteries and veins in the outermost layer of the brain or spinal cord (dura mater). Can be benign or cause symptoms such as headaches, seizures, or other more severe symptoms. MRI angiography detects the altered flow, guiding treatment before hemorrhage or venous congestion develops.