Dural arteriovenous fistulas (DAVF) are malformations between an artery and the tough covering over the brain or spinal cord (dura) and a draining vein. Abnormal pathways between arteries and veins (arteriovenous fistulas) may occur in the brain, spinal cord or other area of the body. DAVFs are the rarest type of fistula and are most commonly found in women over the age of 40. Treatment options for dural arteriovenous fistulas typically involve catheter or endovascular embolization, in which the purpose of these procedures is the close the fistula and prevent further complications.
Symptoms
Symptoms of Dural arteriovenous fistulas depend on their location and size. These include:
- A whooshing sound (pulsatile tinnitus)
- Large venous lake behind the eye (cavernous sinus)
- Persistent or progressive headache
- Slow but progressive loss of limb function
- Bowel and bladder dysfunction
- Brain dysfunction
Causes
A fistula forms when an artery becomes directly connected to a vein. The most common place for fistulas to form is behind the ear which is why the flow of blood though the fistula is heard by the ear. An individual might hear a whooshing sound made by the fistula called “pulsatile tinnitus” because blood flow in the arteries is not uniform but changes speed with each heartbeat thus causing the sound.
DAVF is generally accepted to be an acquired condition with several common causes:
- Dural sinus thrombosis (blocked dural sinuses)
- Injury to the head
- Infection
- Surgery
Risk factors
Factors that are associated with the risk of acquiring DAVFs include the following:
- Traumatic injury to the brain
- Individuals with diabetes
- Certain gastrointestinal diseases (Crohn’s disease, inflammatory bowel disease)
Complications
Complications that can arise from dural arteriovenous fistulas include the following:
- Brain hemorrhage
- Seizures
- Neurological disability (blindness)
- Death
