Dural Arteriovenous Fistula (dAVF): Symptoms and Treatment

In short

What Is a Dural Arteriovenous Fistula?

A dural arteriovenous fistula (dAVF) is an abnormal link between an artery and a vein. It sits inside the dura, the tough membrane that covers the brain. So arterial blood flows straight into a vein or venous sinus, skipping the capillaries.

In contrast to a brain AVM, a dAVF has no tangle of vessels inside the brain. Most dAVFs develop in adulthood, typically around age 50-60, rather than at birth.

The key question is where its blood drains. If blood flows backward into veins on the brain's surface, the fistula becomes dangerous. However, drainage that stays inside a sinus usually remains benign.

Illustration of brain blood vessels with a highlighted area of raised venous pressure from a dural arteriovenous fistula — The brain and its blood vessels. A high-risk dAVF raises pressure in the veins on the brain's surface.

Where do dAVFs form?

Most dAVFs sit next to a large venous sinus. Moreover, their location shapes the symptoms, as the list below shows.

Transverse-sigmoid sinusBehind the ear; the most common site; a pulsing sound
Cavernous sinusBehind the eye; a red, bulging eye and double vision
TentoriumUnder the back of the brain; often drains into brain veins
Anterior cranial fossaAbove the nose; often drains into brain veins
Superior sagittal sinusAlong the top midline; headache, blurred vision, seizures
Spinal duraA separate type that slowly weakens the legs

Start with what you noticed

Which Symptom Brought You Here?

First, pick the change you noticed. Then, each link explains how a dural fistula can cause it.

01A whooshing sound in time with your heartbeatPulsatile tinnitus, usually in one ear
02A red, bulging eye or double visionSigns of a fistula near the cavernous sinus
03Headaches or blurred visionSigns of raised pressure inside the skull
04Memory loss, confusion or unsteady walkingA slow decline from congested brain veins
05A sudden brain bleed or a seizureThe most serious way a dAVF shows itself

Symptoms

Dural Arteriovenous Fistula Symptoms

Symptoms depend on two things: where the fistula sits and which way its blood drains. Some people have none; others, however, first notice a sound, an eye change or a bleed.

Two kinds of symptoms matter. Benign symptoms, such as tinnitus or eye redness, come from extra flow through a sinus. In contrast, aggressive symptoms, such as bleeding or new deficits, come from overloaded brain veins.

Pulsatile tinnitus

Pulsatile tinnitus is a whooshing sound that beats with your pulse, usually in one ear. It is also the most common dAVF symptom, typical of fistulas behind the ear.

A doctor may hear the same noise with a stethoscope. However, other conditions cause it too, for example a glomus jugulare tumor or a narrowed venous sinus.

A change in the sound also matters. If it suddenly stops, the drainage may have shifted toward the brain, so a new angiogram makes sense.

Red, bulging eye or double vision

A fistula near the cavernous sinus pushes blood back into the veins of the eye. As a result, several eye signs can appear:

A red, swollen eye
A bulging eye
Double vision
Eye pain or rising eye pressure
Blurred or failing vision

Doctors often call this an indirect carotid-cavernous fistula. Vision can suffer, so these fistulas need prompt care.

Headache and blurred vision

When a fistula overloads a large sinus, blood from the brain cannot drain well. As a result, pressure inside the skull rises.

This pressure causes headaches, nausea and blurred vision from a swollen optic nerve (papilledema). So these signs need both an eye check and a brain scan.

Memory, thinking and walking problems

Long-standing venous congestion can slowly impair the brain. For example, some patients develop memory loss, confusion, a dementia-like decline, parkinsonism or unsteady walking.

Importantly, these changes often improve once the fistula closes. So doctors consider a dAVF when memory declines quickly without a clear cause.

A brain bleed or seizures

Bleeding happens when an overloaded vein on the brain's surface bursts. It then causes a sudden headache and new weakness, numbness or speech problems.

Seizures and stroke-like symptoms can also occur. Therefore, any dAVF that drains into brain veins needs expert care, even before it bleeds.

What causes a dAVF?

Most dAVFs have no clear cause. However, many seem to follow narrowing or clotting of a venous sinus.

Venous sinus thrombosis
Head injury or previous brain surgery
Infection or a tumor near a sinus
Inherited clotting disorders such as factor V Leiden

Is a dAVF the same as an AVM?

No. A brain AVM has a tangle of vessels (nidus) inside the brain and usually forms before birth. A dAVF, however, sits in the dura, has no nidus and usually develops in adulthood. For the other vessel problems, see brain aneurysms and cavernomas.

Questions at this stage

Is pulsatile tinnitus always a dAVF?

No. Many conditions cause pulsatile tinnitus, and a dAVF is only one of them. However, a new pulsing sound, especially with headache or vision changes, deserves vascular imaging.

Can a dural fistula close on its own?

Occasionally, yes, because some fistulas clot by themselves. However, no one can predict this, and a change in symptoms can also mean the drainage became more dangerous.

Act early

When to See a Doctor

Most ringing in the ears has harmless causes. However, some patterns need a check, and a few need emergency care.

Book a doctor's visit if you notice:

A new pulsing sound in one ear
Eye redness or bulging that does not settle
Headaches with blurred vision
Memory or walking problems that worsen over weeks

Seek emergency care for:

A sudden, severe headache
Sudden weakness, numbness or speech loss
A seizure
Sudden vision loss or a painful, red, bulging eye

A normal CT or MRI does not always rule out a dAVF, because small fistulas can hide on routine scans. So when symptoms fit, a catheter angiogram gives the definite answer.

Classification

Borden and Cognard Classification: Which dAVFs Are Dangerous?

Doctors grade a dAVF by how its blood drains on the angiogram. Above all, they look for cortical venous drainage: blood that runs backward into veins on the brain's surface.

Borden type (Cognard)	Where the blood drains	Backflow into brain veins	Yearly risk of a bleed or new deficit	Usual plan
Type I (Cognard I, IIa)	Into a venous sinus (IIa: backflow within the sinus only)	No	Very low, about 0-0.6%	Treat only bothersome symptoms; recheck if symptoms change
Type II (Cognard IIb, IIa+b)	Into a sinus, with backflow into brain veins	Yes	About 1.5% if found by chance or with tinnitus; about 7.5% after a bleed or new deficit	Treat; urgently after a bleed or deficit
Type III (Cognard III, IV)	Directly into brain veins; type IV adds a ballooned vein	Yes	As type II; higher with a ballooned vein	Treat; urgently after a bleed or deficit
Cognard V	Into veins around the spinal cord	Yes, toward the spinal cord	Progressive spinal cord damage in about half	Treatment advised

These figures come from natural history studies that also weigh the first symptoms. In Cognard's original series, 40% of type III and 65% of type IV fistulas presented with bleeding.

What does cortical venous drainage mean for me?

It means arterial blood flows backward into veins on the brain's surface. These thin veins cannot handle that pressure, so they can swell, leak or burst. That is why doctors usually recommend treatment when they see it.

Treatment options

Dural Arteriovenous Fistula Treatment Options

Treatment aims to close the fistula exactly where the artery meets the vein. So when brain veins receive backward flow, stopping that flow comes first.

Option	How it works	Best suited for	When protection starts	Trade-off
Transarterial embolization	Through an artery, a liquid agent fills the fistula point and the start of the vein	Most dAVFs; the first choice in many centers	At once, if the closure is complete	Must reach the venous side; some sites risk cranial nerves
Transvenous embolization	Through a vein, coils or liquid close the diseased sinus segment	Sinus segments the brain no longer uses, such as many cavernous sinus fistulas	At once	Only if normal brain does not drain through that segment
Microsurgical disconnection	Through a craniotomy, the surgeon clips and cuts the draining vein where it leaves the dura	Fistulas above the nose or on the tentorium; cases catheters cannot reach	At once; usually curative	Open surgery with a site-specific approach
Stereotactic radiosurgery	Focused radiation slowly closes the fistula	Low-risk fistulas with bothersome symptoms, or leftovers after other treatment	After 1-3 years	Too slow for high-risk fistulas
Observation	Regular checks, with a new angiogram if symptoms change	Type I fistulas without troublesome symptoms	None	Symptoms that appear, change or vanish need a recheck

Tying off the feeding arteries alone does not work, because the fistula soon recruits new feeders. Therefore, every method must close the fistula point or the first part of the draining vein.

In experienced centers, embolization alone closes most dAVFs. Surgery, however, remains a reliable cure for fistulas above the nose and on the tentorium.

Can a dural arteriovenous fistula be cured?

Yes. Complete closure of the fistula point cures it, whether by embolization, surgery or radiosurgery. Afterward, a follow-up angiogram confirms the cure.

Related fistulas

What About Spinal dAVFs and Carotid-Cavernous Fistulas?

Two related fistulas behave differently. Therefore, they need their own checks and treatment plans.

Spinal dural arteriovenous fistula

A spinal dAVF forms in the covering of a spinal nerve root. It congests the veins of the spinal cord. As a result, leg weakness, numbness and bladder problems creep up over months.

An MRI often shows a swollen cord; then, a spinal angiogram finds the fistula. Embolization or surgery usually stops the decline, so early diagnosis matters.

Carotid-cavernous fistula

A carotid-cavernous fistula links the carotid artery system to the cavernous sinus behind the eye. Direct types often follow head trauma and flow fast; in contrast, indirect types grow slowly, like other dAVFs.

Both types can threaten vision. So a red, bulging eye with double vision deserves prompt imaging.

Your treatment path

From Diagnosis to Recovery

Care follows four steps. First, the angiogram defines the fistula; then, it guides every later decision.

01 Diagnosis
02 Planning
03 Treatment
04 Recovery

STEP 01

Diagnosis: finding the fistula point

First, MRI and MR or CT angiography often raise the suspicion. For example, they can show enlarged veins, brain swelling or old bleeding.

However, a catheter angiogram (DSA) remains the gold standard. It maps every feeding artery, the exact fistula point and the direction of venous drainage.

Why do I need a catheter angiogram if my MRI shows the fistula?

Only the angiogram shows the direction and speed of blood flow. That direction then decides the grade, and the grade decides the treatment.

STEP 02

Planning: choosing the route

Next, the team studies which arteries feed the fistula. It also checks whether the brain still drains through the involved sinus. These details decide between an arterial route, a venous route or surgery.

For a low-risk fistula, you usually have time to weigh the options. In contrast, a fistula that bled or causes new deficits needs early treatment.

STEP 03

Treatment: closing the connection

Generally, embolization takes place under general anesthesia, through the groin or wrist. Then, the team injects the liquid agent until it fills the fistula point and the start of the vein.

For surgery, the surgeon opens a small window over the fistula and divides the draining vein at the dura.

Is dAVF embolization painful?

No, because it usually takes place under general anesthesia. Afterward, some people have a headache or soreness at the puncture site for a few days.

STEP 04

Recovery and follow-up

After embolization, many patients stay one night for monitoring and go home the next day. Open surgery, in contrast, needs a few more days in hospital.

Next, a follow-up angiogram, usually a few months later, confirms that the fistula stays closed.

Will my tinnitus go away after treatment?

Usually, yes. Once the fistula closes, the pulsing sound often stops within days. However, it may return if part of the fistula reopens, so tell your team.

Can a dAVF come back after treatment?

It can, mainly after incomplete closure or when a new fistula forms. So a follow-up angiogram matters, and any new symptom deserves a recheck.

Your surgeon

Dural AV Fistula Treatment in Istanbul

Prof. Dr. Serdar Baki Albayrak

Neurosurgeon · Cerebrovascular Surgery

Treating a dAVF comes down to one exact point: where the artery empties into the vein. Therefore, a detailed angiogram decides the safest route. The team then weighs embolization against surgical disconnection for that point.

Prof. Albayrak trained at Harvard Medical School's Brigham and Women's Hospital. He also completed a clinical fellowship at the University of Helsinki.

27+Years

5,000+Operations

64Countries

Figures from Prof. Albayrak's professional profile, September 2026.

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FAQ

Frequently Asked Questions

Is a dural arteriovenous fistula serious?

It depends on the drainage. Fistulas without backflow into brain veins carry a very low risk. However, those with backflow can bleed, especially after a first bleed, so most need treatment.

How common are dural arteriovenous fistulas?

They are rare, making up about 10-15% of all vascular malformations inside the skull. Most patients get the diagnosis between the ages of 50 and 60.

Is a dAVF hereditary?

No, not directly. However, inherited clotting disorders can make sinus clots, and therefore dAVFs, more likely.

Which doctor treats dural arteriovenous fistulas?

Generally, a neurovascular team of a neurosurgeon, an interventional neuroradiologist and sometimes a radiosurgery specialist. Prof. Dr. Serdar Baki Albayrak is a neurosurgeon in Istanbul who treats dural fistulas.

Prof. Albayrak's Published Research

Peer-reviewed articles and book chapters written or co-written by Prof. Dr. Serdar Baki Albayrak on cerebrovascular microsurgery. Each link opens the record on PubMed or at the publisher. The full list of his 33 publications is on his profile.

Microneurosurgical management of middle cerebral artery bifurcation aneurysmsSurgical Neurology, 2007 · Co-author
Microneurosurgical management of distal middle cerebral artery aneurysmsSurgical Neurology, 2007 · Co-author
Co-existence of bilateral fetal type posterior cerebral artery and the bilateral giant internal carotid artery aneurysms in an ataxic patientEuropean Journal of Radiology, 2012 · Co-author

This page gives general medical information and does not replace a consultation. Diagnosis and treatment decisions need an examination by your own doctor.

Plan Your dAVF Treatment in Istanbul

Request an appointment with Prof. Dr. Serdar Baki Albayrak. The clinical team then guides international patients through every step of the visit.