A dural arteriovenous fistula (DAVF) or malformation is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus. Signs and symptoms
The most common signs/symptoms of DAVFs are:
Pulsatile tinnitus
Occipital bruit
Headache
Visual impairment
PapilledemaPulsatile tinnitus is the most common symptom in patients, and it is associated with transverse-sigmoid sinus DAVFs. Carotid-cavernous DAVFs, on the other hand, are more closely associated with pulsatile exophthalmos. DAVFs may also be asymptomatic (e.g. cavernous sinus DAVFs). Location
Most commonly found adjacent to dural sinuses in the following locations:
Transverse (lateral) sinus, left-sided slightly more common than right
Intratentorial
From the posterior cavernous sinus, usually draining to the transverse or sigmoid sinuses
Vertebral artery (posterior meningeal branch)

Causes
It is still unclear whether DAVFs are congenital or acquired. Current evidence supports transverse-sigmoid sinus junction dural malformations are acquired defects, occurring in response to thrombosis and collateral revascularization of a venous sinus. Diagnosis
Cerebral angiography is the diagnostic standard. MRIs are typically normal but can identify venous hypertension as a result of arterial-venous shunting. Classification
Borden Classification
The Borden Classification of dural arteriovenous malformations or fistulas, groups into three types based upon their venous drainage:
Type I: dural arterial supply drains anterograde into venous sinus. Type II: dural arterial supply drains into venous sinus. High pressure in sinus results in both anterograde drainage and retrograde drainage via subarachnoid veins. Type III: dural arterial supply drains retrograde into subarachnoid veins. Type I
Type I dural arteriovenous fistulas are supplied by meningeal arteries and drain into a meningeal vein or dural venous sinus.
To simplify the above systems of DAVF classification, the two main factors that should be considered to determine aggressiveness of these lesions are: 

DAVF that have bleed (as opposed to those that have not before)
DAVF resulting in cortical venous refluxTreatment decisions are more complicated and require consultation with a neurosurgeon and team familiar with these lesions. Treatment
Indications
Hemorrhage
Neurologic dysfunction or refractory symptoms

Interventions
Embolization
One approach used for treatment is embolization. A six-vessel angiogram is employed to determine the vascular supply to the fistula. Detachable coils, liquid embolic agents like NBCA, and onyx, or combinations of both are injected into the blood vessel to occlude the DAVF. Preoperative embolization can also be used to supplement surgery. Surgery
DAVFs are also managed surgically. The operative approach varies depending on the location of the lesion. Stereotactic radiosurgery
Stereotactic radiosurgery is used for obliterating DAVFs sometimes in conjunction with embolization or surgery, and is considered an important adjunct and sometimes a primary treatment method for non-aggressive DAVFs. Use of this method, however, is limited as obliteration occurs over the course of up to 2–3 years after the delivery of radiation. Epidemiology
10–15% of intracranial AV malformations are DAVFs. There is a higher preponderance in females (61–66%), and typically patients are in their fourth or fifth generation of life. DAVFs are rarer in children. Research
External Manual Carotid Compression is Effective in Patients with Cavernous Sinus Dural Arteriovenous Fistulaetreatment.