From radiopaedia.org

DAVF (Dural AV Fistula)

• Vascular malformation  from pathologic shunts between dural arteries and dural venous sinuses, meningeal veins, and/or cortical veins
• Etiology:
  – Idiopathic
  – Acquired: previous surgery, trauma, or venous sinus thrombosis
• Pathogenesis: Increased venous flow leads to venous congestion and hypertension, resultant edema, venous ectasia, and (most catastrophically) intracranial hemorrhage
• May present with a range of symptoms depending on location of lesion (i.e., pulsatile tinnitus, ophthalmoplegia). Symptoms of ICB can also present.

Tortuous cortical vein in DAVF (tortuous vessels running along cortex)

• Treatment
  –  Conservative approach with serial imaging for low-grade fistulas (no cortical venous drainage).- Endovascular embolization is the preferred therapy for lesions requiring treatment