Dural arteriovenous fistula (dAVF) - progression from normal to marked
Presentation
Presents with a headache and left-sided pulsatile tinnitus.
Patient Data
MRI presentation
Multiple filling defects are present in the left transverse sinus, sigmoid sinus and jugular bulb consistent with prior dural venous sinus thrombosis. No convincingly abnormal vessels. Normal brain parenchyma.
MRI 2 years later
2 years later an obvious dural arteriovenous fistula is evident with prominent external carotid supply via numerous scalp vessels. Prominent central venous drainage with a venous varicosity in the left cerebellopontine angle.
MRI 3 years later still
A further MRI 5 years post presentation, and 2 years after attempted left-sided onyx embolization, the size of the dAVF has increased further with massive widespread vessels. In the right frontal lobe edema surrounds a transparenchymal draining vein with a focal stenosis or thrombosis seen laterally.
Case Discussion
This case is interesting not only because of the dramatic progression from normal (other than sinus thrombosis) to grossly abnormal, but also because it is a reminder that MRI is insensitive to small/early vascular malformations. In such cases, one should have a low threshold for catheter angiography that can identify very subtle arteriovenous shunting. This is, in fact, what occurred in this case, with the diagnosis of a dural arteriovenous fistula (dAVF) made after the first study.