Case of Intracerebral Hemorrhage During the Untreated Course of a Benign Dural Arteriovenous Fistula

Background The natural history of cranial dural arteriovenous fistulas (DAVFs) without cortical venous drainage (i.e., benign DAVF) is considered a potential predictor of a benign clinical course. We report a case of intracerebral hemorrhage due to the conversion from a benign to an aggressive DAVF during 10 months of conservative therapy, which, to the best of our knowledge, is the first reported case of its kind. Case Description A woman in her 70s without neurologic symptoms was diagnosed with DAVF of the right transverse-sigmoid sinus with Borden type I. After conservative therapy was maintained for 10 months, she had a slight headache without neurologic deficits and magnetic resonance imaging revealed intracerebral hemorrhage in the right temporooccipital area. Routine laboratory tests revealed a slight elevation of D-dimer. Emergent digital subtraction angiography demonstrated new cortical venous drainage and stenosis of the venous outlet. The refluxed cortical vein and right transverse-sigmoid sinus including fistulas were occluded with coils via transvenous embolization. She had no neurologic deficits in the postoperative state. Conclusions Conversion to aggressive DAVF in this patient was probably due to spontaneous stenosis or thrombosis of the venous outflow. Intracranial hemorrhage can occur within 1 year from the detection of benign DAVFs, and elevated D-dimer may predict the conversion to aggressive DAVFs.