Dural arteriovenous fistula with spinal perimedullary venous drainage.

The purpose of this study was to investigate the characteristics of six patients with dural arteriovenous fistula (DAVF) with drainage directly into the perimedullary venous system. In five patients with subarachnoid hemorrhage (SAH), cerebral angiography revealed a DAVF with spinal venous drainage located at the petrosal sinus in one, at the tentorium in one, and at the craniocervical junction in four. In the patient with myelopathy, angiographic exploration began with a spinal angiogram. Bilateral vertebral angiography initially failed to demonstrate the fistula, and a tentorial DAVF was established with carotid artery angiography. Patients had no myelopathy when the venous drainage was limited to the cervical cord; myelopathy was present when the venous drainage descended toward the conus medullaris. Diagnosis of a DAVF presenting with myelopathy is more challenging than of those presenting with SAH.