Spontaneous vertebral arteriovenous fistula--case report.

A 57-year-old male presented with a rare case of spontaneous vertebral arteriovenous fistula manifesting as radiculopathy of the right arm, subsequently associated with pulsating tinnitus and vascular bruit in the nape. He had a past history of chiropractic-induced vertebrobasilar infarction. Angiography showed a simple and direct fistula between the third segment of the right vertebral artery and the epidural veins at the C-1 level, where the artery runs backward above the arch of the C-1 just proximal to the penetration of the dura. The fistula was successfully obliterated by coil embolization, resulting in rapid improvement of the signs and symptoms. Mechanical compression to the nerve roots by the engorged epidural veins with arterial pressure was considered to be the major cause of radiculopathy. Vertebral artery dissection induced by chiropractic manipulation is most likely responsible for the development of the fistula.