Craniocervical Junction Dural Arteriovenous Fistula and Pial Arteriovenous Fistula Presenting Concomitantly in Separate Locations with Subarachnoid Hemorrhage.

Craniocervical junction dural arteriovenous fistula and pial arteriovenous fistula are rare cerebrovascular lesions. While their pathophysiology is different, both conditions can cause intracranial hemorrhage attributable to venous congestion. We present, to our knowledge, the first case report of craniocervical junction dural arteriovenous fistula and pial arteriovenous fistula presenting concomitantly in separate locations with subarachnoid hemorrhage. This case appears to have been due to increased venous hypertension caused by a merging of the venous drainage of the 2 lesions, resulting in hemorrhage.