Progressive myelopathy caused by intracranial dural arteriovenous fistula: report of two cases and review of the literature.

We report two rare cases of progressive myelopathy caused by intracranial dural arteriovenous fistulae with venous drainage into the spinal medullary veins. Both patients were referred to us with a history of progressively worsening quadriparesis. A posterior fossa dural arteriovenous fistula with spinal venous drainage was discovered by angiography in both cases. Treatment consisted of direct clipping of the venous drainage in one patient and of transarterial embolization and excision of the involved dural sinus in the other patient. Such procedures provided a radioanatomical cure and marked neurological recovery in both patients. Only 10 cases of progressive myelopathy caused by an intracranial dural arteriovenous fistula have been previously reported. Dysfunction of the cervical cord by venous engorgement is thought to be the most probable cause of the neurological symptoms in such cases.