Intracranial dural arteriovenous fistulas with spinal venous drainage: relation between clinical presentation and angiographic findings.

PURPOSE To investigate why some patients with an intracranial dural arteriovenous fistula (DAVF) with spinal venous drainage have myelopathy and others do not. METHODS We reviewed the clinical and radiologic data for 12 patients who had a DAVF with spinal venous drainage diagnosed at our institutions from 1982 to 1995. RESULTS Six patients had progressive spinal cord indications of disease (patients with myelopathy) and six others (patients without myelopathy) had cerebral indications (five had intracranial hemorrhage and one had a seizure). Cerebral angiography showed a posterior fossa DAVF with spinal venous drainage in all cases. The clinical presentation of DAVFs with spinal venous drainage was compared with the extent of the drainage. In patients without myelopathy, the spinal venous drainage exited the intradural canal via the cervical medullary-radicular veins and was therefore limited to the cervical perimedullary veins. In patients with myelopathy, no medullary-radicular vein was seen, and the venous drainage descended along the perimedullary veins of the entire spinal cord toward the conus medullaris. CONCLUSION We found an exact relation between clinical presentation and venous drainage of DAVFs with spinal venous drainage. 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.