Concurrent spinal dural and intradural arteriovenous fistulas. Case report.

Among spinal arteriovenous malformations (AVMs), dural arteriovenous fistulas (DAVFs) should be distinguished from intradural AVMs. The authors report the unusual and well-documented case of a 49-year-old man who suffered from a rapidly progressive myelopathy. Two concurrent spinal AVMs (one DAVF and one intradural direct AVF [Anson-Spetzler Type IV-B AVM]) were found located in the midthoracic region and in the conus medullaris, respectively. Both AVMs were successfully treated by surgery. To the authors' knowledge, the association of these two pathological entities has not been previously described. Clinically, if the patient fails to improve or deteriorates after the treatment of a spinal AVM, the presence of another AVM should be investigated by repeated angiography, especially if a complete spinal angiography study was not initially performed.