Background: Spinal dural arteriovenous fistulas (SDAVF) are rare and present with non-specific symptoms. The diagnosis is difficult and it is therefore conceivable that patients may not be recognized.
Methods: We reviewed the intake forms of patients who had been admitted to the spinal cord injury ward of a rehabilitation center in the period 1980-2004 to identify possible patients with an undiagnosed SDAVF. Clinical and radiological data were evaluated in selected cases.
Results: In 20 of 1429 newly admitted patients to the rehabilitation center (in 614 of whom trauma was not the cause), we restudied the CT myelograms, MRI scans or spinal angiograms and in two of these we found an undiagnosed SDAVF, and one cerebral dural arteriovenous fistula. One of these three was diagnosed with SDAVF 8 years after the admission to the rehabilitation center; the other two patients had never been diagnosed with SDAVF. In 9 patients a diagnosis of SDAVF had already been established by the time they were admitted to the spinal cord unit. In 20 other patients the admission diagnosis was a vascular lesion or 'progressive myelopathy' but appropriate radiological studies had been destroyed or had never been performed.
Conclusion: Our results suggest that spinal dural arteriovenous fistulas are an underdiagnosed condition.