Clinical and radiographic features of dural arteriovenous fistula, a treatable cause of myelopathy

Objective: To assess presentation, imaging, treatment, and outcome of patie nts with myelopathy due to a dural arteriovenous fistula (DAVF). Patients and Methods: This retrospective review identified 94 patients with DAVF surgically treated at our institution between June 1985 and December 1999. The mean ages of the 75 men and 19 women were 62.6 years and 63.0 yea rs, respectively (range, 31-83 years). Magnetic resonance imaging was perfo rmed in 87 patients, computed tomography-myelography was performed in 37 pa tients, and spinal angiography was performed in all patients. Initial exami nation findings were retrospectively adjusted to a modified Aminoff-Logue m yelopathy scale. Results: Of the 94 patients, 47 presented with symptoms that worsened with erect posture or Valsalva maneuver. As myelopathy progressed, patients' sym ptoms increased, and 6 patients had paraplegia at presentation. The mean ti me from symptom onset to diagnosis was 23 months (range, 2-120 months). Mag netic resonance imaging confirmed the diagnosis in 86 patients; computed to mography-myelography was needed to confirm the fistula in 1 patient. Spinal angiography detected the fistula in all patients. Surgical obliteration of the DAVF was successful in 93 patients; in I patient surgery failed becaus e the DAVIT was not localized, but acrylic endovascular embolization was su ccessful. No patient experienced permanent morbidity or mortality. or the 9 4 patients, 93 improved postoperatively 1 or 2 levels based on a modified A minoff-Logue scale. Older patients with severe long-term deficits had poor outcomes. Conclusions: The diagnosis of a DAVF seems to be delayed considerably becau se DAVF is not included in the differential diagnosis of myelopathy and bec ause of clinicians' unfamiliarity with suggestive or revealing findings on diagnostic imaging. Neurodiagnostic imaging confirms the diagnosis, and spi nal angiography localizes the fistula. Surgical intradural disconnection of the DAVF clinically reverses the pathophysiology. Additionally, surgical t reatment is associated with low short-term morbidity, no permanent morbidit y, and no mortality. If the diagnosis is made early and treatment initiated in such patients, they generally do well.