title: Clinical and radiographic features of dural arteriovenous fistula, a treatable cause of myelopathy.
abstract: OBJECTIVE
  To assess presentation, imaging, treatment, and outcome of patients with myelopathy due to a dural arteriovenous fistula (DAVF).
  
  
  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 years, respectively (range, 31-83 years). Magnetic resonance imaging was performed in 87 patients, computed tomography-myelography was performed in 37 patients, and spinal angiography was performed in all patients. Initial examination findings were retrospectively adjusted to a modified Aminoff-Logue myelopathy scale.
  
  
  RESULTS
  Of the 94 patients, 47 presented with symptoms that worsened with erect posture or Valsalva maneuver. As myelopathy progressed, patients' symptoms increased, and 6 patients had paraplegia at presentation. The mean time from symptom onset to diagnosis was 23 months (range, 2-120 months). Magnetic resonance imaging confirmed the diagnosis in 86 patients; computed tomography-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 1 patient surgery failed because the DAVF was not localized, but acrylic endovascular embolization was successful. No patient experienced permanent morbidity or mortality. Of the 94 patients, 93 improved postoperatively 1 or 2 levels based on a modified Aminoff-Logue scale. Older patients with severe long-term deficits had poor outcomes.
  
  
  CONCLUSIONS
  The diagnosis of a DAVF seems to be delayed considerably because DAVF is not included in the differential diagnosis of myelopathy and because of clinicians' unfamiliarity with suggestive or revealing findings on diagnostic imaging. Neurodiagnostic imaging confirms the diagnosis, and spinal angiography localizes the fistula. Surgical intradural disconnection of the DAVF clinically reverses the pathophysiology. Additionally, surgical treatment is associated with low short-term morbidity, no permanent morbidity, and no mortality. If the diagnosis is made early and treatment initiated in such patients, they generally do well.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minn 55905, USA. atkinson.john@mayo.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Atkinson
authors.forename: G M
authors.initials: GM
authors.lastname: Miller
authors.forename: W E
authors.initials: WE
authors.lastname: Krauss
authors.forename: W R
authors.initials: WR
authors.lastname: Marsh
authors.forename: D G
authors.initials: DG
authors.lastname: Piepgras
authors.forename: P P
authors.initials: PP
authors.lastname: Atkinson
authors.forename: R D
authors.initials: RD
authors.lastname: Brown
authors.forename: J I
authors.initials: JI
authors.lastname: Lane
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020785:Central Nervous System Vascular Malformations / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012189:Retrospective Studies; D013118:Spinal Cord Diseases / Q000209:etiology* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome