Spinal dural arteriovenous fistula: review of clinical presentation, prognosis and imaging findings

Abstract

Spinal dural arteriovenous fistulas (SDAVF) are rare vascular lesions in the spine. Misdiagnosis is frequent due to non-specific symptoms, which leads to delayed treatment and poorer prognosis. This study reviews the clinical presentation, diagnosis and outcomes of SDAVF cases in Iceland to raise awareness of this rare, but potentially debilitating condition. A retrospective review was conducted of all patients diagnosed with and/or treated for SDAVF at our institution from 2003 to 2024. Medical records were examined for disease duration, severity and prognosis. Imaging was evaluated for features of SDAVF, and outcomes were assessed using the modified Rankin Scale (mRS) and modified Aminoff-Logue Scale (mALS). Seven patients (four males) were identified, with a mean age of 64 and a disease duration of 21 months. Motor, sensory and gait disturbances were present in all patients, as well as bladder dysfunction. Bowel dysfunction (83%) was also common. All patients were wrongfully diagnosed either clinically and/or at imaging, despite showing typical magnetic resonance imaging (MRI) features of SDAVF. All patients underwent successful surgical ligation, with an average of one-point improvement on the mRS and the greatest improvement in gait on the mALS, with an average of one and a half-point improvement. SDAVF should be considered with middle-aged and elderly patients with progressive myelopathy. MRI of at least the thoracic and lumbar spine is essential to include the level of the fistula. Multisegmental T2 hyperintensity and prominent perimedullary flow void should prompt further evaluation with DSA. Post-contrast images and MR angiography may also aid in the diagnosis of SDAVF and guide the DSA.

Keywords: Myelopathy; Neuroimaging; SDAVF; Spinal dural arteriovenous fistula.