[Early Diagnosis of Spinal Dural Arteriovenous Fistula].

Spinal dural arteriovenous fistulas (SDAVF) are rare and most commonly affect men aged >50 years. Patients with SDAVF develop an abnormal vascular dural shunt between the dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Most SDAVFs are located in the thoracolumbar region, and usually patients present with slowly progressive paraparesis and urinary disturbances. SDAVF is diagnostically challenging; this condition may be misdiagnosed as lumbar spinal stenosis or myelitis. Clinicians should be aware of fluctuating symptoms in the early stages to avoid misdiagnosis of SDAVF. Claudication is associated with various activities including walking, bathing, drinking, and singing. On T2-weighted magnetic resonance imaging of the spinal cord, SDAVFs show a high signal intensity with a low signal intensity peripherally and dilated spinal cord veins in the subarachnoid space.