New or rapidly worsening leg weakness, inability to walk, or new loss of bladder or bowel control needs emergency assessment.
What is a spinal dural AVF?
A spinal dural arteriovenous fistula, often called SDAVF, is an abnormal connection between an artery and a vein in the covering around the spinal cord. Blood under arterial pressure enters veins that normally drain the cord. The resulting venous congestion can interfere with spinal cord function. This is different from a spinal AVM, which has a different arrangement of abnormal blood vessels.
References: 1
Symptoms that deserve attention
Symptoms may include gradually increasing leg weakness, heaviness or numbness, balance difficulty, reduced walking ability, and changes in bladder or bowel function. They may progress steadily or in steps. Because these problems can resemble spinal arthritis, neuropathy, or inflammatory spinal cord disease, the diagnosis is sometimes delayed. Persistent or worsening symptoms deserve a neurologic assessment, particularly when the existing diagnosis does not explain the pattern.
From spinal MRI to spinal angiography
Spinal MRI may show cord swelling or abnormal vessels that raise concern for a fistula. The signs can be subtle, and not every patient has the same MRI appearance. Catheter spinal digital subtraction angiography is used to locate the fistula and define its feeding arteries and draining veins. This is a dedicated study of spinal blood vessels, not a routine cerebral angiogram. Detailed imaging guides the choice between endovascular treatment and surgery.
Closing the abnormal connection
Treatment aims to disconnect the fistula while preserving normal blood supply to the spinal cord. Endovascular embolization uses a catheter to deliver material that closes the abnormal connection when the anatomy allows safe, durable treatment. Microsurgery disconnects the fistula directly and may be the better option in other cases. The decision should involve clinicians experienced in both approaches. The choice depends on safe access, the likelihood of complete closure, and the blood supply to the spinal cord.
Recovery and follow-up
An important goal is to stop further spinal cord injury. Walking, strength, or other symptoms may improve after successful treatment, but established injury may not fully reverse. Recovery varies with the severity and duration of symptoms. Follow-up checks whether the fistula is closed and whether neurologic function is recovering; the team may use imaging and recommend rehabilitation. Tell your team promptly if walking, sensation, or bladder function worsens again.
Common questions
Could this explain worsening walking despite treatment for back problems?
It is one possible cause among many. SDAVF can mimic other spinal or nerve disorders. A specialist can review the examination and actual MRI images to decide whether vascular imaging is warranted.
References: 3
Can an MRI always identify the fistula?
No. MRI may show the effects on the spinal cord without identifying the exact connection. If suspicion remains, a dedicated spinal angiogram may be needed for diagnosis and treatment planning.
References: 3
Will treatment restore normal walking immediately?
Not necessarily. Treatment can prevent additional damage, and recovery may take time. Some symptoms persist despite complete closure. Your starting function and the amount of existing spinal cord injury help shape realistic expectations.
Your next step
Sources & further reading
- Columbia Neurosurgery: Spinal Dural Arteriovenous Fistula ↗
- Jablawi et al.: Long-term outcome of patients with spinal dural arteriovenous fistulas (2020) ↗
- Zalewski et al.: MRI findings in spinal dural arteriovenous fistulas (2018) ↗
- Saladino et al.: Surgical treatment of spinal dural AVF, 154 patients (2010) ↗
This guide explains general care options. Your treating team will recommend an evaluation and treatment plan for your individual situation.