Spinal Arteriovenous Malformation (AVM): Symptoms, Causes, Diagnosis, and Treatment
Updated: 6 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is a spinal AVM?
A spinal arteriovenous malformation is a rare, often congenital tangle of blood vessels on, in or near the spinal cord that directly connects arteries and veins, starving spinal tissue of oxygen and possibly bleeding. Symptoms include trouble walking, leg numbness and weakness. MRI and angiography diagnose it, and surgery, embolization or radiosurgery aim to prevent bleeding and disability.
What the research says
Many people present with weakness, sensory symptoms, and bowel or bladder problems. In a series of 110 patients treated for spinal AVFs and AVMs (66 with AVMs), presenting symptoms included paresis or paralysis (75.5%), paresthesias (60%), pain (51.8%), and bowel or bladder dysfunction (41.8%), and rupture was seen in 26.4%. Angiographic obliteration was achieved in 83.6%, but recurrence was found in 15.2% of AVMs, so long-term follow-up is required (Rangel-Castilla et al., Neurosurg Focus, 2014).
Treatment lowers the risk of rebleeding. In 44 patients with spinal cord AVMs, the rebleed rate after a first hemorrhage was 4.8% per year if the lesion was untreated, 2.9% per year after partial treatment, and 0% after complete treatment (Lee et al., Stroke, 2014).
New severe back pain after embolization needs urgent attention. Among 18 patients who had transarterial embolization, 4 (22.2%) worsened within a week, and three of those had delayed venous thrombosis with severe back pain. Postoperative back pain was present in 75% of patients who worsened versus 0% of those who did not, and urgent anticoagulation improved symptoms in two patients (Ryu et al., Clin Neuroradiol, 2024).
What Is a Spinal Arteriovenous Malformation?
A spinal AVM is a tangle of blood vessels that forms on, in, or near the spinal cord, creating irregular connections between arteries and veins. Without treatment, this rare condition can cause lasting damage to the spinal cord.
To see why that matters, it helps to know how normal blood flow works. Oxygen-rich blood enters the spinal cord through arteries. The arteries usually branch into smaller blood vessels called capillaries, and the spinal cord gets its oxygen from the blood in the capillaries. The blood then passes into veins and moves away from the spinal cord to the heart and lungs.
In a spinal AVM, the blood passes directly from the arteries to the veins. This means the surrounding cells don't get the oxygen they need, which can cause cells in the spinal tissue to weaken or die. The tangled arteries and veins can also burst and cause bleeding in the spinal cord. Sometimes the AVM gets bigger as blood flow increases, pressing on the spinal cord and causing weakness or other symptoms.
You might not know you have a spinal AVM unless you have symptoms. The condition can be treated with surgery to stop, or possibly reverse, some of the spinal damage.
What Are the Symptoms of a Spinal AVM?
Symptoms can differ from person to person, depending on where the AVM is and how serious it is. Some people may not notice symptoms for many years, if at all. Others may experience symptoms that are life-threatening. Symptoms often begin in a person's 20s, but they can occur earlier or later, and some people are diagnosed under age 16.
Early symptoms
Symptoms may start suddenly or slowly and may include:
Trouble walking or climbing stairs.
Numbness, tingling, or sudden pain in the legs.
Weakness on one or both sides of the body.
Symptoms as the condition worsens
Sudden, serious back pain.
Lack of feeling in the legs.
Trouble urinating or having bowel movements.
Headache.
Stiff neck.
When to see a doctor
Make an appointment with your healthcare professional if you have symptoms of a spinal AVM, and seek urgent care for sudden, serious back pain or new weakness or loss of feeling in the legs.
Causes and Risk Factors
The cause of spinal arteriovenous malformations isn't known. Most are present at birth (congenital), but others may happen later in life. There are no known risk factors, and the condition occurs equally in men and women.
Question | What is known |
|---|---|
Is there a known cause? | No, the cause isn't known |
Is it present at birth? | Most spinal AVMs are congenital, but others may happen later in life |
Are there known risk factors? | None are known |
Does it affect one sex more? | No, it occurs equally in men and women |
When do symptoms usually begin? | Often in a person's 20s, but earlier or later; some people are diagnosed under age 16 |
What Complications Can Occur Without Treatment?
Without treatment, a spinal AVM can cause disability that gets worse over time from damage to the spinal cord and surrounding tissues.
Complication | What it means |
|---|---|
Trouble moving | Growing difficulty with movement as spinal tissue is damaged |
Pain, tingling, numbness | Ongoing nerve-related sensations from spinal cord damage |
Damage to the spine | Structural harm to the spine and surrounding tissues |
Aneurysm | A bulging blood vessel |
Venous hypertension | High blood pressure in the veins, causing fluid buildup (edema) and tissue death from lack of oxygen (spinal cord infarction) |
Hemorrhage | Bleeding that can speed up spinal cord damage |
How Is a Spinal AVM Diagnosed?
Spinal AVMs can be hard to diagnose because the symptoms are similar to those of other spinal conditions, including spinal dural arteriovenous fistula, spinal stenosis, multiple sclerosis, or a spinal cord tumor. Your healthcare professional may recommend tests to help rule out other causes.
Test | How it works | What it shows |
|---|---|---|
MRI | Powerful magnets and radio waves create detailed images of the spinal cord | A mass caused by the irregularly connected blood vessels of the AVM |
Angiography | A catheter placed in a groin artery is guided to the spinal cord, and dye is injected to make vessels visible under X-ray | The location and characteristics of the blood vessels involved in the AVM |
How Is a Spinal AVM Treated?
Treatment may involve a combination of approaches and can lessen symptoms and lower the risk of complications. The choice depends on the size, location, and blood flow of the AVM, along with your neurological exam results and overall health. The goal is to lower the risk of the AVM bleeding and to stop or prevent disability and other symptoms from getting worse.
Pain-relieving medicines may be used to reduce symptoms such as back pain and stiffness, but most spinal AVMs may eventually need surgery. There are three ways to treat a spinal AVM surgically:
Conventional surgery. A surgeon makes a cut in the skin to remove the AVM, taking care not to damage the spinal cord and surrounding areas. It is usually done when the AVM is fairly small and in an easy-to-reach area of the spinal cord.
Endovascular embolization. A catheter is inserted into an artery in the leg and threaded to an artery in the spinal cord that feeds the AVM. Small particles of a gluelike substance are injected, which blocks the artery and reduces blood flow into the AVM. This doesn't permanently destroy the AVM, and you may need it before other types of surgery to lower the risk of bleeding or shrink the AVM so surgery is more successful.
Radiosurgery. Radiation focused directly on the AVM destroys its blood vessels, which break down and close over time. It is most often used for small AVMs that haven't burst.
Treatment | How it works | Typical use | Key limitation |
|---|---|---|---|
Pain-relieving medicines | Reduce symptoms such as back pain and stiffness | Early symptom management | Most spinal AVMs may eventually need surgery |
Conventional surgery | A cut in the skin to remove the AVM while protecting the spinal cord | Fairly small AVMs in easy-to-reach areas | Complex because of closeness to the spinal cord |
Endovascular embolization | Gluelike particles block the artery feeding the AVM | To lower bleeding risk, often before other surgery | Doesn't permanently destroy the AVM |
Radiosurgery | Focused radiation destroys the AVM's blood vessels over time | Small AVMs that haven't burst | Takes time for vessels to close |
Your healthcare team will discuss the benefits and risks of surgery with you. Because the AVM is so close to the spinal cord, spinal AVM surgery is complex, and you should see an experienced neurosurgeon for this type of surgery.
How Should You Prepare for the Appointment?
You may be referred to a neurologist, a doctor who specializes in disorders of the brain and nervous system. Before your appointment, write down your symptoms (including any that seem unrelated), list all your medicines, vitamins, and supplements, note your key medical information and any recent changes or stressors in your life, and prepare questions to ask. Your doctor will likely ask whether you have trouble walking or leg weakness, numbness, tingling, or pain in your legs, headaches or back pain, when your symptoms began and whether they are continuous or occasional, and whether they worsen with exercise.
Conclusion and Next Steps
A spinal AVM is a rare tangle of blood vessels that shortcuts the normal flow of oxygen-rich blood around the spinal cord. That oxygen shortage, together with the risk of growth and bleeding, is what makes it dangerous. Because it is uncommon and its early symptoms (leg weakness, numbness, trouble walking) mimic many other conditions, diagnosis takes focused imaging: an MRI to reveal the mass and angiography to map the tangled vessels.
Treatment exists and works toward a clear goal: preventing bleeding and stopping disability from getting worse. If you have unexplained trouble walking, leg numbness or tingling, weakness on one or both sides of your body, or new severe back pain with bladder or bowel changes, make an appointment with your healthcare professional rather than waiting. Ruling out a spinal AVM early can make the difference between preserving mobility and facing lasting damage.
Related reading on Rinnit: Understanding Lower Back Pain: Causes, Symptoms, and Solutions
Frequently Asked Questions
What is a spinal arteriovenous malformation?
A spinal AVM is a tangle of blood vessels on, in, or near the spinal cord that creates irregular, direct connections between arteries and veins. It is a rare condition that, without treatment, can cause lasting damage to the spinal cord.
Is a spinal AVM dangerous?
It can be. The tangled vessels can burst and cause bleeding in the spinal cord, the AVM can grow and press on the cord, and the abnormal blood flow starves spinal tissue of oxygen. Untreated, it can cause disability that worsens over time.
What does a spinal AVM feel like?
Early symptoms often include trouble walking or climbing stairs, numbness, tingling, or sudden pain in the legs, and weakness on one or both sides of the body. As it worsens, symptoms can include sudden serious back pain, lack of feeling in the legs, trouble urinating or having bowel movements, headache, and a stiff neck.
At what age does a spinal AVM usually appear?
Symptoms often begin in a person's 20s, but they can occur earlier or later, and some people are diagnosed under age 16. Some people may not notice symptoms for many years, if at all.
What causes a spinal AVM?
The cause isn't known. Most spinal AVMs are present at birth (congenital), but others may happen later in life. There are no known risk factors, and the condition occurs equally in men and women.
Can you have a spinal AVM without knowing it?
Yes. You might not know you have a spinal AVM unless you have symptoms, and some people never notice symptoms. Others may have symptoms that are life-threatening.
How is a spinal AVM diagnosed?
It can be hard to diagnose because symptoms resemble other spinal conditions such as spinal dural arteriovenous fistula, spinal stenosis, multiple sclerosis, or a spinal cord tumor. Doctors use spinal MRI to show a mass from the tangled vessels and angiography, a catheter-guided dye test, to see the location and characteristics of the blood vessels involved.
Can a spinal AVM be treated?
Yes. Treatment may involve a combination of approaches chosen by the size, location, and blood flow of the AVM and your overall health. The goal is to lower the risk of bleeding and stop disability from getting worse.
What are the surgery options?
Three approaches exist: conventional surgery (removing the AVM through a cut in the skin, usually for small, easy-to-reach AVMs), endovascular embolization (threading gluelike particles through a catheter to block the artery feeding the AVM), and radiosurgery (focused radiation that gradually destroys the AVM's blood vessels).
Does endovascular embolization cure a spinal AVM?
It doesn't permanently destroy the AVM. It reduces blood flow into it and lowers bleeding risk, and it is often used before other surgery to shrink the AVM or make surgery safer and more successful.
What happens without treatment?
Without treatment, disability can worsen over time, including trouble moving, pain, tingling, numbness, spine damage, aneurysms, venous hypertension with edema and spinal cord infarction, and hemorrhage that speeds up spinal cord damage.
Who should I see for a spinal AVM?
You may be referred to a neurologist, a doctor who specializes in disorders of the brain and nervous system. Because spinal AVM surgery is complex, an experienced neurosurgeon should be involved in surgical decisions.
References
Mayo Clinic Staff. Spinal arteriovenous malformation (AVM): symptoms and causes. Mayo Clinic. July 10, 2024. https://www.mayoclinic.org/diseases-conditions/spinal-arteriovenous-malformation/symptoms-causes/syc-20355613
Mayo Clinic Staff. Spinal arteriovenous malformation (AVM): diagnosis and treatment. Mayo Clinic. July 10, 2024. https://www.mayoclinic.org/diseases-conditions/spinal-arteriovenous-malformation/diagnosis-treatment/drc-20355618
Rangel-Castilla L, Russin JJ, Zaidi HA, et al. Contemporary management of spinal AVFs and AVMs: lessons learned from 110 cases. Neurosurg Focus. 2014;37(3):E14. PMID 25175433. https://doi.org/10.3171/2014.7.FOCUS14236
Lee YJ, Terbrugge KG, Saliou G, et al. Clinical features and outcomes of spinal cord arteriovenous malformations: comparison between nidus and fistulous types. Stroke. 2014;45(9):2606–2612. PMID 25028446. https://doi.org/10.1161/STROKEAHA.114.006087
Ryu B, Mochizuki T, Shima S, et al. Perioperative management of spinal arteriovenous malformation embolization: delayed venous thrombosis and implications for severe back pain. Clin Neuroradiol. 2024;34(3):639–647. PMID 38592446. https://doi.org/10.1007/s00062-024-01403-5
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
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