Arteriovenous malformations (AVMs) occur when the connections between the veins and arteries don't form the right way. The vessels become entangled. Often, these abnormalities develop in the fetus, or in a newborn baby.

AVMs can occur anywhere in the body. When they happen in the spinal cord and brain, they are called neurological AVMs. These are more likely to cause symptoms in different parts of your body.

AVMs are equally common among different races and ethnicities. Most people don't even know that they have a spinal AVM. It may be found during treatment or diagnosis for another condition.

Spinal AVMs can cause problems with circulation because they interfere with your body's blood flow. Normally, your arteries transport oxygen-rich blood away from your heart and to cells throughout your body. Your veins carry that blood, with its oxygen stores used up, back to your lungs and heart. But the malformations of your arteries and veins in spinal AVMs don't allow this natural cycle to occur because of missing capillaries, which regulate blood flow.

Spinal AVMs can be serious if they rupture. They can cause bleeding into surrounding areas. They can also cause symptoms by compressing or diverting blood from parts of your spinal cord.

Spinal AVMs often don't cause any symptoms. When they do, they're usually minor and hard to notice. In a few people, though, the symptoms can be bad enough to affect their ability to function.

The the most common symptoms of a spinal AVM are:

• Muscles that feel weak or become paralyzed.
• Stiffness in the legs, causing trouble walking.
• Abnormal control of bowel and bladder.
• Problems with balance and coordination (ataxia).
• Pain or unusual feelings throughout your body, such as tingling or numbness.

If you have symptoms, tests your doctor may use to find out if you have a spinal AVM include:

• Angiography. This uses X-rays along with a dye injected into your artery.
• MRI scans.
• CT scans.
• Magnetic resonance angiography.

Treatment depends on the location and type of AVMs you have and the symptoms they cause. Many people have some improvement in symptoms after the AVM is fixed. You may need:

• Surgery. A neurosurgeon removes the AVM.
• Endovascular embolization. This is less invasive than surgery. A radiologist uses a catheter (small, thin tube) to inject an embolizing material to close off certain vessels.
• Radiation therapy. Focused energy is used to damage and seal off the abnormal vessels.
• Certain medicines. Your doctor may give you medicines to treat symptoms, such as back pain.

If spinal AVMs aren't treated, they may cause damage to your spinal cord because it can't get the oxygen it needs from your blood. A spinal AVM may also bleed.

Even though a spinal AVM may not always cause symptoms, it can still be dangerous, particularly if it starts to cause symptoms. Your doctor should check any new symptoms you have. These may include:

• Muscles that feel weak.
• Muscle paralysis.
• Difficulty with balance and coordination (ataxia).
• Unusual feelings, such as numbness, tingling, or pain.

Your doctor needs to evaluate any symptoms that show a problem with your nervous system. Contact your doctor right away if your symptoms include:

• Headaches that won't go away.
• Seizures.
• Problems controlling your muscles, or muscles that feel weak or paralyzed.
• Problems with balance and coordination.
• Pain or unusual feelings, such as numbness or tingling in your body.
• Stiffness in the legs, causing trouble walking.
• Abnormal control of bowel and bladder.

• AVMs occur when the connections between veins and arteries don't form the right way. The vessels become entangled.
• AVMs can occur anywhere in your body. But when they happen in the spinal cord and brain, called neurological AVMs, they are more likely to affect different parts of your body.
• Pay attention to the following symptoms of spinal AVMs and seek care for:
  • Muscles that suddenly feel weak or become paralyzed.
  • Any problems you may be having with balance and coordination or bowel or bladder control.
  • Pain or unusual sensations, such as numbness or tingling in your body.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours or on weekends.