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The sympathetic nerves, a group of nerves found along the front side of the spinal column of the low back, control many bodily functions including pain, sweating, heart rate, digestion and blood pressure.

Sometimes these nerves can continue to transmit pain after a nerve injury even after an injury has healed. When that pain is in the legs, a lumbar sympathetic block often can provide relief.

Conditions Lumbar Sympathetic Blocks Treat

At UM Pain, we use lumbar sympathetic blocks to treat pain in the legs caused by:

How a Lumbar Sympathetic Block Works

During this procedure, the pain specialist injects an anesthetic or numbing medication into the area of the spine near the sympathetic nerves. If these nerves are causing your symptoms, the injection may offer immediate relief that can last weeks or months.

If effective, your doctor may recommend a series of these blocks one to two weeks apart. This may give you more long-term pain relief, and then you can reduce the frequency of injections. 

Patient Information: Lumbar Sympathetic Block

How do I prepare for the procedure? 

Contact your healthcare team for detailed instructions for how to prepare for a lumbar sympathetic block. This includes when you can eat prior to the procedure and what medications you can and cannot take. If you are diabetic, pregnant or taking blood thinners, such as Coumadin (warfarin) or Plavix, let your doctor know.

You should arrange to have someone drive you home from the procedure. 

What happens during the actual procedure?

During the procedure, which typically takes about 15–20 minutes, you will lie on your stomach on an X-ray table. A technician will apply antiseptic to the site of the injection. You will receive an injection of numbing medicine with a very small needle. This may cause a burning or stinging sensation that usually lasts about 10 seconds.

The doctor will use X-ray imaging to guide placement of the needle that will inject the local anesthetic near the sympathetic nerves. A small adhesive bandage will cover the injections site. 
At UM Pain, our team will do our best to make you comfortable. If needed, we also provide a mild sedative through the IV line to help you relax.

For most patients, the mild burning sensation of the numbing medicine is the worst part. You may also feel pressure during the injection. Many patients may feel a warm sensation in the back or down the legs with injection. This can be a sign the medication is working on the nerves. 

What will happen after the procedure?

You will stay in our recovery area for about 30 minutes while we monitor your vital signs and the temperature of the painful leg. If the sympathetic nerves are the source of your pain, you may experience temporary pain relief and the temperature in your painful limb may rise as the blood vessels relax.

Sympathetic nerve blocks may provide long-term pain relief. Typically, patients receive a few blocks one to two weeks apart. If you are having physical therapy, we can schedule the blocks to coincide with your therapy sessions for improved function.

You will receive verbal and written discharge instructions and may go home with your driver after your doctor authorizes discharge.

Your pain may improve immediately after the procedure. We encourage you to move around and do your usual activities. You could experience some localized tenderness around the injection area. Apply an ice pack three or four times a day to help this.

What are the risks of a lumbar sympathetic block?

As with most procedures, there is a risk of bleeding, infection or allergic reaction to the medications used. Some mild short-term side effects include headache, nausea or dizziness. Rare brain or nervous system complications can occur.

Depending on the location of the injection, you may feel some temporary numbness or weakness in your legs or arms caused by the numbing medicine. If this interferes with your ability to walk safely, you will have to remain in our clinic until this resolves.

You may have increased pain for a few days after the injection, including localized pain at the injection site.