What is a Lumbar Sympathetic Block (LSB)?

A lumbar sympathetic block (LSB) is an injection of local anesthetic (numbing medicine) into or around the sympathetic nerves. These sympathetic nerves are a part of the sympathetic nervous system. The nerves are located on either side of the spine, in the lower back. Normally, these nerves control basic functions like regulating blood flow. In certain conditions, these sympathetic nerves can carry pain information from the peripheral tissues back to the spinal cord. A LSB is performed to block the sympathetic nerves that go to the leg on the same side as the injection. This may, in turn, reduce pain, swelling, color, sweating and other unusual changes in the lower extremity and may improve mobility. It is done as a part of the treatment of Reflex Sympathetic Dystrophy (RSD), Sympathetic Maintained Pain, Complex Regional Pain Syndrome and Herpes Zoster (shingles) involving the legs. Certain patients with neuropathy or peripheral vascular disease may also benefit from lumbar sympathetic blocks.

How long does the SGB injection take?

The injection procedure takes about 10 minutes.

What are the pre-requisites in order to perform this procedure?

You may need to stop taking certain medications several days before the procedure, especially anticoagulant or “blood thinning” medications, as well as other prescription and/or over the counter medications, including herbal and vitamin supplements.

Will the injection hurt?

The procedure involves inserting a needle through skin and deeper tissues. We will numb the skin and deeper tissues with a local anesthetic using a very thin needle before inserting the actual block needle. Most of the patients also receive intravenous sedation that makes the procedure easier to tolerate.

What should I expect after the procedure and what are the side effects?

Immediately after the injection, you may feel your lower extremity getting warm. In addition, you may notice that your pain may be gone or quite less. You may also notice some temporary weakness or numbness in the leg, although this is actually not a desired effect of a lumbar sympathetic block.

What should I do after the procedure?

We advise the patients to take it easy for a day or so after the procedure. Perform the activities that you can tolerate. Some of the patients may go for immediate physical therapy. Unless there are complications, you should be able to return to your work the next day. The most common thing you may feel is soreness in the back at the injection site.