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Lumbar Sympathetic Block

A lumbar sympathetic block is a medical procedure that consists of the injection of a local anesthetic into the sympathetic nervous system. The most common site of entry is around the primary nerves of the lower back, which are located alongside the spine. These nerves control autonomic bodily functions, such as the regulation of blood flow, but they also carry signals for sympathetically mediated pain from peripheral body tissues to the spinal cord.

spinal cord cross section with sympathetic ganglia

Indications For A Lumbar Sympathetic Block

The primary purpose of a lumbar sympathetic block is to diagnose and reduce the leg pain and foot pain associated with such conditions as reflex sympathetic dystrophy (RSD). In addition to CRPS I and CRPS II, this procedure may be used to alleviate the symptoms of peripheral vascular disease in the legs and any other conditions associated with sympathetically mediated pain in the lower extremities.

Procedure Overview

A lumbar sympathetic block takes from 10 to 30 minutes to perform, and the actual injection takes only a couple of minutes. The injection is not unduly painful or stressful, so it can be performed with minimal anesthesia.

Lumbar Sympathetic Block

After the sedative has been administered, the patient lies on his or her stomach. The patient’s vital signs are monitored at all times, and the point of entry is sterilized. Next, an X-ray machine is used to guide the needle to the proper location along the spine. Before the medication is injected, a test run is conducted using a colored dye. If the dye spreads out properly, the actual injection follows. Some patients may require more than one injection to completely treat their leg pain or foot pain.

After A Lumbar Sympathetic Block


After this outpatient procedure, most patients experience a feeling of warmth in the legs and a reduction of pain. However, some patients also become weak or numb and are advised to have someone drive them home. In addition, patients are recommended to relax for a day until they can adjust to the treatment. Patients may perform any activities that can be tolerated and should be able to return to work the next day.

Followup Treatment

Most lumbar sympathetic blocks are administered as part of a complete pain-management program. Lumbar sympathetic blocks may be repeated or we may recommend other treatment options such as spinal cord stimulation.