A lumbar sympathetic block is an injection of local anesthetic into the “sympathetic nerve tissue” of the lower back. This injection is primarily utilized as a diagnostic tool to determine whether or not damage to the sympathetic nerve chain is the source of your pain. The lumbar sympathetic nerves are located in front of the spine in the lower back, and are a part of the sympathetic nervous system. The function of these nerves is to control and regulate basic bodily functions such as blood flow, digestion and sweating.

However, in some cases, a malfunction can cause the sympathetic nerves to carry pain signals from the peripheral tissues back to the spinal cord. Disorder in the lumbar sympathetic nerves can cause pain in the lower back, legs and feet. Weakness in the legs is also another sign that sympathetic nerve malfunction may be present in the lumbar (lower) region of the spine.
What Does a Lumbar Sympathetic Block Do?
A lumbar sympathetic block basically “switches off” the sympathetic nervous system in this area in hopes of identifying or eliminating associated pain. If painful symptoms are significantly diminished after the nerve block is administered, then a diagnosis of sympathetically mediated pain is usually established.
Once a diagnosis is made, your physician can develop a more targeted and effective treatment program to address the underlying issue. Your treatment plan moving forward may include a series of nerve blocks, alongside physical therapy and pain medication. While lumbar sympathetic blocks do not work for everyone as a means of pain management, for some, the pain-reducing effects of the anesthetic can last longer than anticipated. In some cases, additional blocks may help to sequentially diminish pain and reset the sympathetic tone to a normal state of regulation.
Aside from its diagnostic purposes, the goal of lumbar sympathetic blocks is to help patients lessen pain in order to allow normal movement and daily activities to be resumed.
How is a Lumbar Sympathetic Block Performed?
Prior to the injection of the nerve block, the skin over the injection site will be cleansed and a numbing agent will be applied to decrease pain or discomfort from the injection. The patient may also receive sedation to make the procedure easier, though this often depends on patient tolerance.
Using x-ray guidance (fluoroscopy), your physician will then guide a needle to the sympathetic plexus of nerves located at the lower part of the spine. Before administering the anesthetic, a contrast dye will be injected to confirm proper placement of the needle. Once this is confirmed, the anesthetic will then be gradually injected.
Shortly after the procedure, you will be instructed to move the affected area to see if your usual pain is provoked. You may notice a feeling of warmness in the lower extremities; this is not uncommon immediately after the injection. Most patients are advised to take it easy for the first day and perform activities that they can tolerate. Others may go for immediate physical therapy.
While the local anesthetic usually wears off in a few hours, the blockade of sympathetic nerves may last quite a bit longer. If you respond well to the first injection, repeat injections will likely be recommended. Often, the duration of symptom relief lasts longer after each injection. The number of nerve blocks you receive will depend on your specific condition and response to the treatment.
As the response to these injections varies from patient to patient, it is difficult to predict the efficacy of lumbar epidural steroid injections. However, patients in the early stages of their condition may respond better than those who have been exhibiting symptoms for a longer time period.
Schedule a Consultation at the Diagnostic Pain Center in Austin
The best way to find out if you are a good candidate for a lumbar sympathetic block is to schedule an evaluation with our Austin pain management providers. If you are experiencing pain, numbness or tingling sensations in your lower extremities, then you may benefit from this treatment. Please call (512) 981-7246 or click the button below to request a visit.