The sympathetic nervous system is one part of the autonomic nervous system, which regulates involuntary actions like heart rate, blood pressure, body temperature and more. The sympathetic nervous system itself manages the body’s response to dangerous or stressful situations, also known as a flight or fight response. It’s also constantly active at a basic level to maintain homeostasis. When talking about a lumbar sympathetic block, that means the sympathetic nerves in your lower back being blocked.
A lumbar sympathetic block is an injection of medication that helps relieve lower back pain or leg pain (sciatica). It can be used to treat:
Sympathetic nerves are located on both sides of your spine, in your lower back. A steroid medication and local anesthetic injected into or around your sympathetic nerves can help reduce pain in that area.
If a lumbar sympathetic block is working well, your doctor may recommend a series of injections. Another alternative is radiofrequency ablation for pain relief that has a longer effect. There aren’t many risks associated with a lumbar sympathetic block, and the most common side effect is temporary pain or soreness at the injection site.
Some patients report pain relief immediately after the injection, but the pain may return a few hours later as the anesthetic wears off. Longer term relief usually begins in two to three days, once the steroid begins to work.
Usually people need a series of injections to continue the pain relief. Sometimes it takes only two injections; sometimes it takes more than 10.