When a workplace or personal injury affects the sciatic nerve, you may experience pain in your lower back or legs.
One way this type of discomfort may be managed is with a lumbar sympathetic block (LSB). Specifically, this type of injectable block targets nerves found on both sides of the spine in the lower back area. Sympathetic nerves begin in the vertebral column and continue into the second or third lumbar segments. The goal with injections is to reduce inflammation and ease nerve irritation.
What is a Lumbar Sympathetic Block?
A lumbar sympathetic block is a combination of a steroid medication and a local anesthetic. It’s directly administered to the lower back area to relieve lower spine or sciatic nerve pain. If there is a need to confirm that your symptoms are related to issues with the sympathetic nerves in the mid or lower spine, a LSB may be given for diagnostic purposes first. If relief is experienced from the local anesthetic, it’s usually assumed that the source of your discomfort has been found. If this is the case, the injection will be given with the longer-lasting steroid medication included.
How Is It Done?
After it has been confirmed that your lower back or sciatic nerve pain is related to your sympathetic nervous system, you’ll be prepared for an injection. A numbing agent may be applied to the area to be injected to make the process more comfortable. If you need help relaxing, IV sedation may be recommended. Since the lower back is the area where the injection will be administered, you’ll likely be lying on your stomach.
A real-time X-ray is used to provide guidance for the needle. A contrast material is typically used to confirm that the local anesthetic is reaching the right spot. If it is, the steroid medication will be injected if the block is being done for pain management purposes.
What Happens After a Lumbar Sympathetic Block?
Following the injection, there may be immediate relief of lower back or sciatica pain because of the anesthetic in the block. There may also be a warm sensation in the lower spine area. However, symptoms may return briefly once the anesthetic wears on, but this is normal. If the block is effective, discomfort should become less noticeable once the steroid medication takes effect. Most people are able to return to their normal activities the next day. Possible benefits for patients include:
- An ability to fully participate in other pain management efforts (e.g., therapeutic exercises, stretching routines)
- Being able to perform work-related tasks without distracting pain – although it may be advised that you wear a lumbar support belt for added support
- Less reliance on medication
As with similar pain management technique, results from a lumbar sympathetic block will vary. However, patients who have only recently had issues with sciatic nerve or lower back pain tend to benefit more from LSBs than those who have had long-term issues with this type of discomfort. Lumbar sympathetic blocks may also relieve symptoms related to complex regional pain syndrome and herpes zoster infection (shingles).