What are Transforaminal and Sympathetic Nerve Blocks?
A transforaminal or selective nerve block is an injection of local anesthetic and steroid injected under x-ray guidance into the area where the nerve exits the spinal column. The block is usually ordered by your provider for pain in the arm or leg that follows the path of a single nerve. This block may be diagnostic or therapeutic.
A sympathetic nerve block is injection therapy that targets the sympathetic nervous system, a series of nerves that spread out from your spine to your body to help control several involuntary body functions or body functions you have no control over. These include blood flow, digestion, and sweating.
Risk Factors of Transforaminal and Sympathetic Nerve Blocks
As with any procedure, there are certain risks associated with a nerve root block You should get some numbness that follows the path of the nerve that is blocked. Weakness is also common. If you get weakness that interferes with your ability to walk, contact your healthcare provider. Other risks include:
- Bleeding
- Infection
- Nerve injury
- Allergic reaction to medication
- Short-term elevation of blood sugar in diabetics
- Increased fluid retention for 1-2 weeks to people prone to fluid retention.
What to Expect with Transforaminal and Sympathetic Nerve Blocks
After the skin is anesthetized, a needle is inserted into the proper location using x-ray guidance. A dye may be injected at this point. Local anesthetic and the steroid are then injected through the needle.
Your pain may be improved immediately after the injection from the local anesthetic. The steroid typically takes 2-3 days to take effect and peaks in about 2 wees. Tenderness at the site of injection is common. It is important to follow your providers instructions and keep track of the amount of pain relief received, as well as how long the pain relief lasted.
If you experience severe back pain, new numbness, weakness in the legs or signs of infection, contact your healthcare provider immediately.
One of three things can happen following the block:
- The pain does not go away – which may mean that the pain is not coming from the nerve at the level of injection.
- The pain goes away for a few hours but comes back and doesn’t get better again – may mean the pain is coming from the nerve at the level of injection, but the steroid did not benefit it.
- The pain goes away after the block – this means the block was of therapeutic value, and the steroid has long lasting effects on the block.