Lumbar Sympathetic Nerve Block
A lumbar sympathetic nerve block is administered to both diagnose and treat pain in the lumbar (lower) region of the spine. It is used to determine whether the lumbar sympathetic nerves, which carry pain impulses from the lower extremities, are the cause of the pain, and, in some cases, serves to eliminate that pain altogether. During the procedure, medication is injected into or around the lumbar sympathetic nerves on one side of the body.
Underlying conditions for which a lumbar sympathetic block may be considered include the following:
- Complex regional pain syndrome
- Herpes zoster (shingles)
- Peripheral vascular disease
When successful, the injections reduce pain, inflammation, abnormal skin color and sweating, and improve the patient's mobility.
Lumbar Sympathetic Nerve Block Procedure
Receiving a lumbar sympathetic nerve block injection takes only a few minutes, although the patient will likely spend a few hours in an outpatient surgical setting or doctor's office. These hours include the time needed for preparation, positioning and recovery. During the procedure, the patient lies facedown, and a local anesthetic is administered. In most cases, patients are also sedated to minimize anxiety. Once the local anesthetic has numbed the skin, the injection is administered.
The injection contains an anesthetic to numb the inflamed area. Sometimes it also contains a corticosteroid to reduce inflammation, or clonidine, a hypotensive agent. These medications are added to provide long-lasting pain relief. Immediately after receiving an injection, a patient may experience warmth in the leg, but the sensation disappears quickly.
Risks of a Lumbar Sympathetic Nerve Block
Although receiving a lumbar sympathetic nerve block is a safe, there is a risk of complications, which includes infection at the injection site, nerve damage, bleeding, or leakage of spinal fluid.
Recovery from a Lumbar Sympathetic Nerve Block
After a lumbar sympathetic nerve block procedure, a patient usually returns home after a few hours, and is able to return to work the next day. The effectiveness of a lumbar sympathetic nerve block varies. Some patients experience permanent relief, whereas others experience relief for only a few weeks or months, and require additional treatment.
If the block relieves the patient's pain, a series of injections may be administered to provide long-lasting relief. If the block does not relieve pain, radiofrequency ablation may be considered.