Sympathetic Nerve Block
A sympathetic nerve block is an injection used to relieve pain caused by problems with the sympathetic nervous system — a network of nerves that controls involuntary functions like blood flow, sweating, and pain signaling.
The procedure involves injecting a local anesthetic (sometimes combined with medication) around a group of sympathetic nerves. By temporarily “turning off” these nerves, the block can:
- Reduce pain
- Improve circulation
- Help determine if the sympathetic nervous system is a source of your pain
Who Benefits from a Sympathetic Nerve Block
At iSpine Clinics, a sympathetic nerve block may be recommended if you have:
- Complex Regional Pain Syndrome (CRPS) in the legs or feet
What to Expect
- Preparation: You may be asked not to eat or drink for a few hours before the procedure. Arrange for someone to drive you home.
- Positioning: You’ll lie on your back or stomach, depending on the nerve group being targeted.
- Anesthesia: The skin over the injection site will be cleaned and numbed with local anesthetic.
- Imaging Guidance: Fluoroscopy (X-ray) or ultrasound is used to guide the needle safely to the medial branch nerves.
- Injection: After numbing the skin, a thin needle is placed near the target nerve, and contrast dye is injected to ensure the medicine reaches the desired area. Then, a small amount of local anesthetic (and sometimes a steroid) is injected.
- Duration: The procedure usually takes under 30 minutes.
- Outpatient: Patients go home the same day.
After the Procedure
- Immediate Effects:
- A feeling of warmth in the treated area
- Reduced pain in the affected region
- Possible temporary weakness or numbness
- Pain Relief: Some patients experience pain relief right away, while others may need a series of blocks for maximum benefit.
- Temporary Side Effects:
- Mild bruising or soreness at the injection site
- Lightheadedness or low blood pressure
- Temporary changes in sensation or muscle control
These usually resolve within a few hours.
Recovery and Aftercare
- Activity: Rest on the day of the procedure; you can usually resume normal activities the next day.
- Monitoring: Track your pain levels and functional improvements — this helps determine if the block was successful.
- Repeat Treatments: Some patients may need multiple injections for longer-lasting relief.
- Comprehensive Care: Often combined with physical therapy, medications, or other treatments to maximize recovery and mobility.
Risks and Considerations
While generally safe, sympathetic nerve blocks carry some risks, including:
- Temporary soreness or bruising at the injection site
- Bleeding or infection (rare)
- Allergic reaction to medication
- Nerve injury (very rare)
- Low blood pressure or dizziness