Sympathetic Nerve Blocks
Stellate ganglion, lumbar sympathetic, and ganglion impar blocks for complex regional pain syndrome (CRPS), tailbone pain, and other nerve-driven pain.
What are the sympathetic nerves?
The sympathetic nervous system controls automatic functions like blood flow, sweating, and skin temperature. In some pain conditions, especially complex regional pain syndrome (CRPS), these nerves help keep pain signals going. A sympathetic block places numbing medicine on a cluster of these nerves, called a ganglion, to interrupt that cycle.1,2
What is CRPS? CRPS is a chronic pain condition that usually affects an arm or leg after an injury, surgery, or fracture. Pain is out of proportion to the original injury and may come with swelling, changes in skin color or temperature, sweating, sensitivity to touch, and stiffness. Early treatment, especially physical and occupational therapy, matters.1,2
Stellate ganglion block
What it treats
CRPS and other sympathetically driven pain of the arm, hand, face, or neck. The stellate ganglion sits at the base of the neck.
What you may notice
Warmth in the arm and hand on the treated side is a sign the block worked. A droopy eyelid, small pupil, stuffy nose, or hoarse voice on that side are common and wear off within hours.
Lumbar sympathetic block
What it treats
CRPS and other sympathetically driven pain of the leg or foot. The lumbar sympathetic nerves lie along the front of the lower spine.
What you may notice
Warmth in the leg and foot is a sign the block worked. The leg may feel heavy or numb for a few hours, so plan on a driver.
Ganglion impar block
The ganglion impar is a small nerve cluster just in front of the tailbone (coccyx). Blocking it can relieve chronic tailbone pain (coccydynia) and some pelvic and perineal pain that hasn’t improved with cushions, medicines, and therapy.
In a 2026 review of 17 studies, ganglion impar blocks reduced tailbone pain in the short and long term with no serious side effects reported, though the overall quality of the evidence is low.3
How it works
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Image guidance
X-ray or ultrasound guides a thin needle to the target nerve cluster.
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Numbing medicine
Local anesthetic, sometimes with a steroid, is placed on the ganglion.
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Check the response
For stellate and lumbar blocks, we check for warming of the arm or leg.
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Move and rehab
Relief is a window to make the most of physical and occupational therapy.
For CRPS, blocks are often done as a short series, timed with therapy so you can work on movement while pain is lower.2
What to expect
Before your block
Tell us about your medications, especially blood thinners, and any allergies to numbing medicine or contrast dye. We’ll tell you whether any medication should be paused. Please don’t stop one on your own.4
During your block
You lie on your back for a stellate ganglion block, or on your stomach for lumbar and ganglion impar blocks. The skin is numbed, and the block usually takes 15 to 30 minutes.
After your block
We monitor you briefly before you go home with a driver. Don’t eat or drink until any hoarseness or trouble swallowing after a stellate block has passed. Track your pain and any warming over the next day.
Common questions
How long does relief last?
It varies from hours to weeks, and sometimes longer after a series. Even short-term relief can be valuable, because it makes therapy possible.
How many blocks will I need?
For CRPS, a series of blocks spaced over several weeks is common. We decide together based on your response.2
Is a droopy eyelid after a stellate block a problem?
No. It is an expected sign that the block reached the right nerves, and it wears off as the medicine does.
Will insurance cover it?
Most plans cover sympathetic blocks for CRPS and related conditions when they are medically necessary. Our staff will check your benefits and request any required prior authorization.
Talk with a specialist about CRPS or nerve pain
Our physicians will review your symptoms, exam, and prior treatments to decide whether a sympathetic nerve block, or another treatment, is the right fit for you.
New pain management patients need a referral. Your provider can fax it to 870-706-2428.
Risks
Possible side effects include soreness, bruising, lightheadedness, temporary numbness or weakness, bleeding, infection, and reactions to medicine. After a stellate ganglion block, hoarseness, a lump-in-the-throat feeling, or trouble swallowing can occur for a few hours. Serious complications are rare. Your physician will review the risks with you before your procedure. Individual results vary.
Sources
- National Institute of Neurological Disorders and Stroke. Complex Regional Pain Syndrome. ninds.nih.gov
- Harden RN, et al. Complex regional pain syndrome: practical diagnostic and treatment guidelines, 5th edition. Pain Med. 2022;23(Suppl 1):S1-S53. doi:10.1093/pm/pnac046
- Jevotovsky DS, et al. Non-neurodestructive ganglion impar blocks for coccydynia and related disorders: a systematic review and meta-analysis. Reg Anesth Pain Med. 2026;51(5):512-523. doi:10.1136/rapm-2024-106055
- Narouze S, et al. Interventional spine and pain procedures in patients on antiplatelet and anticoagulant medications (second edition). Reg Anesth Pain Med. 2018;43(3):225-262. doi:10.1097/AAP.0000000000000700
Coccyx model: BodyParts3D, © The Database Center for Life Science, via Wikimedia Commons, CC BY-SA 2.1 jp, resized.