Stellate Ganglion Block
What Is a Stellate Ganglion Block?
The stellate ganglion is a collection of sympathetic nerve cells located in the neck, at the level of the sixth and seventh cervical vertebrae. These nerves are part of the sympathetic ("fight or flight") nervous system and regulate a wide range of functions including blood flow, sweating, and pain perception in the head, neck, arm, and chest. A stellate ganglion block (SGB) involves injecting a local anesthetic around this nerve cluster to temporarily interrupt its activity, providing relief from a variety of sympathetically mediated conditions.
How It Works
Under ultrasound or fluoroscopic guidance, a needle is carefully advanced to the anterior (front) surface of the cervical spine near the stellate ganglion. A local anesthetic is injected to bathe the nerve cluster and interrupt sympathetic nerve signaling. The resulting temporary "sympathetic blockade" can reduce pain, improve circulation, decrease excessive sweating, and — in emerging research applications — modulate abnormal central nervous system activity associated with hot flashes and PTSD.
•Sympathetic blockade: Temporarily interrupts the overactive sympathetic nervous system
•Image guidance: Ultrasound is the preferred technique for real-time vessel and structure visualization
•Broad effects: Can impact pain, circulation, and autonomic function in the head, neck, and upper extremity
•Diagnostic and therapeutic: Can identify whether pain is sympathetically maintained
What to Expect During the Procedure
•Preparation: You lie on your back with the neck slightly extended; the skin is sterilized and numbed
•Duration: 15–30 minutes including preparation and recovery observation
•Guidance: Ultrasound imaging throughout to avoid nearby vessels and nerves
•Anesthesia: Local anesthetic at the skin; the deeper injection may cause a sensation of pressure
•Same-day recovery: Observation for 30–60 minutes is required; temporary Horner's syndrome (drooping eyelid, smaller pupil) is a normal sign that the block is working and resolves within hours
Conditions Treated
•Complex Regional Pain Syndrome (CRPS) — Type I and Type II — affecting the upper extremity
•Sympathetically maintained pain
•Hyperhidrosis (excessive sweating) of the face, neck, or arm
•Raynaud's phenomenon and vasospastic conditions
•Vascular insufficiency of the upper extremity
•Hot flashes in patients who cannot tolerate hormonal therapy (emerging evidence)
Who Is a Good Candidate?
Patients with CRPS or other sympathetically maintained pain syndromes affecting the head, neck, or upper limb are classic candidates. The procedure is also considered for patients with medically refractory hot flashes and those with vascular insufficiency or hyperhidrosis of the upper extremity. A thorough evaluation and review of imaging is essential before proceeding, given the proximity of the injection to critical neck structures.
Recovery & Results
Immediately after the injection, patients may notice warmth, flushing, or tingling in the treated arm — signs that the block is working. Temporary Horner's syndrome (slight drooping of one eyelid and a smaller pupil) is expected and resolves within 2–6 hours as the anesthetic wears off. Pain relief and autonomic changes may outlast the anesthetic in responding patients, sometimes lasting weeks to months. A series of blocks may be recommended for conditions like CRPS to achieve cumulative benefit.
Frequently Asked Questions
Q: Is the stellate ganglion block safe?
A: When performed by an experienced, board-certified physician using real-time ultrasound guidance, the stellate ganglion block is a well-established procedure with an excellent safety profile. Your physician will review all potential risks — including rare complications related to the adjacent carotid artery and jugular vein — during your consultation.
Q: Will the block affect my ability to swallow or breathe?
A: Temporary hoarseness or a feeling of difficulty swallowing can rarely occur and resolves as the anesthetic wears off. Serious respiratory complications are rare with ultrasound guidance and proper technique.
Q: How many blocks will I need?
A: This varies by condition. CRPS patients may require a series of 3–6 blocks to achieve sustained benefit. Your Echo PMR physician will develop an individualized treatment plan based on your diagnosis and response.