Stellate Ganglion Blocks for Complex Regional Pain Syndrome

Written by Dr. Allison Wells for the RSDSA blog.

Stellate Ganglion Blocks (SGB) can be an excellent treatment option for Complex Regional Pain Syndrome (CRPS). Recent advances in medical technology have significantly enhanced the procedure, extending the possibility of relief to more people.

What is a Stellate Ganglion Block

The stellate ganglia are bundles of nerves on either side of the base of the neck associated with the sympathetic nervous system. A stellate ganglion block – also called SGB, sympathetic nerve block, or sympathetic nerve reset – is an anesthetic block of the nerves limits the signals conducted through those nerves. The procedure involves the introduction of a local anesthetic to the general area, and then targeted injections at the site of the nerve bundles. One side of the neck is treated at a time. The number and frequency of treatments varies, but can be as little as one block on one side of the neck (we start with the right-hand side), often two (one on each side of the neck), and frequently additional treatments in a series depending on the 

SGB works by temporarily blocking the sympathetic nerves in the neck, which are part of the autonomic nervous system responsible for “fight or flight” responses. CRPS is believed to involve abnormal responses of the sympathetic nervous system. By blocking these nerves, SGB can significantly reduce pain and other symptoms associated with CRPS.


The procedure can improve pain scores for many people with CRPS. It is generally more effective for individuals with CRPS type 1 (where there is no clear nerve injury) vs type 2 (where there is likely or confirmed nerve injury). It is particularly beneficial for those suffering with pain manifesting in the upper extremities. As with many potential treatments for CRPS, it is difficult to know if SGB will be a good fit for any one person – due, in part, to the variable potential causes and presentation of CRPS. There is moderate but growing research on SGB for CRPS. Small studies have shown as high as 90+% of participants with CRPS receiving benefits from the procedure, but it is important to know that the effectiveness for any one individual is difficult to estimate with any great certainty.

Other Benefits of Stellate Ganglion Blocks

Stellate ganglion blocks have been studied and used for other conditions including some other types of pain conditions, anxiety and PTSD. This makes the procedure particularly interesting for individuals with CRPS who also suffer from PTSD 

Historical Context and Technological Advancements

Historically, the administration of SGB required the use of x-ray guidance to ensure accuracy or could be done ‘blind’ without the use of image guidance. A blind block in this area has the high potential for adverse consequences, including with complications due to the proximity of the vertebral artery. X-ray guidance, although effective, poses risks due to radiation exposure and typically required sedation, which could complicate the recovery process for patients. The evolution of ultrasound technology has revolutionized the procedure. Ultrasound guidance allows for real-time, precise visualization of the needle and surrounding anatomical structures without the use of x-ray radiation. This advancement not only enhances patient safety but also simplifies the procedure, making it faster and easier to perform.

Benefits of Ultrasound-Guided SGB

One of the significant benefits of ultrasound-guided SGB is the elimination of the need for sedation. Patients remain awake and comfortable throughout the procedure, which typically takes only a few minutes. The non-invasive nature of ultrasound means that patients can leave the clinic immediately afterwards without the lingering effects of sedation, and they are able to drive themselves home. The consultation and procedure typically take from 20 to 40 minutes in my practice, and patients are often in the office for 60 to 90 minutes for their appointment.

Side Effects

While there are certainly potential risks associated with this medical procedure, the ultrasound-guided method in the hands of an appropriately trained and credentialled professional can significantly limit risks.

Common and typically-transient side effects include temporary soreness at the injection site and a set of symptoms generally described as Horner’s syndrome. These symptoms are characterized by drooping of the eyelid, decreased pupil size, and reduced sweating on the affected side of the face. These effects are generally temporary and resolve without intervention.

A useful, and accessible treatment

The Stellate Ganglion Block is a very interesting block whose benefits go beyond those of many other types of blocks. It is useful for a variety of conditions and can be a real benefit to those with CRPS and some other pain conditions. For that alone, it may be useful, and for its ability to also potentially help with PTSD and anxiety it can be even more useful.

Advances in the portability, quality and cost of ultrasound equipment has allowed for ultrasound-guided the SGB procedure to be more effectively and safely completed in the office setting. When combined with expertise of an anesthesiologist trained and experienced in these technical blocks it is a powerful and accessible treatment option. I’m very glad to be able to offer the procedure and very glad to help people suffering with chronic symptoms. If you’re interested in more information, you can start with our page.

About Dr. Allison Wells

Dr. Wells is an anesthesiologist and an experience-leader in ketamine treatments for mood disorders and pain conditions. She founded one of the first focused clinics in the country, has helped many patients with many thousand infusions, and actively contributes to the field with research and advocacy. Wells Medicine, in Houston, TX, provides interventional procedures and a focus on comprehensive mental health toward excellence in evidence-based care.

Dr. Wells holds degrees from Swarthmore College and Baylor College of Medicine. She trained at Baylor College of Medicine and Harvard Medical School. She is a member of the American Society of Anesthesiologists, The Texas Society of Anesthesiologists and the Texas Medical Association. 

Wells Medicine, Houston, TX |

Did this post resonate with you? Do you have questions or would you like to learn more about this topic?
Please reach out to the RSDSA team directly and privately using our form and we'll get back in touch with you as soon as possible!