A few weeks ago, we published the first study demonstrating successful treatment of anxiety symptoms using Stellate Ganglion Block (SGB). *
This is also the first study to demonstrate the benefit of a bilateral SGB over a single side.
Why is this study so important?
- Anxiety disorders are the most common mental illness in the U.S., affecting 40 million adults (~20% of the adult population).
- Anxiety disorders are on the rise.
- Standard anxiety treatments unfortunately are not helpful for many.
- Only half (45-65%) of anxiety patients respond to initial treatment with either psychotherapy or pharmacotherapy.
This rise in anxiety disorders demands that clinicians dig into the contemporary research, collaborate across disciplines, and consider implementing innovative therapies that may augment standard treatments. SGB is a valuable tool which helps treat anxiety and, for many, enhances gains made with talk therapy. Importantly SGB is not new. This is a procedure that’s been around for 100 years and has been safely used to treat thousands and thousands of people since the 1920’s, primarily with pain syndromes.
How did we discover this?
The Stellate Institute physicians have been studying the use of SGB to treat post-traumatic stress (PTSD/PTSI) for over 12 years and have published most of the original research on this topic in the peer-reviewed medical literature (see Evidence page). Over the past decade of treating thousands of trauma survivors, our experiences led us to suspect that, in addition to PTSD, stellate ganglion block may also provide important benefits for anxiety disorders. This seemed plausible due to the significant symptom overlap between PTSD and anxiety disorders. Anxiety symptoms such as “feeling nervous, anxious, or on edge;” “trouble relaxing;” or “becoming easily annoyed or irritable” are rooted in the physiologic expression of the sympathetic nervous system—the fight-or-flight system—which may be inappropriately elevated in those with anxiety.
Understanding precisely HOW SGB works is critical. Once you understand the anatomy and physiology of the sympathetic nervous system, it makes total sense WHY SGB could be so effective in relieving anxiety symptoms.
Calm the body. Calm the mind: The Anatomy of Fight-or-Flight
Our body’s fight-or-flight system is governed by an area in the brain called the amygdala, which is essentially the “fire alarm of the brain.” The way your fire alarm tells your body to respond is critical to your survival. It has to be an immediate reflex to protect you from a bear charging, a deer leaping in front of your car on the highway, or a threatening enemy approaching. This threat signal travels instantaneously (not through a Bluetooth connection!) via a nerve that runs on the side of the neck called the cervical sympathetic chain or trunk. This single nerve is an anatomic funnel in your neck where all fight-or-flight signals travel before spreading out to your entire body, all the way down to your sweat glands and the hairs on your arm! This entire system is hardwired and accessible at a single point in the side of the neck. This is the precise anatomic target that we treat when performing a stellate ganglion block.
Importantly, your cervical sympathetic chain carries fight-or-flight signals in both directions—from the brain to the body, and from the body to the brain. This results in a loop which sometimes gets stuck in an elevated state. You may feel on edge, irritable, or nervous for no apparent reason. When this loop gets stuck in a hyperaroused state it can be very difficult to get “unstuck” because it lives in the autonomic nervous system, which functions beneath our consciousness. The automatic nature of the fight-or-flight system is absolutely critical for our survival because the speed at which we would otherwise respond to threats would be insufficient to survive in many cases.
Therefore, directly treating the anatomic structures which govern the sympathetic nervous system provides a precise mechanism to target the dysfunction. Turning off this “dysfunctional circuit” by temporarily numbing the cervical sympathetic chain with a simple local anesthetic injection disrupts the loop between the brain and the body and allows the circuit to reset itself. This treatment of neurologic dysfunction is not new. In fact, this same principle of utilizing nerve blocks to reset inappropriate nerve signals (such as phantom limb pain) has been a validated treatment modality in pain medicine for many years. We just figured out fairly recently how to apply this same technique to treat PTSD and anxiety.
Click HERE for a short video that explains this anatomy and physiology further.
What effect does SGB have on anxiety symptoms?
Bottom line: SGB cuts anxiety symptoms in half.
We score anxiety symptoms on a 21-point scale called the GAD-7. When tracking the effects of SGB on 285 of our patients, we found that anxiety symptom scores fell about 7 points following SGB treatment on just one side of the neck. In our patients who elected to have a second block the following day to the stellate ganglion on the opposite side of the neck, symptom scores dropped even further. So, we know that an SGB on one side is very effective, but if we treat the stellate ganglion on one side followed by the other side the following day, GAD-7 scores decreased by about 10 points at 1 week and remained 9.5 points lower than baseline still at 1 month. This is over twice the change that is considered clinically important on the GAD-7.
A 10-point drop on a GAD-7 is an extremely meaningful improvement in anxiety symptoms and warrants further investigation. This single study does not prove SGB is a cure for anxiety. Yet, adding stellate ganglion block to standard anxiety treatments may provide hope for 50% of the anxiety sufferers who fail to respond well to psychotherapy and/or pharmacotherapy.
Hope is a powerful thing.
*Lynch JH, Mulvaney SW, Bryan CJ, Hernandez D. Stellate Ganglion Block Reduces Anxiety Symptoms by Half: A Case Series of 285 Patients. Journal of Personalized Medicine. 2023; 13(6):958.
About the author: Dr. James (Jim) Lynch is the co-founder of The Stellate Institute in Annapolis, Maryland. He is a veteran of 31 years in the US Army. His passion is treating anxiety and trauma survivors from all backgrounds.