The sympathetic nervous system is a set of nerves in the body that functions to regulate the body’s unconscious actions such as heart rate, blood pressure, sweating, and digestion. Typically these nerves do not conduct pain signals.
Sometimes, after a peripheral nerve is damaged by trauma, infection or other causes, the sympathetic nervous system can become recruited to now become a generator of pain signals. Associated symptoms with sympathetically-driven pain conditions include color changes, swelling of the affected body part, significant sensitivity to touch and pressure, and abnormal hair growth or sweating.
One specific portion of the sympathetic nervous system is the stellate ganglion. It is a collection of sympathetic nerves found at the level of the sixth and seventh cervical vertebrae (the last vertebra of the neck) and extending down into the first and second thoracic vertebral bodies. The nerves are located in front of the vertebrae and run as a pair to provide sympathetic function for the right and left side of the face and upper extremities.
A stellate ganglion block has two primary purposes:
A stellate ganglion block is administered to block the sympathetic nerves that provide information and function to the arms, and, to some degree, the sympathetic nerves that go to the face. This treatment may in turn, reduce pain, swelling, color and sweating changes in the upper extremity, and may improve mobility.
There are some expected changes that result from blocking the sympathetic nerves. These changes are temporary and may last about 4-6 hours. Such changes include the following symptoms on the same side as the injection: drooping of the eyelid, bloodshot eye, stuffy nose and a temperature increase in the arm. You may also experience some hoarseness.
This procedure is safe. However, with any procedure there are risks, side effects and possibility of complications. The most common side effect is temporary pain at the injection site. Other less common risks include bleeding, infection, spinal block, epidural block, and injection into blood vessels and surrounding organs. Fortunately, serious side effects and complications are uncommon. X-ray guidance to provide your physician visualization of the targeted structures significantly minimizes risk.