Stellate ganglion block

A stellate ganglion block or stellate ganglion blockade or SGB cervicothoracic ganglion block is a nerve block injection in the lower neck/upper back area, either on the left or the right side.

Theory
The stellate or cervicothoracic ganglion is present in 80% of the population, and forms by a natural fusion between the inferior cervical ganglion and first thoracic ganglion.

A stellate ganglion block was proposed as a treatment for dysautonomia symptoms in Long COVID by Liu and Duricka (2021) based on their treatment of just two patients.

Liu and Duricka proposed that a stellate ganglion block on both sides may cause a "reset" of the sympathetic nervous system (SNS), which they propose could allow it to return to homeostasis, resolving or improving dysautonomia symptoms. Changes to the sympathetic nervous system affect the parasympathetic nervous system (PNS), which is the other key part of the autonomic nervous system. Dysautonomia is a range of conditions involving the failure of parts of the SNS and PNS, and sometimes over or underactivation.

Evidence
Liu and Duricka published a case study of two Long COVID patients, both women in their 40s, who had received stellate ganglion blocks on both left and right sides at their clinic. Patient self-reports were the only results:

Risks and safety

 * Horner's syndrome results from a successful stellate ganglion block, which is expected to resolve after the block wears off.

Notable studies

 * 2021, Liu - (Full text)]

Learn more

 * Stellate Ganglion Block - Cedars Sinai Medical Center
 * Neuroanatomy, Stellate Ganglion - StatPearls book