Stellate ganglion block may relieve hot flashes by interrupting the sympathetic nervous system

Stellate ganglion block is routinely used in pain clinics. The mechanism of action of the stellate ganglion block is uncertain; the most common explanation is that it produces peripheral vasodilation, resulting in neural inhibition in the ganglion's sphere of innervation. However, the wide range of conditions that have been reported to respond favorably to stellate ganglion block suggest that its effectiveness may not be solely the result of increased blood flow nor restricted just to its sphere of innervation. We have found that stellate ganglion block is effective in the treatment of hot flashes in postmenopausal women, as well as those with estrogen depletion resulting from breast cancer treatment. Based on evidence that hot flashes may be centrally mediated and that the stellate ganglion has links with the central nervous system nuclei that modulate body temperature, we hypothesize that the stellate ganglion block provides relief of hot flashes by interrupting the central nervous system connections with the sympathetic nervous system, allowing the body's temperature-regulating mechanisms to reset. If this mechanism can be confirmed, this would provide women with intractable hot flashes with an effective, potentially long-lasting means of relieving their symptoms, and potentially widen the range of indications for stellate ganglion block to include other centrally mediated syndromes.