The overall aim of this randomized, sham-controlled clinical trial is to corroborate findings that stellate ganglion block (SGB) is a safe and effective non-hormonal intervention for women seeking relief from vasomotor symptoms (VMS) and to identify the physiologic mechanisms underlying this treatment effect. More than 80% of women experience frequent hot flashes and night sweats (i.e., VMS). These symptoms last on average 7.4 years. VMS are associated with decreased quality of life, increased depressive and anxiety symptoms, sleep disturbance, reduced productivity and memory declines. Safety concerns raised in the Women’s Health Initiative (WHI) led to an 80% decline in the use of hormone therapy in the United States. Identifying safe and effective non-hormonal treatments for VMS remains a priority in women’s health research. The stellate ganglion, a sympathetic neural structure in the cervical spine region, is commonly blocked with local anesthetics in the treatment of chronic and acute pain syndromes. In open-label intervention studies, SGB with local anesthetic reduced VMS by 34 to 90% four weeks to several months after treatment. We conducted the first randomized, sham-controlled (injection of saline into subcutaneous tissue in the neck) trial of SGB (with 0.5% bupivacaine 5 mL) for the reduction of VMS in menopausal women with moderate to very severe VMS (n= 40)1. A single SGB with local anesthetic significantly reduced moderate-to-very severe VMS by 50% more than sham treatment and lasted for up to sixth months. Analyses of secondary outcomes revealed significant improvements in objectively-measured VMS and trends (p = .08) for improvements in depressive symptoms and memory performance with active SGB compared to sham intervention. In this proposal, we aim to conduct a randomized, sham-controlled clinical trial to more definitively assess the effects of SGB on VMS and to conduct foundational studies to identify the mechanisms of SGB action. This clinical trial will include 220 menopausal women who report 28 or more weekly VMS. Secondary outcomes will include objectively measured VMS, mood and anxiety, quality of life, sleep, and memory performance. After an initial baseline assessment, women will be reassessed at 3 and 6 months following the SGB or sham intervention. In a subset of 60 women (30 per arm), we will perform a nested, mechanistic sub study built on foundational work in neuroimaging of VMS and ambulatory monitoring of sympathetic nerve activity. These two mechanistic outcomes will be obtained at baseline and at 3 months following the intervention. We predict that compared to sham intervention, SGB will reduce the frequency of VMS, improve mood and anxiety, increase quality of life, improve memory, modulate brain activity in thermoregulatory brain areas, and reduce sympathetic nerve activity, but have no effect on sleep or other cognitive functions. By providing a more definitive understanding of the effectiveness of SGB, possible secondary benefits, and mechanisms of action, these findings will fill a critical gap in non-hormonal options available to women.
|Effective start/end date||8/1/16 → 4/30/22|
- National Institute on Aging (5R01AG049924-04)