Pilot evaluation of a stellate ganglion block for the treatment of hot flashes

Stellate ganglion block beyond chronic pain: A literature review on its application in painful and non-painful conditions

Cervical sympathetic or stellate ganglion blocks (SGBs) have been commonly used in the treatment of painful conditions like complex regional pain syndrome (CRPS). However, there is literature to suggest its utility in managing non-painful conditions as well. The focus of this literature review is to provide an overview of indications for SGB for painful and non-painful conditions. We identified published journal articles in the past 25 years from Embase and PubMed databases with the keywords "cervical sympathetic block, stellate ganglion blocks, cervical sympathetic chain, and cervical sympathetic trunk". A total of 1556 articles were obtained from a literature search among which 311 articles were reviewed. Among painful conditions, there is a lack of evidence in favor of or against the use of SGB for CRPS despite its common use. SGB can provide postoperative analgesia in selective surgeries and can be effective in temporary pain control of refractory angina and the acute phase of herpes zoster infection. Among non-painful conditions, SGB may have beneficial effects on the management of post-traumatic stress disorder (PTSD), refractory ventricular arrhythmias, hot flashes in postmenopausal women, and breast cancer-related lymphedema. Additionally, there have been various case reports illustrating the benefits of SGB in the management of cerebral vasospasm, upper limb erythromelalgia, thalamic and central post-stroke pain, palmar hyperhidrosis, orofacial pain, etc. In our review of literature, we found that SGB can be useful in the management of various non-painful conditions beyond the well-known treatment for CRPS, although further studies are required to prove its efficacy.

The 2023 nonhormone therapy position statement of The North American Menopause Society

OBJECTIVE

To update the evidence-based Nonhormonal Management of Menopause-Associated Vasomotor Symptoms: 2015 Position Statement of The North American Menopause Society.

METHODS

An advisory panel of clinicians and research experts in women's health were selected to review and evaluate the literature published since the Nonhormonal Management of Menopause-Associated Vasomotor Symptoms: 2015 Position Statement of The North American Menopause Society. Topics were divided into five sections for ease of review: lifestyle; mind-body techniques; prescription therapies; dietary supplements; and acupuncture, other treatments, and technologies. The panel assessed the most current and available literature to determine whether to recommend or not recommend use based on these levels of evidence: Level I, good and consistent scientific evidence; Level II, limited or inconsistent scientific evidence, and Level III, consensus and expert opinion.

RESULTS

Evidence-based review of the literature resulted in several nonhormone options for the treatment of vasomotor symptoms. Recommended: Cognitive-behavioral therapy, clinical hypnosis, selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitors, gabapentin, fezolinetant (Level I); oxybutynin (Levels I-II); weight loss, stellate ganglion block (Levels II-III). Not recommended: Paced respiration (Level I); supplements/herbal remedies (Levels I-II); cooling techniques, avoiding triggers, exercise, yoga, mindfulness-based intervention, relaxation, suvorexant, soy foods and soy extracts, soy metabolite equol, cannabinoids, acupuncture, calibration of neural oscillations (Level II); chiropractic interventions, clonidine; (Levels I-III); dietary modification and pregabalin (Level III).

CONCLUSION

Hormone therapy remains the most effective treatment for vasomotor symptoms and should be considered in menopausal women within 10 years of their final menstrual periods. For women who are not good candidates for hormone therapy because of contraindications (eg, estrogen-dependent cancers or cardiovascular disease) or personal preference, it is important for healthcare professionals to be well informed about nonhormone treatment options for reducing vasomotor symptoms that are supported by the evidence.

A Review of Stellate Ganglion Block as an Adjunctive Treatment Modality

Peripheral nerve blocks are becoming increasingly used as adjunctive treatment modalities for a variety of conditions refractory to medical management. Right or left stellate ganglion blocks (SGB) are a specific type of peripheral nerve block that target the sympathetic blockade of neuronal impulses using the injection of local anesthetic and steroids into nerve bundles in the cervical area. This review article is intended to summarize the common uses of stellate ganglion blocks and explain the procedural technique, which has evolved with technological advances in ultrasonography. The similarities between these disease processes are centered around sympathetic hyperactivity. This sympathetic overdrive state is created by increased levels of nerve growth factor (NGF), which causes a cascade of sympathetic sprouting resulting in increased norepinephrine (NE) systemically. Reversal of this cascade by local anesthetic injection into the stellate ganglion thereby reduces NGF and sympathetic sprouting subsequently lowering overall norepinephrine levels. This is the unifying theory by which SGB is able to provide resolution for the varied clinical conditions described in this article.  This review article discusses the physiology of several conditions where stellate ganglion blocks are being investigated as an adjunct treatment modality, including anosmia, PTSD, long-COVID, chronic fatigue syndrome, menopausal hot flashes, and ventricular tachyarrhythmias. Overall, the current literature supporting the use of stellate ganglion blocks for several esoteric conditions is limited; however, case reports to date have shown promising evidence-based results supporting their use as an adjunctive treatment among patients with refractory symptoms to existing treatment algorithms. In conclusion, SGB should be considered among patients with refractory symptoms for medical management in the conditions discussed in this article. Further research is needed to delineate which patients will benefit from the use of SGB, the use of subsequent blocks and timelines in between injections, and unilateral versus bilateral blockade.

Comparison of the effects of stellate ganglion block and paroxetine on hot flashes and sleep disturbance in breast cancer survivors

Background

The incidence of menopausal symptoms, including hot flashes and sleep disturbance, caused by drug treatment is a common problem in breast cancer survivors. Considering the limitations of hormone therapy in such patients, several studies have been conducted to find alternative methods. The aim of this study was to investigate and compare the effectiveness of stellate ganglion block (SGB) with that of paroxetine, which was approved by the US Food and Drug Administration (FDA) as a medicine for the treatment of hot flashes and ensuing sleep disturbance.

Patients and methods

A total of 40 patients survived from breast cancer and complaining of these symptoms were equally assigned to two groups of 20 each. In the study group, SGB was performed successfully under sonography guidance using 10 mL of 0.5% bupivacaine, and in the control group (paroxetine), the daily administration of 7.5 mg of paroxetine was conducted for 6 weeks. The frequency and severity of hot flash attacks and sleep quality of patients were evaluated prior to the intervention and after 2, 4 and 6 weeks. The incidence of adverse events during treatment or follow-up was recorded.

Results

A significant decrease in hot flash score and sleep disturbance index (SDI) was observed in both groups. Comparison of the results showed no noticeable difference between the two groups. Two participants in the control group had discontinued medication due to gastrointestinal symptoms, and only one case of mild headache was reported in the study group.

Conclusion

SGB is as much effective as paroxetine in controlling hot flashes and sleep disturbances in breast cancer survivors and is associated with few complications.

The Management of Menopausal Symptoms in Women Following Breast Cancer: An Overview

The improved detection and successful treatment of breast cancer, resulting in better survival rates, has led to an increasing number of women living with the effects of treatment modalities and their long-term consequences. Menopausal symptoms following breast cancer can occur at an earlier age, be more severe and significantly influence a woman's overall wellbeing, in particular, sexual function, quality of life and adherence to treatment. There is a dearth of good quality evidence on the safest and most effective treatment options available for these women, and this article aims to summarize the current available treatments. Pertinent to these women is general advice, such as avoidance of triggers, and lifestyle modifications. Following which, non-pharmacological interventions, including cognitive behavior therapy (CBT), hypnosis, acupuncture, stellate ganglion nerve block and complementary agents, are discussed. Pharmacological therapies and their safety profile in these high-risk women are then examined; namely, menopausal hormone therapy, progestogens, antidepressants (selective serotonin reuptake inhibitors and selective noradrenaline reuptake inhibitors), gabapentin, clonidine and intra-vaginal dehydroepiandrosterone (DHEA). Finally, neurokinin 3 receptor antagonists, promising new agents for the treatment of troublesome menopausal vasomotor symptoms, are discussed.

Nonhormonal management of menopause-associated vasomotor symptoms: 2015 position statement of The North American Menopause Society

OBJECTIVE

To update and expand The North American Menopause Society's evidence-based position on nonhormonal management of menopause-associated vasomotor symptoms (VMS), previously a portion of the position statement on the management of VMS.

METHODS

NAMS enlisted clinical and research experts in the field and a reference librarian to identify and review available evidence. Five different electronic search engines were used to cull relevant literature. Using the literature, experts created a document for final approval by the NAMS Board of Trustees.

RESULTS

Nonhormonal management of VMS is an important consideration when hormone therapy is not an option, either because of medical contraindications or a woman's personal choice. Nonhormonal therapies include lifestyle changes, mind-body techniques, dietary management and supplements, prescription therapies, and others. The costs, time, and effort involved as well as adverse effects, lack of long-term studies, and potential interactions with medications all need to be carefully weighed against potential effectiveness during decision making.

CONCLUSIONS

Clinicians need to be well informed about the level of evidence available for the wide array of nonhormonal management options currently available to midlife women to help prevent underuse of effective therapies or use of inappropriate or ineffective therapies. Recommended: Cognitive-behavioral therapy and, to a lesser extent, clinical hypnosis have been shown to be effective in reducing VMS. Paroxetine salt is the only nonhormonal medication approved by the US Food and Drug Administration for the management of VMS, although other selective serotonin reuptake/norepinephrine reuptake inhibitors, gabapentinoids, and clonidine show evidence of efficacy. Recommend with caution: Some therapies that may be beneficial for alleviating VMS are weight loss, mindfulness-based stress reduction, the S-equol derivatives of soy isoflavones, and stellate ganglion block, but additional studies of these therapies are warranted. Do not recommend at this time: There are negative, insufficient, or inconclusive data suggesting the following should not be recommended as proven therapies for managing VMS: cooling techniques, avoidance of triggers, exercise, yoga, paced respiration, relaxation, over-the-counter supplements and herbal therapies, acupuncture, calibration of neural oscillations, and chiropractic interventions. Incorporating the available evidence into clinical practice will help ensure that women receive evidence-based recommendations along with appropriate cautions for appropriate and timely management of VMS.

Management of Hormone Deprivation Symptoms After Cancer

Cancer survivors often experience symptoms related to hormone deprivation, including vasomotor symptoms, genitourinary symptoms, and sexual health concerns. These symptoms can occur due to natural menopause in midlife women, or they can be brought on by oncologic therapies in younger women or men. We searched PubMed for English-language studies from January 1990 through January 2016 to identify relevant articles on the management of hormone deprivation symptoms, including vasomotor, genitourinary, and sexual symptoms in patients with cancer. The search terms used included hormone deprivation, vasomotor symptoms, hot flash, vaginal dryness, sexual dysfunction, and breast cancer. This manuscript provides a comprehensive description of data supporting the treatment of symptoms associated with hormone deprivation.

Stellate ganglion blockade and verbal memory in midlife women: Evidence from a randomized trial

OBJECTIVES

In a pilot randomized clinical trial of active stellate ganglion blockade (SGB) versus sham control, SGB significantly reduced the frequency of reported moderate to severe vasomotor symptoms (VMS) and the frequency of physiologic VMS measured using ambulatory skin conductance monitors. Here we examine secondary effects of SGB on verbal learning and memory.

STUDY DESIGN

In a randomized, sham-controlled study, 36 women met eligibility criteria for cognitive assessments, of whom 17 were randomized to receive fluoroscopy-guided SGB and 19 to sham control.

MAIN OUTCOME MEASURES

At baseline and three months post-treatment, women completed tests of verbal learning and memory (primary outcome) and other cognitive measures and also wore an ambulatory monitor for 24h to measure physiologic VMS and VMS reported in real time.

RESULTS

Verbal learning improved following active SGB (p<0.05) but not sham treatment; however, the interaction between group and time was not significant (p values 0.13-0.20). Two secondary cognitive measures improved only in the sham group. Improvements in physiologic VMS correlated significantly with improvements in verbal learning (r=0.51, p<0.05).

CONCLUSIONS

SGB might confer benefits to memory in relation to the magnitude of improvement in physiologic VMS. Broadly these findings suggest a possible link between physiologic VMS and memory problems in midlife women.

Effects of stellate ganglion block on vasomotor symptoms: findings from a randomized controlled clinical trial in postmenopausal women

OBJECTIVE

Uncontrolled intervention studies, including studies involving breast cancer survivors, have demonstrated improvements in vasomotor symptoms (VMS) after stellate ganglion blockade (SGB) with a local anesthetic. This study presents the first randomized sham-controlled trial of SGB for the treatment of VMS.

METHODS

Participants included 40 postmenopausal women, aged 30 to 70 years, with moderate to severe VMS. The study was a randomized sham-controlled trial comparing the effects of SGB versus sham injection on the frequencies of total and moderate to severe VMS, as measured by daily diaries. Image-guided SGB was performed with 5 mL of 0.5% bupivacaine. Sham injection of saline was performed in subcutaneous tissues in the neck. VMS were recorded at baseline and for 6 months thereafter. Objective VMS were recorded using ambulatory sternal skin conductance monitoring during a 24-hour period at baseline and on 3-month follow-up.

RESULTS

There were no significant group differences in overall VMS frequency, but the frequency of moderate to very severe VMS was reduced more in the active group compared with the sham treatment group (event rate ratio, 0.50; 95% CI, 0.35-0.71; P < 0.001). The frequency of objective VMS was also reduced to a greater degree in the SGB group than in the sham group (event rate ratio, 0.71; 95% CI, 0.64-0.99; P < 0.05). There were no study-related serious adverse events.

CONCLUSIONS

SGB may provide effective treatment of VMS in women who seek nonhormonal treatments because of safety concerns and personal preference. The finding that SGB significantly reduces objectively measured VMS provides further evidence of efficacy. A larger trial is warranted to confirm these findings.

Stellate Ganglion Block for the Treatment of Hot Flashes in Patients with Breast Cancer: A Literature Review

BACKGROUND

Currently, hormone replacement therapy (HRT) is the only US Food and Drug Administration-approved treatment for hot flashes, resulting in clinical improvement in 80%-90% of symptomatic women. However, HRT is not recommended for patients with breast cancer. Current data regarding the use of stellate ganglion block (SGB) for the treatment of vasomotor symptoms in symptomatic women with a diagnosis of breast cancer are promising.

METHODS

A PubMed search for recent articles on the effects of SGB for the treatment of hot flashes in patients with breast cancer identified 11 articles published between 2005-2014.

RESULTS

Five articles described the physiology of hot flashes and the hypothesis of why SGB would be a treatment option, and 6 were clinical articles.

CONCLUSION

The available results of SGB efficacy are promising but demonstrate significant variability. A large prospective randomized controlled trial is required to determine the exact success of SGB on hot flashes and quality of life in breast cancer survivors.

Stellate ganglion block for treating hot flashes: a viable treatment option or sham procedure?

Stellate ganglion block (SGB) has been used for over 70 years to treat various cervical pain syndromes. Over the past 8 years, 4 different groups have reported on SGB's effects on hot flashes from unblinded, open-label trials. Review of these studies has shown markedly disparate results in terms of the magnitude of hot flash reduction from Baseline with one trial showing a 90% reduction in hot flashes and 3 other trials showing 28-44% reductions in hot flashes. The inconsistencies in these results in addition to the known potentially large (>50%) placebo effects that can occur in randomized controlled hot flash clinical trials make it difficult to render any conclusions regarding the efficacy of SGB for hot flashes at this time. A randomized controlled trial, including a sham saline treatment arm, needs to be performed to properly assess SGB's effects on hot flashes, Methodological challenges with such a study design are addressed and several suggestions are proposed to manage these challenges.

Risk factors, pathophysiology, and treatment of hot flashes in cancer

Hot flashes are prevalent and severe symptoms that can interfere with mood, sleep, and quality of life for women and men with cancer. The purpose of this article is to review existing literature on the risk factors, pathophysiology, and treatment of hot flashes in individuals with cancer. Electronic searches were conducted to identify relevant English-language literature published through June 15, 2012. Results indicated that risk factors for hot flashes in cancer include patient-related factors (eg, age, race/ethnicity, educational level, smoking history, cardiovascular risk including body mass index, and genetics) and disease-related factors (eg, cancer diagnosis and dose/type of treatment). In addition, although the pathophysiology of hot flashes has remained elusive, these symptoms are likely attributable to disruptions in thermoregulation and neurochemicals. Therapies that have been offered or tested fall into 4 broad categories: pharmacological, nutraceutical, surgical, and complementary/behavioral strategies. The evidence base for this broad range of therapies varies, with some treatments not yet having been fully tested or showing equivocal results. The evidence base surrounding all therapies is evaluated to enhance hot flash treatment decision-making by clinicians and patients.

Stellate-ganglion block as a treatment for severe postmenopausal flushing

OBJECTIVE

Hormone replacement therapy is the most effective treatment for postmenopausal flushing. Unfortunately, its use is often contraindicated. A limited amount of uncontrolled data suggests that stellate-ganglion block (SGB) may be useful for the treatment of hot flushes. In the present study, we examined whether previously reported results could be reproduced in women with severe postmenopausal flushing.

METHODS

Twenty postmenopausal women with a baseline hot flush score ≥ 15  were treated with SGB in an open, uncontrolled setting. This mean daily hot flush score was calculated as the product of flush frequency and flush severity over a period of 1 week. The response to treatment was evaluated by flush scores and assessment of quality of life at baseline and 4 weeks after SGB.

RESULTS

The per-protocol analysis included 19 women. One woman was excluded because of lack of Horner syndrome after SGB. Four weeks after SGB, the mean flush score had decreased by 34 ± 7.4% (95% confidence interval (CI) 18-49%; p < 0.005). Nine women had a decrease in flush score between 40 and 90%, with a mean response of 65 ± 4.9% (95% CI 53-76%). The other ten women were non-responders with a decrease in flush score between 0 and 11%. Quality of life and sleep, both assessed by questionnaire, improved significantly.

CONCLUSIONS

The results of this study support the observation that SGB may be a useful therapy for a subset of women with severe postmenopausal flushing. A sham-controlled, single-blinded study is warranted to improve the evidence of efficacy.

Androgen deprivation therapy-associated vasomotor symptoms

Androgen deprivation therapy (ADT) is widely used as standard therapy in the treatment of locally advanced and metastatic prostate cancer. While efficacious, ADT is associated with multiple side effects, including decreased libido, erectile dysfunction, diabetes, loss of muscle tone and altered body composition, osteoporosis, lipid changes, memory loss, gynecomastia and hot flashes. The breadth of literature for the treatment of hot flashes is much smaller in men than that in women. While hormonal therapy of hot flashes has been shown to be effective, multiple non-hormonal medications and treatment methods have also been developed. This article reviews current options for the treatment of hot flashes in patients taking ADT.

Stellate ganglion block for the management of hot flashes and sleep disturbances in breast cancer survivors: an uncontrolled experimental study with 24 weeks of follow-up

BACKGROUND

We studied the stellate ganglion block (SGB) recently suggested for the treatment of severe vasomotor symptoms and sleep disturbances in breast cancer survivors. Following an initial pilot study, which focused on the acceptability and safety of SGB for this important problem, we evaluated its short- and long-term efficacy.

MATERIALS AND METHODS

Postmenopausal breast cancer survivors with severe vasomotor symptoms resistant to standard nonhormonal pharmacological intervention were eligible. Diaries were used to measure daily hot flash scores (frequency and intensity) and sleep quality (Pittsburgh Sleep Quality Index) during scheduled visits at baseline, 1, 4, 12 and 24 weeks following the SGB. Efficacy data were analyzed using longitudinal regression models.

RESULTS

Thirty-four patients participated and none refused the SGB procedure. Most patients received more than one SGB. The pilot study found SGB to be safe. In the main study, hot flash scores were reduced from baseline by 64% [95% confidence interval (CI) -74% to -49%] and 47% (95% CI -62% to -27%) at weeks 1 and 24, respectively. The odds ratio of better sleep quality relative to baseline was 3.4 at week 1 (95% CI 1.6-7.2) and 4.3 at week 24 (95% CI 1.9-9.8).

CONCLUSION

In the short term, SGB appears to be an effective treatment with acceptable morbidity for some breast cancer survivors with therapy-resistant vasomotor symptoms and/or sleep disturbances. Although sleep quality was maintained out to 24 weeks the efficacy of SGB for hot flashes was reduced over time. A randomized controlled trial is needed to confirm these findings.

Management of menopause-associated vasomotor symptoms: Current treatment options, challenges and future directions

Hot flashes are one of the most common and distressing symptoms associated with menopause, occurring in more than 75% of postmenopausal women. They are especially problematic in breast cancer patients since some breast cancer therapies can induce hot flashes. For mild hot flashes, it is proposed that behavioral modifications are the first step in management. Hormonal therapies, including estrogens and progestogens, are the most well known effective agents in relieving hot flashes; however, the safety of these agents is controversial. There is an increasing amount of literature on nonhormonal agents for the treatment of hot flashes. The most promising data regard newer antidepressant agents such as venlafaxine, which reduces hot flashes by about 60%. Gabapentin is another nonhormonal agent that is effective in reducing hot flashes. While many complimentary therapies, including phytoestrogens, black cohosh, and dehydroepiandrosterone, have been explored for the treatment of hot flashes; none can be recommended at this time. Furthermore, there is a lack of strong evidence to support exercise, yoga, or relaxation for the treatment of hot flashes. Paced respirations and hypnosis appear to be promising enough to warrant further investigation. Another promising nonpharmacological therapy, currently under investigation, involves a stellate ganglion block.