Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients

BACKGROUND

Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects.

OBJECTIVES

The authors sought to describe the safety and efficacy of PICB in patients with refractory ES.

METHODS

We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes.

RESULTS

A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed.

CONCLUSIONS

In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Interventions for the management of abdominal pain in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammation of the colon characterised by periods of relapse and remission. It starts in the rectum and can extend throughout the colon. UC and Crohn's disease (CD) are the most common inflammatory bowel diseases (IBDs). However, UC tends to be more common than CD. It has no known cure but can be managed with medication and surgery. However, studies have shown that abdominal pain persists in up to one-third of people with UC in remission. Abdominal pain could be a symptom of relapse of the disease due to adverse effects of medication, surgical complications and strictures or adhesions secondary to UC.

OBJECTIVES

To assess the efficacy and safety of interventions for managing abdominal pain in people with ulcerative colitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE and five other databases and clinical trials registries on 28 April 2021. We contacted authors of relevant studies and ongoing or unpublished trials that may be relevant to the review. We also searched references of trials and systematic reviews for any additional trials.

SELECTION CRITERIA

All published, unpublished and ongoing randomised trials that compared interventions for the management of abdominal pain with other active interventions or standard therapy, placebo or no therapy were included. People with both active and inactive disease were included. We excluded studies that did not report on any abdominal pain outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted data extraction and 'Risk of bias' assessments. We analysed data using Review Manager 5. We expressed dichotomous and continuous outcomes as risk ratios (RRs) and mean differences (MDs), respectively, with 95% confidence intervals. We assessed the certainty of the evidence using the GRADE methodology.

MAIN RESULTS

We included five studies (360 randomised participants). Studies considered mainly participants in an inactive state of the disease.   No conclusions could be drawn about the efficacy of any of the interventions on pain frequency, pain intensity, and treatment success. The certainty of the evidence was very low for all comparisons because of imprecision due to sparse data, and risk of bias. One study compared a low FODMAPs diet (n=13) to a sham diet (n=13). The evidence is very uncertain about the effect of this treatment on pain frequency (MD -4.00, 95% CI -20.61 to 12.61) and intensity (MD -9.00, 95% CI -20.07 to 2.07). Treatment success was not reported. One study compared relaxation training (n=20) to wait-list (n=20). The evidence is very uncertain about the effect of this treatment on pain frequency at end of intervention (MD 2.60, 95% CI 1.14 to 4.06) and 6-month follow-up (MD 3.30, 95% CI 1.64 to 4.96). Similarly, the evidence is very uncertain about the effect of this treatment on pain intensity at end of intervention (MD -1.70, 95% CI -2.92 to -0.48) and 6-month follow-up (MD -2.30, 95% CI -3.70 to -0.90). Treatment success was not reported. One study compared yoga (n=30) to no intervention (n=30). The study defined treatment success as the presence or absence of pain; however, the data they provided was unclear. Pain frequency and intensity were not reported. One study compared a kefir diet (Lactobacillus bacteria, n=15) to no intervention (n=15). The evidence is very uncertain about the effect of this treatment on pain intensity (MD -0.17, 95% CI -0.91 to 0.57). Pain frequency and treatment success were not reported. One study compared a stellate ganglion block treatment (n=90) to sulfasalazine treatment (n=30). The study defined treatment success as "stomachache"; however, the data they provided was unclear. Pain frequency and intensity were not reported. Two studies reported withdrawals due to adverse events. One study reported withdrawals due to adverse events as zero. Two studies did not report this outcome.  We cannot draw any conclusions about the effects of any of the interventions on withdrawals due to adverse events because of the very limited evidence. The reporting of secondary outcomes was inconsistent. Adverse events tended to be very low or zero. However, we can make no clear judgements about adverse events for any of the interventions, due to the low number of events. Anxiety was measured and reported at end of intervention in only one study (yoga versus no intervention), and depression was not measured in any of the studies. We can therefore draw no meaningful conclusions about these outcomes.

AUTHORS' CONCLUSIONS

We found very low-certainty evidence on the efficacy and safety of interventions for the management of abdominal pain in ulcerative colitis. Pervasive issues with very serious imprecision from small samples size and high risk of bias have led to very low-certainty outcomes, precluding conclusions. While few adverse events and no serious adverse events were reported, the certainty of these findings was again very low for all comparisons, so no conclusions can be drawn. There is a need for further research. We have identified eight ongoing studies in this review, so an update will be warranted. It is key that future research addresses the issues leading to reduced certainty of outcomes, specifically sample size and reporting that leads to high risk of bias. It is also important that if researchers are considering pain as a critical outcome, they should report clearly if participants were pain-free at baseline; in that case, data would be best presented as separate subgroups throughout their research.

Macrophage depletion in stellate ganglia alleviates cardiac sympathetic overactivation and ventricular arrhythmogenesis by attenuating neuroinflammation in heart failure

Cardiac sympathetic overactivation is involved in arrhythmogenesis in patients with chronic heart failure (CHF). Inflammatory infiltration in the stellate ganglion (SG) is a critical factor for cardiac sympathoexcitation in patients with ventricular arrhythmias. This study aims to investigate if macrophage depletion in SGs decreases cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. Surgical ligation of the coronary artery was used for induction of CHF. Clodronate liposomes were microinjected into bilateral SGs of CHF rats for macrophage depletion. Using cytokine array, immunofluorescence staining, and Western blot analysis, we found that macrophage expansion and expression of TNFα and IL-1β in SGs were markedly increased in CHF rats. Flow cytometry data confirmed that the percentage of macrophages in SGs was higher in CHF rats than that in sham rats. Clodronate liposomes significantly reduced CHF-elevated proinflammatory cytokine levels and macrophage expansion in SGs. Clodronate liposomes also reduced CHF-increased N-type Ca2+ currents and excitability of cardiac sympathetic postganglionic neurons and inhibited CHF-enhanced cardiac sympathetic nerve activity. ECG data from 24-h, continuous telemetry recording in conscious rats demonstrated that clodronate liposomes not only restored CHF-induced heterogeneity of ventricular electrical activities, but also decreased the incidence and duration of ventricular tachycardia/fibrillation in CHF. Macrophage depletion with clodronate liposomes attenuated CHF-induced cardiac sympathetic overactivation and ventricular arrhythmias through reduction of macrophage expansion and neuroinflammation in SGs.

Developmental exposure to DDT or DDE alters sympathetic innervation of brown adipose in adult female mice

BACKGROUND

Exposure to the bioaccumulative pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolite dichlorodiphenyldichloroethylene (DDE) has been associated with increased risk of insulin resistance and obesity in humans and experimental animals. These effects appear to be mediated by reduced brown adipose tissue (BAT) thermogenesis, which is regulated by the sympathetic nervous system. Although the neurotoxicity of DDT is well-established, whether DDT alters sympathetic innervation of BAT is unknown. We hypothesized that perinatal exposure to DDT or DDE promotes thermogenic dysfunction by interfering with sympathetic regulation of BAT thermogenesis.

METHODS

Pregnant C57BL/6 J mice were administered environmentally relevant concentrations of DDTs (p,p'-DDT and o,p'-DDT) or DDE (p,p'-DDE), 1.7 mg/kg and 1.31 mg/kg, respectively, from gestational day 11.5 to postnatal day 5 by oral gavage, and longitudinal body temperature was recorded in male and female offspring. At 4 months of age, metabolic parameters were measured in female offspring via indirect calorimetry with or without the β3 adrenergic receptor agonist, CL 316,243. Immunohistochemical and neurochemical analyses of sympathetic neurons innervating BAT were evaluated.

RESULTS

We observed persistent thermogenic impairment in adult female, but not male, mice perinatally exposed to DDTs or p,p'-DDE. Perinatal DDTs exposure significantly impaired metabolism in adult female mice, an effect rescued by treatment with CL 316,243 immediately prior to calorimetry experiments. Neither DDTs nor p,p'-DDE significantly altered BAT morphology or the concentrations of norepinephrine and its metabolite DHPG in the BAT of DDTs-exposed mice. However, quantitative immunohistochemistry revealed a 20% decrease in sympathetic axons innervating BAT in adult female mice perinatally exposed to DDTs, but not p,p'-DDE, and 48 and 43% fewer synapses in stellate ganglia of mice exposed to either DDTs or p,p'-DDE, respectively, compared to control.

CONCLUSIONS

These data demonstrate that perinatal exposure to DDTs or p,p'-DDE impairs thermogenesis by interfering with patterns of connectivity in sympathetic circuits that regulate BAT.

A Prospective, Randomized Cross-Over Trial of T2 Paravertebral Block as a Sympathetic Block in Complex Regional Pain Syndrome

BACKGROUND

Sympathetic block is commonly performed in clinical practice for management of intractable pain conditions. However, stellate ganglion block (SGB) alone often does not achieve sufficient sympatholysis of the upper extremity. The paravertebral space continues up to the cervical sympathetic chain and includes the stellate ganglion. We compared the sympatholytic and analgesic effect of paravertebral block performed at the T2 level (T2 PVB) with that of SGB in patients with complex regional pain syndrome (CRPS) of the upper extremity.

OBJECTIVES

The aim of this study was to compare the sympatholytic property of T2 PVB with that of the conventional SGB in patients with CRPS of the upper extremity.

STUDY DESIGN

Prospective, randomized cross-over trial.

SETTING

University hospital pain center in Korea.

METHODS

Fifteen patients with upper extremity CRPS were randomly assigned to 1 of 2 intervention methods (SGB or T2 PVB). After effects of the first block receded, the patients were crossed over to the second procedure. A difference in temperature increase between the treated side and the opposite side (DeltaT) DeltaT greater than or equal to1.5°C was considered as a successful primary outcome. Rate of successful primary outcome, degree of pain reduction, duration of effect, and patient satisfaction scores were compared between the 2 intervention methods.

RESULTS

Rate of successful primary outcome (DeltaT greater than or equal to 1.5°C) was significantly higher in the T2 PVB cases than in the SGB cases (80.0% vs. 20.0%; P = 0.003). Numeric Rating Scale scores after the procedure were significantly lower in the T2 PVB group. Patient satisfaction scores were significantly higher, and the duration of the block was significantly longer in the T2 PVB cases than in the SGB cases.

LIMITATIONS

The relatively small sample size from a single center, and the lack of standardization of the injected volume of T2 PVB and SGB were limitations.

CONCLUSIONS

T2 PVB showed superior sympatholytic effect than SGB; other clinical outcomes were also better with T2 PVB than with SGB. T2 PVB can be a useful option for producing sympatholytic and analgesic effect in patients with CRPS of the upper extremity.

KEY WORDS

Sympathetic block, Complex Regional Pain Syndrome, paravertebral block, stellate ganglion block.

Effects of anesthetic and sedative agents on sympathetic nerve activity

BACKGROUND

The effects of sedative and anesthetic agents on sympathetic nerve activity (SNA) are poorly understood.

OBJECTIVE

The purpose of this study was to determine the effects of commonly used sedative and anesthetic agents on SNA in ambulatory dogs and humans.

METHODS

We implanted radiotransmitters in 6 dogs to record stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (ScNA), and blood pressure (BP). After recovery, we injected dexmedetomidine (3 μg/kg), morphine (0.1 mg/kg), hydromorphone (0.05 mg/kg), and midazolam (0.1 mg/kg) on different days. We also studied 12 human patients (10 male; age 68.0 ± 9.1 years old) undergoing cardioversion for atrial fibrillation with propofol (0.77 ± 0.18 mg/kg) or methohexital (0.65 mg/kg) anesthesia. Skin sympathetic nerve activity (SKNA) and electrocardiogram were recorded during the study.

RESULTS

SGNA and ScNA were significantly suppressed immediately after administration of dexmedetomidine (P = .000 and P = .000, respectively), morphine (P = .011 and P = .014, respectively), and hydromorphone (P = .000 and P = .012, respectively), along with decreased BP and heart rate (HR) (P <.001 for each). Midazolam had no significant effect on SGNA and ScNA (P = .248 and P = .149, respectively) but increased HR (P = .015) and decreased BP (P = .004) in ambulatory dogs. In patients undergoing cardioversion, bolus propofol administration significantly suppressed SKNA (from 1.11 ± 0.25 μV to 0.77 ± 0.15 μV; P = .001), and the effects lasted for at least 10 minutes after the final cardioversion shock. Methohexital decreased chest SKNA from 1.59 ± 0.45 μV to 1.22 ± 0.58 μV (P = .000) and arm SKNA from 0.76 ± 0.43 μV to 0.55 ± 0.07 μV (P = .001). The effects lasted for at least 10 minutes after the cardioversion shock.

CONCLUSION

Propofol, methohexital, dexmedetomidine, morphine, and hydromorphone suppressed, but midazolam had no significant effects on, SNA.

Chronic lead exposure enhances the sympathoexcitatory response associated with P2X4 receptor in rat stellate ganglia

Chronic lead exposure causes peripheral sympathetic nerve stimulation, including increased blood pressure and heart rate. Purinergic receptors are involved in the sympathoexcitatory response induced by myocardial ischemia injury. However, whether P2X4 receptor participates in sympathoexcitatory response induced by chronic lead exposure and the possible mechanisms are still unknown. The aim of this study was to explore the change of the sympathoexcitatory response induced by chronic lead exposure via the P2X4 receptor in the stellate ganglion (SG). Rats were given lead acetate through drinking water freely at doses of 0 g/L (control group), 0.5 g/L (low lead group), and 2 g/L (high lead group) for 1 year. Our results demonstrated that lead exposure caused autonomic nervous dysfunction, including blood pressure and heart rate increased and heart rate variability (HRV) decreased. Western blotting results indicated that after lead exposure, the protein expression levels in the SG of P2X4 receptor, IL-1β and Cx43 were up-regulated, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) was activated. Real-time PCR results showed that the mRNA expression of P2X4 receptor in the SG was higher in lead exposure group than that in the control group. Double-labeled immunofluorescence results showed that P2X4 receptor was co-expressed with glutamine synthetase (GS), the marker of satellite glial cells (SGCs). These changes were positively correlated with the dose of lead exposure. The up-regulated expression of P2X4 receptor in SGCs of the SG maybe enhance the sympathoexcitatory response induced by chronic lead exposure.

Neurotransmitter Switching Coupled to β-Adrenergic Signaling in Sympathetic Neurons in Prehypertensive States

Single or combinatorial administration of β-blockers is a mainstay treatment strategy for conditions caused by sympathetic overactivity. Conventional wisdom suggests that the main beneficial effect of β-blockers includes resensitization and restoration of β1-adrenergic signaling pathways in the myocardium, improvements in cardiomyocyte contractility, and reversal of ventricular sensitization. However, emerging evidence indicates that another beneficial effect of β-blockers in disease may reside in sympathetic neurons. We investigated whether β-adrenoceptors are present on postganglionic sympathetic neurons and facilitate neurotransmission in a feed-forward manner. Using a combination of immunocytochemistry, RNA sequencing, Förster resonance energy transfer, and intracellular Ca2+ imaging, we demonstrate the presence of β-adrenoceptors on presynaptic sympathetic neurons in both human and rat stellate ganglia. In diseased neurons from the prehypertensive rat, there was enhanced β-adrenoceptor-mediated signaling predominantly via β2-adrenoceptor activation. Moreover, in human and rat neurons, we identified the presence of the epinephrine-synthesizing enzyme PNMT (phenylethanolamine-N-methyltransferase). Using high-pressure liquid chromatography with electrochemical detection, we measured greater epinephrine content and evoked release from the prehypertensive rat cardiac-stellate ganglia. We conclude that neurotransmitter switching resulting in enhanced epinephrine release, may provide presynaptic positive feedback on β-adrenoceptors to promote further release, that leads to greater postsynaptic excitability in disease, before increases in arterial blood pressure. Targeting neuronal β-adrenoceptor downstream signaling could provide therapeutic opportunity to minimize end-organ damage caused by sympathetic overactivity.

Stellate ganglion block attenuates chronic stress induced depression in rats

Background

Stress is a significant factor in the etiology of depression. Stellate ganglion block (SGB) has been shown to maintain the stability of the autonomic system and to affect the neuroendocrine system, including the hypothalamic–pituitary–adrenal (HPA) axis. The objective of this study was to determine the antidepressant-like effects of SGB on the autonomic system and the HPA axis, apoptosis-related proteins, related spatial learning and memory impairment, and sensorimotor dysfunction.

Methods

Forty-eight Sprague Dawley rats were assigned to four experimental groups: control + saline (sham group), control + SGB (SGB group), unpredictable chronic mild stress (UCMS) + saline (UCMS group), and UCMS + SGB (UCSG group). Stress-induced effects and the function of SGB were assessed using measures of body weight, coat state, sucrose consumption, and behavior in open-field and Y-maze tests. Neuronal damage was assessed histologically using the hematoxylin-eosin (HE) staining method, while western blotting was used to investigate changes in the expression of apoptosis-related proteins. Plasma corticotropin-releasing factor (CRF), adrenocorticotropic hormone (ACTH), corticosterone (CORT), noradrenaline and adrenaline were measured to evaluate changes in the autonomic system and HPA axis.

Results

SGB treatment significantly improved sensorimotor dysfunction and spatial learning and memory impairment following UCMS. Moreover, UCMS significantly decreased body weight, sucrose preference and anti-apoptotic protein Bcl-2, and increased scores on measures of coat state, adrenal gland weight, levels of CORT, CRF, ACTH, noradrenaline and adrenaline, as well as increased neuronal loss, cell shrinkage, nuclear condensation, and the pro-apoptotic protein Bax. These symptoms were attenuated by treatment with SGB.

Conclusions

These findings suggest that SGB can attenuate depression-like behaviors induced by chronic stress. These protective effects appear to be due to an anti-apoptotic mechanism of two stress pathways–the autonomic system and the HPA axis.

Efficacy and safety of stellate ganglion block in chronic ulcerative colitis

AIM

To investigate the efficacy and safety of stellate ganglion block for the treatment of patients with chronic ulcerative colitis.

METHODS

A total of 120 randomly selected patients with chronic ulcerative colitis treated in Cangzhou Central Hospital from January 2014 to January 2016 were included in this study. These patients were divided into two groups: control group (n = 30), patients received oral sulfasalazine treatment; experimental group (n = 90), patients received stellate ganglion block treatment. Clinical symptoms and disease activity in these two groups were compared before and after treatment using endoscopy. Blood was collected from patients on day 0, 10, 20 and 30 after treatment. Enzyme-linked immunosorbent assay was performed to determine interleukin-8 (IL-8) level. The changes in IL-8 level post-treatment in the two groups were compared using repeated measures analysis of variance.

RESULTS

After treatment, clinical symptoms and disease activity were shown to be alleviated by endoscopy in both the control and experimental groups. However, patients in the control group did not have obvious abdominal pain relief. In addition, the degree of pain relief in the experimental group was statistically better than that in the control group (P < 0.05). Ten days after treatment, IL-8 level was found to be significantly lower in the experimental group than in the control group, and the difference was statistically significant (P < 0.05). In addition, adverse events were significantly higher in the control group than in the experimental group, and the difference was statistically significant (χ² = 33.215, P = 0.000).

CONCLUSION

The application of stellate ganglion block effectively improves treatment efficacy in chronic ulcerative colitis, relieves clinical symptoms in patients, and reduces the level of inflammatory factors. Furthermore, this approach also had a positive impact on the disease to a certain extent.

Chemical ablation of stellate ganglion for head and neck cancer pain

We present a case of patient with orofacial cancer having pain on one side of face affecting her ability to speak, chew, swallow and sleep leading to emotional and behavioral deterioration. A diagnostic stellate ganglion block was performed followed by chemical neurolysis using phenol under ultrasound guidance, to prevent complications due to inadvertent spread of drug. Her pain scores decreased drastically, she was able to chew and swallow. Weighing the risk of permanent Horner's syndrome or motor paralysis with benefit of improvement in basic functioning of debilitated patients chemical neurolysis of stellate ganglion can be performed with advanced imaging modalities.

[Clinical observation of dysantonomia treated with transcutaneous electrical stimulation at Renying (ST 9) combined with stellate ganglion block]

OBJECTIVE

To compare the clinical efficacy difference in dysantonomia between transcutaneous electrical stimulation at Renying(ST 9) combined with stellate ganglion block(SGB) and simple SGB.

METHODS

Sixty patients in accord with the diagnostic criteria of dysantonomia were randomly divided into two groups,30 cases in each group. In the observation group,transcutaneous electrical stimulation at Renying(ST 9) combined with SGB were adopted; in the control group,simple SGB was applied. In the two groups, treatment was used three times a week,and nine treatments were considered as one course. There was an interval of one week between courses,and two courses were treated. Total seven weeks were required. Scores were evaluated according to subjective symptoms before treatment,one month and three months after treatment in the two groups.

RESULTS

The scores of subjective symptoms were not statistically different before treatment in the two groups(P>0. 05). The scores of subjective symptoms one month and three months after treatment were all lower than those before treatment(all P< 0. 01), and subjective symptoms scores in the observation group were lower than those in the control group(both P<0. 01).

CONCLUSION

Transcutaneous electrical stimulation at Renying(ST 9) combined with SGB could obviously enhance the clinical effects for dysantonomia, and the control and improvement for clinical symptoms are apparently superior to simple SGB.

Effects of stellate ganglion block on sedation as assessed by bispectral index in normal healthy volunteers

BACKGROUND

The sympathetic nervous system plays an important role in the arousal response. Recently, the stellate ganglion block (SGB) was found to effectively treat anxiety and night awakening in humans and decrease electroencephalogram (EEG) indices of arousal responses in rat. But, the role of the sympathetic block in human arousal responses has not yet been studied.

OBJECTIVE

We performed this prospective, double-blinded, controlled volunteer study to investigate the sedative effects and bispectral index (BIS) changes of SGB.

STUDY DESIGN

A randomized, double-blind trial.

SETTING

Single academic medical center.

METHODS

This study was approved by the Ethics Committee of Kyungpook National University Hospital (ref: KNUH-10-1081) and registered with CRiS (Clinical Research Information Service, http://cris.cdc.go.kr, ref: KCT0000036, 2010. 9.24). Twenty healthy volunteers were enrolled in this study. The volunteers were randomly assigned to one of 2 groups: the SGB group (n = 10) and the sham group (n =10). Volunteers in SGB group received SGB and volunteers in the sham group received a sham procedure. BIS value, heart rate, and blood pressure were measured before and 5, 10, 20, and 30 minutes after the procedure. Observer's Assessment of Alertness/Sedation (OAA/S) scores were assessed before and 10 and 30 minutes after the intervention.

RESULTS

In the SGB group, BIS values and OAA/S scores significantly decreased after the intervention as compared to baseline (P < 0.05). The values were also significantly decreased in the SGB group when compared to the values in sham group after the intervention (P < 0.05). There was a significant change of mean blood pressure 10 to 30 minutes after SGB (P < 0.05). There were no differences in heart rate during study period between groups.

LIMITATIONS

This study is limited by a relatively small sample size.

CONCLUSIONS

This study showed that SGB has a sedative effect in normal healthy volunteers, as evidenced by decreased OAA/S scores and BIS values.

Stellate Ganglion Block, Compared With Xenon Light Irradiation, Is a More Effective Treatment of Neurosensory Deficits Resulting From Orthognathic Surgery, as Measured by Current Perception Threshold

PURPOSE

The aim of this study was to evaluate the relative effectiveness of stellate ganglion blockade (SGB) versus xenon light irradiation (XLI) for the treatment of neurosensory deficits resulting from orthognathic surgery as determined by a comparison of prospective measurements of electrical current perception thresholds (CPTs) and ranged CPTs (R-CPTs).

MATERIALS AND METHODS

CPT and R-CPT in the mental foramen area were measured during electrical stimulation at 98 different sites on the body in patients who had undergone orthognathic surgery. After surgery, patients were assigned to the SGB group or the XLI group. CPT and R-CPT of the 2 groups were measured at stimulation frequencies of 2,000, 250, and 5 Hz before surgery, 1 week after surgery, and after 10 treatment sessions. Furthermore, the influence of surgical factors, such as genioplasty and a surgically exposed inferior alveolar nerve (IAN), was examined in the 2 groups.

RESULTS

Patients' CPT and R-CPT values indicated a considerable amount of sensory disturbance in most cases after surgery. The change in magnitude of all CPT and R-CPT values for the SGB group decreased considerably compared with that for the XLI group after treatment. There was no correlation between CPT or R-CPT values and surgical factors (eg, genioplasty and exposure of the IAN).

CONCLUSION

SGB of the IAN could be an effective method for treating neurosensory deficits after orthognathic surgery on the IAN.

Stellate ganglion block used to treat symptoms associated with combat-related post-traumatic stress disorder: a case series of 166 patients

OBJECTIVE

Report the successful use of stellate ganglion blocks (SGBs) in 166 active duty service members with multiple combat deployments experiencing anxiety symptoms associated with post-traumatic stress disorder (PTSD).

BACKGROUND

Successful treatment of PTSD symptoms with SGB has been reported previously. This is the largest published case series evaluating SGB with a minimum of 3 months follow-up.

METHODS

Following clinical interview including administration of the PTSD Checklist (PCL), 166 service members with symptoms of PTSD elected to receive a SGB. All patients received a SGB on the right side at the level of the sixth cervical vertebrae (C6). The PCL was administered the day before treatment to establish a baseline, repeated 1 week later, and then monthly out to 3 months. A positive response was considered to be an improvement in the PCL score by 10 or greater points. Follow-up PCL scores from 3 to 6 months were obtained and analyzed for 166 patients.

RESULTS

In a military population with multiple combat deployments, over 70% of the patients treated had a clinically significant improvement in their PCL score which persisted beyond 3 to 6 months postprocedure.

CONCLUSION

Selective blockade of the right cervical sympathetic chain at the C6 level is a safe and minimally invasive procedure that may provide durable relief from anxiety symptoms associated with PTSD.

Stellate ganglion block: a therapeutic alternative for patients with medically refractory inappropriate sinus tachycardia?

Inappropriate sinus tachycardia (IST) is a clinical syndrome characterized by presence of non-paroxysmal tachyarrhythmia manifesting with increased resting heart rate and exaggerated or persistent response to exercise or position. When IST is intolerable and medically refractory, invasive therapies such as sinus node modification or atrioventricular node ablation with placement of permanent pacemaker are tried to control symptoms. We present a 34 year old patient with symptomatic IST unresponsive to medical therapy who underwent anesthetic block of the right and left stellate ganglia. At four month follow up the patient demonstrated sustained improvement in heart rate and reported freedom from previous symptoms.

Stellate ganglion block may prevent the development of neurogenic pulmonary edema and improve the outcome

Neurogenic pulmonary edema (NPE) is an acute and serious complication after a central nervous system insult with high mortality. The pronounced activation of sympathetic nervous system and the release of vasoactive substances are necessary prerequisites for the development of NPE. We introduce a hypothesis that stellate ganglion block (SGB) may prevent NPE development on the basis of the inhibition of sympathetic overactivation, reduction of the concentration of norepinephrine and attenuation of baroreflex sensitivity, and improve the outcome by improving cerebral blood flow and pulmonary circulation and maintaining cardiovascular stability. In clinical practice, the guidance technique and close monitoring might guarantee the safety of SGB. If our hypothesis is supported by further experiments, this may open a new doorway for the treatment of NPE.

Effect of early stellate ganglion blockade for facial pain from acute herpes zoster and incidence of postherpetic neuralgia

BACKGROUND

The incidence of postherpetic neuralgia (PHN) has been reported to be 25% among those over the age of 50 years treated with antiviral medication. The role of sympathetic block in its prevention remains questionable.

OBJECTIVES

The aim of this study is to determine whether early stellate ganglion blockade for acute herpes zoster of the face will reduce the intensity and duration of acute herpetic pain, and if the blockade has the potential to prevent or reduce the incidence and/or severity of PHN.

STUDY DESIGN

Randomized, controlled, double blind trial.

SETTING

Hospital, outpatient setting.

METHODS

Sixty-four patients over 50 years were assigned to receive a stellate ganglion block using either 8 mL saline (Group 1) or 6 mL bupivacaine 0.125% and 8 mg dexamethasone in a total volume of 8 mL (Group 2). All procedures were performed under fluoroscopy. All patients received pregabalin in a dose of 150 mg twice daily. Acetaminophen was available as needed. Pain assessment using the visual analog scale and amount of analgesic being taken was measured at the initial visit (basal), weekly for 6 weeks after the procedure and after 2, 3, and 6 months. Once a patient reported mild pain during the trial, pregabalin was tapered by 75 mg every other day; the patients who succeeded in this step were recorded in each group. The time of complete resolution of pain and incidence of persistent postherpetic pain was reported. Each patient's satisfaction was evaluated.

RESULTS

There was a significantly shorter duration of pain noticed in Group 2 (P = 0.002). A significantly lower incidence of PHN was encountered in Group 2 after 3 months (P = 0.043) and 6 months (P = 0.035). Significantly more patient satisfaction was reported in Group 2 after 3 and 6 months. By the fourth week, 29 patients in Group 2 reported no pain. Two patients reported mild pain after 3 months which was resolved by the sixth month. In Group 1, 22 patients reported no pain by the sixth week and 8 patients reported moderate pain after 2 and 3 months; by the sixth month, 4 out of those 8 patients showed spontaneous remission of pain. There was a significant reduction in the total doses of pregabalin and acetaminophen in Group 2 (P < 0.001). No serious adverse effects were reported during the study period.

LIMITATIONS

The sample size was determined using the incidence of PHN (chronic pain) as a main hypothesis. Meanwhile, this study determined the incidence of acute pain as well, which may lead to bias to the results of acute pain.

CONCLUSION

Early stellate ganglion blockade, in combination with an antiviral agent, is a very effective treatment modality; it dramatically decreases the intensity of acute pain and shortens its duration and reduces the incidence of postherpetic neuralgia.

Buprenorphine injection to the stellate ganglion in the treatment of upper body chronic pain syndromes

BACKGROUND

The injection of low dose buprenorphine to the sympathetic ganglia, termed "GLOA", Ganglionide Local Opioid Analgesia, is used to treat chronic pain in several European centres. It is not known whether the clinically observed GLOA effect in chronic pain syndromes is due to a specific effect of buprenorphine at the ganglia. We assessed whether GLOA, plus intramuscular saline, was more efficacious than the reverse, saline injection to the stellate plus intramuscular buprenorphine, termed SSB.

METHODS

We devised a randomized, double-blinded, controlled crossover trial to treat patients with chronic upper body pain syndromes. Patients first received either GLOA or SSB. Pain was assessed using pain diaries both before injection and over the first 8h and 6days afterwards, and was expressed as relative pain intensity post versus pre-injection pain.

RESULTS

The median relative pain intensity after injections did not differ between GLOA and SSB. Four patients reported a low, <50%, relative pain level over the first 8h after SSB only. Four patients did not complete the trial and were excluded. One patient with cardiomyopathy became acutely diaphoretic and fatigued after GLOA, his vital signs however remained stable.

CONCLUSIONS

We failed to show a superiority of GLOA over SSB. Our results suggest it unlikely that the clinically observed effect after a single GLOA injection is due to a specific action of buprenorphine at the stellate ganglion. The efficacy of GLOA is hereby questioned. The use of GLOA in patients with cardiomyopathy should be cautioned.

TRIAL REGISTRATION

ISRCTN59287260; http://www.controlled-trials.com/

Evaluation of effectiveness of stellate ganglion block (SGB) treatment of sudden hearing loss

CONCLUSION

A stellate ganglion block (SGB) based on the goal of improving internal ear circulatory disturbance appears to be beneficial for the treatment of sudden hearing loss.

OBJECTIVES

To evaluate the effectiveness of SGB for sudden hearing loss.

METHODS

This retrospective study reviewed the medical records of 49 patients who received SGBs and 496 patients who received only conservative therapy, primarily with systemic steroids, for treatment of sudden hearing loss. Propensity scores were used in pairwise matching of these patients to avoid selection biases between the two treatment modalities.

RESULTS

Propensity score matching yielded 48 pairs. The mean therapeutic effect of the SGB was calculated to be 0.40 ± 0.20 (mean ± standard error, p = 0.051).

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

PURPOSE

Hot flashes are a significant problem in breast cancer patients, especially because the most effective therapy, estrogen, is often contraindicated. Based on recent pilot data from a single group supporting the use of a stellate ganglion block for the treatment of hot flashes, the present pilot trial was done to further evaluate the hypothesis that a stellate ganglion block may be a safe and effective therapy for hot flashes.

METHODS

In women with breast cancer who had hot flashes, a stellate ganglion block was performed after 1 week of baseline hot flash data collection. The main efficacy measures were the changes from baseline in hot flash frequency and hot flash score during the 6th week.

RESULTS

Ten patients were enrolled between 4/23/2009 and 7/10/2009; eight patients were evaluable. After the stellate ganglion block, the mean hot flash frequency and score decreased from baseline values by over 60% during some of the post-treatment weeks. The mean hot flash frequency and score at week 6 decreased from baseline values by 44% and 45%, respectively. There were no significant adverse events clearly attributed to the stellate ganglion blocks.

CONCLUSIONS

The results of this pilot trial support that stellate ganglion blocks may be a helpful therapy for hot flashes. A prospective placebo-controlled clinical trial should be done to more definitively determine this contention.

Serial stellate ganglion blocks for intractable postherpetic itching in a pediatric patient: a case report

BACKGROUND

While intractable itching may be rarely associated with postherpetic neuralgia, it can have catastrophic complications if present.

METHOD

We highlight a severe case of postherpetic itching in a 10-year-old male with Fanconi's and aplastic anemia, refractory to conventional treatments and requiring intravenous sedation.

RESULTS

Our use of 3 sequential stellate ganglion blocks with 5.5 mL of 0.25% bupivacaine provided significant improvement of the symptoms for 4 months after the last procedure.

CONCLUSION

Although further evaluation is needed, we feel that novel use of sympathetic blockade may provide treatment for intractable itching. Highlighted is the possible influence of the sympathetic system in the pathophysiology of postherpetic itch.

IMPLICATION

The use of serial stellate ganglion blocks may be a treatment option for patients with intractable itching and postherpertic neuralgia of the neck and arm region. This technique may lead to more permanent solutions such as pulse radiofrequency lesion or chemical neurolysis of sympathetic ganglions for postherpetic itch.

Prostaglandin E1 in combination with hyperbaric oxygen therapy for idiopathic sudden sensorineural hearing loss

CONCLUSIONS

Prostaglandin E1 (PGE1) is less effective than stellate ganglion block (SGB) in the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) patients with severe hearing losses when used together with hyperbaric oxygen (HBO) therapy. In contrast with the systemic action of intravenous PGE1, SGB's localized vasodilating action may explain its advantage over intravenous PGE1.

OBJECTIVES

To investigate the effect of PGE1 plus HBO therapy on ISSNHL in comparison with that of SGB plus HBO therapy.

PATIENTS AND METHODS

We retrospectively analyzed 205 consecutive patients with ISSNHL (hearing levels > or = 40 dB; time from the onset of hearing loss to the start of treatment < or = 30 days). Ninety-five patients underwent intravenous PGE1 plus HBO therapy (PG group) and 110 underwent SGB plus HBO therapy (SGB group). Hearing recovery was evaluated by grade assessment and by hearing improvement compared to that in the unaffected contralateral ear.

RESULTS

The overall hearing outcome was not statistically different between the two groups. For patients with initial hearing levels <80 dB, the groups had roughly equivalent hearing outcomes, whereas in patients with initial hearing levels > or = 80 dB, the hearing improvement rate was significantly higher in the SGB group than in the PG group (53.0 +/- 5.0% vs 35.3 +/- 6.8%; p <0.05).

Ultrasound-guided stellate ganglion block successfully prevented esophageal puncture

Stellate ganglion block is utilized in the diagnosis and management of various vascular disorders and sympathetically mediated pain in the upper extremity, head and neck. The cervical sympathetic chain is composed of superior, middle, intermediate, and inferior cervical ganglia. However, in approximately 80% of the population, the inferior cervical ganglion is fused with the first thoracic ganglion, forming the stellate ganglion also known as cervicothoracic ganglion. The stellate ganglion lies medial to the scalene muscles, lateral to the longus coli muscle, esophagus and trachea along with the recurrent laryngeal nerve, anterior to the transverse processes and prevertebral fascia, superior to the subclavian artery and the posterior aspect of the plura, and posterior to the vertebral vessels at C7 level. Consequently, inadvertent placement of the needle into the vertebral artery, thyroid, neural tissues, or esophagus can occur with the fluoroscopic or blind approach. While fluoroscopy is a reliable method for identifying boney structures, ultrasound may identify the vertebral vessels, thyroid gland and vessels, longus coli muscles, nerve roots and the esophagus. Thus, ultrasound may prevent inadvertent placement of the needle into these structures as might happen with either the blind technique or fluoroscopic technique. A patient with complex regional pain syndrome type I of the left upper extremity was scheduled for left stellate ganglion block with the anterior paratracheal approach under fluoroscopy. Real-time ultrasound imaging prevented inadvertent injury to the esophagus as well as the thyroid gland and vessels. Ultrasound-guided block may improve patient safety by avoiding the soft tissue structures in the needle path that can't be readily seen by fluoroscopy. This may be particularly useful in the patient with asymptomatic pharyngoesophageal diverticulum (Zenker diverticulum).

Sympathetically maintained pain presenting first as temporomandibular disorder, then as parotid dysfunction

Complex regional pain syndrome (CRPS) is a chronic condition that usually affects extremities, such as the arms or legs. It is characterized by intense pain, swelling, redness, hypersensitivity in a region not defined by a single peripheral nerve and additional sudomotor effects, such as excessive sweating. The clinical criteria for the diagnosis of sympathetically maintained pain as outlined by the International Association for the Study of Pain include: Onset following an initiating noxious event (CRPS-type I) or nerve injury (CRPS-type II). Spontaneous allodynia that is not limited to peripheral nerve distribution and is not proportionate to the inciting event; abnormal sudomotor activity, skin blood flow abnormality, edema, other autonomic symptoms; and exclusion of other conditions that may otherwise contribute to the extent of the symptoms. Only 13 cases of CRPS involving sympathetically maintained pain in the head and neck region have been described, and all reported trauma as the identifiable etiologic factor. The case presented here is another occurrence of sympathetically maintained pain in the head and neck region, but without nerve injury as a clear initiating factor.

Pre-emptive stellate ganglion block increases the patency of radial artery grafts in coronary artery bypass surgery

BACKGROUND

We evaluated the role of pre-emptive stellate ganglion block (SGB) in preventing radial artery spasm and increasing radial artery graft patency in patients undergoing off-pump coronary artery bypass surgery.

METHODS

In this prospective randomized study, 100 patients were divided into two equal groups (n= 50). In group A, SGB was achieved using 10 ml of ropivacaine and, in group B, SGB was not performed. Radial artery blood flow was measured pre- and intra-operatively. Post-operative clinical determinants (S-T segment elevation, use of inotropic agents, incidence of atrial fibrillation) were recorded. Early coronary angiography was performed.

RESULTS

According to blood flowmeter measurements, the radial artery blood flow was significantly increased in patients with SGB. The incidence of atrial fibrillation, the need for inotropic agents and S-T segment elevation were all decreased in the SGB group. Angiographic intervention revealed that the incidence of graft spasm was also lower in the SGB group.

CONCLUSION

Pre-emptive SGB is an effective method for increasing radial artery blood flow and preventing radial artery spasm. Complications related to radial artery spasm may be decreased and patients may have a more comfortable post-operative period with this method.

Epinephrine in Local Anesthetic Cancels Increase in Tongue Mucosal Blood Flow after Stellate Ganglion Block in Rabbit

The goal of this study was to compare oral mucosal blood flow and duration of anesthetic action after stellate ganglion block (SGB) using lidocaine, with or without epinephrine, and discuss the effect of epinephrine on SGB. Duration of anesthetic action was defined as elapsed time from finish of injection to recovery of common carotid blood flow (CCBF) to within+/-5% of respective control value. Male Japan White rabbits were anesthetized with isoflurane and mechanically ventilated. Common carotid blood flow and tongue mucosal tissue blood flow (TMBF) were measured with an ultrasound flowmeter and laser Doppler flowmeter, respectively. End-tidal partial pressure of carbon dioxide (ETCO(2)) and hemodynamic variables were continuously monitored, including heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). For SGB, the tip of the needle was placed on the left transverse process of the cervical vertebra, 1-2 mm caudal to the cricoid cartilage. Either 0.1 ml of 1% lidocaine (Group L) or 1% lidocaine containing 10 mug/ml epinephrine (Group LE) was injected for SGB. There were no differences in values at immediately before SGB and at the time when maximal change in CCBF was observed after SGB for ETCO(2), HR, SBP, DBP or MAP in either group. CCBF showed a significant increase in Group L after SGB. In contrast, CCBF only showed a slight increase in Group LE. TMBF showed a significant increase in Group L after SGB, but not in Group LE. No differences in time required for maximal effect were observed between the two groups. In contrast, duration of anesthetic action in Group LE was significantly longer than that in Group L. Addition of epinephrine to local anesthetic solutions is not suitable for SGB, as it may not facilitate an increase in tissue blood flow, which is the primary objective of SGB.

Comparison between neurotropin and mepivacaine for stellate ganglion injection

Neurotropin, a nonproteinaceous extract from the inflamed skin of rabbits inoculated with vaccinia virus, is reported to decrease pain effectively when used for stellate ganglion (SG) injection. We compared the effects of neurotropin SG injection with those of mepivacaine on pain relief, as well as comparing the side effects. One hundred and eighty-eight SG injections in 15 patients (5 with postherpetic neuralgia and 10 with sudden deafness) were performed either with 1% mepivacaine 6 ml or with neurotropin 3 ml combined with saline 3 ml in turn. Fifteen min before and after the injection, the pain score, according to a visual analog scale (VAS; only in patients with postherpetic neuralgia); blood pressure; and heart rate were checked, and the number of procedures with Horner's sign was determined. VAS scores decreased significantly with both injections. Horner's sign was observed on the block side in all procedures with the mepivacaine injection, but it was seen in only 48 procedures with the neurotropin injection. Blood pressure and heart rate did not change. In conclusion, the SG injection of neurotropin decreased the VAS score in postherpetic neuralgia to the same extent as mepivacaine. The incidence of Horner's sign was significantly lower with neurotropin than with mepivacaine.

Ganglionic local opioid application (GLOA) for treatment of chronic headache and facial pain

OBJECTIVE

This report describes the effects of ganglionic local opioid application (GLOA) in patients with chronic headache and persistent idiopathic facial pain.

CASE REPORT

We present 2 patients with chronic headaches and 1 patient with persistent idiopathic facial pain who were refractory to medical treatment. These patients responded well to a series of ganglionic local opioid applications (GLOAs) by administration of buprenorphine. The beneficial effect of GLOA was manifested by a decrease in pain intensity, reduction of pain medications, and improvement in quality of life.

CONCLUSIONS

These results support the theory of sympathetically mediated pain in the head and face, the presence of opioid receptors on the sympathetic ganglia, and a possible beneficial role of opioids in modulation of this process. To our knowledge, this case series is the first case series in the English literature of the use of GLOA at the stellate ganglion for head-and-face pain.

Efficacy of Stellate Ganglion Blockade for the Management of Type 1 Complex Regional Pain Syndrome

INTRODUCTION

The purpose of this study was to examine the efficacy of stellate ganglion blockade (SGB) in patients with complex regional pain syndromes (CRPS I) of their hands.

METHODS

After IRB approval and patient informed consent, 25 subjects, with a clinical diagnosis of CRPS I of one hand as defined by the International Association for the Study of Pain (IASP) criteria, had three SGB's performed at weekly intervals. Laser Doppler fluxmetric hand perfusion studies were performed on the normal and CRPS I hands pre- and post-SGB therapy. No patient was included in this study if they used tobacco products or any medication or substance that could affect sympathetic function. The appropriate parametric and nonparametric data analyses were performed and a p value <0.05 was used to reject the null hypothesis.

RESULTS

Symptom onset of CRPS I until the initiation of SGB therapy ranged between 3 to 34 weeks. Following the SGB series, patient pain relief was as follows: group I, 10/25 (40%) had complete symptom relief; group II, 9/25 (36%) had partial relief and group III, 6/25 (24%) had no relief. The duration of symptoms until SGB therapy was: group I, 4.6 +/- 1.8 weeks, group II, 11.9 +/- 1.6 weeks and group III, 35.8 +/- 27 weeks. Compared with the normal control hand, the skin perfusion in the CRPS I affected hand was greater in group I and decreased in groups II and III.

DISCUSSION

The results of our study demonstrate that an inverse relationship exists between hand perfusion and the duration of symptoms of CRPS I. On the other hand, a positive correlation exists between SGB efficacy and how soon SGB therapy is initiated. A duration of symptoms greater than 16 weeks before the initial SGB and/or a decrease in skin perfusion of 22% between the normal and affected hands adversely affects the efficacy of SGB therapy.

Structural domains involved in the regulation of transmitter release by synapsins

Synapsins are a family of neuron-specific phosphoproteins that regulate neurotransmitter release by associating with synaptic vesicles. Synapsins consist of a series of conserved and variable structural domains of unknown function. We performed a systematic structure-function analysis of the various domains of synapsin by assessing the actions of synapsin fragments on neurotransmitter release, presynaptic ultrastructure, and the biochemical interactions of synapsin. Injecting a peptide derived from domain A into the squid giant presynaptic terminal inhibited neurotransmitter release in a phosphorylation-dependent manner. This peptide had no effect on vesicle pool size, synaptic depression, or transmitter release kinetics. In contrast, a peptide fragment from domain C reduced the number of synaptic vesicles in the periphery of the active zone and increased the rate and extent of synaptic depression. This peptide also slowed the kinetics of neurotransmitter release without affecting the number of docked vesicles. The domain C peptide, as well as another peptide from domain E that is known to have identical effects on vesicle pool size and release kinetics, both specifically interfered with the binding of synapsins to actin but not with the binding of synapsins to synaptic vesicles. This suggests that both peptides interfere with release by preventing interactions of synapsins with actin. Thus, interactions of domains C and E with the actin cytoskeleton may allow synapsins to perform two roles in regulating release, whereas domain A has an actin-independent function that regulates transmitter release in a phosphorylation-sensitive manner.

Stellate ganglion blockade provides relief from menopausal hot flashes: a case report series

OBJECTIVE

To investigate whether standard C6 stellate ganglion blockade (SGB) might provide relief from hot flashes associated with menopause.

METHODS

Six women were referred for severe menopausal hot flashes and elected to undergo standard SGB (5 ml 0.375% Marcaine, Abbott Labs, Abbott Park, IL) to evaluate a novel intervention for hot flash relief. Hot flashes were assessed by self-reporting before and after stellate ganglion block.

RESULTS

Initial SGB (SGB1) was successful in all 6 subjects, as evidenced by a positive Horner's syndrome and anhydrosis. Successful SGB caused complete alleviation of hot flashes for times ranging from 2 to 5 weeks. Patients returned for follow-up SGB after mild hot flashes returned. A second SGB produced additional asymptomatic periods of relief ranging from 4 to 18 weeks. In each case, repeated block provided hot flash relief equal to or greater than that of the initial block. Two patients who submitted for a third SGB reported 15 and 48 weeks of relief.

CONCLUSION

Successful SGB appears to be related to relief of hot flashes. Repeat SGB results in efficacious multiple week relief of severe hot flashes associated with menopause.

Differential β-adrenoceptor expression induced by nerve growth factor infusion into the canine right and left stellate ganglia

BACKGROUND

Nerve growth factor (NGF) infusion into the right stellate ganglion (RSG) is antiarrhythmic, while NGF infusion into the left stellate ganglion (LSG) is proarrhythmic in dogs with myocardial infarction (MI) and complete atrioventricular block (CAVB). This functional asymmetry suggests differential neural remodeling.

OBJECTIVES

To test the hypothesis that NGF infusion into the RSG and the LSG can lead to differential beta-adrenoceptor (beta-AR) expression in dogs with MI and CAVB.

METHODS AND RESULTS

We performed immunostaining to quantify beta(1)-AR and beta(3)-AR immunoreactivity in six dogs with MI and CAVB, nine dogs with MI, CAVB, and NGF infusion to the LSG, six dogs with MI, CAVB, and NGF infusion to the RSG, and six normal dogs. There was significantly increased beta(3)-AR immunoreactivity in dogs with NGF infusion into the LSG and significantly decreased beta(3)-AR immunoreactivity in dogs with NGF infusion into the RSG compared with controls and with the MI and CAVB group. There were no significant differences in beta(1)-AR immunoreactivity among these four groups. To determine protein and mRNA expression of beta-ARs, we created MI and CAVB and infused NGF into the LSG in six additional dogs. The noninfarcted left ventricle free wall was harvested 1 week later. The protein level and receptor density of beta(3)-AR (but not beta(1)- or beta(2)-AR) significantly increased in these six dogs compared with normal controls.

CONCLUSIONS

We conclude that NGF infusion into the RSG and the LSG in dogs with MI and CAVB induced differential beta(3)-AR expression in the left ventricular myocardium.

Blunted functional responses to pre- and postjunctional sympathetic stimulation in hibernating myocardium

Regional reductions in norepinephrine-tracer uptake are found in pigs with hibernating myocardium. Clinical studies would suggest that this is evidence for denervation; however, the functional responses to sympathetic stimulation have not been evaluated, and our previous studies with beta-adrenergic stimulation have not suggested denervation hypersensitivity. Therefore, pigs were chronically instrumented to produce hibernating myocardium characterized by chronic regional dysfunction and histological viability. Open-chest studies were performed to determine changes in regional function in response to both pre- and postjunctional stimulation. Regional segment shortening was reduced at rest in hibernating myocardium compared with controls (13 +/- 3% vs. 27 +/- 3%, P = 0.004). During stellate ganglion stimulation, regional function increased in both groups of animals (P = 0.008 vs. baseline), but the increase in hibernating myocardium was blunted compared with controls (Delta%, 3 +/- 2% vs. 8 +/- 3%, P = 0.04). Similar results occurred with intracoronary tyramine (10 mug/kg). Functional improvement during intravenous epinephrine infusion (0.35 mug.kg(-1).min(-1)) was also blunted in hibernating myocardium compared with controls (Delta%, 7 +/- 1% vs. 15 +/- 2%, P = 0.04). Even when the improvement in function was expressed relative to the reduced baseline, there was no evidence for catecholamine-mediated hypersensitivity in hibernating myocardium. We therefore conclude that functional responses to both pre- and postjunctional sympathetic stimulation are blunted in pigs with hibernating myocardium. In contrast to previous studies of infarcted, denervated, and acutely stunned myocardium, there is no catecholamine-induced hypersensitivity in hibernating myocardium. These data suggest a downregulation in functional responses to stimulation that would protect hibernating myocardium from demand-induced ischemia at the expense of contractile reserve during sympathetic stimulation.

Effects of head-up tilt after stellate ganglion block on QT interval and QT dispersion

BACKGROUND AND OBJECTIVES

The aim of this study is to examine the effects of head-up tilt (70 degrees ) 30 minutes after right or left stellate ganglion block (SGB) on RR interval, QT interval, the rate-corrected QT (QTc) interval, QT dispersion (QTD), and the rate-corrected QT dispersion (QTcD) using computerized measurement.

METHODS

Ten healthy volunteers underwent both right and left SGBs using 7 mL 1% mepivacaine with a 7-day interval between the two blocks. A 12-lead electrocardiogram was monitored to measure parameters before SGB; 30 minutes after SGB (before head-up tilt); and immediately, 5, 10, and 15 minutes after head-up tilt.

RESULTS

Right SGB induced significant increases in QT interval, QTc interval, QTD, and QTcD from 30 minutes after the block through 15 minutes after head-up tilt. There were significant increases of QT interval, QTc interval, and QTcD between before and immediately after head-up tilt in right SGB. Left SGB induced significant decreases of QT interval and QTc interval from 30 minutes after SGB through 15 minutes after head-up tilt. Left SGB also induced a significant decrease of QTD from immediately after through 10 minutes after head-up tilt.

CONCLUSIONS

Significant increases of QT interval, QTc interval, and QTcD, which are associated with an increased risk of ventricular arrhythmias and cardiac events, occur immediately after head-up tilt in right SGB. However, head-up tilt does not induce increases of QT interval, QTc interval, QTD, and QTcD in left SGB.

Age-related differences in the response of blood stroke volume to stimulation of the sympathetic ganglion in rats with β-adrenoceptor blockade

Blood stroke volume in rats aging 21 and 56 days decreased during beta-adrenoceptor blockade with propranolol, but increased again by the 15th minute after treatment. Suprathreshold stimulation of the stellate ganglion decreased the stroke volume and increased the heart rate in control animals. Electrical stimulation after beta-adrenoceptor blockade was followed by a further decrease in stroke volume in young rats. In 100-day-old animals this parameter remained unchanged, while the cardiac output improved.

The anatomical rationale for an upper limb sympathetic blockade: preliminary report

Stellate ganglion blockade (SGB) has long been considered pivotal in the diagnosis, determination of prognosis and management of chronic regional pain syndrome (CRPS) by sympathectomy. To date a variety of SGB techniques have been described. An inaccurate SGB may mislead clinicians and deny patients a potentially beneficial procedure. In order to obtain a predictable and readily reproducible blockade of the upper limb, a modified anterior technique was evaluated. This modified sympathetic block was performed in 10 adult cadavers (n=19 sides). Toluidine blue solution (10 ml) was injected and, following median sternotomy, the extent of spread of dye was evaluated. In one cadaver a dual block using both the modified and the standard techniques was performed. Proximal spread to the seventh cervical vertebra was noted in all blocks; distal spread extended to the neck of the third rib (n=3), neck of the fourth rib 7 (n=15) and neck of the seventh rib (n=1). Medial spread was greater than lateral spread and extended to the vertebral bodies (vagus nerve was also stained) while lateral spread in all cases "blocked" lower roots of the brachial plexus and was consistently noted beyond the usual location of the nerve of Kuntz. This modified technique demonstrated that the lower cervical ganglia and proximal thoracic sympathetic trunk were consistently stained. It should be noted that the spread was sufficiently lateral to block the nerve of Kuntz. The pitfalls of this technique aside, we suggest that this technique be reserved for therapeutic purposes, particularly when sympathectomy is not possible.

Cloning and characterization of an ionotropic glutamate receptor subunit expressed in the squid nervous system

In this paper we describe the cloning of a putative ionotropic glutamate receptor subunit, SqGluR, and its distribution in the nervous system of the squid. A full-length cDNA was assembled from a cDNA library of the stellate ganglion/giant fibre lobe complex of Loligo opalescens. The deduced amino acid sequence of the mature SqGluR displayed 44-46% amino acid identity with mammalian GluR1-GluR4 and 53% with Lym-eGluR1 from Lymnaea stagnalis. In situ hybridizations in adult squid confirmed that the SqGluR mRNA is abundant in giant fibre lobe neurons, in large, presumptive motor neurons of the stellate ganglion proper and in the supraoesophageal and optic lobes of the central nervous system. In newborn squid, SqGluR mRNA expression was detected throughout the nervous system but not elsewhere. A synthetic peptide corresponding to the last 15 amino acids of the SqGluR C-terminus was used to generate polyclonal antibodies, which were used for immunoblot analysis to demonstrate widespread expression in the squid central and peripheral nervous systems. Injection of the synthetic peptide into the postsynaptic side of the giant synapse inhibited synaptic transmission.

Modulation of angiotensin II responses in sympathetic neurons by cytosolic calcium

Both stimulatory and suppressive responses of the sympathetic nervous system to angiotensin II (AII) have been reported in intact animals. To elucidate possible cellular mechanisms, we studied AII-induced changes in cytosolic Ca2+ ([Ca2+]i) in primary cultures of rat stellate ganglion neurons. Two different patterns of [Ca2+]i responses to AII were observed: dose-dependent increases in [Ca2+]i in cells with intrinsically low baseline [Ca2+]i (n=64) and dose-dependent suppression of [Ca2+]i in neurons with intrinsically higher baseline [Ca2+]i (n=46). Individual neurons could express both response patterns to AII. In neurons with low basal [Ca2+]i, superfusion with Ca2+ ionophore (ionomycin) increased [Ca2+]i and reversed the initial AII-induced stimulatory pattern. L-type Ca2+ channel antagonism (nifedipine) in neurons with high baseline [Ca2+]i lowered [Ca2+]i and reversed the initial AII-induced suppressive response. Both stimulatory and suppressive responses were abolished by AT1 receptor antagonism (losartan). AII-induced stimulatory responses were blocked by IP3 receptor antagonism (2-APB) and by thapsigargin. AII-induced suppression of neuronal [Ca2+]i was blunted when Na-Ca exchange was impaired. We conclude that [Ca2+]i acts as a switch for AII-mediated stimulatory and suppressive responses in individual sympathetic neurons. AT1 receptor-mediated neuronal stimulation and suppression may allow local homeostatic adaptation to meet complex systemic needs.

[Sympathetic block in dogs by a local anesthetic with addition of clonidine]

BACKGROUND

The aim of this study is to examine the duration and magnitude of vasodilating effect induced by sympathetic block with the addition of different concentrations of clonidine to mepivacaine.

METHODS

In dogs, mean arterial pressure (MAP), heart rate (HR), and right as well as left brachial artery blood flow (BABF) were measured before and after stellate ganglion block (SGB) used as sympathetic block. The experimental protocol was designed as follows: 1) Group 1: left SGB using 0.5% mepivacaine 1 ml (n = 6), 2) Group 2: left SGB using the addition of clonidine 0.5 microgram to 0.5% mepivacaine 1 ml (n = 6), 3) Group 3: left SGB using the addition of clonidine 5 micrograms to 0.5% mepivacaine 1 ml (n = 6).

RESULTS

MAP showed no significant change throughout the study in the groups 1 and 2. In the group 3, MAP was lower than that of the group 1. HR showed no significant change throughout the study in the three groups. Left BABF increased significantly after left SGB in the three groups. The duration of increased BABF in the group 2 was the longest, and that in the group 3 was the shortest among them. Right BABF after left SGB decreased significantly throughout the study in the three groups, and the magnitude of the decrease in BABF in the group 3 was the highest among them.

CONCLUSION

Sympathetic block with the addition of clonidine to local anesthetics increases both duration and magnitude of its vasodilating effect. However, sympathetic block with the addition of higher doses of clonidine to local anesthetics may induce shorter duration and lower magnitude of vasodilating effect compared with local anesthetics alone.

Novel mechanism of action hypothesized for stellate ganglion block related to melatonin

The mechanism of action of stellate ganglion block has generally been explained by vasodilation within its sphere of innervation. However, the success of treatment cannot always be explained by just one mechanism of action, because its clinical indications in Japan extend to many diseases, including systemic diseases. We propose a new mechanism of action for stellate ganglion block that is based on correction of melatonin rhythm disorder resulting from increased sympathetic nerve tone and does not involve vasodilation.