Anatomo-Physiologic Basis for Auricular Stimulation

Vagus nerve stimulation for the treatment of epilepsy: things to note on the protocols, the effects and the mechanisms of action

Epilepsy is a chronic brain disorder that is characterized by repetitive un-triggered seizures that occur severally within 24 h or more. Non-pharmacological methods for the management of epilepsy were discussed. The non-pharmacological methods include the vagus nerve stimulation (VNS) which is subdivided into invasive and non-invasive techniques. For the non-invasive techniques, the auricular VNS, stimulation of the cervical branch of vagus nerve in the neck, manual massage of the neck, and respiratory vagal nerve stimulation were discussed. Similarly, the stimulation parameters used and the mechanisms of actions through which VNS improves seizures were also discussed. Use of VNS to reduce seizure frequency has come a long way. However, considering the cost and side effects of the invasive method, non-invasive techniques should be given a renewed attention. In particular, respiratory vagal nerve stimulation should be considered. In doing this, the patients should for instance carry out slow-deep breathing exercise 6 to 8 times every 3 h during the waking hours. Slow-deep breathing can be carried out by the patients on their own; therefore this can serve as a form of self-management.HIGHLIGHTSEpilepsy can interfere with the patients' ability to carry out their daily activities and ultimately affect their quality of life.Medications are used to manage epilepsy; but they often have their serious side effects.Vagus nerve stimulation (VNS) is gaining ground especially in the management of refractory epilepsy.The VNS is administered through either the invasive or the non-invasive methodsThe invasive method of VNS like the medication has potential side effects, and can be costly.The non-invasive method includes auricular VNS, stimulation of the neck muscles and skin and respiratory vagal nerve stimulation via slow-deep breathing exercises.The respiratory vagal nerve stimulation via slow-deep breathing exercises seems easy to administer even by the patients themselves.Consequently, it is our opinion that patients with epilepsy be made to carry out slow-deep breathing exercise 6-8 times every 3 h during the waking hours.

Bibliometric analysis of auriculotherapy research trends over the past 20 years

OBJECTIVES

Auriculotherapy has long been used to treat various diseases. We analyzed and visualized auriculotherapy's geographical distribution, key contributors, and thematic trends over the past 20 years to provide current trends in auriculotherapy field and to offer recommendations for future research directions.

DESIGN/SETTING

We searched for relevant studies in the Web of Science between January 10, 2003, and December 31, 2022. A bibliometric analysis was performed using VOSviewer for annual publications, journals, countries, institutions, authors, and keywords.

RESULTS

A total of 800 studies were included in the analysis, and the number of studies steadily increased over the 20 examined years. In 2018, there was a noteworthy rise in publications, nearly twice as many as the preceding year. Integrative & complementary medicine was the most researched area, with most articles published in Evidence-Based Complementary and Alternative Medicine. China was the country with the most published research, and the most active organization was Guangzhou University of Chinese Medicine in China, followed by Kyung Hee University in South Korea. The most prolific author was Yeh Mei-ling, who reported the effects of auriculotherapy on dysmenorrhea and smoking cessation. Keyword analysis revealed four clusters: pain, mental health, obesity, and smoking cessation.

CONCLUSION

Auriculotherapy research primarily focused on clinical studies related to pain, obesity, smoking cessation, and depression. Future research should place greater emphasis on verifying the mechanisms of auriculotherapy for specific ailments and may require efforts to enhance the robustness of clinical trials. Through visual analysis, our study may serve as a foundational resource, offering valuable insights into the trajectory of auriculotherapy research.

State- and frequency-dependence in autonomic rebalance mediated by intradermal auricular electroacupuncture stimulation

Background

Vagus nerve stimulation (VNS) improves diseases such as refractory epilepsy and treatment-resistant depression, likely by rebalancing the autonomic nervous system (ANS). Intradermal auricular electro-acupuncture stimulation (iaES) produces similar effects. The aim of this study was to determine the effects of different iaES frequencies on the parasympathetic and sympathetic divisions in different states of ANS imbalance.

Methods

We measured heart rate variability (HRV) and heart rate (HR) of non-modeled (normal) rats with the treatment of various frequencies to determine the optimal iaES frequency. The optimized iaES frequency was then applied to ANS imbalance model rats to elucidate its effects.

Results

30 Hz and 100 Hz iaES clearly affected HRV and HR in normal rats. 30 Hz iaES increased HRV, and decreased HR. 100 Hz iaES decreased HRV, and increased HR. In sympathetic excited state rats, 30 Hz iaES increased HRV. 100 Hz iaES increased HRV, and decreased HR. In parasympathetic excited state rats, 30 Hz and 100 Hz iaES decreased HRV. In sympathetic inhibited state rats, 30 Hz iaES decreased HRV, while 100 Hz iaES decreased HR. In parasympathetic inhibited rats, 30 Hz iaES decreased HR and 100 Hz iaES increased HRV.

Conclusion

30 Hz and 100 Hz iaES contribute to ANS rebalance by increasing vagal and sympathetic activity with different amplifications. The 30 Hz iaES exhibited positive effects in all the imbalanced states. 100 Hz iaES suppressed the sympathetic arm in sympathetic excitation and sympathetic/parasympathetic inhibition and suppressed the vagal arm and promoted the sympathetic arm in parasympathetic excitation and normal states.

Networks of Nerve Fibers, and Blood and Lymphatic Vessels in the Mouse Auricle: The Structural Basis of Ear Acupuncture

Objective

Ear acupuncture, as a system for treating and preventing diseases through stimulation of points on the auricle, has been systematically introduced during the last 60 years. Although the auricular cartography was described somatotopically as an inverted fetus by Paul Nogier, MD, the underlying mechanism of auricular stimulation remains unclear. The aim of this research was to gain an understanding of the structural basis of auricular stimulation, as well as showing the distribution of the nerve fibers, and the blood and lymphatic vessels.

Materials and Methods

The distribution of nerve fibers, and blood and lymphatic vessels was examined in whole-mount auricular skins of mice by combining the biomarkers protein gene product 9.5, cluster of differentiation 31, and lymphatic-vessel endothelial hyaluronan receptor-1 following tissue-clearing treatment with multiple immunofluorescent staining.

Results

The labeled nerve fibers, and the blood and lymphatic vessels were distributed extensively in the inner and outer parts of the auricular skin. Auricular nerves aligning with blood vessels ran from the basal region to the peripheral region and crossed over lymphatic vessels, thus forming the neural, vascular, and lymphatic networks.

Conclusions

As these are important tissue components of auricular skin, this result implies that the auricular nerve fibers, and blood and lymphatic vessels may coordinate with each other to respond directly to auricular stimulation.

Neural, Anti-Inflammatory, and Clinical Effects of Transauricular Vagus Nerve Stimulation in Major Depressive Disorder: A Systematic Review

BACKGROUND

The discovery of effective treatments for major depressive disorder (MDD) may help target different brain pathways. Invasive vagus nerve stimulation (VNS) is an effective neuromodulation technique for the treatment of MDD; however, the effectiveness of the noninvasive technique, transauricular VNS (taVNS), remains unknown. Moreover, a mechanistic understanding of the neural effects behind its biological and therapeutic effects is lacking. This review aimed to evaluate the clinical evidence and the neural and anti-inflammatory effects of taVNS in MDD.

METHODS

Two searches were conducted using a systematic search strategy reviewed the clinical efficacy and neural connectivity of taVNS in MDD in humans and evaluated the changes in inflammatory markers after taVNS in humans or animal models of depression. A risk of bias assessment was performed in all human studies.

RESULTS

Only 5 studies evaluated the effects of taVNS in patients with depression. Although the studies demonstrated the efficacy of taVNS in treating depression, they used heterogeneous methodologies and limited data, thus preventing the conduct of pooled quantitative analyses. Pooled analysis could not be performed for studies that investigated the modulation of connectivity between brain areas; of the 6 publications, 5 were based on the same experiment. The animal studies that analyzed the presence of inflammatory markers showed a reduction in the level of pro-inflammatory cytokines or receptor expression.

CONCLUSIONS

Data on the clinical efficacy of taVNS in the treatment of MDD are limited. Although these studies showed positive results, no conclusions can be drawn regarding this topic considering the heterogeneity of these studies, as in the case of functional connectivity studies. Based on animal studies, the application of taVNS causes a decrease in the level of inflammatory factors in different parts of the brain, which also regulate the immune system. Therefore, further studies are needed to understand the effects of taVNS in patients with MDD.

Effectiveness of auricular acupuncture and pelvic floor muscle training in the management of urinary incontinence following surgical treatment for prostate cancer: A randomized clinical trial

PURPOSE

To evaluate the effectiveness of auricular acupuncture combined with pelvic floor muscle training to manage urinary incontinence following radical prostatectomy.

METHODS

This is a randomized clinical trial that was conducted between April 2019 and April 2020 with 60 participants allocated into two groups, namely: control (pelvic muscle training) and intervention (auricular acupuncture + pelvic muscle training). Interventions were carried out during eight weekly sessions. Generalized estimating equations and proportion difference tests were applied in the statistical analysis with a significance level of 0.05.

RESULTS

Urinary incontinence severity decreased between pre-test and post-test in both groups. There was a statistically significant difference of the impact of urinary incontinence on quality of life between the groups at post-test in the domain "severity measures" (p = 0.013), and only in the intervention group between pre-test and post-test in the domains "emotions" (p < 0.001) and "sleep and mood" (p = 0.008). The intervention group was 20.8% (p = 0.007) and 25.3% (p = 0.002) less likely to present nocturia and urinary urgency, respectively.

CONCLUSIONS

Auricular acupuncture combined with pelvic floor muscle training was more effective, compared to pelvic floor muscle training alone, in reducing the impact of urinary incontinence on quality of life and reducing the odds of nocturia and urinary urgency.

Development and Validation of an Auricular Acupuncture Protocol for the Management of Chemotherapy-Induced Nausea and Vomiting in Cancer Patients

Auricular acupuncture (AA) has been used to manage chemotherapy-induced nausea and vomiting (CINV). However, the application of the technique varies widely among the clinical trials that test its effectiveness. The aim of the present study was to develop and clinically validate an AA protocol for the management of CINV in cancer patients. This study was carried out in two stages: (1) development of the AA protocol for the management of CINV and (2) clinical validation of the protocol. The content validity of the protocol was determined by a panel of specialists, with an agreement rate ranging from 85.7% to 100%. In the clinical validation, when administered to cancer patients, the protocol developed has been shown to reduce the incidence, frequency, severity, and length of nausea and vomiting following chemotherapy, as well as the severity of nausea and anticipatory nausea following chemotherapy. This protocol needs to be tested in future studies, including a pilot study with a sham group and a randomized clinical trial, in order to further evaluate its feasibility, acceptability, safety, and clinical usefulness for the management of CINV.

Effects of auriculotherapy on muscle fatigue: A randomized crossover trial

OBJECTIVE

This study aimed investigate the effect of auriculotherapy on exercise-induced muscle fatigue, isometric torque production, and surface electromyographic activity (EMG).

METHODS

Design: Randomized Crossover Trial. The sample consisted of 18 males' volunteers who exercised at least twice a week.

THE SAMPLE WAS RANDOMLY ASSIGNED TO TWO GROUPS

Placebo Group (n = 9) and Treated Group (n = 9), and after seven days, the groups were crossed. The data analysis included 18 participants in each group.

MAIN OUTCOME MEASURE

The muscle fatigue index, force production rate, and EMG of the quadriceps were used for evaluation. The evaluation moments included baseline pre-fatigue, baseline post-fatigue, 48 h post-intervention pre-fatigue, and 48 h post-intervention post-fatigue. Mixed two-way test ANOVA was used to compare times and groups.

RESULTS

The fatigue index for peak torque and work showed no significant effect on time, groups, or interaction (p > 0.05). However, for isometric torque, force production rate, and EMG median frequency and average, the results indicate a positive change in values over time (p < 0.05) (with little practical relevance), with no differences observed between the groups or interaction (p > 0.05).

CONCLUSIONS

In conclusion, auriculotherapy had no effect on exercise-induced muscle fatigue, isometric torque production, and surface electromyographic activity.

Three-dimensional visualization of the lymphatic, vascular and neural network in rat lung by confocal microscopy

In order to demonstrate the intricate interconnection of pulmonary lymphatic vessels, blood vessels, and nerve fibers, the rat lung was selected as the target and sliced at the thickness of 100 μm for multiply immunofluorescence staining with lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), alpha smooth muscle actin (α-SMA), phalloidin, cluster of differentiation 31 (CD31), and protein gene product 9.5 (PGP9.5) antibodies. Taking the advantages of the thicker tissue section and confocal microscopy, the labeled pulmonary lymphatic vessels, blood vessels, and nerve fibers were demonstrated in rather longer distance, which was more convenient to reconstruct a three-dimensional (3D) view for analyzing their spatial correlation in detail. It was clear that LYVE-1+ lymphatic vessels were widely distributed in pulmonary lobules and closely to the lobar bronchus. Through 3D reconstruction, it was also demonstrated that LYVE-1+ lymphatic vessels ran parallel to or around the α-SMA+ venules, phalloidin+ arterioles and CD31+ capillaries, with PGP9.5+ nerve fibers traversing alongside or wrapping around them, forming a lymphatic, vascular and neural network in the lung. By this study, we provide a detailed histological view to highlight the spatial correlation of pulmonary lymphatic, vascular and neural network, which may help us for insight into the functional role of this network under the physiological and pathological conditions.

Acupuncture for brain diseases: Conception, application, and exploration

The brain is probably the most complex organ in the human body. It has been the hot spot and direction of brain science research all over the world to deeply study the pathogenesis of various kinds of brain diseases and find effective treatment methods. Acupuncture is a nonpharmacological therapy of traditional Chinese medicine originating from ancient clinical practice. The research on the treatment of brain diseases by acupuncture has been constantly enriched and updated with the promotion of interdisciplinary research. In order to account for the current achievements in the field of acupuncture for brain diseases, this article reviews it in terms of conception, application, and exploration. Based on the literature review, we found that in the past decades, acupuncture has received widespread attention worldwide and many literatures have reported the clinical efficacy and underlying mechanisms of acupuncture in the treatment of brain diseases. Presently, the conception, application, and exploration of acupuncture in the treatment of brain diseases have evolved from empirical medicine to evidence-based medicine and precision medicine, and are experiencing a deeper understanding of the information about acupuncture regulating the brain function based on interdisciplinary research.

Cognitive Functions following Trigeminal Neuromodulation

Vast scientific effort in recent years have been focused on the search for effective and safe treatments for cognitive decline. In this regard, non-invasive neuromodulation has gained increasing attention for its reported effectiveness in promoting the recovery of multiple cognitive domains after central nervous system damage. In this short review, we discuss the available evidence supporting a possible cognitive effect of trigeminal nerve stimulation (TNS). In particular, we ask that, while TNS has been widely and successfully used in the treatment of various neuropsychiatric conditions, as far as research in the cognitive field is concerned, where does TNS stand? The trigeminal nerve is the largest cranial nerve, conveying the sensory information from the face to the trigeminal sensory nuclei, and from there to the thalamus and up to the somatosensory cortex. On these bases, a bottom-up mechanism has been proposed, positing that TNS-induced modulation of the brainstem noradrenergic system may affect the function of the brain networks involved in cognition. Nevertheless, despite the promising theories, to date, the use of TNS for cognitive empowering and/or cognitive decline treatment has several challenges ahead of it, mainly due to little uniformity of the stimulation protocols. However, as the field continues to grow, standardization of practice will allow for data comparisons across studies, leading to optimized protocols targeting specific brain circuitries, which may, in turn, influence cognition in a designed manner.

Safety and feasibility of transcutaneous vagus nerve stimulation in mild cognitive impairment: VINCI-AD study protocol

BACKGROUND

Over 55 million adults are living with dementia globally, which is projected to reach 157 million by 2050. Mild cognitive impairment (MCI), a syndrome of memory impairment with intact activities of daily living, may precede dementia by several years. Around 5-15% of individuals with MCI convert to dementia annually. Novel treatments which delay progression of MCI to dementia are urgently needed. Transcutaneous vagal nerve stimulation (tVNS) is a non-invasive neuromodulation technique that targets the vagus nerve. Importantly, tVNS has been shown to improve cognition in healthy volunteers, but has not been extensively examined as a potential therapeutic approach in MCI. VINCI-AD will examine the safety and feasibility of tVNS in older adults with MCI.

DESIGN

VINCI-AD is an investigator-led, single-site, single-blind, sham-controlled crossover pilot study which aims to assess the safety and feasibility of tVNS in 40 participants with amnestic MCI. All participants will attend for three consecutive study visits during which they will be randomised to receive no stimulation (baseline), active tVNS stimulation (stimulation at cymba conchae of left ear) or sham tVNS stimulation (at earlobe). Safety will be primarily assessed by ascertainment of adverse events. Further safety assessment will examine the impact of acute tVNS on subjective (orthostatic symptoms), peripheral (finometry-based blood pressure) and central (assessed via Near Infrared Spectroscopy [NIRS]) haemodynamic responses to active stand. Feasibility will be determined using a custom-designed occupational assessment of device usability. Exploratory secondary analysis in VINCI-AD will examine the potential impact of acute tVNS on associative memory, spatial memory and inhibitory control to inform sample size estimates for future trials of tVNS in older adults with MCI.

DISCUSSION

VINCI-AD will report on the safety (adverse events/haemodynamic responses to active stand) and feasibility of tVNS as a potential therapeutic option in MCI. Detailed reporting of study eligibility and completion rates will be reported. Exploratory analysis will examine the potential cognitive benefits of acute tVNS on cognitive function in MCI to report potential effect sizes that may inform future clinical trials in this cohort.

TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT05514756 . Trial Registration Number NCT05514756 (24th August 2022 for this protocol, version 1.0.).

Potential value of neuroimmunotherapy for COVID-19: efficacies and mechanisms of vagus nerve stimulation, electroacupuncture, and cholinergic drugs

COVID-19 is an inflammatory disease with multiple organs involved, mainly respiratory symptoms. Although the majority of patients with COVID-19 present with a mild to moderate self-limited course of illness, about 5-10% of patients with inflammatory disorders in severe COVID-19 have life-threatening progression. With the exception of a few drugs that have shown outstanding anti-COVID-19 effects, the efficacy of most drugs remains controversial. An increasing number of animal and clinical studies have shown that neuromodulation has a significant effect on reducing inflammatory markers of COVID-19, thus exerting an effective neuroimmunotherapeutic value. Currently, the main neuroimmunomodulatory measures effective against COVID-19 include vagus nerve stimulation, electroacupuncture, and cholinergic drugs. In this review, we will summarize the research progress of potential value of this neuroimmunotherapy measures for COVID-19 and elaborate its efficacies and mechanisms, in order to provide reliable evidence for clinical intervention.

Auricular bean embedding improves urination in epidural labor analgesia: A single center randomized controlled study

BACKGROUND

Acupoint buried beans on the auricle is a feasible method to prevent and treat postpartum urinary retention.

OBJECTIVE

This study investigated the effect of auricular acupoint buried beans on postpartum urination and maternal and fetal outcomes following epidural analgesia for labor.

METHODS

Two hundred forty primiparas underwent vaginal trial labor analgesia from May 2020 to January 2021 and were randomly placed into the intervention and control groups. Both groups received epidural labor analgesia. Maternal urination during labor, 2 h postpartum, and the time for first postpartum urination were recorded as primary outcomes, with maternal and infant outcomes documented as secondary results. Statistical analysis was performed using the independent sample t-test, non-parametric rank-sum, or chi-square test using the SPSS Statistics 25.0 software.

RESULTS

Two hundred eight study participants were subsequently included in the results, i.e., 105 patients in the intervention group and 103 in the control group. The intervention group comprised a significantly lower number of patients with excessive residual urine volume at cervical dilatation of 5-6 cm (P< 0.05). The total postpartum score of the intervention group was lower than in the control group (P< 0.01), and the time to first urination was shorter compared with the control group (P< 0.05). In the intervention group, the time of labor analgesia, the duration of the first stage of labor, and the total labor time were shorter compared with the control group (P< 0.01).

CONCLUSION

Auricular acupoint embedded beans can improve the urination status at cervical dilatation of 5-6 cm and 2 h postpartum, as well as significantly shorten the duration of labor.

Exploratory Investigation of the Effects of Tactile Stimulation Using Air Pressure at the Auricular Vagus Nerve on Heart Rate Variability

OBJECTIVE

To explore the effects of tactile stimulation using air pressure at the auricular branch of the vagus nerve on autonomic activity in healthy individuals.

METHODS

Three types of tactile stimulation were used in this study: continuous low-amplitude, continuous high-amplitude, and pulsed airflow. The tactile stimulations were provided to the cymba concha to investigate autonomic activity in 22 healthy participants. The mean heart rate (HR) and parameters of HR variability, including the standard deviation of R-R intervals (SDNN) and root mean square of successive R-R interval differences (RMSSD) were compared at baseline, stimulation, and recovery periods.

RESULTS

Two-way repeated measures ANOVA indicated a significant main effect of time on HR (p=0.001), SDNN (p=0.003), and RMSSD (p<0.001). These parameters showed significant differences between baseline and stimulation periods and baseline and recovery periods in the post-hoc analyses. There were no significant differences in the changes induced by stimulation type and the interaction between time and stimulation type for all parameters. One-way repeated measures ANOVA showed that HR, SDNN, and RMSSD did not differ significantly among the three time periods during sham stimulation.

CONCLUSION

Parasympathetic activity can be enhanced by auricular tactile stimulation using air pressure, targeting the cymba concha. Further studies are warranted to investigate the optimal stimulation parameters for potential clinical significance.

Auricular Vagus Nerve Stimulation Ameliorates Functional Dyspepsia with Depressive-Like Behavior and Inhibits the Hypothalamus-Pituitary-Adrenal Axis in a Rat Model

BACKGROUND

The hypothalamus-pituitary-adrenal axis is the most important endocrine system to control irritability response. Functional dyspepsia (FD) is closely related to irritability. This study aimed to preliminarily explore the corticotropin-releasing factor (CRF) mechanism of auricular vagus nerve stimulation (aVNS) for FD model rats.

METHODS

Sprague-Dawley adult male rats were randomly divided into normal group, model group, aVNS group, and sham-aVNS group. Except for the normal rats, all other rats were induced into the FD model through tail-clamping stimulation for 3 weeks. Once the rat model was developed successfully, rats in the aVNS group and sham-aVNS group were intervened with aVNS or sham-aVNS for 2 weeks. No intervention was given to rats in the normal and model groups. The effect of aVNS was assessed. The expressions of hippocampal corticotropin-releasing hormone receptor 1 (CRHR1), hypothalamus CRF, adrenocorticotropic hormone (ACTH), and corticosterone in serum were assessed.

RESULTS

1. Compared with normal rats, model-developing rats showed FD-like behavior. 2. Compared with model rats, rats in the aVNS group showed an improved general condition score and gastric motility, and increased horizontal and vertical motion scores. 3. The release of corticosterone, ACTH in serum, and CRF in the hypothalamus all increased in model rats but decreased with aVNS instead of sham-aVNS. 4. The expression of hippocampus CRHR1 was lower in model rats but higher in the aVNS group.

CONCLUSION

aVNS ameliorates gastric motility and improves the mental state in the FD-like rat, probably via inhibiting the CRF pathway.

NSS-Bridge Device for Post-Cesarean Delivery Analgesia: A Randomized Controlled Trial

Introduction

Percutaneous auricular nerve stimulation has been used for the treatment of symptoms associated with opioid withdrawal, including abdominal pain, nausea, and general discomfort. However, its potential utility for pain management and opioid minimization after surgery has not been investigated. The purpose of this study was to test the feasibility and acceptability of a trial protocol designed to assess the effectiveness of the NSS2-Bridge device as a non-pharmacologic alternative to opioids after cesarean delivery.

Methods

In a randomized control design, healthy women receiving cesarean delivery were randomized to receive the active device, placebo device, or no device. Devices were placed on the ear following cesarean delivery and left in place for 5 days. Feasibility and acceptability of the device was assessed by patient reports of device tolerability (rated on a 100mm visual analog scale where 0 is not tolerable at all and 100 is the most tolerable) as well as qualitative reporting. Additional outcomes assessed included proportion of patients not using opioids in hospital, as well as pain at rest, pain with movement, and total opioid consumption in the hospital and for the first 5 days after surgery.

Results

There were 60 patients included in the final analysis. Device tolerability was rated highly, with an average daily score of >75 mm on the visual analog scale. The trial retention rate was 89.7% with most exclusions (42.9%) occurring due to unanticipated development of care complexity (e.g., hemorrhage and additional surgical procedures), with only 1 exclusion (14.3%) due to device discomfort. The active device group achieved the highest proportion of opioid-free hospitalizations (40%) compared to placebo (20%) and no device groups (30%). Pain at rest and with movement was similar between treatment groups.

Conclusions

This trial protocol designed to test the efficacy of NSS2-Bridge device for post-cesarean pain management is feasible and acceptable. Larger proportions of patients not using opioids in the active device group justifies additional investigation on device effectiveness in pregnant and postpartum people at highest risk for pain.

Delivering transcutaneous auricular neurostimulation (tAN) to improve symptoms associated with opioid withdrawal: results from a prospective clinical trial

Background

As pharmacological treatments are the primary option for opioid use disorder, neuromodulation has recently demonstrated efficacy in managing opioid withdrawal syndrome (OWS). This study investigated the safety and effectiveness of transcutaneous auricular neurostimulation (tAN) for managing OWS.

Methods

This prospective inpatient trial included a 30-minute randomized, sham-controlled, double-blind period followed by a 5-day open-label period. Adults with physical dependence on opioids were randomized to receive active or sham tAN following abrupt opioid discontinuation. The Clinical Opiate Withdrawal Scale (COWS) was used to determine withdrawal level, and participants were required to have a baseline COWS score ≥ 13 before enrollment. The double-blind period of the study occurred during the first 30-minutes to assess the acute effects of tAN therapy compared to a sham control. Group 1 received active tAN during both the 30-minute double-blind period and the 5-day open-label period. Group 2 received passive sham tAN (no stimulation) during the double-blind period, followed by active tAN during the 5-day open-label period. The primary outcome was change in COWS from baseline to 60-minutes of active tAN (pooled across groups, accounting for 30-minute delay). Secondary outcomes included difference in change in COWS scores between groups after 30-minutes of active or sham tAN, change in COWS scores after 120-minutes of active tAN, and change in COWS scores on Days 2–5. Non-opioid comfort medications were administered during the trial.

Results

Across all thirty-one participants, the mean (SD) COWS scores relative to baseline were reduced by 7.0 (4.7) points after 60-minutes of active tAN across both groups (p < 0.0001; Cohen’s d = 2.0), demonstrating a significant and clinically meaningful reduction of 45.9%. After 30-minutes of active tAN (Group 1) or sham tAN (Group 2), the active tAN group demonstrated a significantly greater COWS score reduction than the sham tAN group (41.7% vs. 24.1%; p = 0.036). Participants across both groups achieved an average COWS reduction up to 74.7% on Days 2–5.

Conclusion

Results demonstrate tAN is a safe and effective non-opioid approach for reducing symptoms of OWS. This study supported an FDA clearance.

Clinical trial registration

clinicaltrials.gov/ct2/show/NCT04075214, Identifier: NCT04075214, Release Date: August 28, 2019.

Clinical perspectives on vagus nerve stimulation: present and future

The vagus nerve, the great wanderer, is involved in numerous processes throughout the body and vagus nerve stimulation (VNS) has the potential to modulate many of these functions. This wide-reaching capability has generated much interest across a range of disciplines resulting in several clinical trials and studies into the mechanistic basis of VNS. This review discusses current preclinical and clinical evidence supporting the efficacy of VNS in different diseases and highlights recent advancements. Studies that provide insights into the mechanism of VNS are considered.

To Use or Not Use Complementary and Alternative Medicine (CAM) in Psychiatric Care: Interviews with Clinical Decision-Makers in Sweden

Complementary and alternative medicine (CAM) is used as a complementary intervention in psychiatric healthcare. The reasons for using or not using CAM in psychiatric care in Sweden, and how such decisions are taken, are largely unknown. The aim was to investigate arguments for and against the use of CAM in Swedish psychiatric care, and how decisions are made. Interviews with 10 persons in decision-making positions in psychiatric health care were analysed thematically. The result shows diverging understandings of the evidence base for CAM. Arguments against CAM referred to scepticism, the importance of evidence-based practice and the obligation to follow national guidelines. Arguments in favour of CAM were that CAM was person-centred, safe, cost-effective, nursing interventions with positive effects, appreciated and demanded by patients, providing space for non-verbal communication and reflection, supporting the therapeutic alliance. Decision paths were described as top-down through a hierarchical structure, or bottom-up, driven by committed staff members. We discuss how detailed national guidelines should be to achieve equal and evidence-based care, while still allowing clinics to make local exceptions, adjusting the care according to clinical expertise and patients' preferences. Conclusion: Evidence-based, safe and cost-effective CAM methods may be relevant complementary interventions in psychiatric care, or as self-care, not to cure the psychiatric disease, but to reduce symptoms and promote sleep. With better knowledge of CAM, health professionals could guide patients through the jungle of CAM methods. Due to research problems on complex multicomponent interventions, high-quality pragmatic trials, including biomarkers, and qualitative studies are recommended.

Toward Diverse or Standardized: A Systematic Review Identifying Transcutaneous Stimulation of Auricular Branch of the Vagus Nerve in Nomenclature

OBJECTIVES

After 20 years of development, there is confusion in the nomenclature of transcutaneous stimulation of the auricular branch of the vagus nerve (ABVN). We performed a systematic review of transcutaneous stimulation of ABVN in nomenclature.

MATERIALS AND METHODS

A systematic search of the literature was carried out, using the bibliographic search engine PubMed. The search covered articles published up until June 11, 2020. We recorded the full nomenclature and abbreviated nomenclature same or similar to transcutaneous stimulation of ABVN in the selected eligible studies, as well as the time and author information of this nomenclature.

RESULTS

From 261 studies, 67 full nomenclatures and 27 abbreviated nomenclatures were finally screened out, transcutaneous vagus nerve stimulation and tVNS are the most common nomenclature, accounting for 38.38% and 42.06%, respectively. In a total of 97 combinations of full nomenclatures and abbreviations, the most commonly used nomenclature for the combination of transcutaneous vagus nerve stimulation and tVNS, accounting for 30.28%. Interestingly, the combination of full nomenclatures and abbreviations is not always a one-to-one relationship, there are ten abbreviated nomenclatures corresponding to transcutaneous vagus nerve stimulation, and five full nomenclatures corresponding to tVNS. In addition, based on the analysis of the usage habits of nomenclature in 21 teams, it is found that only three teams have fixed habits, while other different teams or the same team do not always use the same nomenclature in their paper.

CONCLUSIONS

The phenomenon of confusion in the nomenclature of transcutaneous stimulation of ABVN is obvious and shows a trend of diversity. The nomenclature of transcutaneous stimulation of ABVN needs to become more standardized in the future.

Multimodal transcutaneous auricular vagus nerve stimulation: An option in the treatment of sleep bruxism in a "polyvagal" context

OBJECTIVE

To consider the possible role of the vagus nerve (VN) in the pathophysiology of sleep bruxism (SB) and introduce a multimodal protocol of transcutaneous auricular stimulation of the VN in the treatment of SB patients.

METHODS

Ten patients with SB underwent four sessions of electric transcutaneous auricular vagus nerve stimulation (ta-VNS) in specific auricular areas. The patients were advised to manually stimulate the same areas between sessions. Masticatory muscle activity and sleep parameters were measured by a polysomnography (PSG) before and after the treatment. Heart rate variability (HRV) parameters were measured during each stimulation.

RESULTS

PSG analysis revealed a statistically significant reduction in tonic SB index and tonic contraction time. HRV parameters showed a statistically significant increase in mean values of the vagal tone after each session of stimulation. No side effect was reported.

CONCLUSION

The stimulation of the VN might have a role in the treatment of SB.

Control of inflammation using non-invasive neuromodulation: past, present and promise

The nervous system has been increasingly recognized as a novel and accessible target in the regulation of inflammation. The use of implantable and invasive devices targeting neural circuits has yielded successful results in clinical settings but does have some risk or adverse effects. Recent advances in technology and understanding of mechanistic pathways have opened new avenues of non-invasive neuromodulation. Through this review we discuss the novel research and outcomes of major modalities of non-invasive neuromodulation in the context of inflammation including transcutaneous electrical, magnetic and ultrasound neuromodulation. In addition to highlighting the scientific observations and breakthroughs, we discuss the underlying mechanisms and pathways for neural regulation of inflammation.

A novel tDCS control condition using optimized anesthetic gel to block peripheral nerve input

Background

Recent studies indicate that some transcranial direct current stimulation (tDCS) effects may be caused by indirect stimulation of peripheral nerves in the scalp rather than the electric field in the brain. To address this, we developed a novel tDCS control condition in which peripheral input is blocked using topical anesthetics. We developed a compounded anesthetic gel containing benzocaine and lidocaine (BL10) that blocks peripheral input during tDCS.

Methods

In a blinded randomized cross-over study of 18 healthy volunteers (M/F), we compared the gel's efficacy to EMLA and an inert placebo gel. Subjects used a visual analog scale (VAS) to rate the stimulation sensation in the scalp produced by 10 s of 2 mA tDCS every 2 min during 1 h. In an additional in-vitro experiment, the effect of a DC current on gel resistivity and temperature was investigated.

Results

Both the BL10 and EMLA gel, lowered the stimulation sensations compared to the placebo gel. The BL10 gel showed a tendency to work faster than the EMLA gel with reported sensations for the BL10 gel being lower than for EMLA for the first 30 min. The DC current caused a drastic increase in gel resistivity for the EMLA gel, while it did not affect gel resistivity for the BL10 and placebo gel, nor did it affect gel temperature.

Conclusions

Topical anesthetics reduce stimulation sensations by blocking peripheral nerve input during tDCS. The BL10 gel tends to work faster and is more electrically stable than EMLA gel.

Clinical trial registration

The study is registered at ClinicalTrials.gov with name "Understanding the Neural Mechanisms Behind tDCS" and number NCT04577677.

Therapeutic applications of transcutaneous auricular vagus nerve stimulation with potential for application in neurodevelopmental or other pediatric disorders

Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) as a newly developed technique involves stimulating the cutaneous receptive field formed by the auricular branch of the vagus nerve in the outer ear, with resulting activation of vagal connections to central and peripheral nervous systems. Increasing evidence indicates that maladaptive neural plasticity may underlie the pathology of several pediatric neurodevelopmental and psychiatric disorders, such as autism spectrum disorder, attention deficit hyperactivity disorder, disruptive behavioral disorder and stress-related disorder. Vagal stimulation may therefore provide a useful intervention for treating maladaptive neural plasticity. In the current review we summarize the current literature primarily on therapeutic use in adults and discuss the prospects of applying taVNS as a therapeutic intervention in specific pediatric neurodevelopmental and other psychiatric disorders. Furthermore, we also briefly discuss factors that would help optimize taVNS protocols in future clinical applications. We conclude from these initial findings that taVNS may be a promising alternative treatment for pediatric disorders which do not respond to other interventions.

Visualization of Complex Processes in Cardiovascular System during Electrical Auricular Vagus Nerve Stimulation

The analysis of human physiological systems from the point of view of complex systems theory remains a very ambitious task. The complexity of the problem often encourages the use of innovative mathematical methods analyzing the processes that take place in space and time. The main goal of this paper is to visualize the cardiovascular system during auricular vagus nerve stimulation (aVNS) using the matrix differences to evaluate the dynamic signal interfaces by cointegrating the initial signal data into the matrices during each case. Algebraic relationships between RR/JT and JT/QRS cardiac intervals are used not only to track the cardiovascular changes during aVNS but also to characterize individual features of the person during the transit through the therapy. This paper presents the computational techniques that can visualize the complex dynamical processes taking place in the cardiovascular system using the electrical aVNS therapy. Four healthy volunteers participated in two verum and two placebo experiments. We discovered that the body's reaction to the stimulation was very different in each of the cases, but the presented techniques opened new possibilities for a novel interpretation of the dynamics of the cardiovascular system.

Auricular field nerve stimulation using the NSS-2 BRIDGE® device as an alternative to opioids following kidney donor surgery

OBJECTIVES

The purpose of this study was to investigate the role that the NSS-2 BRIDGE^® device, an auricular field nerve stimulator, may play in reducing opioid requirement and pain in kidney donor surgery. It was not a randomized study. Electrophysiologic studies have demonstrated that the stimulation of the cranial nerves produced by the NSS-2 BRIDGE^® device modulates the ascending/descending spinal pain pathways, especially at the level of the limbic system.

METHODS

The design compared the effects of the NSS-2 BRIDGE^® device (NSS 2-BRIDGE^® device group; n=10) to a control group (n=10). In both groups, the surgery was performed using the same standard enhanced recovery after surgery protocol based on the use of a multimodal analgesic approach. For the active treatment group, the NSS-2 BRIDGE^® device was placed in the post anesthesia care unit. The primary endpoint was opioid requirement (oral morphine equivalent, OME in mg) at 24 h post-surgery. Secondary endpoints included pain (0-10), at 24 and 48 h, time to discharge from the recovery room, incidence of post-operative nausea and vomiting at 24 h, time to oral intake, time to ambulation, and time to discharge from the hospital. Data was analyzed using unpaired t-test and presented as mean ± standard deviation.

RESULTS

Compared to control, the use of the NSS-2 BRIDGE^® was associated with a 75.4% reduction in OME (33.6 vs. 8.3 mg; p=0.03) and 41.5% reduction in pain (5 vs. 3.28; p=0.06) at 24 h and a 73.3% difference in pain at 48 h (1.6 ± 1.6 vs. 6.0 ± 2.8; p=0.0004). There was no difference in non-opioid analgesics administration between groups.

CONCLUSIONS

The tolerability of NSS-2 BRIDGE^® device was reported by most to be excellent. This study suggests that the NSS-2 BRIDGE^® device may represent a complementary approach for controlling postoperative opioid consumption and pain in patients undergoing kidney donation.

Auricular nerve stimulation using the NSS-2 BRIDGE device to reduce opioid requirement following laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Evidence supports the use of complementary techniques to reduce pain and opioid use after surgery. The NSS-2 BRIDGE device (NBD; Innovative Health Solutions, Inc., Versailles, Indiana) modulates pain via stimulation of the nucleus of the auricular branch of the cranial nerves at the level of the brainstem and the limbic system.

OBJECTIVE

To investigate the role of auricular nerve field stimulation for pain control following gastric bypass surgery.

SETTINGS

U.S. academic medical center.

METHODS

A total of 18 subjects were included. Subjects were divided in 2 groups: NBD group (n = 8) and a control group (n = 10). The NBD was placed following laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery in the recovery room. The effectiveness of NBD was assessed comparing the relative use of opioid consumption (oral morphine equivalents) and pain (0 = no pain to 10= worst possible pain) at 24 and 48 hours after surgery. In addition, the device tolerability (1-10) was assessed, with 8-10 considered excellent. Data were analyzed using unpaired t tests and presented as mean ± standard deviation. Alpha was set up at .1.

RESULTS

Compared with the control group, the use of NBD was associated with a 60.2% reduction in oral morphine equivalents (38.15 vs 15.2 mg; P < .1) and a 28% reduction in pain (5.0 vs 3.6; P = .1) at 24 hours after surgery. The tolerability of NBD was reported to be excellent.

CONCLUSIONS

This report suggests that NBD may represent an interesting alternative to control perioperative pain and limit opioid use following bariatric surgery. This needs to be confirmed by a placebo-controlled, randomized study.

Different modulation effects of 1 Hz and 20 Hz transcutaneous auricular vagus nerve stimulation on the functional connectivity of the periaqueductal gray in patients with migraine

Background

A growing body of evidence suggests that transcutaneous auricular vagus nerve stimulation (taVNS) may relieve symptoms of migraineurs. Frequency is one of the key stimulation parameters. The aim of this study is to investigate the modulation effect of taVNS frequency on the descending pain modulation system (DPMS) in patients with migraine.

Methods

Twenty-four episodic migraineurs without aura (21 females) were recruited for the single-blind, crossover, functional magnetic resonance imaging (fMRI) study. Each participant attended two separate fMRI scan sessions, one for 1 Hz and another for 20 Hz taVNS, in a random order. Seed-based functional connectivity analysis was applied using the ventrolateral periaqueductal gray (PAG) as the region of interest.

Results

Compared with the pre-taVNS resting state, continuous 1 Hz taVNS (during) produced a significant increase in functional connectivity between the PAG and the bilateral middle cingulate cortex (MCC), right precuneus, left middle frontal gyrus (MFG), and left cuneus. Compared with 20 Hz taVNS, 1 Hz taVNS produced greater PAG connectivity increases with the MCC, right precuneus/posterior cingulate cortex, left insula, and anterior cingulate cortex (ACC). A significant negative correlation was observed between the number of migraine attacks in the previous 4 weeks and the PAG-MCC functional connectivity in the pre-taVNS resting-state before 1 Hz taVNS.

Conclusions

Our findings suggest that taVNS with different frequencies may produce different modulation effects on the descending pain modulation system, demonstrating the important role of stimulation frequency in taVNS treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03024-9.

Auricular Point Acupressure Combined with Compound Lidocaine Cream to Manage Arteriovenous Fistula Puncture Pain: A Multicenter Randomized Controlled Trial

Background

Arteriovenous fistula (AVF) puncture pain is an inevitable problem for maintenance hemodialysis (MHD) patients and may seriously endanger the physical and mental health of patients with MHD. Studies have shown that drug or nondrug measures can reduce AVF puncture pain, but much improvement is needed. When combined with compound lidocaine cream (CLC) in the treatment of AVF puncture pain, auricular point acupressure (APA)—a therapeutic method in which specific points on the auricle of the outer ear are stimulated to treat various disorders of the body—and the therapeutic value and synergistic effects of auriculotherapy merit further investigation.

Methods

120 MHD patients were recruited at blood purification centers in three hospitals between January 2016 and April 2019. After completion of the baseline survey, all patients were randomly divided by the envelope method into a control group, APA group, CLC group, and APA combined with CLC, with 30 subjects per group. The numerical rating scale (NRS) of pain was used to measure the pain before intervention and 1, 4, and 8 weeks after intervention. The State-Trait Anxiety Inventory (STAI), General Comfort Questionnaire (GCQ), blood pressure, and heart rates were obtained before and after the intervention.

Results

Pain, anxiety, comfort, blood pressure (BP), and heart rates (HR) of the three groups were better than those of the control group; the difference was statistically significant (P < 0.05). In addition, the APA combined with CLC group was better than the APA group and CLC group, respectively, in those outcomes (P < 0.05).

Conclusion

Both APA and CLC can effectively relieve AVF puncture pain, and the combined application has more outstanding effects.

Risks and Safety of Extended Auricular Therapy: A Review of Reviews and Case Reports of Adverse Events

OBJECTIVE

Auricular acupuncture (AA) and extended auricular therapy (AT) are a part of acupuncture practice shown to benefit patients with pain, anxiety, and other conditions, with cost-effective access enhanced when given in a group setting. Yet there are safety concerns and risks, perhaps unnecessary risks, that attend embedded, indwelling needles applied to the ear as a means of extended AT.

METHODS

Electronic searches were conducted in PubMed, MEDLINE, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL) for "auriculotherapy," "auricular acupuncture" or "auricular acupressure," "safety," "adverse events," "chondritis," and "perichondritis," with additional manual review of titles, links, and reference lists. Individual auricular therapy adverse event (AE) case reports were included, as well as systematic reviews and or meta-analyses if they evaluated AEs associated with AT.

RESULTS

Nineteen auricular AE case reports and nine safety reviews of or including auriculotherapy were included. Ten systematic reviews of AT with eight specific reviews of auricular acupressure (AP) were also included.

CONCLUSIONS

The primary AE risks is infection, perichondritis, and chondritis stemming from embedded or indwelling needles or potential inadvertent needlesticks from contaminated roaming sharps. Extended AP i.e., application of spheres, preferably seeds (natural, nontoxic botanical Vaccaria seeds) provides clinical benefit without the risks associated with embedded needles. More research is needed to establish if embedded needles at the ear are even necessary or have any advantage over in-session auricular acupuncture for immediate pain relief followed by ear acupressure.

Additional value of auricular intradermal acupuncture alongside selective serotonin reuptake inhibitors: a single-blinded, randomized, sham-controlled preliminary clinical study

BACKGROUND

To evaluate the antidepressant effects of auricular intradermal acupuncture (AIA) of areas innervated by both the auricular branch of the vagus nerve and the trigeminal nerve.

METHODS

Forty-nine patients with depression were randomly allocated into an AIA group (n = 25) and a sham AIA group (n = 24). Both groups received selective serotonin reuptake inhibitors (SSRIs) as conventional treatment. The AIA group received AIA stimulation, and the sham AIA group received sham AIA, which constituted being subjected to an attached needle that did not penetrate the skin. The needles were retained for 4 h each session, with five sessions a week for a total duration of 2 weeks. The outcomes were assessed by the 17-item Hamilton depression rating scale (HAMD-17), five factors (sleep disorder, retardation, cognitive dysfunction, anxiety/somatization, and weight) and self-rating depression scale (SDS) at weeks 0, 1, and 2.

RESULTS

Fifty-four patients were randomly assigned to the AIA (n = 27) and sham AIA group (n = 27), of whom 25 patients in the AIA and 24 patients in the sham AIA group were analyzed. AIA-treated patients displayed a significantly greater reduction from baseline in HAMD-17 scores (p = 0.03) and SDS scores (p = 0.02) at week 2 compared to patients receiving sham AIA. The AIA intervention also produced a higher rate of clinically significant responses in sleep disorders (p = 0.07) compared to sham AIA. No adverse events occurred in either group.

CONCLUSION

According to the findings of this preliminary study, AIA appears to have additional value compared to SSRIs alone in treating patients with depressive disorder.

tDCS peripheral nerve stimulation: a neglected mode of action?

Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation method widely used by neuroscientists and clinicians for research and therapeutic purposes. tDCS is currently under investigation as a treatment for a range of psychiatric disorders. Despite its popularity, a full understanding of tDCS's underlying neurophysiological mechanisms is still lacking. tDCS creates a weak electric field in the cerebral cortex which is generally assumed to cause the observed effects. Interestingly, as tDCS is applied directly on the skin, localized peripheral nerve endings are exposed to much higher electric field strengths than the underlying cortices. Yet, the potential contribution of peripheral mechanisms in causing tDCS's effects has never been systemically investigated. We hypothesize that tDCS induces arousal and vigilance through peripheral mechanisms. We suggest that this may involve peripherally-evoked activation of the ascending reticular activating system, in which norepinephrine is distributed throughout the brain by the locus coeruleus. Finally, we provide suggestions to improve tDCS experimental design beyond the standard sham control, such as topical anesthetics to block peripheral nerves and active controls to stimulate non-target areas. Broad adoption of these measures in all tDCS experiments could help disambiguate peripheral from true transcranial tDCS mechanisms.

Transcutaneous Auricular Vagus Nerve Stimulation: From Concept to Application

Whether in the West or the East, the connection between the ear and the rest of the body has been explored for a long time. Especially in the past century or more, the relevant theoretical and applied research on the ear has greatly promoted the development of ear therapy, and finally the concept of transcutaneous auricular vagus nerve stimulation (taVNS) has been proposed. The purpose of taVNS is to treat a disease non-invasively by applying electrical current to the cutaneous receptive field formed by the auricular branch of the vagus nerve in the outer ear. In the past two decades, taVNS has been a topic of basic, clinical, and transformation research. It has been applied as an alternative to drug treatment for a variety of diseases. Based on the rapid understanding of the application of taVNS to human health and disease, some limitations in the development of this field have also been gradually exposed. Here, we comprehensively review the origin and research status of the field.

Non-invasive vagus nerve stimulation attenuates proinflammatory cytokines and augments antioxidant levels in the brainstem and forebrain regions of Dahl salt sensitive rats

The anti-inflammatory effects of vagus nerve stimulation are well known. It has recently been shown that low-level, transcutaneous stimulation of vagus nerve at the tragus (LLTS) reduces cardiac inflammation in a rat model of heart failure with preserved ejection fraction (HFpEF). The mechanisms by which LLTS affect the central neural circuits within the brain regions that are important for the regulation of cardiac vagal tone are not clear. Female Dahl salt-sensitive rats were initially fed with either low salt (LS) or high salt (HS) diet for a period of 6 weeks, followed by sham or active stimulation (LLTS) for 30 min daily for 4 weeks. To study the central effects of LLTS, four brainstem (SP5, NAb, NTS, and RVLM) and two forebrain sites (PVN and SFO) were examined. HS diet significantly increased the gene expression of proinflammatory cytokines in the SP5 and SFO. LLTS reversed HS diet-induced changes at both these sites. Furthermore, LLTS augmented the levels of antioxidant Nrf2 in the SP5 and SFO. Taken together, these findings suggest that LLTS has central anti-inflammatory and antioxidant properties that could mediate the neuromodulation of cardiac vagal tone in the rat model of HFpEF.

The Use of Complementary and Alternative Medicine (CAM) in Psychiatric Units in Sweden

Mental ill-health has been termed the pandemic of the 21^st century, and a large share of those exposed do not receive treatment. Many people with depression, anxiety and other mental health problems consult complementary or alternative medicine (CAM), and CAM is used in conventional psychiatric care, in Sweden and in other countries. However, the extent to which CAM is used in psychiatric care, and for what purposes, are largely unknown. This study is based on a survey distributed to all heads of regional, municipal, private and governmental health care units treating persons with psychiatric symptoms across Sweden in 2019. CAM was reportedly used by 62% of the 489 responding health care units, for symptoms including anxiety, sleep disturbances and depression. Main motivations for CAM use were symptom relief, meeting patients' requests and reduced demand for pharmaceutical medication. Very few respondents reported side effects. The most common reason for interrupting CAM use at a unit was a lack of trained professionals. This study confirms the need for further research about CAM, and for CAM education and training among healthcare professionals.

Non-invasive Auricular Vagus Nerve Stimulation as a Potential Treatment for Covid19-Originated Acute Respiratory Distress Syndrome

Background: Covid-19 is an infectious disease caused by an invasion of the alveolar epithelial cells by coronavirus 19. The most severe outcome of the disease is the Acute Respiratory Distress Syndrome (ARDS) combined with hypoxemia and cardiovascular damage. ARDS and co-morbidities are associated with inflammatory cytokine storms, sympathetic hyperactivity, and respiratory dysfunction. Hypothesis: In the present paper, we present and justify a novel potential treatment for Covid19-originated ARDS and associated co-morbidities, based on the non-invasive stimulation of the auricular branch of the vagus nerve. Methods: Auricular vagus nerve stimulation activates the parasympathetic system including anti-inflammatory pathways (the cholinergic anti-inflammatory pathway and the hypothalamic pituitary adrenal axis) while regulating the abnormal sympatho-vagal balance and improving respiratory control. Results: Along the paper (1) we expose the role of the parasympathetic system and the vagus nerve in the control of inflammatory processes (2) we formulate our physiological and methodological hypotheses (3) we provide a large body of clinical and preclinical data that support the favorable effects of auricular vagus nerve stimulation in inflammation, sympatho-vagal balance as well as in respiratory and cardiac ailments, and (4) we list the (few) possible collateral effects of the treatment. Finally, we discuss auricular vagus nerve stimulation protective potential, especially in the elderly and co-morbid population with already reduced parasympathetic response. Conclusions: Auricular vagus nerve stimulation is a safe clinical procedure and it could be either an effective treatment for ARDS originated by Covid-19 and similar viruses or a supplementary treatment to actual ARDS therapeutic approaches.

Auricular neural stimulation as a new non-invasive treatment for opioid detoxification

The recent opioid crisis is one of the rising challenges in the history of modern health care. New and effective treatment modalities with less adverse effects to alleviate and manage this modern epidemic are critically needed. The FDA has recently approved two non-invasive electrical nerve stimulators for the adjunct treatment of symptoms of acute opioid withdrawal. These devices, placed behind the ear, stimulate certain cranial nerves with auricular projections. This neural stimulation reportedly generates a prompt effect in terms of alleviation of withdrawal symptoms resulting from acute discontinuation of opioid use. Current experimental evidence indicates that this type of non-invasive neural stimulation has excellent potential to supplement medication assisted treatment in opioid detoxification with lower side effects and increased adherence to treatment. Here, we review current findings supporting the use of non-invasive neural stimulation in detoxification from opioid use. We briefly outline the neurophysiology underlying this approach of auricular electrical neural stimulation and its role in enhancing medication assisted treatment in treating symptoms of opioid withdrawal. Considering the growing deleterious impact of addictive disorders on our society, further studies on this emerging treatment modality are warranted.

Magnetic Non-invasive Auricular Acupuncture During Eye-Exam for Retinopathy of Prematurity in Preterm Infants: A Multicentre Randomized Controlled Trial

Background: Eye exam for Retinopathy of prematurity (ROP) is a painful procedure and pharmacological analgesia might be ineffective. We hypothesized that magnetic auricular acupuncture (MAA) compared to placebo will decrease pain during ROP exam in preterm infants. Methods: Multicentre randomized controlled trial conducted in three hospitals (Australia, Canada, and Malaysia). Eligibility: >32 weeks, ROP exam, not sedated, and parental consent. A total of 100 infants were randomized (1:1) to MAA (n = 50) or placebo (n = 50). MAA stickers or placebo were placed on both ears by an unblinded investigator. Pain was assessed using the Premature Infant Pain Profile. Primary analyses were by intention-to-treat. ClinicalTrials.gov:NCT03650621. Findings: The mean (standard deviation, SD) gestation, birthweight, and postnatal age were (MAA 28(3) vs. placebo 28(2) weeks; MAA 1,057(455) vs. placebo 952(273) g; MAA 7(3) vs. placebo 7(3) weeks. Placebo infants had significantly higher PIPP scores during [mean difference 1.6 points (95%CI 0.1-3.1)] and 1 h mean difference 1.5 points (95%CI 0.7-2.2) after the procedure (p < 0.03). Heart rate was lower (173(22) vs. 184(18)/min) and oxygen saturations were higher (93.8(6.2) vs. 91.7(6.1)%, p = 0.05) in MAA infants. No adverse effects. Interpretation: MAA may reduce physiological pain responses during and after ROP exam in preterm infants. Assessment of long-term effects are warranted. Clinical trial registration: www.ClinicalTrials.gov, identifier: NCT03650621.

Auriculotherapy to control chemotherapy-induced nausea and vomiting in patients with cancer: protocol of a systematic review

BACKGROUND

Due to the worldwide rise in cancer incidence, and therefore the rise in the need for antineoplastic chemotherapy, it is important for both healthcare professionals and patients alike that the side effects of chemotherapy, such as chemotherapy-induced nausea and vomiting (CINV), are treated and prevented. Auriculotherapy is a type of acupuncture and may be a low-cost and safe antiemetic measure to control the side effects of chemotherapy. The goal of this systematic review is to synthesize the available evidence in the literature regarding the auriculotherapy effects to treat CINV in people with cancer.

METHODS

The review will only include randomized controlled trials (RCTs) that compare the clinical effects of the auriculotherapy intervention (used alone or as an add-on), with sham auriculotherapy, routine treatment with antiemetic drugs, or other non-pharmacological interventions in patients with cancer with CINV who are undergoing chemotherapy. The outcomes to be evaluated are nausea and vomiting: in acute, delayed, or anticipated stages, when induced by chemotherapy. A comprehensive search for studies will be carried out in these databases: MEDLINE via PubMed, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, ICTRP, LILACS, CUMED, IBECS, BVS MTCI Americas, Web of Science, Scopus, PEDro, CNKI, and CBMdisc up until December 31, 2018. Only articles in English, Portuguese, and Spanish will be selected. Two independent reviewers will evaluate full texts, extract data, and assess the risk of bias of eligible articles. The quality of evidence will be assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). A meta-analysis will be undertaken to assess the interventions and outcomes' homogeneity, assessing statistical heterogeneity using the Cochran's Q test and quantified using Higgins' inconsistency index. If there is insufficient data for a meta-analysis, a narrative synthesis will be presented. This protocol has been prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines.

DISCUSSION

The results of this systematic review will summarize the strength of evidence for the use of auriculotherapy in the control of CINV of patients with cancer and will be used to identify evidence gaps.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018117513.

Current Directions in the Auricular Vagus Nerve Stimulation I - A Physiological Perspective

Electrical stimulation of the auricular vagus nerve (aVNS) is an emerging technology in the field of bioelectronic medicine with applications in therapy. Modulation of the afferent vagus nerve affects a large number of physiological processes and bodily states associated with information transfer between the brain and body. These include disease mitigating effects and sustainable therapeutic applications ranging from chronic pain diseases, neurodegenerative and metabolic ailments to inflammatory and cardiovascular diseases. Given the current evidence from experimental research in animal and clinical studies we discuss basic aVNS mechanisms and their potential clinical effects. Collectively, we provide a focused review on the physiological role of the vagus nerve and formulate a biology-driven rationale for aVNS. For the first time, two international workshops on aVNS have been held in Warsaw and Vienna in 2017 within the framework of EU COST Action "European network for innovative uses of EMFs in biomedical applications (BM1309)." Both workshops focused critically on the driving physiological mechanisms of aVNS, its experimental and clinical studies in animals and humans, in silico aVNS studies, technological advancements, and regulatory barriers. The results of the workshops are covered in two reviews, covering physiological and engineering aspects. The present review summarizes on physiological aspects - a discussion of engineering aspects is provided by our accompanying article (Kaniusas et al., 2019). Both reviews build a reasonable bridge from the rationale of aVNS as a therapeutic tool to current research lines, all of them being highly relevant for the promising aVNS technology to reach the patient.

Current Directions in the Auricular Vagus Nerve Stimulation II - An Engineering Perspective

Electrical stimulation of the auricular vagus nerve (aVNS) is an emerging electroceutical technology in the field of bioelectronic medicine with applications in therapy. Artificial modulation of the afferent vagus nerve - a powerful entrance to the brain - affects a large number of physiological processes implicating interactions between the brain and body. Engineering aspects of aVNS determine its efficiency in application. The relevant safety and regulatory issues need to be appropriately addressed. In particular, in silico modeling acts as a tool for aVNS optimization. The evolution of personalized electroceuticals using novel architectures of the closed-loop aVNS paradigms with biofeedback can be expected to optimally meet therapy needs. For the first time, two international workshops on aVNS have been held in Warsaw and Vienna in 2017 within the scope of EU COST Action "European network for innovative uses of EMFs in biomedical applications (BM1309)." Both workshops focused critically on the driving physiological mechanisms of aVNS, its experimental and clinical studies in animals and humans, in silico aVNS studies, technological advancements, and regulatory barriers. The results of the workshops are covered in two reviews, covering physiological and engineering aspects. The present review summarizes on engineering aspects - a discussion of physiological aspects is provided by our accompanying article (Kaniusas et al., 2019). Both reviews build a reasonable bridge from the rationale of aVNS as a therapeutic tool to current research lines, all of them being highly relevant for the promising aVNS technology to reach the patient.

Auriculotherapy in primary health care: A large-scale educational experience in Brazil

Auriculotherapy consists of physical stimuli applied to the outer ear and is commonly associated with traditional Chinese medicine (TCM). The authors present and discuss the development of a course that offers a semi-on-site auriculotherapy course for Brazilian primary health care (PHC) professionals. The course was funded by the Brazilian Ministry of Health and developed at the Federal University of Santa Catarina in 2015 by a team of experts in auriculotherapy. It consisted of 75 h of distance learning (five sequential modules) and 5 h of on-site learning. The modules included the following items: (1) introduction to integrative practices; (2) ear reflexology; (3) introduction to TCM; (4) biomedical view of auriculotherapy; and (5) auriculotherapy in PHC. The teaching material included a workbook for each module, 14 video lectures and an interactive ear (online resource) to study location and application to the main auricular points. The on-site lectures follow a structured script of ear palpation techniques, auricular seed insertion practice and clinical case discussions, under the supervision of trained instructors. The course was offered in 2016 and 2017 and on-site lectures took place in 25 cities, covering all Brazilian regions, in coordination with municipal or state boards of health. A total of 4273 health professionals concluded the training and their evaluation of the course was highly positive. The Brazilian experience of large-scale training shows the potential to disseminate auriculotherapy in the context of PHC, given that its practice is fast, easy to learn, safe, effective for different health problems and well accepted by the patients.