Transcutaneous Nerve Stimulation Research Articles

Efficacy of Otago versus Bosu ball exercise protocol on core stabilization, static and dynamic balance in non-specific chronic low back pain: a randomized parallel arm clinical trial

Abstract Chronic non-specific low back pain (NSLBP) is a pain and stiffness in the lower back region for which specific cause of the pain is unknown. Otago exercises and Bosu ball exercises aim to improve balance and reduce pain and disability. There is a lack of literature where these approaches are not compared and hence the need arises to evaluate their efficacy in the management of NSLBP. A randomized parallel arm clinical trial was conducted in physiotherapy outpatient department at tertiary care center located in Belagavi city, India. 36 individuals with NSLBP, where 18 individuals were randomly allocated into two groups, i.e. Group A (Otago exercise) and Group B (both sides utilized (Bosu) ball exercise). Both the groups received conventional therapy (hot moist pack and interferential current therapy) 3 times/ week for 4 weeks. Outcome measures like plank holding test, star excursion balance test (SEBT), single-leg stance test (SLST), visual analogue scale (VAS) and Oswestry disability index (ODI) were assessed at baseline and on day 12 post-treatment. A within-group analysis using the Wilcoxon matched-pairs test and the dependent t-test showed statistically significant improvements in all outcome measures (). Between group analysis has shown both interventions to be equally effective in ODI () in individuals with NSLBP. In conclusion both Otago and Bosu ball exercises were effective, Bosu ball exercise demonstrated greater efficacy in enhancing core stability, static and dynamic balance, as well as reducing disability and pain in individuals with chronic NSLBP. Clinical trial registry of India: registration number CTRI/2023/11/059489

Application of Electrical Stimulation in BCI in Patients with Alzheimer’s Disease

This paper systematically discusses the application prospect of neuromodulation technology in the treatment of Alzheimer’s disease (AD). It focuses on the potential role of various techniques, including transcutaneous electrical nerve stimulation (TENS), deep brain stimulation (DBS), repeated transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), in improving the cognitive function of AD patients. With the aggravation of the global aging problem, the incidence of AD is increasing year by year, and the existing treatment methods are difficult to effectively prevent the progress of the disease. Studies have shown that technologies such as TENS and DBS can improve patients’ memory and cognitive function to some extent. For example, a study by Smith et al. (2020) found that DBS applied to the fornix resulted in a 20% improvement in memory scores over a 6-month period. However, due to the small sample size and inconsistent experimental design, the universality and reliability of the existing research results are still limited. Future studies should aim for larger, more diverse sample sizes and standardized experimental protocols to enhance the robustness of findings. This article reviews the latest research results of these neuromodulation techniques, emphasizing the importance of optimizing treatment parameters and expanding the scale of clinical trials. The paper is structured as follows: first, this paper discusses each neuromodulation technique in detail; then, this paper analyzes their potential benefits and limitations; finally, this paper provides recommendations for future research directions.

Home Transcutaneous Electrical Stimulation Rehabilitation Program for Patients With Ankylosing Spondylitis: Crossover Trial.

Maintaining physical function and preserving spinal flexibility have been challenging in managing ankylosing spondylitis (AS). Most rehabilitation programs, including manual therapy, massage, hydrotherapy, and acupuncture, cannot be performed at home. The effect of transcutaneous electrical nerve stimulation (TENS) was validated in treating AS, but no home TENS system has explored its efficacy to date. This study aims to evaluate the efficacy of a home TENS system with a novel treatment program for patients with AS. The modified WeHeal TS-200 TENS and galvanic response system provided home-based TENS treatment for patients with AS. Patients were divided into a 2-month course group and a 1-month course group. After the first treatment course, patients went through a washout period for the same duration of their treatment course. Participants could decide whether to accept the second course of treatment. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Schober test, finger-to-floor flexion test, enthesis score, cytokines, chemokines, inflammatory factors, and immunoglobulins were measured to evaluate its efficacy. The clinical trial protocol (1096607481) received approval from the Ministry of Health and Welfare in Taiwan. A total of 9 patients (5 in a 2-month course group and 4 in a 1-month course group) completed the first treatment course, and 5 patients (4 in a 2-month course group and 1 in a 1-month course group) completed the sequential treatment course. The weighted results showed that patients reported an improving BASFI score (mean difference -0.9, SD 1.7; P=.03) after treatment. Looking into the trajectories, declined BASFI and BASDAI scores were noticed during treatments; this score increased during the washout period. There were improving trends in the Schober test (mean difference 1.9, SD 4.9; P=.11) and finger-to-floor flexion test (mean difference -0.6, SD 9.5; P=.79), but the results were not statistically significant. The response of cytokines, chemokines, inflammatory factors, and immunoglobulins before and after treatment did not show a consistent trend, and all results were not statistically significant (all P>.05). The home TENS device demonstrated a potential role in AS management. It may improve accessibility and adherence for patients with AS and provide remote monitoring for clinicians. Further research can compare the effectiveness of electrotherapy at home or in a medical setting and focus on integrating the home TENS system and exercise program to enhance patients' physical functions and spinal flexibility.

Effects of Cervical Mobilization on Balance and Proprioception in Patients With Nonspecific Neck Pain

ObjectiveThis study investigates the effect of cervical mobilization on balance and cervical proprioception in patients with nonspecific neck pain. MethodsA prospective, double-blind, randomized clinical trial was conducted involving a 3-week treatment protocol for which 66 patients were randomly assigned to 2 groups. Both groups underwent conventional physiotherapy (hot pack and transcutaneous electrical nerve stimulation) twice a week for 3 weeks along with additional cervical mobilization in the mobilization group, and sham mobilization in the sham control group. Static and dynamic balance, cervical proprioception, cervical mobility, and pain intensity were evaluated using a Kinesthetic Skill Training System 3000 device, the “Joint Position Error Test,” Cervical Range-of-Motion Instrument, and the visual analog scale, respectively. ResultsAfter treatment, significant improvements were noted in dynamic balance, mobility, pain intensity (P < .001, P < .001, P < .001, respectively), and proprioception in the left direction of rotation in the mobilization group (P = .003) that were significantly greater than those observed in the sham mobilization group (P < .001, P < .001, P < .001, P = .003, respectively). Although a significant decrease was observed in the deficits of static balance (P = .044) and proprioception in the right direction of rotation (P = .011) after mobilization, the changes were similar in both the mobilization and sham mobilization groups (P = .192, P = .154, respectively). ConclusionCervical mobilization led to significant improvements in dynamic balance, pain intensity, mobility, and partial improvements to proprioception in a comparison with a sham mobilization group, while the effect on static balance was not significant.

Transcutaneous auricular vagus nerve stimulation mitigates gouty inflammation by reducing neutrophil infiltration in BALB/c mice

Gouty inflammation, caused by uric acid crystal deposition, primarily affects tissues around the toe joints and triggers potent inflammatory responses. Current treatments focus on alleviating inflammation and pain using pharmaceutical agents, which can lead to side effects and complications. This has generated interest in non-pharmacological interventions, such as non-invasive vagus nerve stimulation (VNS). In this study, we explored the anti-inflammatory mechanisms of transcutaneous auricular vagus nerve stimulation (taVNS) in a mouse model of acute gout. Gouty inflammation was induced by injecting monosodium urate (MSU) crystals into the ankle joints of BALB/c mice. The effects of taVNS on the expression of inflammatory cytokines and chemokines in the ankle joint tissue were assessed using real-time quantitative PCR (qPCR), western blotting, histological assessments (H&E staining), and immunohistochemistry (IHC). The role of α7 nicotinic acetylcholine receptors (α7nAChR) was also evaluated by signal blocking. Our findings revealed that MSU significantly elevated gout-associated inflammatory cascades and mediators in the ankle joint. Notably, taVNS at 200 µA and 25 Hz effectively reduced these inflammatory responses, decreasing neutrophil infiltration and chemoattraction within the tissue. taVNS showed significant anti-inflammatory properties by suppressing neutrophil activity, offering a novel therapeutic approach for gout beyond conventional pharmacological methods. Additionally, taVNS holds potential for managing various chronic joint diseases. These results highlight taVNS as a promising non-pharmacological therapy for chronic inflammation.

Comparative efficacy of non-pharmacological interventions on xerostomia and salivary flow rate among hemodialysis patients: a systematic review and network meta-analysis

Abstract Background Xerostomia is a distressing symptom experienced by patients undergoing dialysis. We sought to compare and rank the efficacy of different non-pharmacological interventions on xerostomia and salivary flow rate among dialysis patients. Methods A systematic search was conducted in six English databases: Pubmed, CINAHL, Scopus, Web of Science, Embase, and Cochrane trials, in April 2023. Screening, quality appraisal, and data extraction were undertaken by two independent reviewers. A network meta-analysis was performed to assess the relative efficacy of different non-pharmacological interventions. Results The analysis included 11 randomized controlled trials involving 739 patients and eight non-pharmacological interventions. The pairwise analysis indicated that in comparison with the control group, sugarless candy, chewing sugarless gum, acupressure auricular, and licorice mouthwash had a significant positive effect on reducing the severity of xerostomia, also transcutaneous electrical nerve stimulation (TENS), licorice mouthwash, sugarless chewing gum, photobiomodulation, and pure water mouthwash, significantly improved saliva flow rate. The network analysis indicated that sugarless chewing gum significantly reduced the symptoms of xerostomia, while TENS and sugarless chewing gum were effective in improving UWS. Chewing sugarless gum and using TENS were the top-ranked interventions for relieving xerostomia and enhancing saliva flow rate among dialysis patients, respectively. Conclusions Several non-pharmacological interventions have demonstrated effectiveness in relieving xerostomia and enhancing saliva flow rates. While further research may be needed to confirm and refine these findings the interventions used in this review offer promising results and should be incorporated into the standard care of dialysis patients experiencing these symptoms to enhance their quality of life and oral health.

Unilateral and Bilateral Transcutaneous Tibial Nerve Stimulation in Women With Overactive Bladder Syndrome: A Randomized Controlled Study (UBTTNS-OAB Study).

The efficacy of unilateral versus bilateral Transcutaneous Tibial Nerve Stimulation (TTNS) for women with Overactive Bladder Syndrome (OAB) remains uncertain. To compare the efficacy of unilateral and bilateral TTNS in the tibial region in women with OAB. This randomized, controlled, triple-blind clinical trial included women with OAB or urgency-predominant urinary incontinence (UUI). Participants were randomized (1:1) into the Unilateral Tibial Group or Bilateral Tibial Group. Before treatment, they underwent a pre-assessment including peripheral sensitivity examination and completion of sociodemographic data and seven validated questionnaires on urinary symptoms, quality of life, sleep, and psycho-emotional aspects. TTNS interventions were administered twice weekly (12 sessions, 30 min each). Posttreatment, participants underwent another physical examination and completed the same questionnaires, with a 30-day follow-up. Categorical variables were analyzed using Chi-square or Fisher's Exact Test, while numerical variables were assessed with the Mann-Whitney test. Group comparisons over time utilized intention-to-treat ANOVA (p < 0.05). Thirty-five women participated: 17 in the unilateral group and 18 in the bilateral group. Mean ages were 55.1 (±14.7) years and 52.7 (±12.6) years, respectively (p = 0.680). Initial OAB severity (ICIQ-OAB) did not differ significantly between groups (p = 0.561). Both groups showed significant improvement in ICIQ-OAB scores: unilateral group from 10.1 (±3.4) to 5.8 (±3.4) (p < 0.001), bilateral group from 9.3 (±3.3) to 5.1 (±4) (p < 0.001), with no intergroup difference (p = 0.395). Improvement in UUI symptoms was observed: unilateral group from 2.2 (±1.4) to 0.7 (±1.5), bilateral group from 1.5 (±1.9) to 0.2 (±0.5), without significant intergroup difference (p = 0.645). Quality of life scores improved similarly between groups (p = 0.055). TTNS appears to be effective in improving bladder storage and UUI symptoms in women with OAB, with no difference between unilateral and bilateral applications. Brazilian Registry of Clinical Trials (REBEC) (RBR: 96f2fgkn).

Possible Glycemic Effects of Vagus Nerve Stimulation Evaluated by Continuous Glucose Monitoring in People with Diabetes and Autonomic Neuropathy: A Randomized, Sham-Controlled Trial.

Objective: Autonomic neuropathy is associated with dysglycemia that is difficult to control. We investigated if transcutaneous vagus nerve stimulation (tVNS) could improve glycemic levels. Methods: We randomized 145 individuals with type 1 diabetes (T1D) (n = 70) or type 2 diabetes (T2D) (n = 75) and diabetic autonomic neuropathy (DAN) to self-administered treatment with active cervical tVNS (n = 68) or sham (n = 77) for 1 week (4 daily stimulations) and 8 weeks (2 daily stimulations), separated by a wash-out period of at least 2 weeks. Continuous glucose monitoring (CGM) indices were measured for 104 participants starting 5 days prior to intervention periods, during the 1-week period, and at end of the 8-week period. Primary outcomes were between-group differences in changes in coefficient of variation (CV) and in time in range (TIR 3.9-10 mmol/L). Secondary outcomes were other metrics of CGM and HbA1c. Results: For the 1-week period, median [interquartile range] changes of CV from baseline to follow-up were -1.1 [-4.3;2.0] % in active and -1.5 [-4.4;2.5] % in sham, with no significance between groups (P = 0.54). For TIR, the corresponding changes were 2.4 [-2.1;7.4] % in active and 5.1 [-2.6;8.8] in sham group (P = 0.84). For the 8-week treatment period, changes in CV and TIR between groups were also nonsignificant. However, in the subgroup analysis, persons with T1D receiving active tVNS for 8 weeks had a significant reduction in CV compared with the T1D group receiving sham stimulation (estimated treatment effect: -11.6 [95% confidence interval -20.2;-2.0] %, P = 0.009). None of the changes in secondary outcomes between treatment groups were significantly different. Conclusions: Overall, no significant changes were observed in CGM metrics between treatment arms, while individuals with T1D and DAN decreased their CV after 8 weeks of tVNS treatment.

Low-value interventions to deimplement: A secondary analysis of a systematic review of low back pain clinical practice guidelines.

To perform a secondary review of low back pain (LBP) clinical practice guidelines (CPG) identified in a recently conducted systematic review and to synthesize and summarize low-value recommendations as practices that may be candidates for deimplementation. LBP (subacute or chronic) CPGs in English (symptom based, created by a governmental or professional society, published between January 1990 and May 2020) were previously identified using MEDLINE, EMBASE, CINAHL, Ortho Guidelines, CPG Infobase, Emergency Care Research Institute, Guidelines International Network, National Institute of Health and Care Excellence, and Scottish Intercollegiate Guideline Network. Twenty-one CPGs were reviewed from a systematic review (previously published). Full-text review of all 21 CPGs was conducted, and three recommendation categories indicative of low value (recommend strongly against, recommend weakly against, inconclusive/insufficient evidence) were identified using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) language and approach. One hundred thirty-five low-value recommendations were identified and classified under eight intervention categories: orthotics/support, traction, physical modalities, pharmacological interventions, injections, surgery, bed rest, and miscellaneous. Traction, transcutaneous electrical nerve stimulation (TENS), therapeutic ultrasound (TUS), and selective serotonin reuptake inhibitors (SSRI) had the most CPGs recommend strongly against their usage. Opioids were recommended strongly against by four CPGs. No significant difference (p > .05) was found between CPG quality and a specific deimplementation recommendation or between CPG quality and the number of strongly against, weakly against, and inconclusive/insufficient evidence recommendations. Clinicians managing patients with chronic LBP should consider deimplementing these low-value interventions (traction, TENS, TUS, and SSRI).

Beyond Painkillers: A Meta-Analysis of Non-Pharmacological Approaches for Managing Dysmenorrhea Symptoms

Dysmenorrhea, commonly known as painful menstruation, is a highly prevalent gynecological condition affecting millions of women globally. While pharmacological interventions offer temporary relief, they often come with undesirable side effects. Non-pharmacological approaches present a potentially safer and more sustainable alternative for managing dysmenorrhea symptoms. A comprehensive search of electronic databases, including PubMed, Scopus, and Web of Science, was conducted to identify randomized controlled trials (RCTs) published between 2014 and 2024 that investigated the effectiveness of non-pharmacological interventions for dysmenorrhea. The primary outcome was pain intensity reduction, while secondary outcomes included quality of life, absenteeism, and medication use. Data were pooled using a random-effects model, and standardized mean differences (SMDs) were calculated. Six RCTs met the inclusion criteria, encompassing a total of 600 participants. The non-pharmacological interventions evaluated included aerobic exercise, yoga, acupuncture, transcutaneous electrical nerve stimulation (TENS), heat therapy, and relaxation techniques. The pooled analysis revealed significant reductions in pain intensity across all interventions compared to control groups (SMD = -2.00, 95% CI: -2.39 to -1.61, p &lt; 0.001). Aerobic exercise and yoga demonstrated the largest effect sizes (SMD = -2.5 and -2.5, respectively). Significant improvements were also observed in quality of life, absenteeism, and medication use. Non-pharmacological approaches, particularly aerobic exercise and yoga, are effective in managing dysmenorrhea symptoms. These findings strongly support the integration of non-pharmacological interventions into clinical practice as a first-line or adjunctive treatment option for dysmenorrhea.

Immediate modulatory effects of transcutaneous vagus nerve stimulation on patients with Parkinson's disease: a crossover self-controlled fMRI study.

Previous studies have evaluated the safety and efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) for the treatment of Parkinson's disease (PD). However, the mechanism underlying the effect of taVNS on PD remains to be elucidated. This study aimed to investigate the immediate effects of taVNS in PD patients. This crossover self-controlled study included 50 PD patients. Each patient underwent three sessions of resting-state functional magnetic resonance imaging (rs-fMRI) under three conditions: real taVNS, sham taVNS, and no taVNS intervention. We analyzed whole-brain amplitude of low-frequency fluctuations (ALFF) from preprocessed fMRI data across different intervention conditions. ALFF values in altered brain regions were correlated with clinical symptoms in PD patients. Forty-seven participants completed the study and were included in the final analysis. Real taVNS was associated with a widespread decrease in ALFF in the right hemisphere, including the superior parietal lobule, precentral gyrus, postcentral gyrus, middle occipital gyrus, and cuneus (voxel p < 0.001, GRF corrected). The ALFF value in the right superior parietal lobule during real taVNS was negatively correlated with the Unified Parkinson's Disease Rating Scale Part III (r = -0.417, p = 0.004, Bonferroni corrected). TaVNS could immediately modulate the functional activity of brain regions involved in superior parietal lobule, precentral gyrus, postcentral gyrus, middle occipital gyrus, and cuneus. These findings offer preliminary insights into the mechanism of taVNS in treating PD and bolster confidence in its long-term therapeutic potential. TaVNS appears to reduce ALFF values in specific brain regions, suggesting a potential modulation mechanism for treating PD.

Management of menstrual and endometriosis-associated pain from a physiotherapy perspective

Both menstrual pain and endometriosis affect a significant number of individuals worldwide. Although medication and surgery are often recommended paths of treatment, approximately 40% of people still suffer from ongoing problems, especially persistent pain. A growing body of literature suggests that physiotherapy may have a significant role to play in treatment; for example, transcutaneous electrical nerve stimulation for non-invasive pain relief, exercise prescription and addressing the effects of central sensitization. This clinical commentary reviews the issues faced by those dealing with both dysmenorrhea and endometriosis. It also reviews the literature on the current and potential roles of physiotherapy in improving quality of life via a low-risk, low-cost, but very effective, array of interventions within our scope of practice.

Ultrasound guided transcutaneous phrenic nerve stimulation in critically ill patients: a new method to evaluate diaphragmatic function.

Diaphragm dysfunction is common in intensive care unit and associated with weaning failure and mortality. Diagnosis gold standard is the transdiaphragmatic or tracheal pressure induced by magnetic phrenic nerve stimulation. However, the equipment is not commonly available and requires specific technical skills. We aimed to evaluate ultrasound guided transcutaneous phrenic nerve stimulation for daily bedside assessment of diaphragm function by targeted electrical phrenic nerve stimulation. In this randomized cross-over study we compared a new method of ultrasound guided transcutaneous electrical phrenic nerve stimulation (SONOTEPS method) using a peripheral nerve stimulator, with the magnetic phrenic nerve stimulation. Intensive care unit adult patients under mechanical ventilation with a Richmond-Agitation-Sedation-Scale score of -4 or -5 were included. Each patient received the two methods of stimulation, in a randomized order. The primary outcome was the tracheal pressure (Ptrach) induced by stimulation. We analyzed 232 measures of Ptrach from 116 patients of whom 77 presented a diaphragm dysfunction (Ptrach < 11 cmH2O) and 50 a severe diaphragm dysfunction (Ptrach < 8 cmH2O). The Passing-Bablok regression showed no significant differences (intercept A of -0.03 [CI95:-0.83-0.52] and slope B of 0.98 [CI95:0.90-1.05]) between SONOTEPS method and magnetic stimulation which were positively correlated (R²=0.639). The mean bias was -1.08 (CI95 5.02, -7.18) cmH2O. The receiver operating curves showed an excellent performance for the diagnosis of diaphragm dysfunction and severe diaphragm dysfunction with respectively an area under curve of 0.90 (CI95 0.83-0.97) and 0.88 (CI95 0.82-0.95). This performance was not significantly affected by the body mass index or the presence of a neck catheter. The SONOTEPS method is a simple and accurate tool for bedside assessment of diaphragm function with ultrasound guided transcutaneous phrenic nerve stimulation in sedated patients with no or minimal spontaneous respiratory activity.

Transcutaneous Tibial Nerve Stimulation for Quality-of-Life Improvement and Sleep Deficiency in Women with Primary Dysmenorrhea: A Randomized Clinical Trial.

Background: Primary dysmenorrhea is a leading cause of chronic cyclic pelvic pain, contributing to a reduced quality of life and sleep disturbances in women. The objective of this study was to assess the effectiveness of transcutaneous tibial nerve stimulation (TTNS) in improving the quality of life, sleep, and overall health perceptions of participants compared to a control group of women with dysmenorrhea over short-term, medium-term, and long-term periods. Methods: A single-blind, controlled clinical trial was conducted, with participants randomly assigned to an experimental group (receiving TTNS) or a control group (receiving sham TTNS). Both groups underwent 12, weekly 30 min sessions using the NeuroTrac™ PelviTone electrostimulation device. Outcomes related to quality of life, sleep deficiency, and overall improvement were evaluated at three time points: short-term (post-treatment), medium-term (1-3 months), and long-term (6 months). Results: Of the 61 participants initially randomized (31 in the experimental group and 30 in the control group), 55 completed the study and were included in the final analysis. A statistically significant improvement was observed in the experimental group in both physical and mental health components, as measured by the SF-36v2® questionnaire, following 12 weeks of intervention, compared to the control group, persisting 6 months after the intervention. Additionally, statistically significant differences in overall improvement were noted between the two groups, as measured by the PGIC questionnaire at the end of treatment (p = 0.0103) and 6 months post-treatment (p = 0.0432). Conclusions: TTNS appears to be a safe and effective strategy for enhancing quality of life and overall health in women with PD, potentially reducing the reliance on pharmacological treatments or more invasive methods.

Acute transcutaneous auricular vagus nerve stimulation modulates presynaptic SV2A density in healthy rat brain: An invivo microPET study.

Vagus nerve stimulation (VNS) is the subject of exploration as an adjunct treatment for neurological disorders such as epilepsy, chronic migraine, pain, and depression. A non-invasive form of VNS is transcutaneous auricular VNS (taVNS). Combining animal models and positron emission tomography (PET) may lead to a better understanding of the elusive mechanisms of taVNS. We evaluated the acute effect of electrical stimulation of the left vagus nerve via the ear on brain synaptic vesicle glycoprotein 2A (SV2A) as a measure of presynaptic density and glucose metabolism in naïve rats. Female Sprague-Dawley rats were imaged with [11C]UCB-J (n = 11) or [18F]fluorodeoxyglucose ([18F]FDG) PET (n = 13) on two separate days, (1) at baseline, and (2) after acute unilateral left taVNS or sham stimulation (30 min). We calculated the regional volume of distribution (VT) for [11C]UCB-J and standard uptake values (SUV) for [18F]FDG. We observed regional reductions of [11C]UCB-J binding in response to taVNS ranging from 36% to 59%. The changes in taVNS compared to baseline were significantly larger than those induced by sham stimulation. The differences were observed bilaterally in the frontal cortex, striatum, and midbrain. The [18F]FDG PET uptake remained unchanged following acute taVNS or sham stimulation compared to baseline values. This proof-of-concept study shows for the first time that acute taVNS for 30 min can modulate invivo synaptic SV2A density in cortical and subcortical regions of healthy rats. Preclinical disease models and PET ligands of different targets can be a powerful combination to assess the therapeutic potential of taVNS.

Evaluating phasic transcutaneous vagus nerve stimulation (taVNS) with pupil dilation: the importance of stimulation intensity and sensory perception

The efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) as a non-invasive method to modulate physiological markers of noradrenergic activity of the Locus Coeruleus (LC), such as pupil dilation, is increasingly more discussed. However, taVNS studies show high heterogeneity of stimulation effects. Therefore, a taVNS setup was established here to test different frequencies (10 Hz and 25 Hz) and intensities (3 mA and 5 mA) during phasic stimulation (3 s) with time-synchronous recording of pupil dilation in younger adults. Specifically, phasic real taVNS and higher intensity led to increased pupil dilation, which is consistent with phasic invasive VNS studies in animals. The results also suggest that the influence of intensity on pupil dilation may be stronger than that of frequency. However, there was an attenuation of taVNS-induced pupil dilation when differences in perception of sensations were considered. Specifically, pupil dilation during phasic stimulation increased with perceived stimulation intensity. The extent to which the effect of taVNS induces pupil dilation and the involvement of sensory perception in the stimulation process are discussed here and require more extensive research. Additionally, it is crucial to strive for comparable stimulation sensations during systematic parameter testing in order to investigate possible effects of phasic taVNS on pupil dilation in more detail.

Transcutaneous electrical nerve stimulation therapy in the management of temporomandibular joint disorders

A collection of illnesses known as temporomandibular joint disorders (TMD) impact the masticatory system, which includes the temporomandibular joint (TMJ) and the masticatory muscles, functionally. Transcutaneous electrical nerve stimulation (TENS) is one of several known aetiologies that have unique therapy options. A review of TENS use in TMD patient care is included in the current paper. Among the effective therapy modalities for treating TMD is transcutaneous electrical nerve stimulation. It involves carefully exposing the skin's surface to electrical current, which relaxes tense muscles and lessens discomfort.

Acute right-sided transcutaneous vagus nerve stimulation improves cardio-vagal baroreflex gain in patients with chronic heart failure.

The aim of this paper is to investigate the acute effects of short-term transcutaneous vagus nerve stimulation (tVNS) on cardio-vagal baroreflex gain and heart rate variability in patients with chronic heart failure (CHF). A total of 16 adults with CHF and left ventricular ejection fraction (LVEF) < 50% in sinus rhythm were enrolled (65 ± 8years, 63% men, LVEF 40 ± 5%, 88% on beta-blockers, 50% on quadruple CHF therapy). Over a single experimental session, after a 10-min baseline recording, each patient underwent two trials of 10-min tVNS (Parasym Device, 200µs, 30Hz, 1mA below discomfort threshold) at either the right or left tragus in a randomized order, separated by a 10-min recovery. Compared with baseline, tVNS did not affect heart rate, blood pressure, and respiratory rate (p > 0.05), and no patients complained of discomfort or any adverse effect. Right-sided tVNS was associated with a significant increase in cardio-vagal baroreflex gain (from 5.6 ± 3.1 to 7.5 ± 3.8ms/mmHg, ∆ 1.9 ± 1.6ms/mmHg, p < 0.001), while no change was observed with left-sided tVNS (∆ 0.5 ± 2.0ms/mmHg, p = 0.914). These findings were independent of stimulation-side order (excluding any carry-over effect) and consistent across sex, LVEF category, and HF etiology subgroups (p-value for interaction > 0.05). Acute right-sided tVNS increases cardio-vagal baroreflex gain in patients with CHF and LVEF < 50%, with no tolerability concerns.

TVNS alters inflammatory response in adult VPA-induced mouse model of autism: evidence for sexual dimorphism.

Autism is a neurodevelopmental disorder with limited treatment alternatives and which incidence is increasing. Some research suggests that vagus nerve simulation might lead to the reduction of certain symptom. Therefore, we aimed to examine the effect of bilateral transcutaneous auricular vagus nerve stimulation (tVNS) on the inflammatory response in an adult valproic acid (VPA) induced mouse (C57BL6) model of autism for the first time. The autism model was induced by oral VPA administration (600 mg·kg-1) to C57BL/6 pregnant mice on E12.5 days. The study included three groups: the VPA Transcutaneous Auricular Stimulation Group (VPA + tVNS), the VPA Control Group (VPA + sham), and the Healthy Control Group (Control + sham). Each group included 16 mice (8 M/8 F). Our results show that serum IL-1β and IL-6 levels were significantly higher in male VPA-exposed mice than controls. However, IL-1β was significantly lower, and IL-6, TNF- α, and IL-22 were not different in female VPA-exposed mice compared to the control group. Brain NLRP3 levels were significantly higher in both sexes in the VPA autism model (P < 0.05). tVNS application increased brain NLRP3 levels in both sexes and reduced serum IL-1β levels in male mice. We conclude that cytokine dysregulation is associated with the VPA-induced adult autism model, and the inflammatory response is more pronounced in male mice. tVNS application altered the inflammatory response and increased brain NLPR3 levels in both sexes. Further studies are needed to understand the beneficial or detrimental role of the inflammatory response in autism and its sexual dimorphism.

Effects of long-term transcutaneous auricular vagus nerve stimulation on circadian vagal activity in people with Prader-Willi Syndrome: A case-series

BackgroundPrader-Willi Syndrome (PWS) is a genetic neurodevelopmental disorder marked by disruptions in circadian rhythms and autonomic nervous system (ANS) activity, hyperphagia, and episodes of emotional outbursts. Previous trials suggest that both invasive and non-invasive vagus nerve stimulation (VNS) can reduce emotional outbursts in PWS, potentially through its effects on vagal activity. AimThis case series investigated the effects of transcutaneous auricular VNS (taVNS) on cardiac markers of circadian vagal activity, specifically heart rate variability (HRV) and heart rate (HR), and their potential links to improvements in emotional outbursts. MethodsFive individuals with PWS (mean age: 26.9 years; 3 males, 2 females) received four hours of daily taVNS for 12 months, followed by one month of two-hour daily sessions. Outcome measures included daily recording of emotional outbursts and every three months 24-h HRV and HR recordings. Mixed cosinor models were applied to analyze changes in circadian rhythms of HRV and HR. A linear mixed model was used to assess the predictive value of cardiac vagal activity on emotional outbursts. ResultsCircadian amplitudes of HRV and HR were significantly higher at the end of the treatment compared to baseline (all p’s < .01). There was a significant increase in the rhythm-adjusted mean of HRV (p < .01), while the rhythm-adjusted HR mean significantly decreased, both indicating increased cardiac vagal activity. Higher rhythm-adjusted mean HRV predicted a lower number of emotional outbursts. ConclusionThe results suggest that taVNS may be effective by targeting ANS activity in individuals with PWS, contributing to improvements in behavioral regulation.