Resolving Long-Standing Uncertainty about the Clinical Efficacy of Transcutaneous Electrical Nerve Stimulation (TENS) to Relieve Pain: A Comprehensive Review of Factors Influencing Outcome

Non-Invasive Brain Sensing Technologies for Modulation of Neurological Disorders

The non-invasive brain sensing modulation technology field is experiencing rapid development, with new techniques constantly emerging. This study delves into the field of non-invasive brain neuromodulation, a safer and potentially effective approach for treating a spectrum of neurological and psychiatric disorders. Unlike traditional deep brain stimulation (DBS) surgery, non-invasive techniques employ ultrasound, electrical currents, and electromagnetic field stimulation to stimulate the brain from outside the skull, thereby eliminating surgery risks and enhancing patient comfort. This study explores the mechanisms of various modalities, including transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), highlighting their potential to address chronic pain, anxiety, Parkinson's disease, and depression. We also probe into the concept of closed-loop neuromodulation, which personalizes stimulation based on real-time brain activity. While we acknowledge the limitations of current technologies, our study concludes by proposing future research avenues to advance this rapidly evolving field with its immense potential to revolutionize neurological and psychiatric care and lay the foundation for the continuing advancement of innovative non-invasive brain sensing technologies.

High-frequency, high-intensity TENS compared to standard treatment with opioids for postoperative pain relief after laparoscopic cholecystectomy: A multicentre randomized controlled trial

BACKGROUND

Adverse effects of opioids could prolong the duration of stay in the post-anaesthesia care unit (PACU). This study aimed to assess time in the PACU and the pain-relieving effect of high-frequency, high-intensity transcutaneous electrical nerve stimulation (HFHI TENS) versus standard treatment with intravenous (IV) opioids.

METHODS

Patients undergoing laparoscopic cholecystectomy at two Swedish hospitals were invited to participate. Patients reporting postoperative pain intensity ≥3 according to the Numeric Rating Scale (NRS) in the PACU were randomized to receive standard treatment with IV opioids or HFHI TENS, administered with an intensity of 40-60 mA for 1 min, repeated once if insufficient pain relief. If NRS remained ≥3 after two TENS stimulation the patients received IV opioids.

RESULTS

In total, 163 patients were randomized to receive HFHI TENS (n = 85) or IV opioids (n = 78). There was no difference between the HFHI TENS group versus the opioid group regarding time in the PACU (138 min [SD 69] vs. 142 min [SD 95], mean difference -4.42 [95% CI-30:22], p = 0.74), time to pain relief NRS < 3 (median 10 min) and pain intensity at PACU discharge (NRS 1.7 [SD 1.45] vs. 1.6 [SD 1.20], p = 0.58). In the HFHI TENS group, 39 patients (46%) needed additional treatment with IV opioids. Mean opioid consumption was significantly lower in the HFHI TENS group than in the opioid group (4.5 vs. 11.0 morphine equivalents; p < 0.001).

CONCLUSIONS

HFHI TENS may be an opioid-sparing alternative for postoperative pain relief.

SIGNIFICANCE STATEMENT

In this multicentre, RCT time in the PACU and the pain-relieving effect of HFHI TENS was compared to standard treatment with IV opioids. There were no differences between the groups regarding time in the PACU, time to pain relief and side effects but opioid consumption in the HFHI TENS group was significantly lower. Both groups reported high satisfaction with pain treatment and care. In summary, HFHI TENS should be considered a safe, fast-onsetting, opioid-sparing option for postoperative pain relief.

Effect of Transcutaneous Electrical Nerve Stimulation on Gait Parameters in Dogs with Osteoarthritis

Osteoarthritis is a common degenerative disease in dogs, often manifested as pain, joint swelling, and lameness. Despite the lack of scientific evidence for its treatment efficacy, transcutaneous electrical nerve stimulation (TENS) is used in dogs as a pain-relieving treatment. This randomised single-blinded cross-over study investigated the effect of TENS on gait parameters in fifteen dogs with osteoarthritis. Stance time, swing time, stride time, stride length, peak vertical force (%BW), vertical impulse (%BW*sec), and symmetry indices were obtained using a pressure-sensitive mat. TENS treatment of 80 Hz and 100 µs with an individually selected amplitude was conducted for 45 min once daily for a treatment period of seven or ten days. No significant differences were seen between TENS and placebo for any of the gait parameters. Hence, in this study, TENS did not affect gait parameters, compared to placebo. Further studies are needed to confirm the observations.

The Effects Of Transcutaneous Electrical Nerve Stimulation Applied in the Early Postpartum Period After Cesarean Birth on Healing, Pain, and Comfort

INTRODUCTION

This study was conducted to determine the effects of transcutaneous electrical nerve stimulation (TENS) applied in the early postpartum period after cesarean birth on incision site healing, postoperative recovery, pain, and comfort.

METHODS

This randomized, single-blind, placebo-controlled study was conducted with 138 women (TENS group n = 46, placebo group n = 46, control group n = 46) who gave birth by cesarean between January and September 2023. TENS was applied twice at a frequency of 100 Hz with a pulse width of 100 microseconds, at 10 to 12 and 14 to 16 hours after birth, for 30 minutes each. Outcomes were measured with the Postoperative Recovery Index; Redness, Edema, Ecchymosis, Discharge, and Approximation Scale; Visual Analogue Scale; and Postpartum Comfort Questionnaire. Outcomes between groups were compared postintervention, correcting for baseline using analysis of covariance. The study was registered at www.

CLINICALTRIALS

gov (NCT05991921).

RESULTS

Mean scores for postoperative recovery were significantly lower (improved) in the TENS group (113.58) compared with the placebo and control groups (134.67, 136.61; P < .001). The postoperative recovery subscales (psychological symptoms, physical activities, appetite symptoms, bowel symptoms, general symptoms) were also significantly decreased in the TENS group compared with the placebo and control groups. Similarly, mean scores for postpartum comfort, and the corresponding physical comfort, psychospiritual comfort, and sociocultural comfort subscales, were significantly improved in the TENS group (110.26) compared with the placebo and control group (83.80, 81.19; P < .05).

DISCUSSION

TENS application can be preferred as an alternative method to increase pain control, recovery, and patient comfort after cesarean birth.

Device's design and clinical perspectives for resistant hypertension therapy

Introduction

Hypertension is the leading cause of death in the cardiovascular system. Indeed, untreated hypertension can affect one's general health, but medicine can help hypertensive people reduce their chance of developing high blood pressure. However, secondary hypertension remains an unresolved illness.

Areas covered

This review will go through the typical and unusual device-based therapies for resistant hypertension that have arisen in recent years. Further to that, the innovations developed in device-based RH treatment will be covered, as well as the research and studies assessing these novel technologies.

Expert opinion

The innovative device-based techniques that target resistant hypertension provide a potential therapy that has been backed by a number of studies and clinical trials, whereas pharmacological non-adherence and increased sympathetic activity are recognized to be the primary causes of resistant hypertension. Nevertheless, some limitations will be critical for the future of these RH systems, with the device's design and larger RCTs playing a significant role in determining whether a position in routine treatment could be warranted.

Efficacy of Interferential Current Therapy in Patients Diagnosed with Subacromial Impingement Syndrome

OBJECTIVE

The objective of the study was to evaluate the effectiveness of interferential current treatment on a range of motion of joint and shoulder pain, functional status, and quality of life in patients with subacromial impingement syndrome and to compare interferential current with transcutaneous electrical nerve stimulation and sham interferential current.

MATERIALS AND METHODS

Patients complaining of shoulder discomfort participated in the present study. Diagnosis of subacromial impingement syndrome is based on anamnesis, clinical examinations, and shoulder magnetic resonance imaging. A total of 52 patients divided into 3 groups: Group 1 (17 patients, mean age 51.8 years) received interferential current, group 2 (18 patients, mean age 51.8 years) received transcutaneous electrical nerve stimulation, and group 3 (17 patients, mean age 49.1 years) received sham interferential current. Hot pack and exercise treatments were added to all groups. All groups were treated for 3 weeks, 5 times a week, for 15 sessions and 20 minutes for each session. Evaluations were made before treatment (T0), in the middle of treatment (T1; end of 8th session), and at the end of treatment (T2; end of 15th session) using active range of motion and visual analog scale for pain, the Arm, Shoulder, and Hand Problems Questionnaire for functional status, and Short Form-36 for quality of life.

RESULTS

There were significant improvement effects on all of the range of motion, visual analog scale, and the Arm, Shoulder, and Hand Problems Questionnaire scores at T2 and on the scores in some subparameters of Short Form-36 in all groups (P < .05). However, there was no statistically significant difference at T2 between the groups (P > .05).

CONCLUSION

Interferential current and transcutaneous electrical nerve stimulation exhibited equivalent results regarding range of motion, pain, function, and quality of life of patients with subacromial impingement syndrome, with no significant difference between interferential current and transcutaneous electrical nerve stimulation. Adding interferential current or transcutaneous electrical nerve stimulation treatments to hot pack +exercise therapy did not result in any extra benefits to the patients.

Electrochemical Devices in Cutaneous Wound Healing

In healthy skin, vectorial ion transport gives rise to a transepithelial potential which directly impacts many physiological aspects of skin function. A wound is a physical defect that breaches the epithelial barrier and changes the electrochemical environment of skin. Electroceutical dressings are devices that manipulate the electrochemical environment, host as well as microbial, of a wound. In this review, electroceuticals are organized into three mechanistic classes: ionic, wireless, and battery powered. All three classes of electroceutical dressing show encouraging effects on infection management and wound healing with evidence of favorable impact on keratinocyte migration and disruption of wound biofilm infection. This foundation sets the stage for further mechanistic as well as interventional studies. Successful conduct of such studies will determine the best dosage, timing, and class of stimulus necessary to maximize therapeutic efficacy.

Broadening the lens through which we view pain and its management: an interview with Mark Johnson

Mark Johnson, PhD is Professor of Pain and Analgesia and Director of the Centre for Pain Research at Leeds Beckett University. Having initially trained as a neurophysiologist, Professor Johnson has expanded his research into the science of pain and its management, leading a team of pain scholars at the university. His research covers a wide range of topics including studying the effects of nonpharmacological interventions (transcutaneous electrical nerve stimulation [TENS], acupuncture, low-level laser therapy and Kinesio tape) for pain management, individuality and pain, epidemiology of pain and more recently health promotion and pain. His expertise spans a range of research methodologies including evidence syntheses such as meta-ethnography and meta-analysis including Cochrane Reviews, as well as conducting clinical trials and laboratory studies. In addition to his research, Professor Johnson is involved in pain education for healthcare professionals, patients, and the general public to provide people with up-to-date knowledge for a better understanding of the science of pain and its management.

The dose-dependent effects of transcutaneous electrical nerve stimulation for pain relief in individuals with fibromyalgia: a systematic review and meta-analysis

ABSTRACT

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological modality widely used to manage pain; however, its effectiveness for individuals with fibromyalgia (FM) has been questioned. In previous studies and systematic reviews, variables related to dose of TENS application have not been considered. The objectives of this meta-analysis were (1) to determine the effect of TENS on pain in individuals with FM and (2) determine the dose-dependent effect of TENS dose parameters on pain relief in individuals with FM. We searched the PubMed, PEDro, Cochrane, and EMBASE databases for relevant manuscripts. Data were extracted from 11 of the 1575 studies. The quality of the studies was assessed using the PEDro scale and RoB-2 assessment. This meta-analysis was performed using a random-effects model that, when not considering the TENS dosage applied, showed that the treatment had no overall effect on pain (d+ = 0.51, P > 0.050, k = 14). However, the moderator analyses, which were performed assuming a mixed-effect model, revealed that 3 of the categorical variables were significantly associated with effect sizes: the number of sessions (P = 0.005), the frequency (P = 0.014), and the intensity (P = 0.047). The electrode placement was not significantly associated with any effect sizes. Thus, there is evidence that TENS can effectively reduce pain in individuals with FM when applied at high or at mixed frequencies, a high intensity, or in long-term interventions involving 10 or more sessions. This review protocol was registered at PROSPERO (CRD42021252113).

Transcutaneous electrical nerve stimulation for pelvic pain: A scoping review of treatment protocols, practical indications, and caveats

BACKGROUND

Neuromodulation (NM) is a family of therapies based on electrical stimulation to target specific nerves that control LUTS (Lower Urinary Tract Symptoms) and pain. The aim is to modulate what is happening within the nervous system to achieve therapeutic effects. A particular type of neuromodulation, called TENS (Transcutaneous Electrical Nerve Stimulation), has proven effective for treating pelvic pain. The available evidence provides indications regarding the many aspects of TENS that influence therapeutic effects, but a comprehensive review has yet to be conducted.

METHODS

Scoping review on Pubmed, CINAHL, Embase, Scopus, and Web of Science, including clinical trials, reviews, case studies or series, and other descriptive studies, according to the Joanna Briggs and PRISMA methodology.

RESULTS

The 31 papers retrieved allowed the formulation of precise indications about the DOs and DON'Ts of electrode placement, waveform, pulse duration, pulse frequency, amplitude, session duration, and frequency of sessions. This paper also discusses the biochemical and neuro urological mechanisms of TENS.

CONCLUSION

TENS effectiveness is influenced by many factors, some self-evident, others subtle, which this paper elucidates. Pelvic pain requires a multimodal approach, of which TENS is just a part. TENS should therefore be viewed as one of the components of the rehabilitation program in the frame of thorough and continuous patient assessment.

Perioperative Management in the Collegiate Athlete: An Integrated Approach

Collegiate athletes face rigorous physical, academic, and emotional demands. While significant attention has been paid to injury prevention among young athletes in the past two decades, orthopedic injury rates remain high among collegiate athletes, and a significant number will undergo surgical management for injuries each year. In this narrative review, we describe techniques for perioperative management of pain and stress after surgery in collegiate athletes. In particular, we outline pharmacologic and non-pharmacologic management of surgical pain, with a goal of minimizing opiate consumption. We emphasize a multi-disciplinary approach to optimizing post-operative recovery in collegiate athletes help minimize reliance on opiate pain medication. Additionally, we recommend that institutional resources should be harnessed to support athletes in their well-being, from a nutritional, psychological and sleep standpoint. Critical to success in perioperative pain management is the communication among the athletic medicine team members and with the athlete and family to address pain and stress management and encourage timely, safe return to play.

Potential novel therapeutic strategies for neuropathic pain

Purpose

To explore the potential therapeutic strategies of different types of neuropathic pain (NP) and to summarize the cutting-edge novel approaches for NP treatment based on the clinical trials registered on ClinicalTrials.gov.

Methods

The relevant clinical trials were searched using ClinicalTrials.gov Dec 08, 2022. NP is defined as a painful condition caused by neurological lesions or diseases. All data were obtained and reviewed by the investigators to confirm whether they were related to the current topic.

Results

A total of 914 trials were included in this study. They were divided into painful diabetic neuropathy (PDN), postherpetic neuralgia (PHN), sciatica (SC), peripheral nerve injury-related NP (PNI), trigeminal neuralgia (TN), chemotherapy-induced NP (CINP), general peripheral NP (GPNP) and spinal cord injury NP (SCI-NP). Potential novel therapeutic strategies, such as novel drug targets and physical means, were discussed for each type of NP.

Conclusion

NP treatment is mainly dominated by drug therapy, and physical means have become increasingly popular. It is worth noting that novel drug targets, new implications of conventional medicine, and novel physical means can serve as promising strategies for the treatment of NP. However, more attention needs to be paid to the challenges of translating research findings into clinical practice.

Using TENS for Pain Control: Update on the State of the Evidence

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological intervention used in the treatment of acute and chronic pain conditions. The first clinical studies on TENS were published over 50 years ago, when effective parameters of stimulation were unclear and clinical trial design was in its infancy. Over the last two decades, a better understanding of the mechanisms underlying TENS efficacy has led to the development of an adequate dose and has improved outcome measure utilization. The continued uncertainty about the clinical efficacy of TENS to alleviate pain, despite years of research, is related to the quality of the clinical trials included in systematic reviews. This summary of the evidence includes only trials with pain as the primary outcome. The outcomes will be rated as positive (+), negative (−), undecided (U), or equivalent to other effective interventions (=). In comparison with our 2014 review, there appears to be improvement in adverse events and parameter reporting. Importantly, stimulation intensity has been documented as critical to therapeutic success. Examinations of the outcomes beyond resting pain, analgesic tolerance, and identification of TENS responders remain less studied areas of research. This literature review supports the conclusion that TENS may have efficacy for a variety of acute and chronic pain conditions, although the magnitude of the effect remains uncertain due to the low quality of existing literature. In order to provide information to individuals with pain and to clinicians treating those with pain, we suggest that resources for research should target larger, high-quality clinical trials including an adequate TENS dose and adequate timing of the outcome and should monitor risks of bias. Systematic reviews and meta-analyses should focus only on areas with sufficiently strong clinical trials that will result in adequate sample size.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

Role of Transcutaneous Electric Nerve Stimulation in Pain and Pulmonary Function in Patients after Bariatric Surgery

Background

Changes in lifestyle, a carbohydrate-rich diet, and decreased physical activity are part of the context that led to an obesity pandemic. Treating obesity is a task that requires multidisciplinary care; however, in many cases, conventional therapy has no effect, requiring surgical intervention. This, in turn, is not without risks and causes important changes in lung function. Therefore, the aim of this study is to evaluate the effect of electroanalgesia through conventional transcutaneous electrical nerve stimulation (TENS) on the pain and lung function in the postoperative period of bariatric surgery.

Methods

This is a controlled and blinded clinical trial with 66 subjects who underwent bariatric surgery. The participants were randomized into 2 groups as follows: an intervention group treated with TENS (n = 33) and a placebo group (n = 33). The participants underwent 4 TENS sessions, and the effect on pain was assessed using a visual analogue scale (VAS pain). Lung function was measured by spirometry.

Results

There were no differences between the 2 groups regarding time of surgery and time of mechanical ventilation. Compared to placebo, TENS reduced pain in the intervention group (p = 0.001). Regarding the effect of electroanalgesia on pulmonary function, the spirometric parameters were similar between the groups. However, regarding muscle strength between the preoperative and postoperative periods, maximal inspiratory pressure (MIP) was maintained in the intervention group and decreased in the placebo group (p = 0.03). Compared with that in the intervention group, the respiratory rate in the placebo group increased during the application of TENS (p = 0.003).

Conclusion

Electroanalgesia reduces pain in patients who underwent bariatric surgery. Importantly, in these patients, the MIP is maintained between the preoperative and postoperative periods. However, electroanalgesia does not contribute to improvements in spirometric data. This trial is registered with NCT04800640.

Efficacy of transcutaneous electrical nerve stimulation in people with pain after spinal cord injury: a meta-analysis

Study Design

Meta-analysis.

Objectives

This study aimed to evaluate the effect of transcutaneous electrical nerve stimulation in people with pain after spinal cord injury by meta-analysis.

Methods

Reviewed PubMed, Embase, Cochrane library, as well as China National Knowledge Infrastructure (CNKI), Wanfang, and Vip databases to search the randomized controlled trials of pain after spinal cord injury through transcutaneous electrical nerve stimulation from the beginning of the library to March 2021, and analyze the literature with RevMan 5.3 software and the bias in the literature with STATA 12.0 software.

Results

There are six randomized controlled trials in the study with 165 cases. 83 cases in the test group were given transcutaneous electrical nerve stimulation, and 82 cases in the control group used sham stimulation or other treatments. Meta-analysis results showed the experimental group’s visual analog scale (MD = −1.52, 95%CI, −2.44 to −0.60, P = 0.001) and short-form McGill pain questionnaire scores (MD = −0.70, 95% CI, −1.03 to −0.25, P = 0.002) were lower than those of the control group.

Conclusions

Transcutaneous electrical nerve stimulation has some clinical therapeutic effects on persons with pain after spinal cord injury, but due to the lack of literature, the sample size is not large, and clinical trials need to be further improved later.

Efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for acute and chronic pain in adults: a systematic review and meta-analysis of 381 studies (the meta-TENS study)

OBJECTIVE

To investigate the efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for relief of pain in adults.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Cochrane Central, Embase (and others) from inception to July 2019 and updated on 17 May 2020.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised controlled trials (RCTs) comparing strong non-painful TENS at or close to the site of pain versus placebo or other treatments in adults with pain, irrespective of diagnosis.

DATA EXTRACTION AND SYNTHESIS

Reviewers independently screened, extracted data and assessed risk of bias (RoB, Cochrane tool) and certainty of evidence (Grading and Recommendations, Assessment, Development and Evaluation). Mean pain intensity and proportions of participants achieving reductions of pain intensity (≥30% or >50%) during or immediately after TENS. Random effect models were used to calculate standardised mean differences (SMD) and risk ratios. Subgroup analyses were related to trial methodology and characteristics of pain.

RESULTS

The review included 381 RCTs (24 532 participants). Pain intensity was lower during or immediately after TENS compared with placebo (91 RCTs, 92 samples, n=4841, SMD=-0·96 (95% CI -1·14 to -0·78), moderate-certainty evidence). Methodological (eg, RoB, sample size) and pain characteristics (eg, acute vs chronic, diagnosis) did not modify the effect. Pain intensity was lower during or immediately after TENS compared with pharmacological and non-pharmacological treatments used as part of standard of care (61 RCTs, 61 samples, n=3155, SMD = -0·72 (95% CI -0·95 to -0·50], low-certainty evidence). Levels of evidence were downgraded because of small-sized trials contributing to imprecision in magnitude estimates. Data were limited for other outcomes including adverse events which were poorly reported, generally mild and not different to comparators.

CONCLUSION

There was moderate-certainty evidence that pain intensity is lower during or immediately after TENS compared with placebo and without serious adverse events.

PROSPERO REGISTRATION NUMBER

CRD42019125054.

Foundational Research Could Improve Future Transcutaneous Electrical Nerve Stimulation Evaluations

Background and objectives: There is a lack of good quality evidence regarding the effectiveness of transcutaneous electrical nerve stimulation (TENS) for chronic musculoskeletal pain, including chronic low back pain. High quality randomised controlled trials (RCTs) have been called for to establish effectiveness over and above placebo and some guidance has already been offered regarding the design of such trials. This article expands the discussion regarding the design of future TENS trials. There is qualitative evidence of the complexity of TENS as an intervention which should be considered in future TENS evaluations. This complexity includes multiple benefits reported by patients, depending on their chosen contexts of TENS use. The ideal content and delivery of support for patients to optimise TENS use also lacks consensus. There is no evidence that a TENS education package has been designed to support the complex set of behaviours and choices which experienced users suggest are required to optimise TENS benefits. Finally, clinical and research outcomes have not been contextualised and related to the specific strategies of use. Conclusions: We suggest that research is required to develop consensus about the content and delivery of training in TENS use for patients who live with pain, informed by the experience of patients, clinicians, and researchers. Once a consensus about the content of TENS training has been reached, there is then a need to develop a TENS training course (TTC) based on this content. An effective and acceptable TTC is needed to develop the knowledge and skills required to optimise TENS use, supporting patients to build confidence in using TENS in everyday life situations with the aim of reducing the impact of chronic pain on function and quality of life. Further research is required to extend the evidence base regarding appropriate, contextualised TENS patient-reported outcomes.

Does TENS Reduce the Intensity of Acute and Chronic Pain? A Comprehensive Appraisal of the Characteristics and Outcomes of 169 Reviews and 49 Meta-Analyses

Background and Objectives: Uncertainty about the clinical efficacy of transcutaneous electric nerve stimulation (TENS) to alleviate pain spans half a century. There has been no attempt to synthesise the entire body of systematic review evidence. The aim of this comprehensive review was to critically appraise the characteristics and outcomes of systematic reviews evaluating the clinical efficacy of TENS for any type of acute and chronic pain in adults. Materials and Methods: We searched electronic databases for full reports of systematic reviews of studies, overviews of systematic reviews, and hybrid reviews that evaluated the efficacy of TENS for any type of clinical pain in adults. We screened reports against eligibility criteria and extracted data related to the characteristics and outcomes of the review, including effect size estimates. We conducted a descriptive analysis of extracted data. Results: We included 169 reviews consisting of eight overviews, seven hybrid reviews and 154 systematic reviews with 49 meta-analyses. A tally of authors' conclusions found a tendency toward benefits from TENS in 69/169 reviews, no benefits in 13/169 reviews, and inconclusive evidence in 87/169 reviews. Only three meta-analyses pooled sufficient data to have confidence in the effect size estimate (i.e., pooled analysis of >500 events). Lower pain intensity was found during TENS compared with control for chronic musculoskeletal pain and labour pain, and lower analgesic consumption was found post-surgery during TENS. The appraisal revealed repeated shortcomings in RCTs that have hindered confident judgements about efficacy, resulting in stagnation of evidence. Conclusions: Our appraisal reveals examples of meta-analyses with 'sufficient data' demonstrating benefit. There were no examples of meta-analyses with 'sufficient data' demonstrating no benefit. Therefore, we recommend that TENS should be considered as a treatment option. The considerable quantity of reviews with 'insufficient data' and meaningless findings have clouded the issue of efficacy. We offer solutions to these issues going forward.

Maintenance of physical activity level, functioning and health after non-pharmacological treatment of pelvic girdle pain with either transcutaneous electrical nerve stimulation or acupuncture: a randomised controlled trial

OBJECTIVE

To investigate if there are differences between acupuncture and transcutaneous electrical nerve stimulation (TENS) as treatment for pelvic girdle pain (PGP) in pregnancy in order to manage pain and thus maintain health and functioning in daily activities and physical activity (PA).

DESIGN

Randomised controlled trial.

SETTING AND PARTICIPANTS

Pregnant women (n=113) with clinically verified PGP in gestational weeks 12-28, recruited from maternity healthcare centres, randomised (1:1) into two groups.

EXCLUSION CRITERIA

any obstetrical complication, systemic disease or previous disorder that could contradict tests or treatment.

INTERVENTIONS

The intervention consisted of either 10 acupuncture sessions (two sessions per week) provided by a physiotherapist or daily home-based TENS during 5 weeks.

PRIMARY OUTCOME VARIABLES

Disability (Oswestry Disability Index), functioning (Patient Specific Functional Scale), work ability (Work Ability Index) and PA-level according to general recommendations.

SECONDARY OUTCOME VARIABLES

Functioning related to PGP (Pelvic Girdle Questionnaire), evening pain intensity (Numeric Rating Scale, NRS), concern about pain (NRS), health (EuroQoL 5-dimension), symptoms of depression/catastrophising (Edinburgh Postnatal Depression Scale/Coping Strategies Questionnaire).

RESULTS

No mean differences were detected between the groups. Both groups managed to preserve their functioning and PA level at follow-up. This may be due to significantly (p<0.05) reduced within groups evening pain intensity; acupuncture -0.96 (95% CI -1.91 to -0.01; p=0.049), TENS -1.29 (95% CI -2.13 to -0.44; p=0.003) and concern about pain; acupuncture -1.44 (95% CI -2.31 to -0.57; p=0.0012), TENS -1.99 (95% CI -2.81 to -1.17; p<0.0001). The acupuncture group showed an improvement in functioning at follow-up; 0.82 (95% CI 0.01 to 1.63; p=0.048) CONCLUSION: Treating PGP with acupuncture or TENS resulted in maintenance of functioning and physical activity and also less pain and concern about pain. Either intervention could be recommended as a non-pharmacological alternative for pain relief and may enable pregnant women to stay active.

TRIAL REGISTRATION NUMBER

12726. https://www.researchweb.org/is/sverige/project/127261.