Efficacy of cranial electrotherapy stimulation in patients with burning mouth syndrome: a randomized, controlled, double-blind pilot study.

Background: The Burning mouth syndrome (BMS) is a chronic pain syndrome characterized by a burning sensation in the oral mucous membranes. The etiology and pathophysiology of BMS is largely unexplained. To date, there is no evidence-based treatment strategy for BMS. Cranial electrical stimulation (CES) represents a non-invasive treatment option with a low side effect profile that is approved for the treatment of pain, depression, anxiety disorder and insomnia. It has shown efficacy in studies for chronic pain such as fibromyalgia and neuropathic pain after spinal cord injury. This study aimed to investigate the therapeutic effectiveness of CES in combination with local transcutaneous electrical nerve stimulation (TENS) as an adjunct therapy in patients with BMS compared to sham stimulation. Methods: This randomized, double-blind, sham-controlled pilot study enrolled 22 patients, aged 18 years and over, with the diagnosis of BMS meeting the ICHD-3 criteria from August 2020 to June 2021. The study duration was 4 weeks (28 days) per participant. After randomization, the active group participants (n = 11) received a 100 µA CES treatment for 60 min a day whereas the devices in the Sham group did not emit electricity. Simple linear regression was used to determine whether the interventions promoted significant differences in pain intensity. Results: The linear regression showed that the period of stimulation significantly predicted decrease in the intensity of pain in the active group [ß = -0.036; t(26) = -7.219; p < 0.001] as in the sham group [ß = -0.026; t(26) = -2.56; p < 0.017]. With the applied cutoff of 30% pain reduction within the stimulation period, both the active and sham groups had 36% responders (n = 4) (Fisher's exact test, p = 1.00). In both groups (active stimulation and sham group), a significant decrease in the intensity of pain, somatic symptoms and an improvement in sleep quality over the study period was observed. Subjects reported no adverse events during the study. Conclusion: Although CES is an easily applicable and safe therapeutic option for chronic facial pain, active stimulation was not superior to sham stimulation. Among other reasons, this could be due to the short double-blinded treatment period, duration of the daily stimulation session or the small sample size.

Reduction of Edema and Pain in Transcutaneous Electrical Nerve Stimulation Treated-Arthritic Rat.

Transcutaneous electrical nerve stimulation (TENS) has been used to reduce pain or improve motor function in musculoskeletal and neurological disorders in the clinic. Although some studies have suggested electrotherapy as an intervention for edema, the effects and mechanisms of TENS on inflammation-induced edema remain unclear. Thus, we aimed to investigate the effects of TENS on arthritic pain with edema. 1% carrageenan was injected into the right tibiofemoral joint of 69 male Sprague-Dawley rats (200-250 g). After the development of arthritic pain, low-frequency (4-Hz, Low-TENS, n = 25) and high-frequency (100-Hz, High-TENS, n = 25) TENS with sub-motor threshold or placebo-TENS (n = 19) was applied for 20-min to medio-lateral part of the ipsilateral side. Weight bearing and knee-bend tests were used to assess pain-like behaviors. Also, we examined the size of edema and measured tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in the synovium by western blot. Eight rats in each of the two TENS groups were injected with Naloxone. Edema was reduced in the low- and high-frequency TENS groups at 6-h. TENS-treated rats showed reduced pain in the knee-bend test at 6-h. We observed decreased weight load shifts on the ipsilateral side in TENS groups. Naloxone reduced these effects. TNF-α and IL-1ß expression decreased in the synovial membrane at 6-h. These results suggest that low- and high-frequency TENS have acutely positive effects on inflammatory edema, with the management of arthritic pain and reduction in pro-inflammatory mediators. Therefore, Low-TENS and High-TENS may be useful in treating acute inflammatory pain and edema.

Comparing the effect of transcutaneous electrical nerve stimulation and massage therapy on post laparoscopic shoulder pain: a randomized clinical trial.

BACKGROUND: Shoulder pain is a common clinical problem after laparoscopic surgeries. The use of non-pharmacological massage and transcutaneous electrical nerve stimulation (TENS) as an adjunct to routine treatment is increasing to provide optimal pain relief. Therefore, we aimed to determine the effect of TENS and massage therapy on post laparoscopic shoulder pain (PLSP). METHODS: This study was conducted on 138 patients who underwent laparoscopic cholecystectomy. Patients were randomly divided into three groups: massage plus conventional pharmacological treatment (n = 46), TENS plus conventional pharmacological treatment (n = 46), and conventional pharmacological treatment (n = 46). Massage and TENS were performed three consecutive times after the patients regained consciousness in the inpatient wards. The intensity of Shoulder pain was evaluated using a visual analog scale before and 20 min after each treatment. RESULTS: Both massage therapy and TENS led to a significant reduction in the intensity of PLPS compared to the control group in all three measured times (p < 0.001). However, no significant difference was observed between TENS and massage at any of the three-time points. CONCLUSIONS: This study's findings demonstrated that massage and TENS techniques could reduce PLSP. TRIAL REGISTRATION: Registered in the Iranian registry of clinical trials ( www.irct.ir ) in 05/02/2022 with the following code: IRCT20200206046395N1.

The effect of TENS on sleep: A pilot study.

BACKGROUND: Insomnia is the second most common neuropsychiatric disorder, but the current treatments are not very effective. There is therefore an urgent need to develop better treatments. Transcutaneous electrical nerve stimulation (TENS) may be a promising means of treating insomnia. OBJECTIVE: This work aims to explore whether and how TENS modulate sleep and the effect of stimulation waveforms on sleep. METHODS: Forty-five healthy subjects participated in this study. Electroencephalography (EEG) data were recorded before and after four mode low-frequency (1 Hz) TENS with different waveforms, which were formed by superimposing sine waves of different high frequencies (60-210 Hz) and low frequencies (1-6 Hz). The four waveform modes are formed by combining sine waves of varying frequencies. Mode 1 (M1) consists of a combination of high frequencies (60-110 Hz) and low frequencies (1-6 Hz). Mode 2 (M2) is made up of high frequencies (60-210 Hz) and low frequencies (1-6 Hz). Mode 3 (M3) consists of high frequencies (110-160 Hz) and low frequencies (1-6 Hz), while mode 4 (M4) is composed of high frequencies (160-210 Hz) and low frequencies (1-6 Hz). For M1, M3 and M4, the high frequency portions of the stimulus waveforms account for 50%, while for M2, the high frequency portion of the waveform accounts for 65%. For each mode, the current intensities ranged from 4 mA to 7 mA, with values for each participant adjusted according to individual tolerance. During stimulation, the subjects were stimulated at the greater occipital nerve by the four mode TENS. RESULTS: M1, M3, and M4 slowed down the frequency of neural activity, broadened the distribution of theta waves, and caused a decrease in activity in wakefulness-related regions and an increase in activity in sleep-related regions. However, M2 has the opposite modulation effect. CONCLUSION: These results indicated that low-frequency TENS (1 Hz) may facilitate sleep in a waveform-specific manner. Our findings provide new insights into the mechanisms of sleep modulation by TENS and the design of effective insomnia treatments.

Transcutaneous electrical nerve stimulation over acupoint for chronic obstructive pulmonary disease: A systematic review and meta-analysis.

Background: Transcutaneous electrical nerve stimulation over an acupoint (acu-TENS), a new technique applied in pulmonary rehabilitation programs, has been gradually used in the management of chronic obstructive pulmonary disease (COPD). However, the effects of acu-TENS have not been fully evaluated. Therefore, this review was conducted to assess the effects of acu-TENS on COPD. Methods: A total of seven electronic databases were searched from their inception to September 2021 for randomized controlled trials of acu-TENS for COPD. Two investigators independently performed data extraction and methodological quality assessment. Heterogeneity was examined by Cochrane χ2 and I 2 tests. The source of heterogeneity was investigated by subgroup analysis or sensitivity analysis. Results: In our review, ten studies between 2008 and 2021 were included. The aggregated results indicated that acu-TENS showed positive effects in forced expiratory volume in 1 s (FEV1) [MD = 0.13 L, 95% CI (0.11-0.16), P < 0.00001], FEV1% predicted [MD = 5.92%, 95% CI (3.43-8.41), P < 0.00001], 6-min walk distance (6MWD) [MD = 14.68m, 95% CI (6.92-22.44), P = 0.0002], dyspnea visual analog scale (DVAS) [MD = -7.58, 95%CI (-14.33 to -0.84), P = 0.03], modified Borg scale (MBS) [MD = -0.46, 95% CI (-0.86 to -0.06), P = 0.03], and COPD assessment test (CAT) [MD = -4.25, 95% CI (-5.24 to -3.27), P < 0.00001]. Although six studies reported adverse effects, only one patient had shoulder pain after acu-TENS. Conclusion: Acu-TENS seems to be effective in improving pulmonary function and health status in patients with COPD, with little effect on exercise capacity and dyspnea. However, this result should be interpreted with caution, and high-quality RCTs were needed for further verification.

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.

Identifying oscillations under multi-site sensory stimulation for high-level peripheral nerve injured patients: a pilot study.

Objective.For high-level peripheral nerve injuryed (PNI) patients with severe sensory dysfunction of upper extremities, identifying the multi-site tactile stimulation is of great importance to provide neurorehabilitation with sensory feedback. In this pilot study, we showed the feasibility of identifying multi-site and multi-intensity tactile stimulation in terms of electroencephalography (EEG).Approach.Three high-level PNI patients and eight non-PNI participants were recruited in this study. Four different sites over the upper arm, forearm, thumb finger and little finger were randomly stimulated at two intensities (both sensory-level) based on the transcutaneous electrical nerve stimulation. Meanwhile, 64-channel EEG signals were recorded during the passive tactile sense stimulation on each side.Main results.The spatial-spectral distribution of brain oscillations underlying multi-site sensory stimulation showed dominant power attenuation over the somatosensory and prefrontal cortices in both alpha-band (8-12 Hz) and beta-band (13-30 Hz). But there was no significant difference among different stimulation sites in terms of the averaged power spectral density over the region of interest. By further identifying different stimulation sites using temporal-spectral features, we found the classification accuracies were all above 89% for the affected arm of PNI patients, comparable to that from their intact side and that from the non-PNI group. When the stimulation site-intensity combinations were treated as eight separate classes, the classification accuracies were ranging from 88.89% to 99.30% for the affected side of PNI subjects, similar to that from their non-affected side and that from the non-PNI group. Other performance metrics, including specificity, precision, and F1-score, also showed a sound identification performance for both PNI patients and non-PNI subjects.Significance.These results suggest that reliable brain oscillations could be evoked and identified well, even though induced tactile sense could not be discerned by the PNI patients. This study have implication for facilitating bidirectional neurorehabilitation systems with sensory feedback.

Transcutaneous Electrical Nerve Stimulation (TENS) for the Treatment of Renal Colic in the ED: A Randomized, Double-Blind, Placebo-Controlled Trial.

STUDY OBJECTIVE: To determine the analgesic efficacy of TENS treatment in patients with renal colic in the emergency department (ED). METHODS: This double-blind, randomized controlled trial was conducted in a tertiary care ED. Patients with a definitive diagnosis of renal colic were assigned (1:1) as randomized to receive the real TENS with frequency 100 Hz, pulse width 200 microseconds, voltage 2 mA, or placebo with sham TENS. Pain intensity was measured using visual analog scales (VAS) at baseline, after 15 and 30th minutes. RESULTS: A total of 100 patients were included in the final analysis: 50 patients treated with real TENS and 50 patients treated with sham TENS. VAS scores in both groups were similar at baseline. The mean reduction in VAS score at 15 min was 33.3 ± 17.6 (95% Confidence interval (CI): 28.3 to 38.3) for the real TENS group and 14.9 ± 11.6 (95% CI 11.6 to 18.2) for the sham TENS group (mean difference: 18.4 (95% CI: 12.5 to 24.4, P < 0.0001). The mean reduction in VAS score at 30 min was 63.7 ± 21.1 (95% CI: 57.7 to 69.7) for the real TENS group and 14.9 ± 16.2 (95% CI: 19.5 to 10.3) for the sham TENS group (mean difference: 48.8, 95% CI: 41.4 to 56.3, P < 0.0001). Four patients (8%) in the real TENS group and 24 patients (48%) in the sham TENS group required the rescue medication after 30th minutes. CONCLUSIONS: TENS is effective for acute pain treatment in renal colic patients in the ED. TENS therapy could be a treatment option for renal colic.

Evaluation of multiple perceptual qualities of transcutaneous electrical nerve stimulation for evoked tactile sensation in forearm amputees.

Objective. Evoked tactile sensation (ETS) elicited by transcutaneous electrical nerve stimulation (TENS) is promising to convey digit-specific sensory information to amputees naturally and non-invasively. Fitting ETS-based sensory feedback to amputees entails customizing coding of multiple sensory information for each stimulation site. This study was to elucidate the consistency of percepts and qualities by TENS at multiple stimulation sites in amputees retaining ETS.Approach. Five transradial amputees with ETS and fourteen able-bodied subjects participated in this study. Surface electrodes with small size (10 mm in diameter) were adopted to fit the restricted projected finger map on the forearm stump of amputees. Effects of stimulus frequency on sensory types were assessed, and the map of perceptual threshold for each sensation was characterized. Sensitivity for vibration and buzz sensations was measured using distinguishable difference in stimulus pulse width. Rapid assessments for modulation ranges of pulse width at fixed amplitude and frequency were developed for coding sensory information. Buzz sensation was demonstrated for location discrimination relating to prosthetic fingers.Main results. Vibration and buzz sensations were consistently evoked at 20 Hz and 50 Hz as dominant sensation types in all amputees and able-bodied subjects. Perceptual thresholds of different sensations followed a similar strength-duration curve relating stimulus amplitude to pulse width. The averaged distinguishable difference in pulse width was 12.84 ± 7.23µs for vibration and 15.21 ± 6.47µs for buzz in able-bodied subjects, and 14.91 ± 10.54µs for vibration and 11.30 ± 3.42µs for buzz in amputees. Buzz coding strategy enabled five amputees to discriminate contact of individual fingers with an overall accuracy of 77.85%.Significance. The consistency in perceptual qualities of dominant sensations can be exploited for coding multi-modality sensory feedback. A fast protocol of sensory coding is possible for fitting ETS-based, non-invasive sensory feedback to amputees.

Analgesic efficacy of a portable, disposable, and self-applied transcutaneous electrical nerve stimulation device during migraine attacks: A real-life randomized controlled trial.

OBJECTIVE: The objective of this study was to evaluate the analgesic efficacy of a portable, disposable, and home self-applied transcutaneous electrical nerve stimulation (TENS) device during migraine attacks. BACKGROUND: TENS has been used as a noninvasive treatment for migraine, but there are no reports on the outcomes following use of this treatment option for use at home during migraine attacks. DESIGN AND METHODS: A double-blind, randomized controlled trial was conducted over 3 months, with monthly assessments. Active placebos (sham group) were in place and were allocated at a 1:1 ratio. Adult patients who had been diagnosed with migraine by a specialist were included. Pain intensity levels and functional disability were measured before and after the 20-min self-applied TENS intervention during the migraine attacks. RESULTS: Seventy-four participants were randomly allocated to the sham and intervention groups. Although both groups of subjects reported lower pain scores, the intervention group showed a statistically significant reduction in pain scores compared to the sham group. CONCLUSION: In our controlled trial, the use of a self-applied, TENS device is safe and effective in relieving pain associated with migraine attacks. Participants in the intervention group showed a statistically significant improvement in pain and functional disability scores. TENS has been used as a noninvasive treatment for migraine, but there are no reports on the outcomes following use of this treatment option for use at home during migraine attacks. This double-blind, randomized controlled trial had 2 groups: active-placebo and intervention. Seventy-four participants were randomly allocated. Participants in the intervention group showed a statistically significant improvement in pain and functional disability scores.

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

Pain is managed using a biopsychosocial approach and pharmacological and non-pharmacological treatments. Transcutaneous electrical nerve stimulation (TENS) is a technique whereby pulsed electrical currents are administered through the intact surface of the skin with the intention of alleviating pain, akin to 'electrically rubbing pain away'. Despite over 50 years of published research, uncertainty about the clinical efficacy of TENS remains. The purpose of this comprehensive review is to critically appraise clinical research on TENS to inform future strategies to resolve the 'efficacy-impasse'. The principles and practices of TENS are described to provide context for readers unfamiliar with TENS treatment. The findings of systematic reviews evaluating TENS are described from a historical perspective to provide context for a critical evaluation of factors influencing the outcomes of randomized controlled trials (RCTs); including sample populations, outcome measures, TENS techniques, and comparator interventions. Three possibilities are offered to resolve the impasse. Firstly, to conduct large multi-centered RCTs using an enriched enrolment with randomized withdrawal design, that incorporates a 'run-in phase' to screen for potential TENS responders and to optimise TENS treatment according to individual need. Secondly, to meta-analyze published RCT data, irrespective of type of pain, to determine whether TENS reduces the intensity of pain during stimulation, and to include a detailed assessment of levels of certainty and precision. Thirdly, to concede that it may be impossible to determine efficacy due to insurmountable methodological, logistical and financial challenges. The consequences to clinicians, policy makers and funders of this third scenario are discussed. I argue that patients will continue to use TENS irrespective of the views of clinicians, policy makers, funders or guideline panel recommendations, because TENS is readily available without prescription; TENS generates a pleasant sensory experience that is similar to easing pain using warming and cooling techniques; and technological developments such as smart wearable TENS devices will improve usability in the future. Thus, research is needed on how best to integrate TENS into existing pain management strategies by analyzing data of TENS usage by expert-patients in real-world settings.

Supraspinal neural mechanisms of the analgesic effect produced by transcutaneous electrical nerve stimulation.

Although the analgesic effects of conventional transcutaneous electrical nerve stimulation (TENS) and acupuncture-like TENS are evident, their respective neural mechanisms in humans remain controversial. To elucidate and compare the supraspinal neural mechanisms of the analgesic effects produced by conventional TENS (high frequency and low intensity) and acupuncture-like TENS (low frequency and high intensity), we employed a between-subject sham-controlled experimental design with conventional, acupuncture-like, and sham TENS in 60 healthy human volunteers. In addition to assessing the TENS-induced changes of subjective ratings of perceived pain, we examined the TENS associated brainstem activities (fractional amplitude of low frequency fluctuations, fALFF) and their corresponding resting state functional connectivity (RSFC) with higher-order brain areas using functional magnetic resonance imaging. The analgesic effect of conventional TENS was only detected in the forearm that received TENS, coupled with decreased pons activity and RSFC between pons and contralateral primary somatosensory cortex. In contrast, acupuncture-like TENS produced a spatially diffuse analgesic effect, coupled with increased activities in both subnucleus reticularis dorsalis (SRD) and rostral ventromedial medulla (RVM), and decreased RSFC between SRD and medial frontal regions as well as between SRD and lingual gyrus. To sum up, our data demonstrated that conventional TENS and acupuncture-like TENS have different analgesic effects, which are mediated by different supraspinal neural mechanisms.

Mediating different-diameter Aß nerve fibers using a biomimetic 3D TENS computational model.

BACKGROUND: Significant progress has been made over the last 50 years in the design, development and testing of transcutaneous electrical nerve stimulation (TENS) in mediating different levels of tactile sensations. However, without knowing how best to stimulate the nerve fibers, the elicited sensation quality will always remain poor and unnatural. NEW METHOD: A new biomimetic 3D TENS computational model is developed to quantify the neural activation mechanism with varied surface electrodes. This model includes seven-layered anatomical structure of the forearm and biophysically-detailed myelinated Aß fibers. The Aß-fiber diameters from 1.5 - 7.5 µm were randomly distributed beneath the skin to mimic the physiologically-realistic fiber population. The arithmetic averaging algorithm and Gaussian filter were adopted to identify the sensation center and to quantify sensation intensities under different stimulation conditions. RESULTS: Fibers larger than 4.5 µm can usually be activated producing tactile sensations such as light touch, pressure, buzz, and vibration. While, fibers with diameters of 3.5 and 3 µm can only be excited at uncomfortable numb and pain sensations. The resulted modelling predictions match the recent psychophysical experimental data. COMPARISON WITH EXISTING METHOD(S): The new TENS model is more physiologically-realistic by introducing a detailed morphological information and key ionic mechanisms in nerve fibers. CONCLUSIONS: Our results indicate that TENS may be a promising method to target functionally-distinct neural pathways in an effort to improve the elicited tactile sensations quality with electrical stimulation. This work provides a promising platform of discovering neural mechanisms under TENS.

Transcutaneous Electrical Nerve Stimulation As A Pain-Relieving Approach in Labor Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a non-invasive electrophysical pain-relieving modality that also can be used in labor pain. Compared to other methods, TENS is not commonly practiced in intrapartum care due to a lack of knowledge about its clinical efficacy. Hence, a comprehensive overview of all types of randomized controlled trials (RCTs) on TENS can provide a better insight into this method and its efficacy in labor pain. OBJECTIVES: To perform a systematic review to assess the efficacy of TENS for labor pain control compared to other treatments. SEARCH STRATEGY: PubMed, Cochrane Library, Embase, and Web of Science databases were searched for studies using keywords "TENS" combined with "labor pain" and "labor." SELECTION CRITERIA: Eligible criteria included RCTs, full-text studies, English, and Danish literature, whereas exclusion criteria included animal studies and abstracts. DATA EXTRACTION AND ANALYSIS: The selection of eligible items and assessment of methodological quality were performed independently by two researchers (KT and PG). A meta-analysis was performed to analyze the treatment effects on pain intensity reduction, additional analgesia, and satisfaction of TENS. MAIN RESULTS: Twenty-six RCTs were included in this review involving a total of 3348 parturients. TENS showed significant efficacy in the reduction of pain intensity (pooled RR 1.52, 95% CI [1.35; 1.70]). Most of the studies had a high risk of bias, and the average grade of the studies indicated low quality. CONCLUSIONS: The forest plot showed a small, but statistically significant efficacy of TENS on the reduction of pain intensity. However, it is not clear if the results were affected by the poor quality of the studies. This systematic review is the first that shows the application of TENS has significant efficacy in lowering labor pain. Findings from this review encourage the application of qualified methods for future and prospective studies with TENS applied in labor pain.

Evaluating the effectiveness of TENS for maternal satisfaction in laboring parturients - Comparison with epidural analgesia.

BACKGROUND AND AIMS: Labor pain is one of the most severe pain that a woman experiences in her lifetime. Various methods are being used to relieve this pain and to achieve higher maternal satisfaction. One such technique is transcutaneous electrical nerve stimulation (TENS) that uses low-frequency electrotherapy. The aim of our study was to evaluate TENS by comparing it to an established labor analgesia technique, i.e., epidural analgesia in terms of maternal satisfaction. MATERIAL AND METHODS: This prospective study was conducted on 60 parturients in active stage of labor. The choice of analgesia was made by the parturient after informed consent. In group A (n = 30) TENS was used, while in group B (n = 30) epidural ropivacaine 0.125% + 2 µg/ml fentanyl was given. Continuous monitoring of maternal vitals, visual analogue score, and fetal heart rate (FHR) was done. Maternal satisfaction was scored considering pain relief, ability to move and experience of labor at the end of delivery and outcome was labeled as favorable and unfavorable. RESULTS: TENS was found to be favorable in 90% of parturients as compared to 96.6% in epidural (P 0.301). The number of highly satisfied parturients was 4 (13.3%) in TENS group and 17 (56.6%) in the epidural group (P= 0.000). Three patients in the epidural group had assisted delivery and two had cesarean section whereas all patients in TENS group delivered normally (P= 0.065). No significant difference was found in the fetal outcome. CONCLUSIONS: TENS is a good alternate choice for providing labor analgesia and may have a major role in future.

Effect of active TENS versus de-tuned TENS on walking capacity in patients with lumbar spinal stenosis: a randomized controlled trial.

Background context: Lumbar spinal stenosis (LSS) leads to diminished blood flow to the spinal nerves causing neurogenic claudication and impaired walking ability. Animal studies have demonstrated increased blood flow to the spinal nerves and spinal cord with superficial para-spinal electrical stimulation of the skin. Purpose: The aim of this study was to assess the effectiveness of active para-spinal transcutaneous electrical nerve stimulation (TENS) compared to de-tuned TENS applied while walking, on improving walking ability in LSS. Study design: This was a two-arm double-blinded (participant and assessor) randomized controlled trial. Patient sample: We recruited 104 participants 50 years of age or older with neurogenic claudication, imaging confirmed LSS and limited walking ability. Outcome measures: The primary measure was walking distance measured by the self-paced walking test (SPWT) and the primary outcome was the difference in proportions among participants in both groups who achieved at least a 30% improvement in walking distance from baseline using relative risk with 95% confidence intervals. Methods: The active TENS group (n = 49) received para-spinal TENS from L3-S1 at a frequency of 65-100 Hz modulated over 3-s intervals with a pulse width of 100-200 usec, and turned on 2 min before the start and maintained during the SPWT. The de-tuned TENS group (n = 51) received similarly applied TENS for 30 s followed by ramping down to zero stimulus and turned off before the start and during the SPWT.Study funded by The Arthritis Society ($365,000 CAN) and salary support for Carlo Ammendolia funded by the Canadian Chiropractic Research Foundation ($500,000 CAN over 5 years). Results: From August 2014 to January 2016 a total of 640 potential participants were screened for eligibility; 106 were eligible and 104 were randomly allocated to active TENS or de-tuned TENS. Both groups showed significant improvement in walking distance but there was no significant difference between groups. The mean difference between active and de-tuned TENS groups was 46.9 m; 95% CI (- 118.4 to 212.1); P = 0.57. A total of 71% (35/49) of active TENS and 74% (38/51) of de-tuned TENS participants achieved at least 30% improvement in walking distance; relative risk (RR), 0.96; 95% CI, (0.7 to 1.2) P = 0.77. Conclusions: Active TENS applied while walking is no better than de-tuned TENS for improving walking ability in patients with degenerative LSS and therefore should not be a recommended treatment in clinical practice. Registration: ClinicalTrials.gov ID: NCT02592642. Registration October 30, 2015.

Neurobiological mechanisms of TENS-induced analgesia.

Pain inhibition by additional somatosensory input is the rationale for the widespread use of Transcutaneous Electrical Nerve Stimulation (TENS) to relieve pain. Two main types of TENS produce analgesia in animal models: high-frequency (∼50-100 Hz) and low-intensity 'conventional' TENS, and low-frequency (∼2-4 Hz) and high-intensity 'acupuncture-like' TENS. However, TENS efficacy in human participants is debated, raising the question of whether the analgesic mechanisms identified in animal models are valid in humans. Here, we used a sham-controlled experimental design to clarify the efficacy and the neurobiological effects of 'conventional' and 'acupuncture-like' TENS in 80 human volunteers. To test the analgesic effect of TENS we recorded the perceptual and brain responses elicited by radiant heat laser pulses that activate selectively Aδ and C cutaneous nociceptors. To test whether TENS has a long-lasting effect on brain state we recorded spontaneous electrocortical oscillations. The analgesic effect of 'conventional' TENS was maximal when nociceptive stimuli were delivered homotopically, to the same hand that received the TENS. In contrast, 'acupuncture-like' TENS produced a spatially-diffuse analgesic effect, coupled with long-lasting changes both in the state of the primary sensorimotor cortex (S1/M1) and in the functional connectivity between S1/M1 and the medial prefrontal cortex, a core region in the descending pain inhibitory system. These results demonstrate that 'conventional' and 'acupuncture-like' TENS have different analgesic effects, which are mediated by different neurobiological mechanisms.

[Transcutaneous electrical nerve stimulation at Neiguan(PC 6) and Zusanli(ST 36) for clinical symptoms and life quality of gastroesophageal reflux patients].

OBJECTIVE: To explore the effect of transcutaneous electrical nerve stimulation(TENS) for symptoms,life quality and sleep quality in patients with gastroesophageal reflux disease(GERD). METHODS: A total of 46 GERD patients were randomly assigned into an observation group and a control group,23 cases in each one. The conventional medication and nursing were applied in the two groups. TENS was used at Neiguan(PC 6) and Zusanli(ST 36) in the observation group for 4 weeks,20 min a time,twice a day. The indexes were compared between the two groups before and after treatment,including reflux disease questionnaire,the MOS 36-item short-form,Pittsburgh sleep quality index(PSQI). RESULTS: Except the factor score of gengral health in the control group, the symptoms,life quality and sleep quality were superior to those before treatment in the two group (all P<0.01). The symptom and PSQI scores in the observation group were lower than those in the control group(P<0.01,P<0.05). The scores of general health, life vitality and mental health in the observation group were more apparently improved than those in the control group (all P<0.05). CONCLUSIONS: TENS at Neiguan(PC 6) and Zusanli(ST 36) can improve the clinical symptoms,life quality and sleep quality of GERD based on the conventional treatment.

Transcutaneous electrical nerve stimulation (TENS) as an adjunct for pain management in perioperative settings: a critical review.

INTRODUCTION: Surgical procedures are ever more complex. Day-case surgical loads are increasing and the length of hospital stays are reducing. Management of pain in perioperative settings remains a challenge. Expert panels recommend a multimodal approach which is often interpreted by medical practitioners as polypharmacy. There is variability in non-pharmacological interventions offered to patients, although transcutaneous electrical nerve stimulation (TENS) has been used since the 1970s. Recommendations from expert panels are inconsistent about the use of TENS in perioperative pain settings. Areas covered: This critical review outlines the challenges of managing pain in perioperative settings and uses a narrative synthesis to evaluate the findings of systematic reviews on the clinical efficacy of TENS for pain in perioperative settings. Expert commentary: Moderate evidence from systematic reviews suggests that TENS is superior to placebo (no current) TENS for reducing analgesic consumption and improving pain, pulmonary function, and nausea and vomiting. Therefore, it seems reasonable to offer TENS as an adjunct to core treatment for surgical pain, especially because it is inexpensive and has a favorable safety profile compared with long-term medication. Practical considerations for the integration of TENS into service delivery are discussed.

The influence of Task-Related Training combined with Transcutaneous Electrical Nerve Stimulation on paretic upper limb muscle activation in patients with chronic stroke.

OBJECTIVES: This study investigated the efficacy of Task-Related Training (TRT) Combined with Transcutaneous Electrical Nerve Stimulation (TENS) on the improvement of upper limb muscle activation in chronic stroke survivors with mild or moderate paresis. METHODS: A single-blind, randomized clinical trial was conducted with 46stroke survivors with chronic paresis. They were randomly allocated two groups: the TRT+TENS group (n = 23) and the TRT+ placebo TENS (TRT+PLBO) group (n = 23). The TRT+TENS group received 30 minutes of high-frequency TENS on wrist and elbow extensors, while the TRT+PLBO group received placebo TENS that was not real ES. Both groups did 30 minutes of TRT after TENS application. Intervention was given five days a week for four weeks. The primary outcomes of upper limb muscle activation were measured by integrated EMG (IEMG), a digital manual muscle tester for muscle strength, active range of motion (AROM) and Fugl-Meyer Assessment of the upper extremity (FMA-UE). The measurements were performed before and after the 4 weeks intervention period. RESULTS: Both groups demonstrated significant improvements of outcomes in IEMG, AROM, muscle strength and FMA-UE during intervention period. When compared with the TRT+PLBO group, the TRT+TENS group showed significantly greater improvement in muscle activation (wrist extensors, P = 0.045; elbow extensors, P = 0.004), muscle strength (wrist extensors, P = 0.044; elbow extensors, P = 0.012), AROM (wrist extension, P = 0.042; elbow extensors, P = 0.040) and FMA-UE (total, P < 0.001; shoulder/elbow/forearm, P = 0.001; wrist, P = 0.002; coordination, P = 0.008) at the end of intervention. CONCLUSIONS: Our findings indicate that TRT Combined with TENS can improve paretic muscle activity in upper limb paresis, highlighting the benefits of somatosensory stimulation from TENS.