Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain

Retrospective Evaluation of Bipolar Peripheral Nerve Stimulation for Nociceptive and Neuropathic Pain: A Pilot Study

Purpose

This retrospective review evaluates pain and patient-defined functional goal improvement utilizing bipolar peripheral nerve stimulation (PNS) in chronic neuropathic and nociceptive pain states.

Patients and Methods

Our dataset includes 24 patients who underwent implantation of a permanent peripheral nerve stimulator from January 2018 through December 2022. A total of 29 leads were implanted amongst 24 patients, with 5 patients having leads at 2 different dermatomes. Fifteen leads were placed for primarily neuropathic pain, and 14 leads were placed for nociceptive pain. Inclusion criteria were the following: pain duration greater than 6 months, documented peri-procedural Numerical Pain Rating Scale (NPRS) and greater than 60 days follow-up post implant.

Results

Data was collected and analyzed showing that 89.6% of implants at 6 months follow-up and 70% at 12 months follow-up achieved 50% or greater pain relief. A significant reduction in NPRS scores when comparing pre-procedure pain scores (Median = 7, n = 29) to 6-month follow-up data (Median = 2, n = 29), p<0.001 with a large effect size, r = 0.61. Ninety-three percent of patients reported achieving their personal functional goal. Twelve of the fourteen (86%) leads implanted for primary nociceptive pain and fourteen of the fifteen (93%) leads implanted for neuropathic pain achieved ≥50% relief at 6 months. At twelve months, seven leads in each group provided ≥50% sustained pain relief. Of the 14 patients that were on opioids, 6 discontinued, while another 2 had a reduction in oral morphine milligram equivalents (MME) at the 12-month follow-up.

Conclusion

This retrospective review demonstrates the potential clinical application of PNS in both nociceptive and neuropathic pain states. Further prospective studies are warranted to validate the effectiveness of PNS in the treatment of refractory nociceptive and neuropathic pain states.

Comparison of the efficacy of auricular vagus nerve stimulation and conventional low back rehabilitation in patients with chronic low back pain

BACKGROUND

In recent years, human and animal studies have provided increasing evidence that vagus nerve stimulation (VNS) can produce analgesic effects as well as alleviating resistant epilepsy and depression. Our study was designed to compare the efficacy of transcutaneous auricular vagus nerve stimulation with conventional low back rehabilitation in patients with chronic low back pain (CLBP).

METHODS

Sixty patients with LBP were randomly divided into two groups. Group 1 received conventional rehabilitation and home exercise, and Group 2 received transcutaneous auricular VNS and home exercise. Both groups received treatment five days a week for three weeks. Trunk mobility (Modified Schober test, fingertip-to-floor test), muscle strength (CSMI-Cybex Humac-Norm isokinetic dynamometer and Lafayette manual muscle strength measuring device), trunk endurance, balance tests, Visual Analog Scale, Beck Depression Scale, Pittsburgh Sleep Quality Index, Oswestry Disability Index were evaluated.

RESULTS

At the end of three weeks, within-group assessment results showed positive effects on mobility, functional status, depression and sleep in all groups (p < 0.05). Pain level, endurance time and flexion trunk muscle strength results showed more improvement in Group 2 (p < 0.05). Some parameters of isokinetic lower extremity quadriceps muscle strength and fall risk scores showed a significant improvement in Group 1 (p < 0.05).

DISCUSSION

VNS has been observed to be more effective on pain, trunk muscle strength and endurance duration and sleep status. Auricular VNS may be included in the treatment of patients with CLBP in whom conventional physical therapy is inadequate or not applicable.

Effectiveness of Hybrid Form Impulse Therapy (HFIT) Compared to Traditional Transcutaneous Electronic Nerve Stimulation (TENS) in Patients with Chronic Low Back and Knee Pain: A Randomized Controlled Trial

Purpose

Physical therapy (PT) and conservative care are recommended first-line treatments for musculoskeletal (MSK) pain. While essential to high-quality care, these solutions often do not provide immediate or sufficient pain relief. Traditional transcutaneous electronic nerve stimulation (TENS) devices are often recommended; however, there is mixed evidence behind their effectiveness. A novel approach called hybrid form impulse therapy (HFIT) incorporates a priming pulse with a traditional TENS pulse width and frequency. This randomized controlled trial (RCT) aimed to compare the effectiveness of HFIT versus traditional TENS versus usual care among members of a digital MSK program.

Patients and Methods

A three-arm RCT comparing HFIT versus TENS versus usual care was conducted. A total of 325 people with chronic back or knee pain who were members of a digital MSK program consisting of PT-guided exercise therapy, education, and coaching were randomized. Outcomes including pain, function, anxiety, and depression were examined at 1, 2, and 4 weeks (primary endpoint). Engagement was measured through exercise therapy (ET) sessions completed. Unadjusted and adjusted logistic generalized estimating equations were conducted.

Results

Adjusted per-protocol results at 4 weeks showed significantly lower odds of achieving pain improvement for both TENS (OR: 0.42, 95% CI: [0.19, 0.92]) and usual care (OR: 0.35, 95% CI: [0.17, 0.72]) groups, compared to HFIT group. Both HFIT and usual care users had significantly higher engagement than the TENS users (p=0.026 and p=0.002, respectively). No adverse events were reported throughout the study.

Conclusion

More participants of a digital MSK program who were randomized to the HFIT group experienced meaningful pain improvement at 4 weeks than participants who used TENS and usual care. HFIT can be an effective, non-pharmaceutical solution for relief as a complement to first-line treatments for patients with chronic back and knee pain.

The effect of EMS, IFC, and TENS on patient-reported outcome measures for chronic low back pain: a systematic review and meta-analysis

Introduction

Chronic low back pain (CLBP) is the leading cause of years lived with disability worldwide. Transcutaneous electrotherapies have been widely used to treat CLBP but, with the partial exception of transcutaneous electrical nerve stimulation (TENS), their effect on pain, disability, quality-of-life, and psychosocial outcomes have not been systematically reviewed. The purpose of this systematic review and meta-analysis was to clarify the overall effect of transcutaneous electrotherapies on patient-reported outcome measures (PROMs) in CLBP patients.

Methods

Four databases and two study registries were searched for studies that utilized transcutaneous electrotherapies as a primary intervention for CLBP, compared against active or passive controls. Two reviewers independently extracted study data and assessed risk of bias. Studies were grouped by intervention vs. comparison, and by time of follow-up. Meta-analyses were conducted where appropriate.

Results

A total of 89 full-text were assessed for eligibility; 14 studies were included, with 6 in the meta-analyses (all TENS or mixed TENS). Pain: meta-analyses revealed no significant difference for TENS vs. active control, TENS vs. passive control, or mixed TENS vs. active control at post-intervention, nor for mixed TENS vs. active control at 1-month post-intervention. Interferential current (IFC) was more effective than active control (2 studies), while electromyostimulation (EMS) was generally superior to passive, but not active, controls (6 studies).

Disability

Meta-analyses revealed no significant difference for TENS vs. active control at post-intervention, mixed TENS vs. active control at post-intervention, or mixed TENS vs. active control at 1-month post-intervention. IFC was more effective than active control (2 studies), while the EMS results were mixed (6 studies). We were unable to perform meta-analyses for quality-of-life or psychosocial outcomes.

Conclusion

There is moderate evidence that TENS is similar to all controls for improving pain and disability. There is limited evidence that IFC is superior to active controls for improving pain and disability. There is limited evidence that EMS is superior to passive but not active controls for improving pain, and similar to all controls for improving disability.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=452851, Identifier (CRD42023452851).

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.

Acceptability, values, and preferences of older people for chronic low back pain management; a qualitative evidence synthesis

BACKGROUND

Chronic primary low back pain (CPLBP) and other musculoskeletal conditions represent a sizable attribution to the global burden of disability, with rates greatest in older age. There are multiple and varied interventions for CPLBP, delivered by a wide range of health and care workers. However, it is not known if these are acceptable to or align with the values and preferences of care recipients. The objective of this synthesis was to understand the key factors influencing the acceptability of, and values and preferences for, interventions/care for CPLBP from the perspective of people over 60 and their caregivers.

METHODS

We searched MEDLINE, CINAHL and OpenAlex, for eligible studies from inception until April 2022. We included studies that used qualitative methods for data collection and analysis; explored the perceptions and experiences of older people and their caregivers about interventions to treat CPLBP; from any setting globally. We conducted a best fit framework synthesis using a framework developed specifically for this review. We assessed our certainty in the findings using GRADE-CERQual.

RESULTS

All 22 included studies represented older people's experiences and had representation across a range of geographies and economic contexts. No studies were identified on caregivers. Older people living with CPLBP express values and preferences for their care that relate to therapeutic encounters and the importance of therapeutic alliance, irrespective of the type of treatment, choice of intervention, and intervention delivery modalities. Older people with CPLBP value therapeutic encounters that validate, legitimise, and respect their pain experience, consider their context holistically, prioritise their needs and preferences, adopt a person-centred and tailored approach to care, and are supported by interprofessional communication. Older people valued care that provided benefit to them, included interventions beyond analgesic medicines alone and was financially and geographically accessible.

CONCLUSIONS

These findings provide critical context to the implementation of clinical guidelines into practice, particularly related to how care providers interact with older people and how components of care are delivered, their location and their cost. Further research is needed focusing on low- and middle-income settings, vulnerable populations, and caregivers.

Sexual Disability in Low Back Pain: Diagnostic and Therapeutic Framework for Physical Therapists

BACKGROUND

The literature shows a relationship between sexual activity and low back pain (LBP). The aim of this work is to provide a theoretical framework and practical proposal for the management of sexual disability in individuals with LBP.

METHODS

Based on a literature review, a team of specialized physical therapists developed a pattern for the management of LBP-related sexual disability.

RESULTS

A patient reporting LBP-related sexual disability may be included in one of four clinical decision-making pathways corresponding to one of the following: #1 standard physical therapy (PT); #2 psychologically informed physical therapy (PIPT); #3 PIPT with referral; or #4 immediate referral. Standard PT concerns the management of LBP-related sexual disability in the absence of psychosocial or pathological issues. It includes strategies for pain modulation, stiffness management, motor control, stabilization, functional training, pacing activities comprising education, and stay-active advice. PIPT refers to patients with yellow flags or concerns about their relationship with partners; this treatment is oriented towards a specific psychological approach. "PIPT with referral" and "Immediate referral" pathways concern patients needing to be referred to specialists in other fields due to relationship problems or conditions requiring medical management or pelvic floor or sexual rehabilitation.

CONCLUSIONS

The proposed framework can help clinicians properly manage patients with LBP-related sexual disability.

Do Electrical Stimulation Devices Reduce Pain and Improve Function?-A Comparative Review

BACKGROUND

Multiple forms of electrical stimulation (ES) potentially offer widely varying clinical benefits. Diminished function commonly associated with acute and chronic pain lessens productivity and increases medical costs. This review aims to compare the relative effects of various forms of ES on functional and pain outcomes.

METHODS

A comprehensive literature search focused on studies of commonly marketed forms of ES used for treatment of pain and improvement of function. Peer-reviewed manuscripts were categorized as "Important" (systematic review or meta-analysis, randomized controlled trial, observational cohort study) and "Minor" (retrospective case series, case report, opinion review) for each identified form of ES.

RESULTS AND DISCUSSION

Varying forms of ES have markedly different technical parameters, applications, and indications, based on clinically meaningful impact on pain perception, function improvement, and medication reduction. Despite being around for decades, there is limited quality evidence for most forms of ES, although there are several notable exceptions for treatment of specific indications. Neuromuscular electrical stimulation (NMES) has well-demonstrated beneficial effects for rehabilitation of selective spinal cord injured (SCI), post-stroke, and debilitated inpatients. Functional electrical stimulation (FES) has similarly shown effectiveness in rehabilitation of some stroke, SCI, and foot drop outpatients. H-Wave® device stimulation (HWDS) has moderate supportive evidence for treatment of acute and refractory chronic pain, consistently demonstrating improvements in function and pain measures across diverse populations. Interestingly, transcutaneous electrical nerve stimulation (TENS), the most widely used form of ES, demonstrated insignificant or very low levels of pain and functional improvement.

CONCLUSION

Ten of 13 reviewed forms of ES have only limited quality evidence for clinically significant reduction of pain or improvement of function across different patient populations. NMES and FES have reasonably demonstrated effectiveness, albeit for specific clinical rehabilitation indications. HWDS was associated with the most clinically significant outcomes, in terms of functional improvement combined with reduction of pain and medication use. More rigorous long-term clinical trials are needed to further validate appropriate use and specific indications for most forms of ES.

LEVEL OF EVIDENCE

II.

Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress

BACKGROUND

Chronic pain conditions impose significant burdens worldwide. Pharmacological treatments like opioids have limitations. Non-invasive non-pharmacological therapies (NINPT) encompass diverse interventions including physical, psychological, complementary and alternative approaches, and other innovative techniques that provide analgesic options for chronic pain without medications.

MAIN BODY

This review elucidates the mechanisms of major NINPT modalities and synthesizes evidence for their clinical potential across chronic pain populations. NINPT leverages peripheral, spinal, and supraspinal mechanisms to restore normal pain processing and limit central sensitization. However, heterogeneity in treatment protocols and individual responses warrants optimization through precision medicine approaches.

CONCLUSION

Future adoption of NINPT requires addressing limitations in standardization and accessibility as well as synergistic combination with emerging therapies. Overall, this review highlights the promise of NINPT as a valuable complementary option ready for integration into contemporary pain medicine paradigms to improve patient care and outcomes.

Effect of Transcutaneous Electrical Nerve Stimulation on Pain-related Quantitative Sensory Tests in Chronic Musculoskeletal Pain and Acute Experimental Pain: Systematic Review and Meta-analysis

This report provides a systematic review of the literature to analyze the effects of transcutaneous electrical nerve stimulation (TENS) on analgesia on sensitization measures, in studies with chronic musculoskeletal pain and in studies with acute experimental pain. The protocol was registered at PROSPERO (CRD42020213473). The authors searched Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Latin American and Caribbean Health Sciences Literature via Biblioteca Virtual de Saúde, Physiotherapy Evidence Database, PubMed, ScienceDirect, Web of Science, Google Scholar, and hand-searched reference lists were also conducted. Among 22,252 manuscripts found, 58 studies were included in the systematic review and 35 in the meta-analysis. Thirty-four studies assessed pain intensity; 24 studies investigated hyperalgesia; temporal summation was only evaluated in 2 studies; and conditioned pain modulation was not observed in the included studies. Meta-analyses favored TENS, despite its limitations and heterogeneity. Primary hyperalgesia in studies with musculoskeletal pain presented a high level of evidence, while other outcomes presented moderate evidence in the studies that were included. It is not possible to infer results about both temporal summation and conditioned pain modulation. Moderate evidence suggests that TENS promotes analgesia by reducing both central and peripheral sensitization, as shown by the reduction in primary and secondary hyperalgesia, pain intensity at rest, and during movement in experimental acute pain and chronic musculoskeletal pain. Overall, both types of studies analyzed in this review presented meta-analyses favorable to the use of TENS (compared to placebo TENS), showing reductions in both primary and secondary hyperalgesia, as well as decreases in pain intensity at rest and in motion. PERSPECTIVE: This article presents data from the literature on the effect of TENS through sensitization assessments in individuals with chronic musculoskeletal pain, or acute experimental pain. These data contribute to knowledge about pain neuroscience research, using TENS technology.

Evaluation of the reliability and quality of YouTube videos as a source of information for transcutaneous electrical nerve stimulation

Background

YouTube plays an influential role in disseminating health-related information in the digital age. This study aimed to evaluate YouTube videos on transcutaneous electrical nerve stimulation (TENS) in terms of their information value and quality.

Methods

In this descriptive study, we ranked the first 100 videos that met the inclusion criteria using the search term "transcutaneous electrical nerve stimulation" on October 30, 2022. These videos were classified according to the number of views, likes, dislikes, comments, duration, popularity and content categories. Reliability, quality, and accuracy of the videos were assessed using the Journal of American Medical Association (JAMA) Benchmark Criteria and Modified DISCERN Questionnaire and Global Quality Score (GQS). Video popularity were calculated by the Video Power Index (VPI).

Results

Based on the GQS results, we found that 59, 27, and 14 videos had low, intermediate, and high quality, respectively. In addition, based on the JAMA results, 79 and 21 videos had poor and high reliability, respectively. No statistically significant difference was found between the JAMA, modified DISCERN and GQS scores in terms of the sources of videos (p = 0.226, p = 0.115, p = 0.812). Notably, there was a weak positive correlation between the JAMA scores and the number of views (r = 0.204, p = 0.041).

Conclusion

According to our study results, most YouTube videos on TENS were of low quality and reliability. Additionally, most videos were uploaded from sources created by doctors; the most frequently found content was about the TENS procedure, and content on complications of the procedure became less frequent as the videos became more recent. In particular, it was found that videos uploaded by academics have longer duration. It has been found that reliable videos with high JAMA scores also have high number of views. Accordingly, it can be concluded that videos with higher quality and more reliability that are created by healthcare providers will be more useful for patients seeking information about TENS.

The Effect of Transcutaneous Electrotherapy on Lumbar Range of Motion and Paraspinal Muscle Characteristics in Chronic Low Back Pain Patients: A Systematic Review and Meta-Analysis

Chronic low back pain (CLBP) affects paraspinal muscle size, quality (e.g., fatty infiltration), range of motion (ROM), and strength. Although transcutaneous electrotherapies are used to treat CLBP, their effects on paraspinal-related outcomes are not fully known. The aim of this systematic review and meta-analysis was to assess the overall effect of transcutaneous electrotherapies on trunk/lumbar ROM, paraspinal muscle morphology, and trunk muscle function (including strength and endurance) in CLBP patients. A systematic search of four databases and two study registers was conducted between 1 February 2022 and 15 September 2022. Two reviewers were responsible for screening and data extraction. Of the 3939 independent records screened, 10 were included in the systematic review and 2 in the meta-analysis. The results suggest there is limited evidence that both EMS and EMS plus exercise are superior to passive and active controls, respectively, for improving trunk muscle endurance. There is limited evidence that neither TENS nor mixed TENS are superior to controls for improving trunk muscle endurance. There is limited evidence that NMES is superior to passive controls for improving trunk muscle strength. The effect of transcutaneous electrotherapy on the other investigated outcomes was inconclusive. Future transcutaneous electrotherapy studies should focus on paraspinal-based outcomes that are under-studied.

Effects of transcutaneous electrical acupoint stimulation on upper-limb impairment after stroke: A randomized, controlled, single-blind trial

OBJECTIVE

To evaluate the effects of transcutaneous electrical acupoint stimulation (TEAS) on upper limb motor recovery during post-stroke rehabilitation.

DESIGN

Single-blind, randomized controlled trial.

SETTING

Four inpatient rehabilitation facilities.

SUBJECTS

A total of 204 stroke patients with unilateral upper limb motor impairment were randomly 1:1 allocated to TEAS or sham TEAS group. Baseline demographic and clinical characteristics were comparable between the two groups.

INTERVENTIONS

Both groups received conventional physical and occupational therapies. TEAS and sham TEAS therapy were administered to two acupoints (LI10 and TE5) with a pulse duration of 300 µs at 2 Hz on the affected forearm for 30 times over 6 weeks.

OUTCOME MEASURES

The upper-extremity Fugl-Meyer score (primary outcome), manual muscle testing, modified Ashworth scale, Lindmark hand function score, and Barthel index were evaluated by blinded assessors at baseline, 2, 4, 6, 10, and 18 weeks.

RESULTS

The number of patients who completed the treatment was 99 and 97 in the TEAS and the sham group. No significant between-group difference was found in the Upper-Extremity Fugl-Meyer score, Modified Ashworth Scale, Lindmark hand function score, and Barthel Index after intervention and during follow-up. However, the TEAS group exhibited 0.29 (95% CI 0.02 to 0.55) greater improvements in Manual Muscle Testing of wrist extension than the sham group (p  =  0.037) at 18 weeks.

CONCLUSIONS

Administration of TEAS therapy to hemiplegic forearm could not improve the upper extremity motor recovery. However, TEAS on the forearm might provide potential benefits for strength improvement of the wrist.

Evaluating the readability, quality and reliability of online patient education materials on transcutaneuous electrical nerve stimulation (TENS)

Increasing digitization also raises concerns regarding the reliability and comprehensibility of online health information. In this study, we aimed to examine the readability, reliability, and quality of internet-based patient education materials on "transcutaneous electrical nerve stimulation." On September 15, 2022, we used Google search engine to search the keyword "Transcutaneous Electrical Nerve Stimulation" and obtained information from 200 websites. The readability of the websites was evaluated using the Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, and Gunning Fog. The Journal of American Medical Association score and Health on the Net Foundation code of conduct were used to determine the reliability of the websites, whereas the DISCERN score and Global Quality Score were used to evaluate the quality of the websites. In the readability analysis of 102 websites that met the inclusion criteria of this study, we found that the Flesch Reading Ease Score was 47.91 ± 13.79 (difficult), average Flesch-Kincaid Grade Level and Simple Measure of Gobbledygook were 11.20 ± 2.85 and 10.53 ± 2.11 years, respectively, and average Gunning Fog score was 14.04 ± 2.74 (very difficult). Commercial websites constituted the highest proportion of websites (n = 36, 35.5%). Overall, 16.7% of the websites were found to be of high quality according to the Global Quality Score, 16 (15.7%) websites had Health on the Net Foundation code of conduct certification, and 8.8% of the websites were found to be highly reliable according to the Journal of American Medical Association scores. There was a statistically significant difference between website typologies and quality and reliability scores (P < .001). Compared with the sixth-grade level recommended by the American Medical Association and the National Institute of Health, the readability of transcutaneous electrical nerve stimulation-related internet-based patient education materials was considerably high, but they showed low reliability and moderate-to-poor quality. Thus, the quality, reliability, and readability of websites developed by health professionals play a major role in conveying accurate and easily understandable information.

Transcutaneous electrical nerve stimulation effects on patients with subacute vertebral fracture: a case report using an ABAB study design

[Purpose] This study investigated the effects of transcutaneous electrical nerve stimulation on trunk extension muscle strength, walking ability, and the Japanese Orthopedic Association Back Pain Evaluation Questionnaire items of gait disturbance in one case of a subacute osteoporotic vertebral fracture. [Participant and Methods] An 88-year-old female with the first and third lumbar vertebral fractures underwent standard physical therapy (A1 and A2 phases) and transcutaneous electrical nerve stimulation to the sclerotome region of the fractured vertebra (B1 and B2 phases). Assessments were performed before the A1 phase and the day after each phase. Assessment items included the Visual Analog Scale scores for pain during rest, getting up, standing up, and walking; isometric trunk extension muscle strength; walking ability (10-meter walking, continuous walking distance); and the Japanese Orthopedic Association Back Pain Evaluation Questionnaire items. [Results] Even though the pain intensity did not change, isometric trunk extension muscle strength, continuous walking distance, and the Japanese Orthopedic Association Back Pain Evaluation Questionnaire items of gait disturbance were improved in phase B compared to phase A. [Conclusion] Standard physical therapy and transcutaneous electrical nerve stimulation to the sclerotome area may improve trunk extension muscle strength, walking ability, and the Japanese Orthopedic Association Back Pain Evaluation Questionnaire items of gait disturbance in patients with subacute osteoporotic vertebral fractures.

Bibliometric and Visual Analysis of the Scientific Literature on Percutaneous Electrical Nerve Stimulation (PENS) for Pain Treatment

Background: Percutaneous electrical nerve stimulation (PENS) is a minimally invasive peripheral neuromodulation approach implemented against chronic neuropathic and mixed pain. This bibliometric study aims to quantitatively evaluate the output of PENS for pain treatment in the scientific literature. The main purpose is to stimulate research in the field and bridge potential scientific gaps. Methods: Articles were retrieved from the Web of Science (WOS) database. The search key term was “percutaneous electrical nerve stimulation (All Fields) and pain (All Fields)”. Year of publication, journal metrics (impact factor and quartile, Q), title, document type, topic, and citations were extracted. The join-point regression was implemented to assess differences in time points for the publication output. The software tool VOSviewer (version 1.6.17) was used for the visual analysis. Results: One thousand three hundred and eighteen articles were included in the knowledge visualization process. A linear upward trend for annual new publications was found. Almost two-thirds of the documents were published in top-ranked journals (Q1 and Q2). The topic “efficacy” was prevalent (12.81%). Concerning article type, the search strategy yielded 307 clinical investigations (23.3%). Articles were cited 36,610 times with a mean of 42.4 citations per article. Approximately one-half of the articles were cited less than 23 times in a range of 21 years. The semantic network analysis for keywords found eight clusters. The analysis of collaborative efforts among researchers showed five thematic clusters including 102 authors with a minimum of five documents produced in collaborations. Most partnerships involved the United States, England, and Germany. Conclusions: despite the upward trend in the number of publications on the subject and the publication of articles in top-ranked journals, there is a need to increase scientific collaborations between researchers and institutions from different countries.

Transcutaneous electrical nerve stimulation for pain during propofol injection: a randomized clinical trial

Background

Propofol is a short-acting intravenous sedative widely used for procedural sedation and general anesthesia. However, pain during propofol injection is a distressing adverse effect. This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) could reduce pain during propofol injection compared to sham TENS.

Methods

In a randomized controlled trial, 80 patients were allocated to two groups: the active TENS group received electrical stimulation via two electrodes on the venous cannulation site, whereas the sham TENS group received no stimulus. After 20 min following TENS, propofol 0.5 mg/kg pain was injected intravenously and pain was evaluated using a four-point score (0 = none, 1 = mild, 2 = moderate, 3 = severe). Adverse effects associated with TENS were also recorded.

Results

The overall incidence of pain during propofol injection was 47.5% in the TENS group and 87.5% in the sham group (P < 0.001). The incidence of moderate pain was significantly lower in the TENS group (7.5%) than in the sham TENS group (42.5%) (P < 0.001). There were no complications associated with TENS.

Conclusion

Pre-treatment with TENS significantly reduced the incidence and intensity of pain during propofol injection.

Analysis of Spin in the Reporting of Studies on Electroanalgesia for Musculoskeletal Pain

OBJECTIVE

The purpose of this study was to analyze the quality of reporting and presence of spin in abstracts of randomized clinical trials (RCTs) on the use of electroanalgesia for musculoskeletal pain.

METHODS

The Physiotherapy Evidence Database (PEDro) was searched from 2010 to June 2021. Inclusion criteria were RCTs using electroanalgesia in individuals with musculoskeletal pain, written in any language, comparing 2 or more groups, and with pain as 1 of the outcomes. Two blinded, independent, and calibrated evaluators (Gwet's AC1 agreement analysis) performed eligibility and data extraction. General characteristics, report of outcomes, quality of reporting (Consolidated Standards of Reporting Trials for Abstracts [CONSORT-A]), and spin analysis (7-item spin checklist and spin analysis per section) were extracted from abstracts.

RESULTS

Of 989 studies selected, 173 abstracts were analyzed after screening and eligibility criteria. Mean risk of bias on the PEDro scale was 6.02 ± 1.6 points. Most abstracts did not report significant differences for primary (51.4%) and secondary (63%) outcomes. Mean quality of reporting was 5.10 ± 2.4 points in the CONSORT-A, and spin was 2.97 ± 1.7. Abstracts had at least 1 type of spin (93%), and the conclusion presented the greatest number of spin types. More than 50% of abstracts recommended an intervention without significant differences between groups.

CONCLUSION

This study found that the majority of RCT abstracts on electroanalgesia for musculoskeletal conditions in our sample had a moderate to high risk of bias, incomplete or missing information, and some type of spin. We recommend that health care providers who use electroanalgesia and the scientific community be aware of spin in published studies.

Best Practices for Chiropractic Management of Adult Patients With Mechanical Low Back Pain: A Clinical Practice Guideline for Chiropractors in the United States

OBJECTIVE

The purpose of this paper was to update the previously published 2016 best-practice recommendations for chiropractic management of adults with mechanical low back pain (LBP) in the United States.

METHODS

Two experienced health librarians conducted the literature searches for clinical practice guidelines and other relevant literature, and the investigators performed quality assessment of included studies. PubMed was searched from March 2015 to September 2021. A steering committee of 10 experts in chiropractic research, education, and practice used the most current relevant guidelines and publications to update care recommendations. A panel of 69 experts used a modified Delphi process to rate the recommendations.

RESULTS

The literature search yielded 14 clinical practice guidelines, 10 systematic reviews, and 5 randomized controlled trials (all high quality). Sixty-nine members of the panel rated 38 recommendations. All but 1 statement achieved consensus in the first round, and the final statement reached consensus in the second round. Recommendations covered the clinical encounter from history, physical examination, and diagnostic considerations through informed consent, co-management, and treatment considerations for patients with mechanical LBP.

CONCLUSION

This paper updates a previously published best-practice document for chiropractic management of adults with mechanical LBP.

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.

Advances in Non-Invasive Neuromodulation

PURPOSE OF REVIEW

Pain medicine is rapidly expanding. The gap in treatment for patients with chronic pain in between traditional conservative therapy and major invasive surgery is closing. Neuromodulation is one therapeutic area that has continued to show promise for treatment of chronic pain. Our aim is to review updates in non-invasive neuromodulation (NIN) techniques as an adjunct for various chronic pain conditions.

RECENT FINDINGS

Overall, the literature suggests that NIN techniques such as tCDS, TMS, TENS, tVNS, and HIFUS/LIFUS have utility in treating various types of chronic pain and have a promising future. There is a better understanding of the mechanistic basis for pain relief from NIN, as well as refinement in technology improving NIN therapy success. Future studies will need to focus on continuing to refine protocols for optimal benefit from NIN as well as implementing larger RCTs to improve the quality of data being generated in the field.

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.

It Hurts to Move! Intervention Effects and Assessment Methods for Movement-Evoked Pain in Patients With Musculoskeletal Pain: A Systematic Review with Meta-analysis

OBJECTIVES

To estimate the effects of musculoskeletal rehabilitation interventions on movementevoked pain and to explore the assessment methods/protocols used to evaluate movement-evoked pain in adults with musculoskeletal pain.

DESIGN

Systematic review with meta-analysis.

LITERATURE SEARCH

Three electronic databases (PubMed, Web of Science, and Scopus) were searched.

STUDY SELECTION CRITERIA

Randomized controlled trials investigating musculoskeletal rehabilitation interventions for movement-evoked pain in adults with musculoskeletal pain were included.

DATA SYNTHESIS

Meta-analysis was conducted for outcomes with homogeneous data from at least 2 trials. The mean change in movementevoked pain was the primary outcome measure. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework.

RESULTS

Thirty-eight trials were included, and 60 different interventions were assessed. There was moderate-certainty evidence of a beneficial effect of exercise therapy compared to no treatment (standardized mean difference [SMD], -0.65; 95% confidence interval [CI]: -0.83, -0.47; P<.001) on movement-evoked pain in adults with musculoskeletal pain. There was low-certainty evidence of a beneficial effect of transcutaneous electrical nerve stimulation compared to no treatment (SMD, -0.46; 95% CI: -0.71, -0.21; P = .0004). There was no benefit of transcutaneous electrical nerve stimulation when compared to sham transcutaneous electrical nerve stimulation (SMD, -0.28; 95% CI: -0.60, 0.05; P = .09; moderate-certainty evidence).

CONCLUSION

There was moderate-certainty evidence that exercise therapy is effective for reducing movement-evoked pain in patients with musculoskeletal pain compared to no treatment. Consider exercise therapy as the first-choice treatment for movement-evoked pain in clinical practice. J Orthop Sports Phys Ther 2022;52(6):345-374. Epub: 05 Feb 2022. doi:10.2519/jospt.2022.10527.

Electrical dry needling versus conventional physiotherapy in the treatment of active and latent myofascial trigger points in patients with nonspecific chronic low back pain

Background

Chronic low back pain is considered to be one of the main causes of absenteeism from work and primary and specialized consultations. The symptoms of nonspecific chronic low back pain may be accompanied by the activation of myofascial trigger points in the muscles, together with local and/or referred pain. Electrical dry needling is increasingly used in the treatment of lumbar myofascial pain. Conventional physiotherapy, however, is a popular approach to chronic pathologies, and there is evidence of different modalities of physiotherapy being used in the treatment of chronic low back pain. The aim of this study has been to determine the effectiveness of electrical dry needling versus conventional physiotherapy when applied to active and latent myofascial trigger points in patients with nonspecific chronic low back pain.

Methods

This is a controlled, randomized, two-arm, double-blind study. A total of 92 patients with chronic low back pain (time to onset ≥ 3 months, Roland Morris Disability Questionnaire score ≥ 4) will be recruited from the University of Almería. Participants will be divided into two study groups (n = 40) to receive treatment of low back pain with electrical dry needling and conventional physiotherapy (ischaemic compression, analytic stretching and postural education training dossier). A total of 6 sessions will be administered once a week for 6 weeks. Pain intensity, disability, fear of movement, quality of life, quality of sleep, anxiety and depression, pressure pain threshold, abdominal strength and lumbar mobility will be recorded at 6 weeks (post-immediate) and 2 months after the end of treatment.

Discussion

We believe that an approach including electrical dry needling to chronic low back pain dysfunction will be more effective in these patients. The results of this study will inform clinicians on which type of treatment is more beneficial for patients with chronic low back pain.

Trial registration

ClinicalTrials.gov NCT04804228. Registered on 14 January 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06179-y.

Comparison of the effectiveness of an e-health program versus a home rehabilitation program in patients with chronic low back pain: A double blind randomized controlled trial

OBJETIVE

We conducted a randomized double blind clinical trial, to compare the effectiveness of McKenzie exercises and electroanalgesia via an e-Health program versus a home rehabilitation program on functionality, pain, fear of movement and quality of life in patients with non-specific chronic low back pain.

METHODS

Seventy-four participants with non-specific chronic low back pain were randomized to either the e- Health program group (n = 39) or the home rehabilitation program group (n = 35). The interventions consisted of the e-Health program group performing McKenzie exercises and received transcutaneous electrical nerve stimulation, while the home rehabilitation group attended an information session to explain the exercises, which they then performed at home with printed instructions. Both groups performed 3 weekly sessions for 8 weeks. The following were analyzed main measures: pain, disability, fear of movement, quality of life, trunk muscle endurance and trunk anteflexion motion were assessed at baseline and at 2 months.

RESULTS

Independent samples Student's t-tests showed that although the patients who followed the e-Health program showed significantly greater improvement than those who followed the home disability rehabilitation program in terms of intensity of pain, lumbar flexion mobility (P < 0.001), and the following dimensions of quality of life (P < 0.005), both groups improved significantly in the immediate post-treatment follow up compared with baseline scores.

CONCLUSIONS

Patients with chronic low back pain who followed an unsupervised home intervention supported by an individualized video exercise program showed greater post-treatment improvement than those who followed the same program with printed instructions.

The Added Value of Subcutaneous Peripheral Nerve Field Stimulation Combined with SCS, as Salvage Therapy, for Refractory Low Back Pain Component in Persistent Spinal Pain Syndrome Implanted Patients: A Randomized Controlled Study (CUMPNS Study) Based on 3D-Mapping Composite Pain Assessment

While Spinal Cord Stimulation (SCS) provides satisfaction to almost 2/3 of Persistent Spinal Pain Syndrome-Type 2 (PSPS-T2) patients implanted for refractory chronic back and/or leg pain, when not adequately addressed the back pain component, leaves patients in a therapeutic cul-de-sac. Peripheral Nerve field Stimulation (PNfS) has shown interesting results addressing back pain in the same population. Far from placing these two techniques in opposition, we suggest that these approaches could be combined to better treat PSPS-T2 patients. We designed a RCT (CUMPNS), with a 12-month follow-up, to assess the potential added value of PNfS, as a salvage therapy, in PSPS-T2 patients experiencing a "Failed SCS Syndrome" in the back pain component. Fourteen patients were included in this study and randomized into 2 groups ("SCS + PNfS" group/n = 6 vs. "SCS only" group/n = 8). The primary objective of the study was to compare the percentage of back pain surface decrease after 3 months, using a computerized interface to obtain quantitative pain mappings, combined with multi-dimensional SCS outcomes. Back pain surface decreased significantly greater for the "SCS + PNfS" group (80.2% ± 21.3%) compared to the "SCS only" group (13.2% ± 94.8%) (p = 0.012), highlighting the clinical interest of SCS + PNfS, in cases where SCS fails to address back pain.

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.

High-Frequency Impulse Therapy for Treatment of Chronic Back Pain: A Multicenter Randomized Controlled Pilot Study

Purpose

This study aims to examine high-frequency impulse therapy (HFIT) impact on pain and function among patients undergoing care for chronic low back pain (CLBP).

Methods

A pilot randomized-controlled trial of HFIT system versus sham was conducted across 5 orthopedic and pain center sites in California, USA. Thirty-six patients seeking clinical care for CLBP were randomized. Primary outcome was function measured by the Six Minute Walk Test (6MWT). Secondary outcomes were function (Timed Up and Go [TUG] and Oswestry Disability Index [ODI]), pain (Numerical Rating Scale [NRS]), quality of life (Patient Global Impression of Change [PGIC]), and device use. Patients were assessed at baseline and every week for 4 weeks of follow-up. Mann–Whitney U-test was used to analyze changes in each outcome. Repeated measures ANOVA was used to assess the effect of treatment over time.

Results

The average age of subjects was 53.9 ± 15.7 (mean ± SD) years, with 12.1 ± 8.8 years of chronic low back pain. Patients who received an HFIT device had a significantly higher 6MWT score at weeks 2 [Cohen’s d (95% CI): 0.33 (0.02, 0.61)], 3 [0.32 (0.01, 0.59)] and 4 [0.31 (0.01, 0.60)], respectively, as compared to their baseline scores (p < 0.05). Patients in the treatment group had significantly lower TUG scores at week 3 [0.30 (0.04, 0.57)] and significantly lower NRS scores at weeks 2 [0.34 (0.02, 0.58)] and 4 [0.41 (0.10, 0.67)] (p < 0.05).

Conclusion

A larger-scale RCT can build on the findings of this study to test whether HFIT is effective in reducing pain and improving function in CLBP patients. This study shows encouraging evidence of functional improvement and reduction in pain in subjects who used HFIT. The efficacy and minimally invasive nature of HFIT is anticipated to substantially improve the management of CLBP patients.

Effects of transcutaneous electrical nerve stimulation and instrument-assisted soft tissue mobilization combined treatment on chronic low back pain: A randomized controlled trial

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) for chronic low back pain (CLBP) requires a treatment period of ⩾ 6 weeks to decrease pain and disability and is ineffective as sole treatment. Instrument-assisted soft tissue mobilization (IASTM) has rapid effects in musculoskeletal disorders.

OBJECTIVE

This study aimed to investigate the effects of a 3-week combined TENS and IASTM treatment (TICT) on CLBP.

METHODS

Thirty-two young men with CLBP were randomly divided into the TICT and control groups (n= 16 each). Patients were evaluated with the visual analog (VAS) and face pain-rating scales (FPRS) for pain, the Oswestry Disability Index (ODI) and passive straight leg raise (PSLR) test for flexibility, and the supine bridge test (SBT) for endurance before and after the treatment course. The TICT group received TICT on the lower back, glutes, and hamstrings, six times in 3 weeks.

RESULTS

Group, time, and group × time interaction effects on pain were significant (VAS and FPRS, all p< 0.001). Group × time interaction (ODI, p< 0.001; PSLR, p< 0.05; SBT, p< 0.01) and group (ODI, p< 0.05) and time main effects (ODI, p< 0.001; PSLR, p< 0.01; SBT, p< 0.001) on motor function were significant.

CONCLUSION

Thus, short-term TICT decreased pain level and increased motor function in CLBP patients, yet further investigation is needed on different age and gender groups.

Role of Neuroimmune Crosstalk in Mediating the Anti-inflammatory and Analgesic Effects of Acupuncture on Inflammatory Pain

Inflammatory pain is caused by peripheral tissue injury and inflammation. Inflammation leads to peripheral sensitization, which may further cause central sensitization, resulting in chronic pain and progressive functional disability. Neuroimmune crosstalk plays an essential role in the development and maintenance of inflammatory pain. Studies in recent years have shown that acupuncture can exert anti-inflammatory and analgesic effects by regulating peripheral (i.e., involving local acupoints and inflamed regions) and central neuroimmune interactions. At the local acupoints, acupuncture can activate the TRPV1 and TRPV2 channels of mast cells, thereby promoting degranulation and the release of histamine, adenosine, and other immune mediators, which interact with receptors on nerve endings and initiate neuroimmune regulation. At sites of inflammation, acupuncture enables the recruitment of immune cells, causing the release of opioid peptides, while also exerting direct analgesic effects via nerve endings. Furthermore, acupuncture promotes the balance of immune cells and regulates the release of inflammatory factors, thereby reducing the stimulation of nociceptive receptors in peripheral organs. Acupuncture also alleviates peripheral neurogenic inflammation by inhibiting the release of substance P (SP) and calcitonin gene-related peptide from the dorsal root ganglia. At the central nervous system level, acupuncture inhibits the crosstalk between glial cells and neurons by inhibiting the p38 MAPK, ERK, and JNK signaling pathways and regulating the release of inflammatory mediators. It also reduces the excitability of the pain pathway by reducing the release of excitatory neurotransmitters and promoting the release of inhibitory neurotransmitters from neurons and glial cells. In conclusion, the regulation of neuroimmune crosstalk at the peripheral and central levels mediates the anti-inflammatory and analgesic effects of acupuncture on inflammatory pain in an integrated manner. These findings provide novel insights enabling the clinical application of acupuncture in the treatment of inflammatory diseases.

Complementary and Alternative Modalities (CAM) for pain management in musculoskeletal diseases (MSDs)

Musculoskeletal diseases are a group of clinical conditions affecting the body's movement and remain a common source of pain affecting the quality of life. The aetio-pathological reasons for pain associated with musculoskeletal diseases can be varied and complex. Conventional medicine can treat or modify pain due to musculoskeletal diseases; however, these may be associated with some side effects and at times may not be able to relieve pain completely. These treatment modalities also have ceiling effects like doses of analgesics, the number of nerve blocks, etc. Complementary and Alternative Medicine (CAM) provides a supplementary, unconventional modality to alleviate discomfort and disability associated with these mostly chronic conditions to manage activities of daily living. These modalities have been variedly combined with conventional management for symptom control and thus improve day-to-day activities. We assess the role of commonly used CAM modalities in the management of pain arising from Musculoskeletal diseases.

A Comprehensive Review of Over the Counter Treatment for Chronic Low Back Pain

PURPOSE OF THE REVIEW

Chronic low back pain (CLBP) is a major contributor to societal disease burden and years lived with disability. Nonspecific low back pain (LBP) is attributed to physical and psychosocial factors, including lifestyle factors, obesity, and depression. Mechanical low back pain occurs related to repeated trauma to or overuse of the spine, intervertebral disks, and surrounding tissues. This causes disc herniation, vertebral compression fractures, lumbar spondylosis, spondylolisthesis, and lumbosacral muscle strain.

RECENT FINDINGS

A systematic review of relevant literature was conducted. CENTRAL, MEDLINE, EMBASE, PubMed, and two clinical trials registry databases up to 24 June 2015 were included in this review. Search terms included: low back pain, over the counter, non-steroidal anti-inflammatory (NSAID), CLBP, ibuprofen, naproxen, acetaminophen, disk herniation, lumbar spondylosis, vertebral compression fractures, spondylolisthesis, and lumbosacral muscle strain. Over-the-counter analgesics are the most frequently used first-line medication for LBP, and current guidelines indicate that over-the-counter medications should be the first prescribed treatment for non-specific LBP. Current literature suggests that NSAIDs and acetaminophen as well as antidepressants, muscle relaxants, and opioids are effective treatments for CLBP. Recent randomized controlled trials also evaluate the benefit of buprenorphine, tramadol, and strong opioids such as oxycodone. This systematic review discusses current evidence pertaining to non-prescription treatment options for chronic low back pain.

Neuromodulation for chronic pain

Neuromodulation is an expanding area of pain medicine that incorporates an array of non-invasive, minimally invasive, and surgical electrical therapies. In this Series paper, we focus on spinal cord stimulation (SCS) therapies discussed within the framework of other invasive, minimally invasive, and non-invasive neuromodulation therapies. These therapies include deep brain and motor cortex stimulation, peripheral nerve stimulation, and the non-invasive treatments of repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and transcutaneous electrical nerve stimulation. SCS methods with electrical variables that differ from traditional SCS have been approved. Although methods devoid of paraesthesias (eg, high frequency) should theoretically allow for placebo-controlled trials, few have been done. There is low-to-moderate quality evidence that SCS is superior to reoperation or conventional medical management for failed back surgery syndrome, and conflicting evidence as to the superiority of traditional SCS over sham stimulation or between different SCS modalities. Peripheral nerve stimulation technologies have also undergone rapid development and become less invasive, including many that are placed percutaneously. There is low-to-moderate quality evidence that peripheral nerve stimulation is effective for neuropathic pain in an extremity, low quality evidence that it is effective for back pain with or without leg pain, and conflicting evidence that it can prevent migraines. In the USA and many areas in Europe, deep brain and motor cortex stimulation are not approved for chronic pain, but are used off-label for refractory cases. Overall, there is mixed evidence supporting brain stimulation, with most sham-controlled trials yielding negative findings. Regarding non-invasive modalities, there is moderate quality evidence that repetitive transcranial magnetic stimulation does not provide meaningful benefit for chronic pain in general, but conflicting evidence regarding pain relief for neuropathic pain and headaches. For transcranial direct current stimulation, there is low-quality evidence supporting its benefit for chronic pain, but conflicting evidence regarding a small treatment effect for neuropathic pain and headaches. For transcutaneous electrical nerve stimulation, there is low-quality evidence that it is superior to sham or no treatment for neuropathic pain, but conflicting evidence for non-neuropathic pain. Future research should focus on better evaluating the short-term and long-term effectiveness of all neuromodulation modalities and whether they decrease health-care use, and on refining selection criteria and treatment variables.

Percutaneous Electrical Nerve Stimulation (PENS) as a Rehabilitation Approach for Reducing Mixed Chronic Pain in Patients with Musculoskeletal Disorders

“Mixed pain” is a term recently introduced to define the overlapping of nociceptive, neuropathic and nociplastic pain. To date, it has been reported that pharmacological treatments might have a modest effectiveness on patients affected by mixed chronic pain, with detrimental consequences in terms of disability, physical function and health-related quality of life. In this scenario, Percutaneous Electrical Nerve Stimulation (PENS), a mini-invasive neuromodulation technique, has been recently suggested as a promising approach for the complex management of mixed pain in musculoskeletal disorders. Albeit PENS showed to be effective in reducing unspecified pain in several chronic pain conditions, there is still a lack of evidence in the literature about its role in the management of neuropathic or mixed pain not responsive to pharmacological treatments. Therefore, by the present scoping review, we portray the potential effects of PENS in the multidisciplinary and multidimensional management of mixed chronic pain in patients with musculoskeletal disorders.

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.

Transcutaneous electrical nerve stimulation and heat to reduce pain in a chronic low back pain population: a randomized controlled clinical trial

BACKGROUND

Low back pain is the leading cause of disability worldwide. The therapeutic management of patients with chronic LBP is challenging.

OBJECTIVES

The aim of this study is to evaluate the effects of heat and transcutaneous electrical nerve stimulation combined on pain relief in participants with chronic low back pain.

METHODS

Fifty participants with chronic (≥3 months) low back pain were randomly assigned to two groups: HeatTens (n=25) and control group (n=25). Primary outcome was pain. Secondary outcomes were pressure pain thresholds, temporal summation, conditioned pain modulation, fear-avoidance and beliefs questionnaire, central sensitization inventory, quality of life, and medication use. The control group received no treatment and continued usual care. After four weeks of treatment, all measurements were repeated.

RESULTS

Fifty individuals participated in this study. Significant higher pressure pain threshold measures after both 30min and 4 weeks for the lower back region and the second plantar toe were found only in the experimental group.

CONCLUSION

The combination of heat and transcutaneous electrical nerve stimulation does not reduce pain scores in patients with chronic low back pain. Pressure pain threshold values significantly improved, showing beneficial effects of the experimental treatment. ClinicalTrials.gov: NCT03643731 (https://clinicaltrials.gov/ct2/show/NCT03643731).

Study protocol randomised controlled trial comparison of cost-utility and cost-effectiveness of a face-to-face rehabilitation programme versus a telemedicine programme in the treatment of patients with chronic low back pain

INTRODUCTION

Chronic lower back pain is a highly prevalent medical condition in Western countries, which that incurs a considerable social and economic burden. Although prescription exercise at home for chronic pain has become a widely used alternative to reduce healthcare costs, the evidence regarding patient adherence and decreased in costs in European countries is scarce and inconclusive. The objective of this study is to examine the cost-utility and cost-effectiveness in patients with chronic lower back pain treated with the McKenzie Method and electroanalgesia via a telemedicine programme versus a face-to-face programme.

METHODS AND ANALYSIS

This study reports the protocol for a randomised, two-arm, multicentre, parallel controlled trial. A total of 540 patients with chronic lower back pain (onset time ≥3 months, Roland Morris Disability Questionnaire ≥4) will be recruited in three hospitals in Andalusia. Participants will be assigned to one of two groups (n=270, respectively) to receive electroanalgesia and Mckenzie method exercises through a telemedicine or a face-to-face programme. A total of 24 sessions will be administered three times a week for 8 weeks. Since the study design does not allow participant blinding, the outcome assessor and the statistician will be blinded. Use of helth care resources and costs due to work absenteeism will be captured and analysed. In addition, pain, intensity, fear of movement, quality of life and strength of the core muscle and anteflexion lumbar will be recorded at 2 and 6 months after the start of treatment.

ETHICS AND DISSEMINATION

Human Research and Local Ethics Committee of the 'Hospital Complex Torrecárdenas of Almeria, University Hospital of Granada and Virgen Macarena de Sevilla Hospital-Andalusian Health Service'. Study findings will be released to the research, clinical and health service through publication in international journals and conferences.

TRIAL REGISTRATION NUMBER

NCT04266366.

Effect of adjuvant frequency-specific microcurrents on pain and disability in patients treated with physical rehabilitation for neck and low back pain

OBJECTIVES

To evaluate the efficacy of adjuvant frequency-specific microcurrent (FSM) application on pain and disability in patients treated with physical rehabilitation for mechanical low back pain (LBP) and neck pain (NP).

METHODS

In this retrospective case-control study, pre- and post-treatment numerical pain rating scale (NPRS) score, Oswestry disability index (ODI) score, neck disability index (NDI) score, disability categories, and treatment outcome categories were compared between 213 patients in the FSM group (167 patients with LBP, 46 patients with NP) and 78 patients in the control group (61 patients with LBP, 17 patients with NP).

RESULTS

In LBP patients, mean post-treatment NPRS score was significantly lower (p = 0.02) and a significantly higher percentage of patients were in the ≤3 NPRS score (p = 0.02), in the minimal disability (p = 0.01), and the full success (p = 0.006) categories post-treatment in the FSM group when compared to the control group. In NP patients, there was no significant difference in the post-treatment pain intensity, disability or treatment outcome when the 2 groups were compared.

CONCLUSIONS

The use of adjuvant FSM application in patients treated with physical rehabilitation for LBP significantly improved pain and disability when compared to patients in the control group. Frequency specific microcurrent could be a useful adjuvant in the rehabilitation treatment of patients with low back pain.

Best Practices for Chiropractic Management of Patients with Chronic Musculoskeletal Pain: A Clinical Practice Guideline

Objective: To develop an evidence-based clinical practice guideline (CPG) through a broad-based consensus process on best practices for chiropractic management of patients with chronic musculoskeletal (MSK) pain. Design: CPG based on evidence-based recommendations of a panel of experts in chronic MSK pain management. Methods: Using systematic reviews identified in an initial literature search, a steering committee of experts in research and management of patients with chronic MSK pain drafted a set of recommendations. Additional supportive literature was identified to supplement gaps in the evidence base. A multidisciplinary panel of experienced practitioners and educators rated the recommendations through a formal Delphi consensus process using the RAND Corporation/University of California, Los Angeles, methodology. Results: The Delphi process was conducted January-February 2020. The 62-member Delphi panel reached consensus on chiropractic management of five common chronic MSK pain conditions: low-back pain (LBP), neck pain, tension headache, osteoarthritis (knee and hip), and fibromyalgia. Recommendations were made for nonpharmacological treatments, including acupuncture, spinal manipulation/mobilization, and other manual therapy; modalities such as low-level laser and interferential current; exercise, including yoga; mind-body interventions, including mindfulness meditation and cognitive behavior therapy; and lifestyle modifications such as diet and tobacco cessation. Recommendations covered many aspects of the clinical encounter, from informed consent through diagnosis, assessment, treatment planning and implementation, and concurrent management and referral. Appropriate referral and comanagement were emphasized. Conclusions: These evidence-based recommendations for a variety of conservative treatment approaches to the management of common chronic MSK pain conditions may advance consistency of care, foster collaboration between provider groups, and thereby improve patient outcomes.

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.

Effectiveness of percutaneous electrical nerve stimulation for musculoskeletal pain: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

To evaluate the effects of percutaneous electrical stimulation (PENS) alone or as an adjunct with other interventions on pain and related disability in musculoskeletal pain conditions.

DATABASES AND DATA TREATMENT

Search of MEDLINE, EMBASE, AMED, CINAHL, EBSCO, PubMed, PEDro, Cochrane Library, SCOPUS and Web of Science databases. Randomized controlled trials where at least one group received any form of PENS for musculoskeletal condition. Studies had to include humans and collect outcomes on pain and related disability in musculoskeletal pain. Risk of bias was assessed by the Cochrane Guidelines, the quality of evidence by using the GRADE approach. Standardized mean differences (SMD) were calculated.

RESULTS

Sixteen studies were included and included heterogeneous musculoskeletal conditions with short- or midterm follow-ups. PENS alone had a large effect (SMD -1.22, 95% CI -1.66 to -0.79) on pain and a small effect (SMD -0.33, 95% CI -0.61 to -0.06) on related disability at short-term as compared with sham. A moderate effect of PENS alone (SMD -0.71, 95% CI -1.23 to -0.19) on pain when compared with other interventions was observed. The inclusion of PENS with other interventions had a moderate effect for decreasing pain at short- (SMD -0.70, 95% CI -1.02 to -0.37) and midterm (SMD -0.68, 95% CI -1.10 to -0.27). No effect at midterm (SMD -0.21, 95% CI -0.52 to 0.10) on related disability was seen. The risk of bias was generally low; but the heterogenicity of the results downgraded the level of evidence.

CONCLUSION

There is low level of evidence suggesting the effects of PENS alone or in combination for pain, but not related disability, in musculoskeletal pain.

LEVEL OF EVIDENCE

Therapy, level 1a. Registration number: CRD42019131331.

SIGNIFICANCE

This meta-analysis investigating the effectiveness of PENS for the management of pain and related disability in musculoskeletal pain conditions found that PENS could decrease level of pain intensity but not relateddisability in musculoskeletal pain disorders.

Transcutaneous Electrical Nerve Stimulation Reduces Knee Osteoarthritic Pain by Inhibiting Spinal Glial Cells in Rats

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is commonly used for pain control. However, the effects of TENS on osteoarthritis (OA) pain and potential underlying mechanisms remain unclear.

OBJECTIVE

The objective of this study was to investigate the effect of TENS on OA pain treatment and underlying mechanisms related to glial cell inhibition.

DESIGN

This was an experimental study.

METHODS

OA was induced by injection of monosodium iodoacetate into the synovial space of the right knee joint of rats. High-frequency (HF) TENS (100 Hz), low-frequency (LF) TENS (4 Hz), or sham TENS was applied to the ipsilateral knee joint for 20 minutes. Paw withdrawal threshold (PWT), weight bearing, and knee bend score (KBS) were measured. Immunohistochemistry for microglia and astrocytes was performed with L3 to L5 spinal segment samples. To investigate the effects of glial inhibition on OA pain, minocycline, l-α-aminoadipate, or artificial cerebrospinal fluid was injected intrathecally, and PWT and KBS were measured.

RESULTS

Compared with sham TENS, both HF TENS and LF TENS significantly increased PWT, decreased KBS, and inhibited activated microglia in the L3 to L5 segments but did not decrease the total number of microglia, except in the L4 segment (HF TENS). Astrocyte expression was significantly decreased in the L3 to L5 segments following LF TENS and in the L3 segment following HF TENS. Compared with artificial cerebrospinal fluid, both minocycline and l-α-aminoadipate increased PWT and decreased KBS.

LIMITATIONS

These results cannot be generalized to humans.

CONCLUSIONS

TENS alleviates OA pain in rats by inhibiting activated microglia and reducing astrocyte expression in the spinal cord. Although these results may not be generalizable to chronic pain in patients with OA, within the limitation of the experimental animal model used in the present study, they suggest a possible mechanism and preclinical evidence supporting further experimentation or clinical use of TENS in humans.

Best Evidence Rehabilitation for Chronic Pain Part 3: Low Back Pain

Chronic Low Back Pain (CLBP) is a major and highly prevalent health problem. Given the high number of papers available, clinicians might be overwhelmed by the evidence on CLBP management. Taking into account the scale and costs of CLBP, it is imperative that healthcare professionals have access to up-to-date, evidence-based information to assist them in treatment decision-making. Therefore, this paper provides a state-of-the-art overview of the best evidence non-invasive rehabilitation for CLBP. Taking together up-to-date evidence from systematic reviews, meta-analysis and available treatment guidelines, most physically inactive therapies should not be considered for CLBP management, except for pain neuroscience education and spinal manipulative therapy if combined with exercise therapy, with or without psychological therapy. Regarding active therapy, back schools, sensory discrimination training, proprioceptive exercises, and sling exercises should not be considered due to low-quality and/or conflicting evidence. Exercise interventions on the other hand are recommended, but while all exercise modalities appear effective compared to minimal/passive/conservative/no intervention, there is no evidence that some specific types of exercises are superior to others. Therefore, we recommend choosing exercises in line with the patient's preferences and abilities. When exercise interventions are combined with a psychological component, effects are better and maintain longer over time.