Objective: To determine whether transcutaneous electrical nerve stimulation (TENS) has an analgesic effect greater than placebo or other treatments in patients with fibromyalgia. Furthermore, it was intended to analyze the optimal application parameters to achieve a greater reduction of pain. Design: A systematic review. Data source: Randomized clinical trials on the effect of TENS on fibromyalgia in the databases Pubmed, Cochrane and PEDro until November 2016. Selection of studies: 8 studies out of a total of 62 were selected. Controlled clinical trials in which TENS was applied in patients with fibromyalgia were included. Data extraction: Pain was analyzed as the main variable, although other variables such as fatigue, quality of life and impact, range of motion and depression were also included. Results: 6 out of 8 studies obtained a significant decrease of pain. In 2 studies, TENS was applied as complementary treatment to therapeutic exercise with results evidencing a decrease in pain. The rest of the variables studied presented a great variability and conclusive results could not be established. Conclusions: Treatment with TENS is effective for reducing pain in people with fibromyalgia. In addition, the inclusion of TENS in therapeutic exercise programs seems to have a greater effect than practicing therapeutic exercise in isolation. However, no efficacy has been demonstrated in other variables different to pain. Further studies are needed to investigate the optimization of the parameters of the TENS and a greater consensus among the variables used
BACKGROUND: Fibromyalgia is characterised by persistent, widespread pain; sleep problems; and fatigue. Transcutaneous electrical nerve stimulation (TENS) is the delivery of pulsed electrical currents across the intact surface of the skin to stimulate peripheral nerves and is used extensively to manage painful conditions. TENS is inexpensive, safe, and can be self-administered. TENS reduces pain during movement in some people so it may be a useful adjunct to assist participation in exercise and activities of daily living. To date, there has been only one systematic review in 2012 which included TENS, amongst other treatments, for fibromyalgia, and the authors concluded that TENS was not effective.
OBJECTIVES: To assess the analgesic efficacy and adverse events of TENS alone or added to usual care (including exercise) compared with placebo (sham) TENS; no treatment; exercise alone; or other treatment including medication, electroacupuncture, warmth therapy, or hydrotherapy for fibromyalgia in adults.
SEARCH METHODS: We searched the following electronic databases up to 18 January 2017: CENTRAL (CRSO); MEDLINE (Ovid); Embase (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS; PEDRO; Web of Science (ISI); AMED (Ovid); and SPORTDiscus (EBSCO). We also searched three trial registries. There were no language restrictions.
SELECTION CRITERIA: We included randomised controlled trials (RCTs) or quasi-randomised trials of TENS treatment for pain associated with fibromyalgia in adults. We included cross-over and parallel-group trial designs. We included studies that evaluated TENS administered using non-invasive techniques at intensities that produced perceptible TENS sensations during stimulation at either the site of pain or over nerve bundles proximal (or near) to the site of pain. We included TENS administered as a sole treatment or TENS in combination with other treatments, and TENS given as a single treatment or as a course of treatments.
DATA COLLECTION AND ANALYSIS: Two review authors independently determined study eligibility by assessing each record and reaching agreement by discussion. A third review author acted as arbiter. We did not anonymise the records of studies before assessment. Two review authors independently extracted data and assessed risk of bias of included studies before entering information into a 'Characteristics of included studies' table. Primary outcomes were participant-reported pain relief from baseline of 30% or greater or 50% or greater, and Patient Global Impression of Change (PGIC). We assessed the evidence using GRADE and added 'Summary of findings' tables.
MAIN RESULTS: We included eight studies (seven RCTs, one quasi-RCT, 315 adults (299 women), aged 18 to 75 years): six used a parallel-group design and two used a cross-over design. Sample sizes of intervention arms were five to 43 participants.Two studies, one of which was a cross-over design, compared TENS with placebo TENS (82 participants), one study compared TENS with no treatment (43 participants), and four studies compared TENS with other treatments (medication (two studies, 74 participants), electroacupuncture (one study, 44 participants), superficial warmth (one cross-over study, 32 participants), and hydrotherapy (one study, 10 participants)). Two studies compared TENS plus exercise with exercise alone (98 participants, 49 per treatment arm). None of the studies measured participant-reported pain relief of 50% or greater or PGIC. Overall, the studies were at unclear or high risk of bias, and in particular all were at high risk of bias for sample size.Only one study (14 participants) measured the primary outcome participant-reported pain relief of 30% or greater. Thirty percent achieved 30% or greater reduction in pain with TENS and exercise compared with 13% with exercise alone. One study found 10/28 participants reported pain relief of 25% or greater with TENS compared with 10/24 participants using superficial warmth (42 °C). We judged that statistical pooling was not possible because there were insufficient data and outcomes were not homogeneous.There were no data for the primary outcomes participant-reported pain relief from baseline of 50% or greater and PGIC.There was a paucity of data for secondary outcomes. One pilot cross-over study of 43 participants found that the mean (95% confidence intervals (CI)) decrease in pain intensity on movement (100-mm visual analogue scale (VAS)) during one 30-minute treatment was 11.1 mm (95% CI 5.9 to 16.3) for TENS and 2.3 mm (95% CI 2.4 to 7.7) for placebo TENS. There were no significant differences between TENS and placebo for pain at rest. One parallel group study of 39 participants found that mean ± standard deviation (SD) pain intensity (100-mm VAS) decreased from 85 ± 20 mm at baseline to 43 ± 20 mm after one week of dual-site TENS; decreased from 85 ± 10 mm at baseline to 60 ± 10 mm after single-site TENS; and decreased from 82 ± 20 mm at baseline to 80 ± 20 mm after one week of placebo TENS. The authors of seven studies concluded that TENS relieved pain but the findings of single small studies are unlikely to be correct.One study found clinically important improvements in Fibromyalgia Impact Questionnaire (FIQ) subscales for work performance, fatigue, stiffness, anxiety, and depression for TENS with exercise compared with exercise alone. One study found no additional improvements in FIQ scores when TENS was added to the first three weeks of a 12-week supervised exercise programme.No serious adverse events were reported in any of the studies although there were reports of TENS causing minor discomfort in a total of 3 participants.The quality of evidence was very low. We downgraded the GRADE rating mostly due to a lack of data; therefore, we have little confidence in the effect estimates where available.
AUTHORS' CONCLUSIONS: There was insufficient high-quality evidence to support or refute the use of TENS for fibromyalgia. We found a small number of inadequately powered studies with incomplete reporting of methodologies and treatment interventions.
Resumen Objetivos Revisar la literatura más actual para comprobar los efectos de la fisioterapia pasiva en el tratamiento de los síntomas de la fibromialgia, diferenciando según técnicas de aplicación y valorando la efectividad según síntoma. Estrategia de búsqueda Se realiza una búsqueda bibliográfica en Medline a través de Pubmed para localizar ensayos clínicos de los últimos 5 años. Selección de estudios Se hallan 683 estudios de los que 18 son seleccionados y evaluados según la calidad metodológica con la escala PEDro. Síntesis de resultados La fisioterapia pasiva puede ser un tratamiento efectivo, ya que técnicas como la electroterapia, la liberación miofascial y la balneoterapia producen analgesia y mejoran la calidad de vida de los sujetos. La depresión mejora con la terapia manual y la balneoterapia; el sueño mejora con la TENS y la terapia manual. Conclusiones La fisioterapia pasiva puede ser un tratamiento efectivo a nivel sintomático, siendo algunas técnicas más indicadas que otras según los síntomas de mayor severidad en los pacientes. Objectives To review the most recent literature on the effects of passive physiotherapy in the treatment of fibromyalgia, including the different techniques used and the measurement of their effectiveness on each symptom. Search strategy a bibliographic search was carried out in PubMed database to locate clinical trials conducted in the previous five years. Study selection Of the 683 studies found, 18 of them were selected and assessed according to their methodological quality using the PEDro scale. Summary of results passive physiotherapy could be an effective treatment, since techniques such as electrotherapy, balneotherapy, and myofascial release improve pain and quality of life in the subjects. Depression is improved by manual therapy and balneotherapy. Transcutaneous electrical nerve stimulation (TENS) and manual therapy improve sleep. Conclusions Passive physiotherapy could be an effective symptomatic treatment. The choice of the technique must depend on the specific symptom required to be treat.
BACKGROUND: Fibromyalgia (FM) is a syndrome whose primary symptoms include chronic widespread muscle pain and fatigue. The treatment of patients with FM aims to provide symptomatic relief and improvement in physical capacities to perform daily tasks and quality of life. Invasive or non-invasive electric stimulation (ES) is used for pain relief in patients with FM.
OBJECTIVE: This systematic review aimed to assess the effects of treatment with ES, combined or not combined with other types of therapy, for pain relief in patients with FM.
STUDY DESIGN: Systematic review and meta-analysis.
SETTING: Electronic search was conducted on databases (from the inception to April 2016): MEDLINE (accessed by PubMed), EMBASE, Cochrane Central Register of Controlled Trials (Cochrane CENTRAL), and Physiotherapy Evidence Database (PEDro).
METHODS: Two independent reviewers assessed the eligibility of studies based on the inclusion criteria: randomized controlled trials (RCTs) examining the effects of ES combined or not with other types of treatment for pain relief in patients with FM (according to the American College of Rheumatology), regardless of the ES dosages. The primary outcome was pain, assessed by the visual analogue scale (VAS). The secondary outcomes extracted were quality of life, assessed by short form-36 health survey (SF- 36), and fatigue, assessed by VAS.
RESULTS: Nine studies were included, with 301 patients. The meta-analysis for pain showed positive effect of ES treatment versus control [-1.24 (95% CI: -2.39 to -0.08; I²: 87%, P = 0.04) n = 8 RCTs]. The sensitivity analysis for pain showed significant results for invasive ES, combined or not with other types of therapy [-0.94 (95% CI, -1.50 to -0.38; I² 0%, P = 0.001) n = 3 RCTs]. No significant improvement was found regarding quality of life [-3.48 (95% CI: -12.58 to 5.62; I²: 0%, P = 0.45), n = 2 RCTs] or fatigue [-0.57 (95% CI, -1.25 to 0.11; I² 34%, P = 0.100; n = 4 RCTs].
LIMITATIONS: This systematic review included a small number of studies and reduced number of participants in each study. Furthermore, most of the studies showed some biases and lack of methodological quality.
CONCLUSIONS: This meta-analysis indicates that there is low-quality evidence for the effectiveness of ES for pain relief in patients with FM. However, moderate-quality evidence for the effectiveness of electroacupuncture (EA), combined or not combined with other types of treatment, was found for pain relief.
CLINICAL TRIAL REGISTRATION INFORMATION: PROSPERO under the identification CRD42015025323Key words: Electric stimulation, electroacupuncture, transcutaneous electric nerve stimulation, pain, fibromyalgia, review, physical therapy, rehabilitation.
Objective: To determine whether transcutaneous electrical nerve stimulation (TENS) has an analgesic effect greater than placebo or other treatments in patients with fibromyalgia. Furthermore, it was intended to analyze the optimal application parameters to achieve a greater reduction of pain. Design: A systematic review. Data source: Randomized clinical trials on the effect of TENS on fibromyalgia in the databases Pubmed, Cochrane and PEDro until November 2016. Selection of studies: 8 studies out of a total of 62 were selected. Controlled clinical trials in which TENS was applied in patients with fibromyalgia were included. Data extraction: Pain was analyzed as the main variable, although other variables such as fatigue, quality of life and impact, range of motion and depression were also included. Results: 6 out of 8 studies obtained a significant decrease of pain. In 2 studies, TENS was applied as complementary treatment to therapeutic exercise with results evidencing a decrease in pain. The rest of the variables studied presented a great variability and conclusive results could not be established. Conclusions: Treatment with TENS is effective for reducing pain in people with fibromyalgia. In addition, the inclusion of TENS in therapeutic exercise programs seems to have a greater effect than practicing therapeutic exercise in isolation. However, no efficacy has been demonstrated in other variables different to pain. Further studies are needed to investigate the optimization of the parameters of the TENS and a greater consensus among the variables used
