The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial. Repetitive magnetic stimulation: a novel therapeutic approach for myofascial pain syndrome. A pilot investigation of the hypoalgesic effects of transcutaneous electrical nerve stimulation upon low back pain in people with multiple sclerosis. Pain reducing effect of three types of transcutaneous electrical nerve stimulation in patients with chronic pain: a randomized crossover trial. Prospective comparison of the effect of direct current electrical stimulation and pulsed electromagnetic fields on instrumented posterolateral lumbar arthrodesis. Evaluation of TENS during screening flexible sigmoidoscopy. Acupuncture in the management of chronic low back pain: a blinded randomized controlled trial. Transcutaneous electrical nerve stimulation vs. transcutaneous spinal electroanalgesia for chronic pain associated with breast cancer treatments. Immediate effects of various physical therapeutic modalities on cervical myofascial pain and trigger-point sensitivity. Efficacy of transcutaneous electrical nerve stimulation (tens) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial. Efficacy of electroacupuncture and TENS in the rehabilitation of chronic low back pain patients. A randomized clinical trial of TENS and exercise for patients with chronic neck pain. Feasibility study of Transcutaneous Electrical Nerve Stimulation (TENS) for cancer bone pain. The impact of pharmaceutical company funding on results of randomized trials of nicotine replacement therapy for smoking cessation: a meta-analysis. The immediate effectiveness of electrical nerve stimulation and electrical muscle stimulation on myofascial trigger points.
The purpose of this study was to evaluate the effect of electromagnetic field therapy (PEMF) on pain, range of motion (ROM) and functional status in patients with cervical osteoarthritis (COA). Thirty-four patients with COA were included in a randomized, double-blind study. PEMF was administrated to the whole body using a mat 1.8 x 0.6 m in size. During the treatment, the patients lay on the mat for 30 min per session, twice a day for 3 weeks. Pain levels in the PEMF group decreased significantly after therapy (p<0.001), but no change was observed in the placebo group. The active ROM, paravertebral muscle spasm and neck pain and disability scale (NPDS) scores improved significantly after PEMF therapy (p<0.001) but no change was observed in the sham group. The results of this study are promising, in that PEMF treatment may offer a potential therapeutic adjunct to current COA therapies in the future. The aim of this study was to evaluate the short, medium and long-term effects of peripheral repetitive magnetic stimulation (rMS) on myofascial pain compared with transcutaneous electrical nerve stimulation (TENS).Fifty-three subjects with myofascial trigger points (TPs) at the level of the superior trapezius muscle were allocated randomly to three groups. The first group (n=17) was treated with rMS, the second (n=18) with TENS and the third (n=18) received a placebo treatment. Each treatment consisted of ten daily 20-minute sessions. Patients were evaluated before and immediately following treatment, and at one and three months after the end of treatment. Outcome measures were: the "neck pain and disability visual analogue scale" (NPDVAS), an algometric evaluation of pain, an evaluation of the TP characteristics, and the range of cervical bending and rotation contralateral to the affected trapezius muscle. At the end of treatment, the rMS group showed a significant improvement in the NPDVAS, algometry, TP characteristics, and cervical contralateral rotation. This improvement also persisted at one and three months post-therapy. After treatment, the TENS group showed significant improvement in the same outcome measures except for algometry. At the one month follow-up visit, this improvement had returned to non significant levels in all outcome measures with the exception of NPDVAS. No significant effect of TENS was seen at the three-month follow-up visit. The placebo group showed no significant improvement in any measure. Our results strongly suggest that at medium and longer term intervals peripheral rMS may be more effective than TENS for the treatment of myofascial pain. To investigate the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) upon low back pain (LBP) in people with multiple sclerosis (MS).
                A randomized double-blind placebo controlled clinical pilot study.
                Fifteen people with MS were recruited and randomly allocated to one of the following groups under double blind conditions (n = 5 per group): TENS 1 (4 Hz, 200 micros), TENS 2 (110 Hz, 200 micros), placebo TENS.
                Treatment was applied for 45 minutes three times a week for six weeks with a four-week follow-up.
                The following outcome measures were taken at weeks 1, 6, and 10: visual analogue scale (VAS) (for current LBP, right leg pain, left leg pain); Leeds Multiple Sclerosis Quality of Life Questionnaire; Roland Morris Disability Questionnaire; Short Form-36 (SF-36) Version 1; and the McGill Pain Questionnaire (MPQ). VAS for current LBP, right and left leg pain were also taken before and after treatment, and once a week during the follow-up period.
                Analysis showed no statistically significant effects for any of the data. However, both active treatment groups showed a trend of improvement in the majority of the outcome measures.
                Active TENS was more effective than placebo TENS in decreasing VAS scores following each treatment although results were not statistically significant. Further work in this area is warranted and should include a larger number of participants in the form of a randomized controlled clinical trial to determine the efficacy of this modality. Transcutaneous electrical nerve stimulation (TENS) is a frequently applied therapy in chronic pain although evidence for effectiveness is inconclusive. Several types of TENS, based on different combinations of frequency, pulse duration and intensity, exist. The precise mechanism of action and the relevance of combinations of stimulus parameters are still unclear. To compare the effectiveness of three types of TENS we conducted a randomized, single blinded crossover trial. Patients received two times a 2-week period of daily TENS treatment, separated by a washout period of 2 weeks. In total, 180 chronic pain patients were randomized into three groups. In group 1, high frequency, low intensity TENS (HFT) was compared with high frequency, high intensity TENS (HIT). In groups 2 and 3, HFT and HIT were compared with a control TENS (COT). The order of applying the different modalities of TENS in each group was also randomized. Primary outcome was the patient's overall assessment of effectiveness and pain reduction (VAS). No differences were found in patient's assessment or pain reducing effect between the three groups, indicating no superiority of one type of TENS. In total, 56% continued TENS after the 2-week treatment period. At 6 months, 42% of all patients still used TENS. We concluded that there were no differences in effectiveness for the three types of TENS used in this study. Because no placebo group was included, no definite conclusions on effectiveness of TENS in general in the treatment of chronic pain could be made. The purpose of this prospective study was to compare the effect of adjunctive direct current (DC) electrical stimulation and pulsed electromagnetic field therapy (PEMF) on augmentation of instrumented lumbar fusion. Sixty-one patients undergoing lumbar spine fusion were enrolled in the study and randomized to one of three treatment protocols: 1) adjunctive PEMF group (n = 22) fitted with Spinal-Stim model 8212(AME) within 30 days of surgery; 2) DC group (n = 17) had a SpF-2T stimulator(EBI) implanted at the time of surgery; or 3) control group (n = 22). The fusion mass bone mineral density (BMD) assessment was performed on 3-month and 1-year radiographs for each patient. Lateral flexion-extension and anteroposterior radiographs were evaluated at 1 year to determine the presence of fusion. Clinical outcome patient analyses were performed at 1 year. At 1-year follow-up, radiographic fusion and fusion mass bone density were not significantly different among the groups. In the nonstimulated group, there were 43% excellent, 43% good, and 14% fair results. In the PEMF group, there were 35% excellent, 50% good, 10% fair, and 5% poor results. In the DC group, there were 32% excellent, 37% good, and 31% fair results. The results of the current study suggest that electrical stimulation does not significantly enhance fusion rate in instrumented lumbar arthrodesis, although we observed a statistically insignificant trend toward increased fusion mass BMD in the electrically stimulated groups. The significance of increased BMD remains unknown. The expectation of pain is a statistically significant factor negatively affecting patient compliance with current screening flexible sigmoidoscopy recommendations. Numerous pain reduction modalities have been studied with limited success. Transcutaneous electrical nerve stimulation (TENS) has been used to treat pain of various origins. The purpose of this pilot study was to determine the efficacy of TENS in reducing discomfort experienced during screening flexible sigmoidoscopy.A double-blind study was conducted in which 90 subjects were randomized to receive TENS, sham TENS, or control (standard care). The same pulse frequency and intensity were used for all subjects in the TENS group. Subjects completed preprocedural and postprocedural questionnaires, and the endoscopist completed a postprocedural questionnaire. A slight, but statistically insignificant (p =.526) reduction in the mean pain score reported by the TENS group was noted when compared with the sham TENS and control groups (2.00, 2.27, and 2.23 respectively). In light of the fact that only one pulse frequency and intensity of the TENS intervention were used in this study, further study with this safe and cost-effective modality is warranted. To assess the efficacy of acupuncture in the treatment of chronic low back pain.
                Patients (n = 60) with chronic low back pain were recruited and randomly allocated to either Acupuncture therapy or Placebo transcutaneous electrical nerve stimulation (TENS) groups. Patients were treated weekly for 6 weeks, and blinded assessments were carried out pre- and post-treatment using the McGill Pain Questionnaire (MPQ) and visual analog scales (VAS) for pain, the Short-form 36 quality-of-life questionnaire, and a simple range of motion measurement. A total of 46 patients completed the trial and were followed up at 6 months.
                Analysis of results using t tests showed that in both groups there were significant pre-post improvements for all scores, except for MPQ scores in the Placebo-TENS group. There was no significant difference between the 2 groups for any of the outcome measures at the end of treatment. Results from the 6-month follow-up would suggest that the response was better in the acupuncture group.
                Further research is necessary to fully assess the efficacy of this treatment in combating chronic low back pain using larger sample sizes or alternative control groups. Chronic pain associated with breast cancer treatment is becoming increasingly recognized. Patients with this condition can experience significant physical and psychological morbidity and may benefit from nonpharmacological interventions as part of a multidisciplinary team approach. We compared the effectiveness of transcutaneous electrical nerve stimulation (TENS), transcutaneous spinal electroanalgesia (TSE), and a placebo (sham TSE) in a randomized controlled trial. The study sample comprised 41 women with chronic pain following breast cancer treatment, and outcome measures included pain report, pain relief, pain interference, anxiety and depression, arm mobility, and analgesic consumption. There was little evidence to suggest that TENS or TSE were more effective than placebo. All three interventions had beneficial effects on both pain report and quality of life, a finding that may be due to either psychophysical improvements resulting from the personal interaction involved in the treatment or a placebo response. Although electrical stimulation appears to be well tolerated in this population, further research is needed to establish its effectiveness for chronic cancer treatment-related pain. To investigate the immediate effect of physical therapeutic modalities on myofascial pain in the upper trapezius muscle.
                Randomized controlled trial.
                Institutional practice.
                One hundred nineteen subjects with palpably active myofascial trigger points (MTrPs).
                Stage 1 evaluated the immediate effect of ischemic compression, including 2 treatment pressures (P1, pain threshold; P2, averaged pain threshold and tolerance) and 3 durations (T1, 30s; T2, 60s; T3, 90s). Stage 2 evaluated 6 therapeutics combinations, including groups B1 (hot pack plus active range of motion [ROM]), B2 (B1 plus ischemic compression), B3 (B2 plus transcutaneous electric nerve stimulation [TENS]), B4 (B1 plus stretch with spray), B5 (B4 plus TENS), and B6 (B1 plus interferential current and myofascial release).
                The indexes of changes in pain threshold (IThC), pain tolerance (IToC), visual analog scale (IVC), and ROM (IRC) were evaluated for treatment effect.
                In stage 1, the IThC, IToC, IVC, and IRC were significantly improved in the groups P1T3, P2T2, and P2T3 compared with the P1T1 and P1T2 treatments (P<.05). In stage 2, groups B3, B5, and B6 showed significant improvement in IThC, ItoC, and IVC compared with the B1 group; groups B4, B5, and B6 showed significant improvement in IRC compared with group B1 (P<.05).
                Ischemic compression therapy provides alternative treatments using either low pressure (pain threshold) and a long duration (90s) or high pressure (the average of pain threshold and pain tolerance) and short duration (30s) for immediate pain relief and MTrP sensitivity suppression. Results suggest that therapeutic combinations such as hot pack plus active ROM and stretch with spray, hot pack plus active ROM and stretch with spray as well as TENS, and hot pack plus active ROM and interferential current as well as myofascial release technique, are most effective for easing MTrP pain and increasing cervical ROM.
                Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation This study was designed to investigate the hypoalgesic effects of self-applied transcutaneous electrical nerve stimulation (TENS) on chronic low-back pain (LBP) in a multiple sclerosis (MS) population.
                Ninety participants with probable or definite MS (aged 21 to 78 y) presenting with chronic LBP were recruited and randomized into 3 groups (n=30 per group): (1) low-frequency TENS group (4 Hz, 200 micros); (2) high-frequency TENS group (110 Hz, 200 micros); and (3) placebo TENS. Participants self-applied TENS for 45 minutes, a minimum of twice daily, for 6 weeks. Outcome measures were recorded at weeks 1, 6, 10, and 32. Primary outcome measures included: Visual Analog Scale for average LBP and the McGill Pain Questionnaire. Secondary outcome measures included: Visual Analog Scale for worst and weekly LBP, back and leg spasm; Roland Morris Disability Questionnaire; Barthel Index; Rivermead Mobility Index; Multiple Sclerosis Quality of Life-54 Instrument, and a daily logbook. Data were analyzed blind using parametric and nonparametric tests, as appropriate.
                Results indicated a statistically significant interactive effect between groups for average LBP (P=0.008); 1-way analysis of covariance did not show any significant effects at any time point once a Bonferonni correction was applied (P>0.05). However, clinically important differences were observed in some of the outcome measures in both active treatment groups during the treatment and follow-up periods.
                Although not statistically significant, the observed effects may have implications for the clinical prescription and the use of TENS within this population. Fifty-four patients treated in a 3-week inpatient rehabilitation program were randomly assigned to and accepted treatment with electroacupuncture (n = 17), TENS (low intensity transcutaneous nerve stimulation, n = 18), and TENS dead-battery (placebo, n = 18). Outcome measures included estimates of pain (on a Visual Analogue Scale) and disability by both physician and patient, physical measures of trunk strength and spine range of motion, as well as the patient's perceptions of the relative contribution of the education, exercise training, and the electrical stimulation. Analyses of variance were utilized to determine effects of treatment (electroacupuncture, TENS, placebo) across time (admission, discharge, and return) for the outcome measures. There were no significant differences between treatment groups with respect to their overall rehabilitation. All 3 treatment groups ranked the contribution of the education as being greater than the electrical stimulation. However, the electroacupuncture group consistently demonstrated greater improvement on the outcome measures than the other treatment groups. For the visual analogue scale measure of average pain, there was a statistical trend at the return visit suggesting that the acupuncture group was experiencing less pain. To investigate the effect of transcutaneous electrical nerve stimulation (TENS) on acupuncture points and neck exercise in chronic neck pain patients.
                A randomized clinical trial.
                Hospital-based practice.
                Two hundred and eighteen patients with chronic neck pain.
                Subjects were randomized into three groups, receiving either (1) TENS over the acupuncture points plus infrared irradiation (TENS group); (2) exercise training plus infrared irradiation (exercise group); or (3) infrared irradiation alone (control); twice a week for six weeks.
                The values of verbal numeric pain scale, Northwick Park Neck Pain Questionnaire, and isometric neck muscle strength were assessed before, at the end of the six-week treatment, and at the six-month follow-up.
                Results demonstrated that after the six-week treatment, significant improvement in the verbal numerical pain scale was found only in the TENS group (0.60+/-2.54, p = 0.027) and the exercise group (1.57+/-2.67, p < 0.001). Though significant reduction in Northwick Park Neck Pain Questionnaire score was found in all three groups, post-hoc tests showed that both the TENS and the exercise group produced better improvement (0.38+/-0.60% and 0.39+/-0.62% respectively) than the control group (0.23+/-0.63%). Significant improvement (p = < 0.001 to 0.03) in neck muscle strength was observed in all three groups, however, the improvement in the control group was not clinically significant and it could not be maintained at the six-month follow-up.
                After the six-week treatment, patients in the TENS and exercise group had a better and clinically relevant improvement in disability, isometric neck muscle strength, and pain. All the improvements in the intervention groups were maintained at the six-month follow-up. This multicenter study assessed the feasibility of conducting a phase III trial of transcutaneous electrical nerve stimulation (TENS) in patients with cancer bone pain recruited from palliative care services. Eligible patients received active and placebo TENS for 1 hour at site of pain in a randomized crossover design; median interval between applications 3 days. Responses assessed at 30 and 60 minutes included numerical and verbal ratings of pain at rest and on movement, and pain relief. Recruitment, tolerability, adverse events, and effectiveness of blinding were also evaluated. Twenty-four patients were randomised and 19 completed both applications. The intervention was well tolerated. Five patients withdrew: 3 due to deteriorating performance status, and 2 due to increased pain (1 each following active and placebo TENS). Confidence interval estimation around the differences in outcomes between active and placebo TENS suggests that TENS has the potential to decrease pain on movement more than pain on rest. Nine patients did not consider that a placebo was used; the remaining 10 correctly identified placebo TENS. Feasibility studies are important in palliative care prior to undertaking clinical trials. Our findings suggest that further work is required on recruitment strategies and refining the control arm before evaluating TENS in cancer bone pain.
                Cancer bone pain is common and severe, and partly mediated by hyperexcitability. Animal studies suggest that Transcutaneous Electrical Nerve Stimulation can reduce hyperalgesia. This study examined the feasibility of evaluating TENS in patients with cancer bone pain in order to optimize methods before a phase III trial.
                Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved. To assess whether source of funding affected the results of trials of nicotine replacement therapy (NRT) for smoking cessation.
                We reviewed all randomized controlled trials included in the Cochrane review. There were insufficient non-industry trials of the newer products for these to be included. We included 90 trials of either the nicotine gum (52) or nicotine patch (38). They comprised 18 238 treatment and 16 235 control participants. Forty-nine showed evidence of industry support (18 gum, 31 patch).
                Industry (31 of 49, 63%) compared with non-industry (seven of 41, 17%, P < 0.001) supported a higher proportion of nicotine patch studies and had larger sample sizes (479 versus 268, P = 0.04). Twenty-five (51%) industry trials reported statistically significant (P < 0.05) results, compared with nine (22%) non-industry trials (OR = 3.70, 95% CI = 1.46-9.35). This difference was not explained by trial characteristics. Industry-supported trials had a pooled odds ratio of 1.90 (1.67-2.16), compared with 1.61 (1.43-1.80) for other studies (chi(2) = 3.6, P = 0.058). There was evidence of funnel-plot asymmetry among industry trials (t = 4.35, P < 0.001), but not among other trials, indicating that several small null-effect industry trials may not have reached publication. After imputation adjustment, the odds ratio for industry trials reduced to 1.64 (1.43-1.89) and the overall NRT odds ratio reduced from 1.73 (1.60-1.90) to 1.62 (1.49-1.77).
                Compared with independent trials, industry-supported trials were more likely to produce statistically significant results and larger odds ratios. These differences persisted after adjustment for basic trial characteristics. Although we had no data on the amount of funding for each trial, it is possible that more resources led to higher treatment compliance and therefore greater efficacy in industry-supported trials. Differences can also possibly be explained by publication bias with several small, null-effect industry studies not having reached publication. After adjustment for this possible bias, results for industry trials were lower and similar to non-industry results. Similarly, the overall estimate of the net effect for these products reduces to about 5% attributable 1-year successes. This remains of considerable public health benefit. Registration of clinical trials has become mandatory in many countries since most of the trials considered here were conducted, and this should reduce the potential for publication bias in future. This study is designed to investigate the immediate effectiveness of electrotherapy on myofascial trigger points of upper trapezius muscle. Sixty patients (25 males and 35 females) who had myofascial trigger points in one side of the upper trapezius muscles were studied. The involved upper trapezius muscles were treated with three different methods according to a random assignment: group A muscles (n = 18) were given placebo treatment (control group); group B muscles (n = 20) were treated with electrical nerve stimulation (ENS) therapy; and group C muscles (n = 22) were given electrical muscle stimulation (EMS) therapy. The effectiveness of treatment was assessed by conducting three measurements on each muscle before and immediately after treatment: subjective pain intensity [(PI) with a visual analog scale], pressure pain threshold [(PT) with algometry], and range of motion [(ROM) with a goniometer] of upper trapezius muscle (lateral bending of cervical spine to the opposite side). When the effectiveness of treatment was compared with that of the placebo group (group A), there was significant improvement in PI and PT in group B (P < 0.01) but not in group C (P > 0.05). The improvement of ROM was significantly more in group C (P < 0.01) as compared with that in group A or group B. When each group was divided into two additional subgroups based on the initial PI, it was found that ENS could reduce PI and increase PT significantly (P < 0.05), but did not significantly (P > 0.05) improve ROM, as compared with the placebo group for both subgroups. EMS could significantly (P < 0.05) improve ROM, but not PT, better than the placebo groups, for either subgroup. It could reduce PI significantly more (P < 0.05) than placebo controls only for the subgroup with mild to moderate pain, but not with severe pain. For pain relief, ENS was significantly better (P < 0.05) than EMS; but for the improvement of ROM, EMS was significantly better (P < 0.05) than ENS. It is concluded that ENS is more effective for immediate relief of myofascial trigger point pain than EMS, and EMS has a better effect on immediate release of muscle tightness than ENS.
We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the quality of evidence is low or very low, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo but not other interventions. Funding bias should be considered, especially in PEMF studies.  Galvanic current, iontophoresis, electric muscle stimulation(EMS), and static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples and include more precise standardization and description of all treatment characteristics.