Diabetic peripheral neuropathy: amelioration of pain with transcutaneous electrostimulation. Transcutaneous electrical nerve stimulation (TNS) for painful osteoarthrosis of the knee. Optimal stimulation duration of tens in the management of osteoarthritic knee pain. The analgesic effect of transcutaneous electrical nerve stimulation (TNS) in patients with rheumatoid arthritis. A comparative study of different pulse patterns. Comparative effectiveness of different stimulation modes in relieving pain. Part II. A double-blind controlled long-term clinical trial. Comparative effectiveness of different stimulation modes in relieving pain. Part I. A pilot study. Transcutaneous electrical nerve stimulation in rheumatoid arthritis. Transcutaneous nerve stimulation in a group of patients with rheumatic disease involving the temporomandibular joint. TNS and osteo-arthritic pain. Preliminary study to establish a controlled method of assessing transcutaneous nerve stimulation as a treatment for the pain caused by osteo-arthritis of the knee. The immediate effectiveness of electrical nerve stimulation and electrical muscle stimulation on myofascial trigger points. Pain reducing effect of three types of transcutaneous electrical nerve stimulation in patients with chronic pain: a randomized crossover trial. The comparative analgesic efficacy of transcutaneous electrical nerve stimulation and a non-steroidal anti-inflammatory drug for painful osteoarthritis. Outcome of transcutaneous electrical nerve stimulation in chronic pain: short-term results of a double-blind, randomised, placebo-controlled trial. A pilot investigation of the hypoalgesic effects of transcutaneous electrical nerve stimulation upon low back pain in people with multiple sclerosis. The placebo effect of transcutaneous electrical stimulation. Transcutaneous electrical nerve stimulation in osteoarthrosis: a therapeutic alternative? Combined neuromuscular electrical stimulation and transcutaneous electrical nerve stimulation for treatment of chronic back pain: a double-blind, repeated measures comparison. [Transcutaneous nerve-stimulation for relief of pain in patients with rheumatoid arthritis]. Efficacy of transcutaneous electrical nerve stimulation (tens) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial. Acupuncture and transcutaneous electric nerve stimulation in the treatment of pain associated with chronic pancreatitis. A randomized study.
To evaluate the efficacy of transcutaneous electrotherapy for chronic painful peripheral neuropathy in patients with type 2 diabetes.
                Thirty-one patients with symptoms and signs of peripheral neuropathy were randomized to the electrotherapy or sham treatment (control) group. The electrostimulation was given by a portable unit (H-Wave machine) than generated a biphasic, exponentially decaying waveform (pulse width 4 ms, 25-35 V, > or = 2 Hz). Patients treated each of their lower extremities for 30 min daily for 4 weeks at home. Nine patients from the sham-treatment group participated for a second period, during which all of them received the active electrotherapy. Patient's degree of pain and discomfort was graded on a scale of 0 to 5.
                In the sham-treated group (n = 13), the neuropathic symptoms improved in five (38%) patients, and the pain score declined from 2.92 +/- 0.13 to 2.38 +/- 0.26 (P < 0.04), suggesting a procedure-related placebo effect. In the electrotherapy group (n = 18), symptomatic improvement was seen in 15 (83%) cases, 3 of which were completely asymptomatic; the pain score declined from 3.17 +/- 0.12 to 1.44 +/- 0.25 (P < 0.01) and the posttreatment pain scores were considerably lower (P < 0.03), indicating a substantial treatment effect over and above any placebo influence. Patients in the electrotherapy group reported greater reduction in symptoms (52 +/- 7% vs. 27 +/- 10% in control subjects, P < 0.05) on an analog scale. Moreover, the electrotherapy decreased pain scores (from 3.0 +/- 0.62 to 1.56 +/- 0.32, P < 0.02) in nine patients who had received sham treatment earlier.
                A form of transcutaneous electrotherapy ameliorated the pain and discomfort associated with peripheral neuropathy. This novel modality offers a potential non-pharmacological treatment option. nan This study examined the optimal stimulation duration of transcutaneous electrical nerve stimulation (TENS) for relieving osteoarthritic knee pain and the duration (as measured by half-life) of post-stimulation analgesia.
                Thirty-eight patients received either: (i) 20 minutes (TENS20); (ii) 40 minutes (TENS40); (iii) 60 minutes (TENS60) of TENS; or (iv) 60 minutes of placebo TENS (TENS(PL)) 5 days a week for 2 weeks.
                A visual analogue scale recorded the magnitude and pain relief period for up to 10 hours after stimulation.
                By Day10, a significantly greater cumulative reduction in the visual analogue scale scores was found in the TENS40 (83.40%) and TENS60 (68.37%) groups than in the TENS20 (54.59%) and TENS(PL) (6.14%) groups (p < 0.000), such a group difference was maintained in the 2-week follow-up session (p < 0.000). In terms of the duration of post-stimulation analgesia period, the duration for the TENS40 (256 minutes) and TENS60 (258 minutes) groups was more prolonged than in the other 2 groups (TENS20 = 168 minutes, TENS(PL) = 35 minutes) by Day10 (p < 0.000). However, the TENS40 group produced the longest pain relief period by the follow-up session.
                40 minutes is the optimal treatment duration of TENS, in terms of both the magnitude (VAS scores) of pain reduction and the duration of post-stimulation analgesia for knee osetoarthritis. Transcutaneous electrical nerve stimulation (TNS) was used on 20 patients with severe wrist pain due to rheumatoid arthritis. Three different stimulation frequencies were used: high 70 Hz stimulation (70 TNS), low frequency 3 Hz stimulation (3 TNS) and brief trains of stimuli with an internal frequency of 70 Hz and with a repetition rate of 3 Hz (3-70 TNS). The analgesic effect was evaluated on the patient's own estimate of pain relief and by means of a loading test in which the length of time the patient could hold a weight before and after TNS was used. The loading test and the patients' own estimate of pain relief corresponded well. After 70 TNS, 18 patients could double their loading time. The corresponding figure for 3-70 TNS was 16 patients and for 3 TNS 5 patients. The average duration of pain relief after cessation of stimulation was 18 h for 70 TNS and 15 h for 3-70 TNS, while those who responded to 3 TNS experienced pain relief for only 4 h on average. Part I of our earlier pilot study demonstrated that patients preferred modulated stimulation forms - frequency modulation and burst - rather than conventional continuous mode. To assess whether long-term therapeutic effects validate the immediate test results, this trial was performed in 14 patients with 21 pain conditions. Considering the results of the pilot study, the test stimulator was modified and 4 different forms of transcutaneous electrical nerve stimulation were randomly delivered to each patient who was blind to the modes of stimulation for 20 min. A second observer assessed the pain scores using visual analogue scales. The stimulation modes employed were: (1) conventional continuous stimulation (continuous pulses with a constant frequency of 70 Hz), (2) burst stimulation (80 msec long trains of pulses, each train consisting of 8 pulses, with an internal frequency of 90 Hz repeated 1.3 times a second), (3) high-rate frequency modulation, HRFM (continuous pulses changed from 90 Hz to 55 Hz over 90 msec, 1.3 times a second), (4) low-rate frequency modulation, LRFM (continuous pulses changed from 60 Hz to 20 Hz over 90 msec, 1.3 times a second). After the test treatment of 4 sessions in the clinic, depending on the pain scores and duration of pain relief recorded, the most effective stimulation mode was determined for each patient and a portable stimulator preset appropriately for that mode was given to be used at home, under our supervision, for 3 months. Fourteen pain conditions out of 21 (66%) responded well to the therapy; the majority preferred was the HRFM and burst-type stimulation.(ABSTRACT TRUNCATED AT 250 WORDS) In this pilot study, to assess the optimal stimulation parameters, 3 different forms of transcutaneous electrical nerve stimulation were performed in 27 patients. Conventional continuous stimulation with a constant frequency of 70 Hz, burst stimulation (90 msec trains of pulses with an internal frequency of 100 Hz repeated at 2 Hz, each train consisting of 10 pulses), and frequency-modulated stimulation (continuous pulses changed from 90 Hz to 55 Hz over 90 msec) were randomly delivered to the patients for half an hour in 3 separate sessions. The patients were blind to the modes of stimulation. This pilot study demonstrated that patients preferred modulated stimulation modes such as frequency modulation and burst rather than conventional constant mode. The therapeutic effect of once weekly transcutaneous electrical nerve stimulation in patients with rheumatoid arthritis was compared with placebo in a randomised, double-blind, non-crossover study lasting three weeks. Thirty-two patients with classic or definite rheumatoid arthritis and wrist involvement were evaluated. Transcutaneous electrical nerve stimulation was better than the placebo in relieving pain at rest and while gripping. In addition, grip strength, measured as power and work done, immediately improved following transcutaneous electrical nerve stimulation but returned almost to initial values between assessments. No significant improvement was shown for the placebo group. The effect of transcutaneous nerve stimulation (TNS) was evaluated and compared with placebo TNS in 19 patients (17 women, mean age 33 years) with orofacial functional pain and rheumatic disease involving the temporomandibular joint. In two double-blind noncrossover experiments, high frequency TNS (100 Hz) and low frequency TNS (2 Hz) were evaluated by comparison of the patients' functional and rest pain, muscle and joint tenderness, and jaw function. A significant treatment effect was obtained for all treatment methods regarding functional and rest pain and muscle and joint tenderness. None of the parameters except functional pain, which improved significantly more after high frequency TNS than placebo TNS, revealed any difference between the methods. Jaw function, however, revealed a few differences between high frequency TNS and placebo TNS. nan 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. 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. Thirty-six non-hospitalized subjects with chronic pain from OA of the knee participated in an evaluation of transcutaneous electrical nerve stimulation (TENS) and naproxen, an NSAID. All pre-experiment treatment was withdrawn. Each subject experienced in some order three 3-week treatment phases: NSAID plus placebo TENS; TENS plus placebo drug; and double placebo. A broad range of pain measures was used, including daily diary ratings, and four-times-per-day ratings entered into a small electronic data logger (the PIPER) worn by the subject. A substantial placebo response occurred across all conditions, which may have masked treatment differences. Broad comparisons across subjects, combining the four main measures of pain, found no significant differences among the three experimental treatments. Analysis of diary and PIPER data for individuals suggested that, in a small minority of subjects, the NSAID plus placebo TENS combination may be more effective than double placebo. The PIPER ratings seemed to tap aspects of the pain experience different from those captured by conventional measures, suggesting the value of very frequent pain assessments, such as those entered by a subject into the PIPER, in the study of chronic pain. The aim of this study was to test the efficacy of shortterm transcutaneous electrical nerve stimulation (TENS) treatment in chronic pain with respect to pain intensity and patients' satisfaction with treatment results. We therefore performed a randomised controlled trial comparing TENS and sham TENS. Patients, researchers and therapists were blinded for treatment allocation. One hundred and sixty-three patients with chronic pain referred to the Pain Centre entered the study. Conventional TENS and sham TENS were applied in the segments of pain, for a period of ten days. Outcome measures were pain intensity (visual analogue scale) and patients' satisfaction with treatment result (yes or no). The proportions of patients satisfied with treatment result differed significantly for TENS compared to sham TENS (58 and 42.7% respectively, chi(2)=3.8, p=0.05). However, no differences in pain intensity were found for patients treated with TENS or sham TENS. Only for patients satisfied with treatment results pain intensity gradually decrease equally both for TENS and sham TENS with repeated treatment application. 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. The placebo effect of transcutaneous electrical stimulation was studied in 93 patients in a double-blind cross-over trial using a genuine stimulator and a placebo machine. Placebo analgesic effect occurred in 32% of trials, as compared with 48% for actual stimulation. The placebo effect of the transcutaneous electrical stimulator is similar to the placebo effect that is noted in other double-blind studies in which medications are used. Thirty patients with chronic pain due to osteoarthrosis (OA) of the knee were enrolled in a randomised double-blind cross-over trial of self-administered transcutaneous electrical nerve stimulation (TENS) and placebo TENS. Medication was standardised to paracetamol tablets only. As measured on visual analogue scales for pain relief 46% of patients responded to active therapy and 43% to placebo. The length of pain relief during active therapy was significantly longer than that during placebo. At the end of the trial more patients wanted to continue using active TENS in preference to placebo or their original medication. Although most of the parameters observed favoured active TENS, it was not possible to establish its clear superiority over placebo, because the response rate to placebo TENS was high and sustained for at least 3 weeks. This trial suggests that a longer study is required to establish the role of TENS as a therapeutic agent in the treatment of the pain of chronic arthritis. A preliminary examination of NMES and combined NMES/TENS for the management of chronic back pain.
                Double-blind, placebo-controlled, randomized repeated measures.
                Consecutive sample of 24 chronic back pain patients (16 women and 8 men) attending an outpatient pain clinic (mean age 51.67 years, mean pain duration 3.83 years). All treatments were administered at home.
                Subjects self-administered NMES, combined NMES/TENS, TENS, and placebo treatments. Each treatment had a duration of 5 consecutive hours per day over 2 consecutive days, with a 2-day hiatus between treatments to minimize carryover effects.
                Pain reduction was assessed through pretreatment to posttreatment differences on the Present Pain Intensity (PPI) scale, and a visual analogue scale of Pain Intensity (VAS-I). Posttreatment pain relief was assessed using a visual analogue scale of Pain Relief (VAS-R).
                Combined treatment, NMES, and TENS each produced significant pretreatment to posttreatment reductions in pain intensity as measured by both the PPI and VAS-I (p < .05). Combined treatment was superior to placebo on pain reduction (p = .001, p = .016) as well as pain relief (p < .001). Combined treatment was also superior to both TENS and NMES for pain reduction and pain relief (p < .01). NMES and TENS were superior only to placebo for pain relief (p < .001).
                Combined NMES/TENS treatment consistently produced greater pain reduction and pain relief than placebo, TENS, or NMES. NMES alone, although less effective, did produce as much pain relief as TENS. Although preliminary, this pattern of results suggests that combined NMES/TENS may be a valuable adjunct in the management of chronic back pain. Further research investigating the effectiveness of both NMES and combined NMES/TENS seems warranted. nan 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. In 23 patients with pancreatitis, daily pain for at least 3 months, and no abuse of alcohol, the pain-relieving effect of electroacupuncture (13 patients) or transcutaneous electric nerve stimulation (TENS) (16 patients) was studied. In two prospective studies with a cross-over design, active acupuncture was compared with sham acupuncture, and TENS of the segmental points of the pancreas with sham treatment. Neither electroacupuncture nor TENS brought about pain relief that could substitute for or supplement medical treatment.
Since the last version of this review, new relevant studies have not provided additional information to change the conclusions. Published literature on the subject lacks the methodological rigour or robust reporting needed to make confident assessments of the role of TENS in chronic pain management. Large multi-centre RCTs of TENS in chronic pain are still needed.