A pilot investigation of the hypoalgesic effects of transcutaneous electrical nerve stimulation upon low back pain in people with multiple sclerosis

Electrical stimulation therapy for pain and related symptoms in multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

The effectiveness of electrical stimulation therapy (EST) for pain, depression, fatigue, disability, and quality of life in multiple sclerosis (MS) remains uncertain. This study aims to analyze and discuss the efficacy of various EST treatments in alleviating pain among MS patients.

METHODS

The primary search was conducted using PubMed, Web of Science, Cochrane Library, Embase, and the Cumulative Index of Nursing and Allied Health Literature databases until September 25, 2023. Randomized controlled trials (RCTs) including patients with MS pain receiving EST compared with other therapies were included. Pain intensity, quality of life, and neuropsychiatric symptoms were reported. The mean difference (MD) with 95 % confidence intervals (CIs) was estimated separately for outcomes to understand the mean effect size.

RESULTS

Ten RCTs containing 315 participants were included. The pooled data from 8 trials including 267 participants showed that the EST was superior in alleviating pain (MD = -1.75, 95 % CI -2.85--0.64, P = 0.002, I2=73 %) evaluated by the visual analog scale. In subgroup analysis, medium-term EST treatment showed the highest effect size compared to short-term and long-term treatment (MDmedium-term = -2.17, 95 % CI -3.51--0.84, P = 0.001, I2 = 0 %). However, no significant differences were found in terms of pain-related quality of life, depression, fatigue, and pain-related disability. No adverse events related to EST were reported. A high risk of bias was identified in three of the ten included studies.

CONCLUSIONS

EST is effective and safe for alleviating pain in MS, but it should be noted that limited sample sizes and methodological issues were present in the included studies. More robust assessment criteria and high-quality RCTs are required for patients with MS.

TRIAL REGISTRATION

CRD42023406787. (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=406787).

Effectiveness of non-pharmacological rehabilitation interventions in pain management in patients with multiple sclerosis: Systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is a progressive inflammatory and autoimmune neurological disease caused by inflammation and demyelination of the central nervous system. Pain is a typical symptom of central nervous system demyelination, affecting 63% of adults with MS. Recently, the role of non-pharmacological pain management in patients is growing because the non-pharmacological interventions are considered safe, affordable, easy, and accessible. However, to date, no systematic reviews or meta-analyses have comprehensively examined the therapeutic effects of the variety of non-pharmacological therapeutic interventions in the management of pain in patients with MS.

OBJECTIVE

The study aimed to conduct a systematic review with meta-analysis to assess the effectiveness of the non-pharmacological rehabilitation interventions in pain management in patients with MS.

METHODS

A comprehensive search using PubMed, Cochrane, and Science Direct databases was performed and included all randomized controlled trials, randomized cross-over trials, and quasi-experimental trials assessing the effect of non-pharmacological interventions for managing pain in patients with MS. This study was conducted according to PRISMA guidelines of a systematic review and pair-wise meta-analysis. Meta-analyses were performed by calculating the standardized mean difference at a 95% confidence interval using Review Manager software.

RESULTS

Twenty-nine papers were included in the systematic review, and only 22 of them were included in the meta-analysis. The pooled analysis showed a significant effect of neuromodulation and transcranial direct current stimulation on pain intensity reduction in patients with MS (SMD -0.51, 95% CI -0.51 to -0.09, P = 0.02), (SMD -0.67, 95% CI -1.18 to -0.16 P = 0.01), respectively. The analysis showed significant improvement in pain intensity in patient with MS after mind-body therapies (SMD -0.45, 95% CI -0.82 to -0.7, P = 0.02), mindfulness (SMD -0.55, 95% CI -0.96 to -0.14, P = 0.009), hypnosis (SMD -0.88, 95% CI -1.30 to -0.46, P = 0.0001), trigger point therapies (SMD -0.83, 95% CI -1.65 to -0.01, P = 0.05) and cognitive behavioral therapy (SMD -0.64, 95% CI -1.18 to -0.11, P = 0.02). However, there is no significant effect of relaxation therapy on pain reduction in patients with MS (SMD -0.82, 95% CI -1.94 to 0.31, P = 0.15).

CONCLUSIONS

The results indicated that the majority of the non-pharmacological rehabilitation interventions showed potential therapeutic effects in reducing pain intensity in patients with MS.

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.

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.

Low back pain in patients with multiple sclerosis: A systematic review and the prevalence in a French multiple sclerosis population

PURPOSE

The prevalence and management of back pain in MS patients was assessed by a systematic review, and the results of a survey on the characteristics of low back pain in a sample of French MS patients are reported.

METHODS

A systematic search was conducted according to the PRISMA guidelines. The outcomes of interest included the prevalence of back pain, severity of pain and impact on daily activities. Moreover, the prevalence of low back pain and its consequences on daily living in a large French MS population were assessed.

RESULTS

Fourteen studies were included in the systematic review. The prevalence of back pain in MS patients ranged from 8.6 to 50%, but that of low back pain in particular ranged from 41.6 to 52.4%. Concerning the survey, 237 patients participated in the online questionnaire. The prevalence of low back pain in the French MS patients was 76.4%. The patients with chronic low back pain had more limitations in their daily life activities than those without chronic low back pain.

CONCLUSION

Patients with MS commonly suffer from low back pain, but it is still an underdiagnosed cause of pain that reduces one's ability to perform activities in daily life.

Effectiveness of monopolar dielectric transmission of pulsed electromagnetic fields for multiple sclerosis-related pain: a pilot study

INTRODUCTION

Pain is highly prevalent in patients with multiple sclerosis (MS); it is chronic in 50% of cases and is classified as nociceptive, neuropathic, or mixed-type. Pain affects quality of life, sleep, and the activities of daily living. Electrotherapy is an interesting alternative or complementary treatment in the management of pain in MS, with new innovations constantly appearing.

MATERIAL AND METHODS

This study evaluates the effectiveness of treatment with monopolar dielectric transmission of pulsed electromagnetic fields (PEMF) for pain associated with MS. We performed a randomised, placebo-controlled clinical trial including 24 patients, who were assessed with the Brief Pain Inventory, the Multiple Sclerosis International Quality of Life questionnaire, the Beck Depression Inventory, and the Modified Fatigue Impact Scale.

RESULTS

Statistically significant improvements were observed in maximum and mean pain scores, as well as in the impact of pain on work, personal relationships, and sleep and rest. Not significant differences were found between the treatment and placebo groups.

CONCLUSIONS

Treatment with PEMF may be effective in reducing pain in patients with MS, although further research is necessary to confirm its effectiveness over placebo and to differentiate which type of pain may be more susceptible to this treatment.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain - an overview of Cochrane Reviews

BACKGROUND

Chronic pain, considered to be pain lasting more than three months, is a common and often difficult to treat condition that can significantly impact upon function and quality of life. Treatment typically includes pharmacological and non-pharmacological approaches. Transcutaneous electrical nerve stimulation (TENS) is an adjunct non-pharmacological treatment commonly recommended by clinicians and often used by people with pain.

OBJECTIVES

To provide an overview of evidence from Cochrane Reviews of the effectiveness of TENS to reduce pain in adults with chronic pain (excluding headache or migraine).To provide an overview of evidence from Cochrane Reviews of the safety of TENS when used to reduce pain in adults with chronic pain (excluding headache or migraine).To identify possible sources of inconsistency in the approaches taken to evaluating the evidence related to TENS for chronic pain (excluding headache or migraine) in the Cochrane Library with a view to recommending strategies to improve consistency in methodology and reporting.To highlight areas of remaining uncertainty regarding the effectiveness of TENS for chronic pain (excluding headache or migraine) with a view to recommending strategies to reduce any uncertainty.

METHODS

Search methodsWe searched the Cochrane Database of Systematic Reviews (CDSR), in the Cochrane Library, across all years up to Issue 11 of 12, 2018.Selection of reviewsTwo authors independently screened the results of the electronic search by title and abstract against inclusion/exclusion criteria. We included all Cochrane Reviews of randomised controlled trials (RCTs) assessing the effectiveness of TENS in people with chronic pain. We included reviews if they investigated the following: TENS versus sham; TENS versus usual care or no treatment/waiting list control; TENS plus active intervention versus active intervention alone; comparisons between different types of TENS; or TENS delivered using different stimulation parameters.Data extraction and analysisTwo authors independently extracted relevant data, assessed review quality using the AMSTAR checklist and applied GRADE judgements where required to individual reviews. Our primary outcomes included pain intensity and nature/incidence of adverse effects; our secondary outcomes included disability, health-related quality of life, analgesic medication use and participant global impression of change.

MAIN RESULTS

We included nine reviews investigating TENS use in people with defined chronic pain or in people with chronic conditions associated with ongoing pain. One review investigating TENS for phantom or stump-associated pain in people following amputation did not have any included studies. We therefore extracted data from eight reviews which represented 51 TENS-related RCTs representing 2895 TENS-comparison participants entered into the studies.The included reviews followed consistent methods and achieved overall high scores on the AMSTAR checklist. The evidence reported within each review was consistently rated as very low quality. Using review authors' assessment of risk of bias, there were significant methodological limitations in included studies; and for all reviews, sample sizes were consistently small (the majority of studies included fewer than 50 participants per group).Six of the eight reviews presented a narrative synthesis of included studies. Two reviews reported a pooled analysis.Primary and secondary outcomes One review reported a beneficial effect of TENS versus sham therapy at reducing pain intensity on a 0 to 10 scale (MD -1.58, 95% CI -2.08 to -1.09, P < 0.001, I² = 29%, P = 0.22, 5 studies, 207 participants). However the quality of the evidence was very low due to significant methodological limitations and imprecision. A second review investigating pain intensity performed a pooled analysis by combining studies that compared TENS to sham with studies that compared TENS to no intervention (SMD -0.85, 95% CI -1.36 to -0.34, P = 0.001, I² = 83%, P < 0.001). This pooled analysis was judged as offering very low quality evidence due to significant methodological limitations, large between-trial heterogeneity and imprecision. We considered the approach of combining sham and no intervention data to be problematic since we would predict these different comparisons may be estimating different true effects. All remaining reviews also reported pain intensity as an outcome measure; however the data were presented in narrative review form only.Due to methodological limitation and lack of useable data, we were unable to offer any meaningful report on the remaining primary outcome regarding nature/incidence of adverse effects, nor for the remaining secondary outcomes: disability, health-related quality of life, analgesic medication use and participant global impression of change for any comparisons.We found the included reviews had a number of inconsistencies when evaluating the evidence from TENS studies. Approaches to assessing risk of bias around the participant, personnel and outcome-assessor blinding were perhaps the most obvious area of difference across included reviews. We also found wide variability in terms of primary and secondary outcome measures, and inclusion/exclusion criteria for studies varied with respect to including studies which assessed immediate effects of single interventions.

AUTHORS' CONCLUSIONS

We found the methodological quality of the reviews was good, but quality of the evidence within them was very low. We were therefore unable to conclude with any confidence that, in people with chronic pain, TENS is harmful, or beneficial for pain control, disability, health-related quality of life, use of pain relieving medicines, or global impression of change. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment in people with chronic pain.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain - an overview of Cochrane Reviews

BACKGROUND

Chronic pain, considered to be pain lasting more than three months, is a common and often difficult to treat condition that can significantly impact upon function and quality of life. Treatment typically includes pharmacological and non-pharmacological approaches. Transcutaneous electrical nerve stimulation (TENS) is an adjunct non-pharmacological treatment commonly recommended by clinicians and often used by people with pain.

OBJECTIVES

To provide an overview of evidence from Cochrane Reviews of the effectiveness of TENS to reduce pain in adults with chronic pain (excluding headache or migraine).To provide an overview of evidence from Cochrane Reviews of the safety of TENS when used to reduce pain in adults with chronic pain (excluding headache or migraine).To identify possible sources of inconsistency in the approaches taken to evaluating the evidence related to TENS for chronic pain (excluding headache or migraine) in the Cochrane Library with a view to recommending strategies to improve consistency in methodology and reporting.To highlight areas of remaining uncertainty regarding the effectiveness of TENS for chronic pain (excluding headache or migraine) with a view to recommending strategies to reduce any uncertainty.

METHODS

Search methodsWe searched the Cochrane Database of Systematic Reviews (CDSR), in the Cochrane Library, across all years up to Issue 11 of 12, 2018.Selection of reviewsTwo authors independently screened the results of the electronic search by title and abstract against inclusion/exclusion criteria. We included all Cochrane Reviews of randomised controlled trials (RCTs) assessing the effectiveness of TENS in people with chronic pain. We included reviews if they investigated the following: TENS versus sham; TENS versus usual care or no treatment/waiting list control; TENS plus active intervention versus active intervention alone; comparisons between different types of TENS; or TENS delivered using different stimulation parameters.Data extraction and analysisTwo authors independently extracted relevant data, assessed review quality using the AMSTAR checklist and applied GRADE judgements where required to individual reviews. Our primary outcomes included pain intensity and nature/incidence of adverse effects; our secondary outcomes included disability, health-related quality of life, analgesic medication use and participant global impression of change.

MAIN RESULTS

We included nine reviews investigating TENS use in people with defined chronic pain or in people with chronic conditions associated with ongoing pain. One review investigating TENS for phantom or stump-associated pain in people following amputation did not have any included studies. We therefore extracted data from eight reviews which represented 51 TENS-related RCTs representing 2895 TENS-comparison participants entered into the studies.The included reviews followed consistent methods and achieved overall high scores on the AMSTAR checklist. The evidence reported within each review was consistently rated as very low quality. Using review authors' assessment of risk of bias, there were significant methodological limitations in included studies; and for all reviews, sample sizes were consistently small (the majority of studies included fewer than 50 participants per group).Six of the eight reviews presented a narrative synthesis of included studies. Two reviews reported a pooled analysis.Primary and secondary outcomes One review reported a beneficial effect of TENS versus sham therapy at reducing pain intensity on a 0 to 10 scale (MD -1.58, 95% CI -2.08 to -1.09, P < 0.001, I² = 29%, P = 0.22, 5 studies, 207 participants). However the quality of the evidence was very low due to significant methodological limitations and imprecision. A second review investigating pain intensity performed a pooled analysis by combining studies that compared TENS to sham with studies that compared TENS to no intervention (SMD -0.85, 95% CI -1.36 to -0.34, P = 0.001, I² = 83%, P < 0.001). This pooled analysis was judged as offering very low quality evidence due to significant methodological limitations, large between-trial heterogeneity and imprecision. We considered the approach of combining sham and no intervention data to be problematic since we would predict these different comparisons may be estimating different true effects. All remaining reviews also reported pain intensity as an outcome measure; however the data were presented in narrative review form only.Due to methodological limitation and lack of useable data, we were unable to offer any meaningful report on the remaining primary outcome regarding nature/incidence of adverse effects, nor for the remaining secondary outcomes: disability, health-related quality of life, analgesic medication use and participant global impression of change for any comparisons.We found the included reviews had a number of inconsistencies when evaluating the evidence from TENS studies. Approaches to assessing risk of bias around the participant, personnel and outcome-assessor blinding were perhaps the most obvious area of difference across included reviews. We also found wide variability in terms of primary and secondary outcome measures, and inclusion/exclusion criteria for studies varied with respect to including studies which assessed immediate effects of single interventions.

AUTHORS' CONCLUSIONS

We found the methodological quality of the reviews was good, but quality of the evidence within them was very low. We were therefore unable to conclude with any confidence that, in people with chronic pain, TENS is harmful, or beneficial for pain control, disability, health-related quality of life, use of pain relieving medicines, or global impression of change. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment in people with chronic pain.

Non-pharmacological interventions for chronic pain in multiple sclerosis

BACKGROUND

Chronic pain is common and significantly impacts on the lives of persons with multiple sclerosis (pwMS). Various types of non-pharmacological interventions are widely used, both in hospital and ambulatory/mobility settings to improve pain control in pwMS, but the effectiveness and safety of many non-pharmacological modalities is still unknown.

OBJECTIVES

This review aimed to investigate the effectiveness and safety of non-pharmacological therapies for the management of chronic pain in pwMS. Specific questions to be addressed by this review include the following.Are non-pharmacological interventions (unidisciplinary and/or multidisciplinary rehabilitation) effective in reducing chronic pain in pwMS?What type of non-pharmacological interventions (unidisciplinary and/or multidisciplinary rehabilitation) are effective (least and most effective) and in what setting, in reducing chronic pain in pwMS?

SEARCH METHODS

A literature search was performed using the specialised register of the Cochrane MS and Rare Diseases of the Central Nervous System Review Group, using the Cochrane MS Group Trials Register which contains CENTRAL, MEDLINE, Embase, CINAHL, LILACUS, Clinical trials.gov and the World Health Organization International Clinical Trials Registry Platform on 10 December 2017. Handsearching of relevant journals and screening of reference lists of relevant studies was carried out.

SELECTION CRITERIA

All published randomised controlled trials (RCTs)and cross-over studies that compared non-pharmacological therapies with a control intervention for managing chronic pain in pwMS were included. Clinical controlled trials (CCTs) were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

All three review authors independently selected studies, extracted data and assessed the methodological quality of the studies using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) tool for best-evidence synthesis. Pooling data for meta-analysis was not possible due to methodological, clinical and statistically heterogeneity of the included studies.

MAIN RESULTS

Overall, 10 RCTs with 565 participants which investigated different non-pharmacological interventions for the management of chronic pain in MS fulfilled the review inclusion criteria. The non-pharmacological interventions evaluated included: transcutaneous electrical nerve stimulation (TENS), psychotherapy (telephone self-management, hypnosis and electroencephalogram (EEG) biofeedback), transcranial random noise stimulation (tRNS), transcranial direct stimulation (tDCS), hydrotherapy (Ai Chi) and reflexology.There is very low-level evidence for the use of non-pharmacological interventions for chronic pain such as TENS, Ai Chi, tDCS, tRNS, telephone-delivered self-management program, EEG biofeedback and reflexology in pain intensity in pwMS. Although there were improved changes in pain scores and secondary outcomes (such as fatigue, psychological symptoms, spasm in some interventions), these were limited by methodological biases within the studies.

AUTHORS' CONCLUSIONS

Despite the use of a wide range of non-pharmacological interventions for the treatment of chronic pain in pwMS, the evidence for these interventions is still limited or insufficient, or both. More studies with robust methodology and greater numbers of participants are needed to justify the effect of these interventions for the management of chronic pain in pwMS.

Effectiveness of monopolar dielectric transmission of pulsed electromagnetic fields for multiple sclerosis-related pain: A pilot study

INTRODUCTION

Pain is highly prevalent in patients with multiple sclerosis (MS); it is chronic in 50% of cases and is classified as nociceptive, neuropathic, or mixed-type. Pain affects quality of life, sleep, and the activities of daily living. Electrotherapy is an interesting alternative or complementary treatment in the management of pain in MS, with new innovations constantly appearing.

MATERIAL AND METHODS

This study evaluates the effectiveness of treatment with monopolar dielectric transmission of pulsed electromagnetic fields (PEMF) for pain associated with MS. We performed a randomised, placebo-controlled clinical trial including 24 patients, who were assessed with the Brief Pain Inventory, the Multiple Sclerosis International Quality of Life questionnaire, the Beck Depression Inventory, and the Modified Fatigue Impact Scale.

RESULTS

Statistically significant improvements were observed in maximum and mean pain scores, as well as in the impact of pain on work, personal relationships, and sleep and rest. Not significant differences were found between the treatment and placebo groups.

CONCLUSIONS

Treatment with PEMF may be effective in reducing pain in patients with MS, although further research is necessary to confirm its effectiveness over placebo and to differentiate which type of pain may be more susceptible to this treatment.

Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults

BACKGROUND

Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn.

OBJECTIVES

To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies.

SELECTION CRITERIA

We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE.

MAIN RESULTS

We included 15 studies with 724 participants. We found a range of treatment protocols in terms of duration of care, TENS application times and intensity of application. Briefly, duration of care ranged from four days through to three months. Similarly, we found variation of TENS application times; from 15 minutes up to hourly sessions applied four times daily. We typically found intensity of TENS set to comfortable perceptible tingling with very few studies titrating the dose to maintain this perception. Of the comparisons, we had planned to explore, we were only able to undertake a quantitative synthesis for TENS versus sham TENS. Insufficient data and large diversity in the control conditions prevented us from undertaking a quantitative synthesis for the remaining comparisons.For TENS compared to sham TENS, five studies were suitable for pooled analysis. We described the remainder of the studies in narrative form. Overall, we judged 11 studies at high risk of bias, and four at unclear risk. Due to the small number of eligible studies, the high levels of risk of bias across the studies and small sample sizes, we rated the quality of the evidence as very low for the pooled analysis and very low individual GRADE rating of outcomes from single studies. For the individual studies discussed in narrative form, the methodological limitations, quality of reporting and heterogeneous nature of interventions compared did not allow for reliable overall estimates of the effect of TENS.Five studies (across various neuropathic conditions) were suitable for pooled analysis of TENS versus sham TENS investigating change in pain intensity using a visual analogue scale. We found a mean postintervention difference in effect size favouring TENS of -1.58 (95% confidence interval (CI) -2.08 to -1.09, P < 0.00001, n = 207, six comparisons from five studies) (very low quality evidence). There was no significant heterogeneity in this analysis. While this exceeded our prespecified minimally important difference for pain outcomes, we assessed the quality of evidence as very low meaning we have very little confidence in this effect estimate and the true effect is likely to be substantially different from that reported in this review. Only one study of these five investigated health related quality of life as an outcome meaning we were unable to report on this outcome in this comparison. Similarly, we were unable to report on global impression of change or changes in analgesic use in this pooled analysis.Ten small studies compared TENS to some form of usual care. However, there was great diversity in what constituted usual care, precluding pooling of data. Most of these studies found either no difference in pain outcomes between TENS versus other active treatments or favoured the comparator intervention (very low quality evidence). We were unable to report on other primary and secondary outcomes in these single trials (health-related quality of life, global impression of change and changes in analgesic use).Of the 15 included studies, three reported adverse events which were minor and limited to 'skin irritation' at or around the site of electrode placement (very low quality evidence). Three studies reported no adverse events while the remainder did not report any detail with regard adverse events.

AUTHORS' CONCLUSIONS

In this review, we reported on the comparison between TENS and sham TENS. The quality of the evidence was very low meaning we were unable to confidently state whether TENS is effective for pain control in people with neuropathic pain. The very low quality of evidence means we have very limited confidence in the effect estimate reported; the true effect is likely to be substantially different. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment modality.

Effect of low frequency transcutaneous electrical nerve stimulation of TE5 (waiguan) and PC6 (neiguan) acupoints on cold-induced pain

[Purpose] This study assesse the effect of low frequency transcutaneous electrical nerve stimulation (TENS) of theTE5 (waiguan) and PC6 (neiguan) acupoints on cold-induced pain. [Subjects and Methods] Forty-eight subjects were divided by convenience into three groups: TENS with electrodes of 1 cm(2) area, TENS with electrodes of area 15 cm(2) and a placebo group. The study consisted of three phases: cold-induced pain without electroanalgesia, cold-induced pain with electroanalgesia or placebo, and cold-induced pain post-electroanalgesia or placebo. [Results] Acupuncture like TENS increased the pain threshold latency during treatment (45.7 ± 11.7s) compared to pre-treatment (30.9 ± 8.9s) in the TENS group with 1 cm(2) electrodes. In the TENS group with 15 cm(2) electrodes, the pain threshold latency increased at post-treatment (36.2 ± 12.9s) compared to pre-treatment (25.5 ± 7.4s). The placebo group showed no significant changes. The group with 1 cm(2) electrodes showed a significantly higher pain threshold latency (45.7 ± 11.7s) than the other two groups. At post-treatment, the pain threshold latencies of both the 1 cm(2) (39.4 ± 11.5s) and 15 cm(2) (36.2 ± 12.9s) TENS group were higher than that of the placebo group (22.4 ± 7.4s). [Conclusion] Acupuncture like TENS applied to PC6 and TE5 acupoints increased the pain threshold latency. The pain intensity was reduced by TENS with an electrode area of 1 cm(2).

Pharmacological treatment of pain in multiple sclerosis

Pain is a common symptom in multiple sclerosis (MS) and was recently estimated to be experienced by up to 75% of patients. Nociceptive and neuropathic pain in MS may be present concurrently and at different stages of the disease and may be associated with other symptoms. Evidence for treating pain in MS is limited. Many clinical features of pain are often unrecognized by clinicians and are difficult for patients to describe. Treatment is often based on anecdotal reports and clinical experience. We present a review of treatment options for pain in MS that should serve to update current knowledge, highlight shortcomings in clinical research and provide indications towards achieving evidence-based treatment of pain in MS.

Symptomatic treatment and management of multiple sclerosis

The range of symptoms which occur in multiple sclerosis (MS) can have disabling functional consequences for patients and lead to significant reductions in their quality of life. MS symptoms can also interact with each other, making their management challenging. Clinical trials aimed at identifying symptomatic therapies have generally been poorly designed and have tended to be underpowered. Therefore, the evidence base for the management of MS symptoms with pharmacologic therapies is not strong and tends to rely upon open-label studies, case reports, and clinical trials with small numbers of patients and poorly validated clinical outcome measures. Recently, there has been a growing interest in the management of MS symptoms with pharmacologic treatments, and better-designed, randomized, double-blind, controlled trials have been reported. This chapter will describe the evidence base predominantly behind the various pharmacologic approaches to the management of MS symptoms, which in most, if not all, cases, requires multidisciplinary input. Drugs routinely recommended for individual symptoms and new therapies, which are currently in the development pipeline, will be reviewed. More interventional therapies related to symptoms that are refractory to pharmacotherapy will also be discussed, where relevant.

Placebo acupuncture devices: considerations for acupuncture research

Determining an appropriate control for use in acupuncture research remains one of the largest methodological challenges acupuncture researchers face. In general, acupuncture controls fall under one of two categories: (1) sham acupuncture, in which the skin is punctured with real acupuncture needles either fully at nonacupoint locations or shallowly at acupoint locations or both and (2) placebo acupuncture, which utilizes nonpenetrating acupuncture devices. In this study, we will focus on non-penetrating placebo acupuncture devices (blunted-needle and nonneedle devices) that are currently available in acupuncture research. We will describe each device and discuss each device's validation and application in previous studies. In addition, we will outline the advantages and disadvantages of these devices and highlight how the differences among placebo devices can be used to isolate distinct components of acupuncture treatment and investigate their effects. We would like to emphasize that there is no single placebo device that can serve as the best control for all acupuncture studies; the choice of an acupuncture control should be determined by the specific aim of the study.

Pain relief by transcutaneous electric nerve stimulation with bidirectional modulated sine waves in patients with chronic back pain: a randomized, double-blind, sham-controlled study

Objectives.  Newly developed bidirectional modulated sine waves (BMW) might provide some derived benefit to patients with low back pain. Pain relief by transcutaneous electric nerve stimulation (TENS) with BMWs was tested. Materials and Methods.  Analgesic effects of BMWs and conventional bidirectional pulsed waves on chronic back pain in 28 patients were compared, and effects of repeated TENS using BMWs on chronic back pain were investigated in 21 patients by means of a randomized double-blind, sham-controlled, parallel-group method. Pain intensity was assessed using numerical rating scale (NRS). Results.  There was significant immediate reduction in NRS in patients receiving BMWs, and 60 min after treatment compared to sham TENS. Weekly repeated treatments using massage and TENS with BMWs for 5 weeks resulted in a decrease of NRS, but there were no significant differences between the TENS plus massage and sham TENS plus massage groups. Conclusions.  This study shows that TENS with BMWs significantly inhibits chronic back pain, and treatment effects are attained within a day. The results also suggest that there were no statistically significant long-term effects of TENS with BMW in the repeated treatment.

The effects of clinical interventions on health-related quality of life in multiple sclerosis: a meta-analysis

The objective is to estimate the extent to which existing health care interventions designed specifically to target health-related quality of life (HRQL) in persons with multiple sclerosis (MS) achieve this aim. The structured literature search was conducted using multiple electronic databases including Ovid MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature and the Cochrane Central Register of Controlled Trial, for the years 1960 to 2011. The methodological quality of selected randomized controlled trials (RCTs) was assessed using the Cochrane Collaboration's recommended domain-based method. Effect size (ES) was used to measure the effect of each intervention on HRQL. The studies were combined using a random-effects model to account for inter-study variation. Heterogeneity was tested for using the I-test and publication bias was assessed using funnel plots and the Egger weighted regression statistic. Thirty-nine RCTs met the criteria, all with acceptable methodological quality. Six major types of interventions were identified through the search. The smallest effect was observed for self-management and complementary and alternative medicine (ES=0.2), followed by medication (ES=0.3) then cognitive training and exercise (ES=0.4), and psychological interventions to improve mood (ES=0.7). The magnitude of positive effect on HRQL varied between the different types of interventions. The extent to which interventions are able to improve HRQL depends on delivering a potent intervention to those persons who have the potential to benefit.

Symptomatic therapy and rehabilitation in primary progressive multiple sclerosis

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the central nervous system and a major cause of chronic neurological disability in young adults. Primary progressive MS (PPMS) constitutes about 10% of cases, and is characterized by a steady decline in function with no acute attacks. The rate of deterioration from disease onset is more rapid than relapsing remitting and secondary progressive MS types. Multiple system involvement at onset and rapid early progression have a worse prognosis. PPMS can cause significant disability and impact on quality of life. Recent studies are biased in favour of relapsing remitting patients as treatment is now available for them and they are more likely to be seen at MS clinics. Since prognosis for PPMS is worse than other types of MS, the focus of rehabilitation is on managing disability and enhancing participation, and application of a "neuropalliative" approach as the disease progresses. This chapter presents the symptomatic treatment and rehabilitation for persons with MS, including PPMS. A multidisciplinary approach optimizes the intermediate and long-term medical, psychological and social outcomes in this population. Restoration and maintenance of functional independence and societal reintegration, and issues relating to quality of life are addressed in rehabilitation processes.

Methodological quality in randomised controlled trials of transcutaneous electric nerve stimulation for pain: low fidelity may explain negative findings

The benefits of transcutaneous electrical nerve stimulation (TENS) for pain relief have not been reliably established, as most systematic reviews find poor methodological quality in many studies. The paradox within the evidence base for TENS is that despite identified sources of bias that may lead to an overestimation of treatment effects, no benefits for TENS can be clearly demonstrated. Conventional assessments of quality assume a single direction of bias, and little work has been undertaken examining other directions of bias. Our hypothesis was that low fidelity in studies (bias leading to an underestimation of treatment effects) may account for inconclusive findings. We included 38 studies from 3 recently published Cochrane systematic reviews that examined TENS for acute, chronic, and cancer pain. We extracted data relating to treatment allocation, application of TENS and to the assessment of outcomes. We quantified these data and judged this against standardised assessment criteria using a "traffic light" approach based on the number of studies reaching the standard. We identified significant sources of potential bias in both directions in relation to study design and implementation fidelity that have not been quantified previously. Suboptimal dosing of TENS and inappropriate outcome assessment were particularly prevalent weaknesses indicating low fidelity. We propose criteria for judging directions of bias in future studies of TENS that may be adapted to assess other trials in which implementation fidelity is important, such as other nonpharmacological interventions for pain. Poor implementation fidelity was identified as a significant source of bias in systematic reviews of TENS studies and might explain lack of consistent treatment effects of TENS in pain. Here, criteria for assessing methodology are proposed for use in designing future clinical trials of TENS.

Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) was introduced more than 30 years ago as a therapeutic adjunct to the pharmacological management of pain. However, despite widespread use, its effectiveness in chronic low-back pain (LBP) is still controversial.

OBJECTIVES

To determine whether TENS is more effective than placebo for the management of chronic LBP.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PEDro and CINAHL were searched up to July 19, 2007.

SELECTION CRITERIA

Only randomized controlled clinical trials (RCTs) comparing TENS to placebo in patients with chronic LBP were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the trials, assessed their methodological quality and extracted relevant data. If quantitative meta-analysis was not possible, a qualitative synthesis was performed, taking into consideration 5 levels of evidence as recommended by the Cochrane Collaboration Back Review Group.

MAIN RESULTS

Four high-quality RCTs (585 patients) met the selection criteria. Clinical heterogeneity prevented the use of meta-analysis. Therefore, a qualitative synthesis was completed. There was conflicting evidence about whether TENS was beneficial in reducing back pain intensity and consistent evidence in two trials (410 patients) that it did not improve back-specific functional status. There was moderate evidence that work status and the use of medical services did not change with treatment. Conflicting results were obtained from two studies regarding generic health status, with one study showing no improvement on the modified Sickness Impact Profile and another study showing significant improvements on several, but not all subsections of the SF-36 questionnaire. Multiple physical outcome measures lacked statistically significant improvement relative to placebo. In general, patients treated with acupuncture-like TENS responded similarly to those treated with conventional TENS. However, in two of the trials, an inadequate stimulation intensity was used for acupuncture-like TENS, given that muscle twitching was not induced. Optimal treatment schedules could not be reliably determined based on the available data. Adverse effects included minor skin irritation at the site of electrode placement.

AUTHORS' CONCLUSIONS

At this time, the evidence from the small number of placebo-controlled trials does not support the use of TENS in the routine management of chronic LBP. Further research is encouraged.

Transcutaneous electrical nerve stimulation (TENS) for chronic pain

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a popular pain treatment modality but its effectiveness in chronic pain management is unknown. This review is an update of the original Cochrane review published in Issue 3, 2001.

OBJECTIVES

To evaluate the effectiveness of TENS in chronic pain.

SEARCH STRATEGY

The Cochrane Library, EMBASE, MEDLINE and CINAHL were searched. Reference lists from retrieved reports and reviews were examined. Date of the most recent search: April 2008.

SELECTION CRITERIA

RCTs were eligible if they compared active TENS versus sham TENS controls; active TENS versus 'no treatment' controls; or active TENS versus active TENS controls (e.g. High Frequency TENS (HFTENS) versus Low Frequency TENS (LFTENS)). Studies of chronic pain for three months or more which included subjective outcome measures for pain intensity or relief were eligible for evaluation. No restrictions were made to language or sample size. Abstracts, letters, or unpublished studies, and studies of TENS in angina, headache, migraine, dysmenorrhoea and cancer-related pain were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted and summarised on the following items: patients and details of pain condition, treatments, study duration, design, methods, subjective pain outcome measures, methodological quality, results for pain outcome measures and adverse effects, and conclusions by authors of the studies. Extracted data and methodological quality of studies were confirmed by the review authors.

MAIN RESULTS

Of 124 studies identified from the searches, 99 did not fulfil pre-defined entry criteria. Twenty-five RCTs involving 1281 participants were evaluated. Included studies varied in design, analgesic outcomes, chronic pain conditions, TENS treatments and methodological quality. The reporting of methods and results for analgesic outcomes were inconsistent across studies and generally poor. Meta-analysis was not possible. Overall in 13 of 22 inactive control studies, there was a positive analgesic outcome in favour of active TENS treatments. For multiple dose treatment comparison studies, eight of fifteen were considered to be in favour of the active TENS treatments. Seven of the nine active controlled studies found no difference in analgesic efficacy between High Frequency (HF) TENS and Low Frequency (LF) TENS.

AUTHORS' CONCLUSIONS

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.

Current management of pain associated with multiple sclerosis

While pain is a common problem in patients with multiple sclerosis (MS), it is not frequently mentioned by patients and a more direct approach is required in order to obtain information about pain from patients. Many patients with MS experience more than one pain syndrome; combinations of dysaesthesia, headaches and/or back or muscle and joint pain are frequent. For each pain syndrome a clear diagnosis and therapeutic concept needs to be established. Pain in MS can be classified into four diagnostically and therapeutically relevant categories: (i) neuropathic pain due to MS (pain directly related to MS); (ii) pain indirectly related to MS; (iii) MS treatment-related pain; and (iv) pain unrelated to MS. Painful paroxysmal symptoms such as trigeminal neuralgia (TN), or painful tonic spasms are treated with antiepileptics as first choice, e.g. carbamazepine, oxcarbazepine, lamotrigine, gabapentin, pregabalin, etc. Painful 'burning' dysaesthesias, the most frequent chronic pain syndrome, are treated with TCAs such as amitriptyline, or antiepileptics such as gabapentin, pregabalin, lamotrigine, etc. Combinations of drugs with different modes of action can be particularly useful for reducing adverse effects. While escalation therapy may require opioids, there are encouraging results from studies regarding cannabinoids, but their future role in the treatment of MS-related pain has still to be determined. Pain related to spasticity often improves with adequate physiotherapy. Drug treatment includes antispastic agents such as baclofen or tizanidine and in patients with phasic spasticity, gabapentin or levetiracetam are administered. In patients with severe spasticity, botulinum toxin injections or intrathecal baclofen merit consideration. While physiotherapy may ameliorate malposition-induced joint and muscle pain, additional drug treatment with paracetamol (acetaminophen) or NSAIDs may be useful. Moreover, painful pressure lesions should be avoided by using optimally adjusted aids. Treatment-related pain associated with MS can occur with subcutaneous injections of interferon-beta or glatiramer acetate, and may be reduced by optimizing the injection technique and by local cooling. Systemic (particularly 'flu-like') adverse effects of interferons, e.g. myalgias, can be reduced by administering paracetamol, ibuprofen or naproxen. A potential increase in the frequency of pre-existing headaches after starting treatment with interferons may require optimization of headache attack therapy or even prophylactic treatment. Pain unrelated to MS, such as back pain or headache, is common in patients with MS and may deteriorate as a result of the disease. In summary, a careful analysis of each pain syndrome will allow the design of the appropriate treatment plan using various medical and nonmedical options (multimodal therapy), and will thus help to improve the quality of life (QOL) of the patients.

Physiotherapy and related activities in multiple sclerosis

There are now about 50 randomized controlled trials into rehabilitation packages, physiotherapy or related specific and non-specific techniques in multiple sclerosis (MS). Generally these, and related systematic reviews, report benefits. Particular problems arise, however, with the blinding of assessment, determination of what is the active or beneficial input by the therapist, the use of multiple domains of assessment of quality of life and function without, sometimes, a clear statement of a trial hypothesis or primary outcome and the short-term nature of many studies. Therapy inputs can be broadly broken down into verbal interactions with the patient, physical inputs and referral/recommendation processes. Each may be relevant to the outcome. ‘Response-shift’ may be an important internal mechanism of mind whereby changes in ‘quality of life’ may not always parallel function emphasizing the case for clearly separating quality of life from functional assessment and attempting to make the latter as objective as possible. Trials of such complex interventions will need to randomize specified components of therapy against appropriate placebos or active treatment arms rather than no therapy, which will be ethically harder to sustain. Classification of physiotherapy inputs by type and ‘dosage’, a primary hypothesis under test and attention to concealed allocation of treatment, assessor blinding and intention to treat analysis together with improved measurements of function will assist in the consolidation of the evidence base for physiotherapy as an important component of management for MS patients.

Palliative care in amyotrophic lateral sclerosis, Parkinson's disease, and multiple sclerosis

BACKGROUND

Amyotrophic lateral sclerosis, Parkinson's disease, atypical parkinsonian syndromes, and multiple sclerosis are progressive neurologic disorders that cumulatively afflict a large number of people. Effective end-of-life palliative care depends upon an understanding of the clinical aspects of each of these disorders.

OBJECTIVES

The authors review the unique and overlapping aspects of each of these disorders with an emphasis upon the clinical management of symptoms.

DESIGN

The authors review current management and the supporting literature.

CONCLUSIONS

Clinicians have many effective therapeutic options to choose from when managing the symptoms produced by these disorders.

Analysis of nociception, sex and peripheral nerve innervation in the TMEV animal model of multiple sclerosis

Although pain was previously not considered an important element of multiple sclerosis (MS), recent evidence indicates that over 50% of MS patients suffer from chronic pain. In the present study, we utilized the Theiler's murine encephalomyelitis virus (TMEV) model of MS to examine whether changes in nociception occur during disease progression and to investigate whether sex influences the development of nociception or disease-associated neurological symptoms. Using the rotarod assay, TMEV infected male mice displayed increased neurological deficits when compared to TMEV infected female mice, which mimics what is observed in human MS. While both male and female TMEV infected mice exhibited thermal hyperalgesia and mechanical allodynia, female mice developed mechanical allodynia at a faster rate and displayed significantly more mechanical allodynia than male mice. Since neuropathic symptoms have been described in MS patients, we quantified sensory nerve fibers in the epidermis of TMEV-infected and non-infected mice to determine if there were alterations in epidermal nerve density. There was a significantly higher density of PGP9.5 and CGRP-immunoreactive axons in the epidermis of TMEV-infected mice versus controls. Collectively these results indicate that the TMEV model is well suited to study the mechanisms of MS-induced nociception and suggest that alterations in peripheral nerve innervation may contribute to MS pain.

Multiple Sclerosis as A Painful Disease

Pain is a common problem of patients with multiple sclerosis (MS) and may be due to central/neuropathic or peripheral/somatic pathology. Rarely MS may present with pain, or pain may herald an MS exacerbation, such as in painful tonic spasms or Lhermitte's sign. In other patients, pain may become chronic as a long-term sequela of damage to nerve root entry zones (trigeminal neuralgia) or structures in central sensory pathways. Migraine headache may develop as a consequence of MS, and headache can also be a side effect of interferon treatment. The pathophysiology of pain in MS may be linked to certain plaque locations which disrupt the spinothalamic and quintothalamic pathways, abnormal impulses through motor axons, development of an acquired channelopathy in affected nerves, or involve glial cell inflammatory immune mechanisms. At this time, the treatment of pain in MS employs the use of antiepileptic drugs, muscle relaxers/antispasmodic agents, anti-inflammatory drugs, and nonpharmacological measures. Research concerning cannabis-based treatments shows promising results, and substances which block microglial or astrocytic involvement in pain processing are also under investigation.

Transcutaneous electrical nerve stimulation for the treatment of chronic low back pain: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the effectiveness of transcutaneous electrical nerve stimulation (TENS) in the management of chronic LBP.

SUMMARY OF BACKGROUND DATA

Chronic low back pain (LBP) affects a significant proportion of the population. TENS was introduced more than 30 years ago as an adjunct to pharmacologic pain management. However, despite its widespread use, the usefulness of TENS in chronic LBP is still controversial.

METHODS

We searched MEDLINE, EMBASE, PEDro, and the Cochrane Central Register of Controlled Trials (Issue 2, 2005), up to April 1, 2005. Only randomized controlled clinical trials (RCTs) evaluating the effect of TENS on chronic LBP were included. Two reviewers independently selected trials and extracted data using predetermined forms. Heterogeneity was tested with Cochrane's Q test. A fixed effect model was used throughout for calculating continuous variables, except where heterogeneity existed, in which case a random effects model was used. Results are presented as weighted mean differences with 95% confidence intervals (95% CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences were calculated by dividing the difference between the treated and control by the baseline variance. Standardized mean differences were used when different scales were used to measure the same concept. Dichotomous outcomes were analyzed with odds ratios.

RESULTS

Two RCTs (175 patients) were included. They differed with respect to study design, methodologic quality, inclusion and exclusion criteria, characteristics of TENS application, treatment schedule, cointerventions, and measured outcomes. In one RCT, TENS produced significantly greater pain relief than the placebo control. However, in the other RCT, no statistically significant differences between treatment and control groups were shown for multiple outcome measures. Preplanned subgroup analyses, intended to examine the impact of different stimulation parameters, sites of TENS application, treatment durations, and baseline patient characteristics were not possible because of the small number of included trials.

CONCLUSIONS

Evidence for the efficacy of TENS as an isolated intervention in the management of chronic LBP is limited and inconsistent. Larger, multicenter, RCTs are needed to better resolve its role in this condition. Increased attention should be given to the risks and benefits of long-term use, which more appropriately addresses the realities of managing chronic low back pain.

Transcutaneous electrical nerve stimulation (TENS) for chronic low-back pain

BACKGROUND

Chronic low-back pain (LBP) affects a significant proportion of the population. Transcutaneous electrical nerve stimulation (TENS) was introduced more than 30 years ago as an adjunct to the pharmacological management of pain. However, despite its widespread use, the usefulness of TENS in chronic LBP is still controversial.

OBJECTIVES

The aim of this systematic review was to determine the effectiveness of TENS in the management of chronic LBP.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 2, 2005), MEDLINE, EMBASE and PEDro up to April 1, 2005.

SELECTION CRITERIA

Only randomized controlled clinical trials (RCTs) evaluating the effect of TENS on chronic LBP were included. Abstracts were excluded unless further data could be obtained from the authors.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials and extracted data using predetermined forms. Heterogeneity was tested with Cochrane's Q test. A fixed effect model was used throughout for calculating continuous variables, except where heterogeneity existed, in which case, a random effects model was used. Results are presented as weighted mean differences (WMD) with 95% confidence intervals (95% CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences (SMD) were calculated by dividing the difference between the treated and control by the baseline variance. SMD were used when different scales were used to measure the same concept. Dichotomous outcomes were analyzed with odds ratios.

MAIN RESULTS

The only two RCTs (175 patients) meeting eligibility criteria differed in study design, methodological quality, inclusion and exclusion criteria, type and method of TENS application, treatment schedule, co-interventions and final outcomes. In one RCT, TENS produced significantly greater pain relief than the placebo control. However, in the other RCT, no statistically significant differences between treatment and control groups were shown for multiple outcome measures. Pre-planned subgroup analyses, intended to examine the impact of different stimulation parameters, sites of TENS application, treatment durations and baseline patient characteristics were not possible due to the small number of included trials.

AUTHORS' CONCLUSIONS

There is inconsistent evidence to support the use of TENS as a single treatment in the management of chronic LBP. Larger, multi-center, randomized controlled trials are needed to better assess the true effectiveness of TENS. Special attention should be given to the risks and benefits of long-term use, which more appropriately addresses the realities of managing chronic low-back pain.

Exercise and Rehabilitation for Individuals with Multiple Sclerosis

It is the coexistence of physical and cognitive impairments, together with emotional and social issues in a disease with an uncertain course, that makes MS rehabilitation unique and challenging. Inpatient rehabilitation improves functional independence but has only limited success improving the level of neurologic impairment. Benefits are usually not long lasting. Severely disabled people derive equal or more benefit than those who are less disabled, but cognitive problems and ataxia tend to be refractory. There is now good evidence that exercise can improve fitness and function for those with mild MS and helps to maintain function for those with moderate to severe disability. Therapy can be performed over 6 to 15 weeks in outpatient or home-based settings or as a weekly day program lasting several months. Several different forms of exercise have been investigated. For most individuals, aerobic exercise that incorporates a degree of balance training and socialization is recommended. Time constraints, access, impairment level, personal preferences, motivations, and funding sources influence the prescription for exercise and other components of rehabilitation. Just as immunomodulatory drugs must be taken on a continual basis and be adjusted as the disease progresses, so should rehabilitation be viewed as an ongoing process to maintain and restore maximum function and QOL.