Effects of Wearable Transcutaneous Electrical Nerve Stimulation on Fibromyalgia: A Randomized Controlled Trial

Why is low educational attainment linked to worse pain and function in fibromyalgia?

Lower educational attainment has been linked to worse pain in individuals with chronic pain, but the mechanisms of this relationship are not fully elucidated. This observational study analyzed the relationship between educational attainment and pain in patients with fibromyalgia (FM) and the potential psychological mechanisms driving this relationship. We hypothesized that (1) lower educational attainment would be associated with greater pain intensity and interference, and that (2) concerns about pain (CAP), anxiety, and depression would mediate the relationship between educational attainment and pain. A total of 119 adults (93.3% female, 79.7% White, Mage=50.4) with FM completed questionnaires including demographics, Brief Pain Inventory (BPI), Pain Catastrophizing Scale (PCS), and Hospital Anxiety and Depression Scales (HADS). Pearson correlations and bootstrapped mediation analyses were conducted to examine the relationships among education, psychological variables, and pain variables. Education was inversely correlated with pain intensity and interference, CAP, anxiety, and depression (p<.05). CAP significantly mediated the relationship between education and pain intensity (95% CI [0.151, 0.026]), while both CAP and depression mediated the effects of education on pain interference (95% CI [0.195, -0.025]; 95% CI [-0.163, -0.004]). However, anxiety did not mediate either relationship. These findings suggest that greater CAP, and in part depression, may be possible mechanisms in the relationships between lower educational attainment and worse pain intensity and interference. This work has important implications in reducing pain disparities and provides direction for psychological treatment, suggesting that both depression and CAP may be critical targets especially for people with lower education attainment. PERSPECTIVES: This study examined the relationship between educational attainment, psychological variables, and pain. Results have implications for psychological intervention aimed at concerns about pain and depression, especially among individuals with low educational attainment.

Effectiveness of transcutaneous electrical nerve stimulation improves pain intensity, disability and quality of life in patients with fibromyalgia syndrome: a systematic review with meta-analysis

PURPOSE

The transcutaneous electrical nerve stimulation (TENS) is one of the most frequently electrophysical agents employed in reducing the impact of FMS. This meta-analysis intended to determine the effectiveness of TENS on pain, disability, and quality of life (QoL) in patients with FMS.

METHODS

According to PRISMA, we performed a meta-analysis (CRD42023456439), searching in PubMed Medline, PEDro, CINAHL Complete, Web of Science, and Scopus, since inception up to October 2023. This review focused on controlled clinical trials evaluating the effect of TENS on pain, disability, and QoL in patients with FMS. The pooled effect was estimated using Cohen's standardized mean difference (SMD) and its 95% confidence interval (95%CI).

RESULTS

Twelve studies, providing data from 944 patients, were included (PEDro score of 5.6 points). Meta-analyses showed that TENS interventions are effective in improving pain (SMD = -0.61; 95%CI -1 to -0.16); disability (SMD = -0.27; 95%CI -0.41 to -0.12); and physical dimension of QoL (SMD = 0.26; 95%CI 0.08 to 0.44). Additionally, when TENS is used as a unique therapy, it represents the best therapeutic option for improving pain, disability, and QoL.

CONCLUSIONS

This meta-analysis, including the largest number of studies, showed that TENS intervention is an effective therapy to reduce pain and disability and increase QoL in FMS patients.

Transcutaneous electrical nerve stimulation for fibromyalgia-like syndrome in patients with Long-COVID: a pilot randomized clinical trial

This study investigated the effect of Transcutaneous Electrical Nerve Stimulation (TENS) for fibromyalgia-like symptoms including chronic widespread musculoskeletal pain, fatigue, and/or gait impairment in twenty-five individuals with long-COVID. Participants were randomized to a high dose (intervention group, IG) or low dose (placebo group, PG) TENS device. Both groups received daily 3-5 h of TENS therapy for 4-weeks. The Brief Pain Inventory assessed functional interference from pain (BPI-I), and pain severity (BPI-S). The global fatigue index (GFI) assessed functional interference from fatigue. Wearable technology measured gait parameters during three 30-feet consecutive walking tasks. At 4-weeks, the IG exhibited a greater decrease in BPI-I compared to the PG (mean difference = 2.61, p = 0.008), and improved in gait parameters including stride time (4-8%, test condition dependent), cadence (4-10%, depending on condition), and double-support phase (12% in dual-task) when compared to baseline. A sub-group meeting the 2010 American College of Rheumatology Fibromyalgia diagnostic criteria undergoing high-dose TENS showed GFI improvement at 4-weeks from baseline (mean change = 6.08, p = 0.005). Daily TENS therapy showed potential in reducing functional interference from pain, fatigue, and gait alterations in long-COVID individuals. The study's limited power could affect the confirmation of certain observations. Extending the intervention period may improve treatment effectiveness.

Temporal Summation but Not Expectations of Pain Relief Predict Response to Acupuncture Treatment in Fibromyalgia

Fibromyalgia (FM) is a common chronic pain condition for which acupuncture treatment is increasingly utilized. However, there is no universally accepted measure to predict whether a specific patient will benefit from acupuncture. This is a single-center, single-blind, sham-controlled, randomized, noncrossover, longitudinal trial of 76 subjects with FM, assigned to either electroacupuncture (EA) or a placebo control, mock laser (ML) acupuncture. Outcome measures included clinical pain severity (Brief Pain Inventory [BPI]), degree of nociplastic pain (Fibromyalgia Survey Questionnaire), and pressure pain tolerance (PPtol). Baseline measures of temporal summation of pain and expectations for treatment relief were used as predictors. Individuals in both treatment groups experienced significant reductions in BPI (EA: P < .001, ML: P = .018) and Fibromyalgia Survey Questionnaire (EA: P = .032, ML: P = .002) after treatment; however, neither group showed a significant increase in PPtol. Lower temporal summation at baseline was correlated with greater post-treatment improvement in BPI in the EA group (rho = .389, P = .025) but not in the ML group (rho = -.272, P = .109). Lower-baseline temporal summation was correlated with greater decreases in PPtol following EA (rho = .400, P = .040), whereas the opposite was seen for ML (rho = -.562, P = .001). Treatment expectancy at baseline was not correlated with any outcome after EA or ML treatments. Our results support using a quantitative sensory testing metric, temporal summation of pain, but not expectations, to predict analgesia following acupuncture treatment for pain. PERSPECTIVE: A randomized study of acupuncture in FM found baseline temporal summation, but not expectations of pain relief, to be predictive of treatment response. CLINICAL TRIAL REGISTRATION: Registered under ClinicalTrials.gov identifier NCT02064296.

Underestimating or Overestimating Improvement in Pain on a Smartphone Pain App: Role of Disability, Negative Affect, and Pain App Engagement

Clinicians often ask people with chronic pain about their perceived benefit from interventions designed to improve their pain. The aim of this study is to identify factors that contribute to underestimating or overestimating perceived changes in daily pain intensity over a month of daily assessments. We examined data from individuals with chronic pain who provided at least 28 daily assessments using a pain app as secondary analyses. Participants provided baseline demographic information and completed questionnaires assessing pain, activity interference, mood, pain disability, and catastrophizing. Using the pain app, they entered daily ratings of pain (0 = none, 10 = worst pain possible) and impressions of perceived day-to-day change (0 = better, 5 = same, and 10 = worse). Two hundred fifty-two (N = 252) subjects with chronic pain met the inclusion criteria of completing at least 28 daily assessments. Those who underestimated their improvement tended to have higher pain intensity at baseline (P < .001), reported greater activity interference and disability (P < .001), and were prone to greater catastrophizing and anxiety and depression (P < .01). People who were more accurate in assessing their improvement engaged less with the app with fewer 2-way messages compared with those who either underestimated or overestimated their improvement and who had more 2-way messaging (P < .05). This longitudinal study suggests that those who report greater levels of catastrophizing and anxiety and depression are more likely to underestimate any improvements in their pain over time but seem to engage more with a pain app. Future research will help in our understanding of what magnitude of perceived change in pain ratings is clinically meaningful. PERSPECTIVE: Those who report greater levels of pain, disability, anxiety, depression, and catastrophizing are most prone to underestimate improvements of their pain over time.

A transcutaneous electrical nerve stimulation device for the relief of neuropathic pain in NMOSD: A randomized, double-blind, sham-controlled trial

Background

Individuals with neuromyelitis optica spectrum disorder (NMOSD) often suffer from severe, disabling, and treatment-refractory neuropathic pain. Transcutaneous electrical nerve stimulation (TENS) therapy is a non-invasive, pain-modifying device.

Objective

To determine whether TENS therapy is safe, tolerable, and effective for neuropathic pain in patients with NMOSD.

Methods

We conducted a four-week, randomized, double-blind, sham-controlled, remote trial of TENS in patients with NMOSD who have neuropathic pain, followed by a 12-week open-label extension period. The difference in the Numeric Rating Scale current pain scores between 0 weeks and 4 weeks was the primary outcome measure.

Results

Forty-six patients (23 per arm) were enrolled in this trial, of which 40 were included in the primary analysis (four in the intervention arm and two in the sham arm withdrew prior to assessment of the primary outcome). Both the sham and intervention arms demonstrated significant decreases in average pain, worst pain, and current pain rating between baseline and 4 weeks, but there was no significant difference between the two arms.

Conclusions

In conclusion, there was no demonstrated benefit of TENS over sham TENS treatment, however, both arms demonstrated significant decreases in reported pain between baseline and 4 weeks. This trial is registered with ClinicalTrials.gov, NCT04614454.

Comparative Efficacy of Neuromodulation and Structured Exercise Program on Autonomic Modulation in Fibromyalgia Patients: Pilot Study

Background: Fibromyalgia is a chronic disorder marked by widespread muscle and joint pain, persistent fatigue, sleep disturbances, and irregularities in the autonomic nervous system (ANS). Methods: This study compared the effectiveness of neuromodulation using the EXOPULSE Mollii suit with a structured exercise program in regulating ANS function in fibromyalgia patients. In this randomized, longitudinal crossover study, 10 female patients were randomly assigned to either the Suit + Exercise group or the Exercise + Suit group. Each group participated in two sessions per week for eight weeks, followed by a two-week washout period before switching to the other intervention. We measured cortical arousal, microcirculation, and heart rate variability (HRV) before and after the 1st, 8th, and 16th sessions. Results: The results showed significant improvements in cortical arousal, HRV, and microcirculation with the neuromodulation treatment whereas the exercise program only produced short-term improvements in cortical arousal. Conclusion: The EXOPULSE Mollii suit exhibited cumulative benefits on ANS modulation over time, suggesting potential long-term advantages for managing fibromyalgia. However, further research is needed to explore the delayed effects of both treatments on ANS modulation.

Influence of Transcutaneous Electrical Nerve Stimulation (TENS) on Pressure Pain Thresholds and Conditioned Pain Modulation in a Randomized Controlled Trial in Women With Fibromyalgia

Transcutaneous electrical nerve stimulation (TENS) effectively reduces pain in fibromyalgia (FM). The purpose of this study was to examine the influence of TENS use on pressure pain thresholds (PPT) and conditioned pain modulation (CPM) in individuals with FM using data from the Fibromyalgia Activity Study with TENS trial (NCT01888640). Individuals with FM were randomly assigned to receive active TENS, placebo TENS, or no TENS for 4 weeks. A total of 238 females satisfied the per-protocol analysis among the active TENS (n = 76), placebo TENS (n = 68), and no TENS (n = 94) groups. Following 4 weeks of group allocation, the active TENS group continued for an additional 4 weeks of active TENS totaling 8 weeks (n = 66), the placebo and no TENS groups transitioned to receive 4 weeks of active TENS (delayed TENS, n = 161). Assessment of resting pain, movement-evoked pain (MEP), PPT, and CPM occurred prior to and following active, placebo, or no TENS. There were no significant changes in PPT or CPM among the active TENS, placebo TENS, or no TENS groups after 4 weeks. Individuals who reported clinically relevant improvements in MEP (≥30% decrease) demonstrated increases in PPT (P < .001), but not CPM, when compared to MEP non-responders. There were no significant correlations among the change in PPT or CPM compared to MEP and resting pain following active TENS use (active TENS + delayed TENS). PPT and CPM may provide insight to underlying mechanisms contributing to pain; however, these measures may not relate to self-reported pain symptoms. PERSPECTIVE: Pressure pain threshold increased in individuals with clinically relevant improvement (≥30%) in MEP, indicating the clinical relevance of PPT for understanding mechanisms contributing to pain. CPM was not a reliable indicator of treatment response in MEP responders.

Efficacy of neuromodulation on the treatment of fibromyalgia: A network meta-analysis

OBJECTIVE

Several types of neuromodulation have been investigated for the treatment of fibromyalgia, but they show varied efficacy on pain, functioning, comorbid depression and comorbid anxiety. Whether some types of neuromodulation or some factors are associated with a better response also awaits clarification.

METHODS

We conducted a systematic review and network meta-analysis of randomized controlled trials to evaluate the efficacy of neuromodulation in patients with fibromyalgia. We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and PsycINFO before March 2022. We employed a frequentist random-effects network meta-analysis.

RESULTS

Forty trials involving 1541 participants were included. Compared with sham control interventions, several types of transcranial direct current stimulation (tDCS), transcranial random noise stimulation (tRNS), and high-frequency repetitive transcranial magnetic stimulation (rTMS) were associated with significant reduction of pain, depression, anxiety, and improvement in functioning. Many significantly effective treatment options involve stimulation of the primary motor cortex or dorsolateral prefrontal cortex.

CONCLUSION

We concluded that several types of rTMS, tDCS and tRNS may have the potential to be applied for clinical purposes.

Efficacy of rehabilitation treatments in improving functioning in patients with fibromyalgia: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Fibromyalgia is a debilitating condition marked by persistent pain and reduced functionality. Various therapeutic methods have been suggested to alleviate symptoms in individuals with fibromyalgia, yet the impact of diverse rehabilitation strategies remains unclear.

OBJECTIVE

This systematic review and meta-analysis aimed at assessing the efficacy of rehabilitation interventions in improving functioning in fibromyalgia patients.

METHODS

We conducted a comprehensive literature search of multiple international databases (PubMed, Scopus, and Web of Science) from their inception until November 22nd, 2023. We identified 23 randomized controlled trials (RCTs) assessing multiple rehabilitation strategies. The primary outcome was the Fibromyalgia Impact Questionnaire (FIQ). Study quality was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials (RoB 2). The study protocol was registered in PROSPERO (CRD42020197666).

RESULTS

Our meta-analysis rehabilitation interventions significantly reduce FIQ scores (MD =-11.74, 95% CI: -16.88 to -6.59, p< 0.0001). Notably, the subgroup analysis showed that different rehabilitation modalities seem to induce different therapeutic responses.

CONCLUSIONS

Rehabilitation strategies hold promise in addressing the functional impairments and improving the overall well-being of individuals with fibromyalgia. The study underscores the need for further research to determine the optimal rehabilitation approach and its potential impact on the multilevel disability characterizing patients with fibromyalgia.

Efficacy of electrophysical agents in fibromyalgia: A systematic review and network meta-analysis

OBJECTIVE

To examine the effectiveness of electrophysical agents in fibromyalgia.

DATA SOURCES

CINAHL, Cochrane Library, Embase, Medline, PEDro, and Web of Science were searched from their inceptions to March 27, 2023.

METHODS

This study was registered in PROSPERO (CRD42022354326). Methodological quality of included trials was assessed using PEDro scale, and the quality of evidence was determined according to the Grading of Recommendations Assessment, Development, and Evaluation system. The primary outcomes were pain, functional status, and mood.

RESULTS

Fifty-four studies involving 3045 patients with fibromyalgia were eligible for qualitative synthesis and 47 (pain), 31 (functional status), and 26 (mood) for network meta-analysis. The network consistency model revealed that, when compared with true control, transcutaneous electrical nerve stimulation and microcurrent improved pain symptoms (P = 0.006 and P = 0.037, respectively); repetitive transcranial magnetic stimulation improved patient functional status (P = 0.018); and microcurrent (P = 0.001), repetitive transcranial magnetic stimulation (P = 0.022), and no treatment (P = 0.038) significantly improved mood after intervention. Surface under the cumulative ranking indicated that microcurrent was most likely to be the best for managing pain and mood (surface under the cumulative ranking: 70% and 100%, respectively); low-level laser therapy for pain and mood (80% and 70%, respectively); and repetitive transcranial magnetic stimulation for improving functional status and mood (80% and 70%, respectively).

CONCLUSION

This review found low to moderate quality evidence that microcurrent, laser therapy, and repetitive transcranial magnetic stimulation are the most effective electrophysical agents for improving at least one outcome in fibromyalgia.

Treating fibromyalgia with electrical neuromodulation: A systematic review and meta-analysis

OBJECTIVE

Several types of electrical neuromodulation (such as transcranial direct current stimulation, tDCS; transcutaneous electrical nerve stimulation) have been applied in the treatment of fibromyalgia. These trials had different outcome measurements, such as subjective pain, pain threshold, depression, anxiety, and functioning. We intended to integrate data from different trials into a meta-analysis to clearly present the clinical value of electrical neuromodulation in fibromyalgia.

METHODS

A systematic review and meta-analysis of randomized controlled trials comparing the effect of all types of electrical neuromodulation in patients with fibromyalgia was conducted. The main outcome was subjective pain; the secondary outcomes included depression, anxiety, and functioning.

RESULTS

Twenty-five studies and 1061 fibromyalgia patients were included in the quantitative analysis. Active electrical neuromodulation and active tDCS both showed significant effects on subjective pain, depression, and functioning. For different anode tDCS electrode positions, only F3-F4 revealed a significant effect on depression. Meta-regression tDCS effects on depression were significantly associated with age.

CONCLUSIONS

Electrical neuromodulation is significantly effective in treating pain, depression, and functioning in patients with fibromyalgia.

SIGNIFICANCE

The results may help clinicians to arrange effective treatment plans for patients with fibromyalgia, especially in those patients who reveal limited response to pharmacotherapy and psychotherapy.

The dose-dependent effects of transcutaneous electrical nerve stimulation for pain relief in individuals with fibromyalgia: a systematic review and meta-analysis

ABSTRACT

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological modality widely used to manage pain; however, its effectiveness for individuals with fibromyalgia (FM) has been questioned. In previous studies and systematic reviews, variables related to dose of TENS application have not been considered. The objectives of this meta-analysis were (1) to determine the effect of TENS on pain in individuals with FM and (2) determine the dose-dependent effect of TENS dose parameters on pain relief in individuals with FM. We searched the PubMed, PEDro, Cochrane, and EMBASE databases for relevant manuscripts. Data were extracted from 11 of the 1575 studies. The quality of the studies was assessed using the PEDro scale and RoB-2 assessment. This meta-analysis was performed using a random-effects model that, when not considering the TENS dosage applied, showed that the treatment had no overall effect on pain (d+ = 0.51, P > 0.050, k = 14). However, the moderator analyses, which were performed assuming a mixed-effect model, revealed that 3 of the categorical variables were significantly associated with effect sizes: the number of sessions (P = 0.005), the frequency (P = 0.014), and the intensity (P = 0.047). The electrode placement was not significantly associated with any effect sizes. Thus, there is evidence that TENS can effectively reduce pain in individuals with FM when applied at high or at mixed frequencies, a high intensity, or in long-term interventions involving 10 or more sessions. This review protocol was registered at PROSPERO (CRD42021252113).

Optimizing and Accelerating the Development of Precision Pain Treatments for Chronic Pain: IMMPACT Review and Recommendations

Large variability in the individual response to even the most-efficacious pain treatments is observed clinically, which has led to calls for a more personalized, tailored approach to treating patients with pain (ie, "precision pain medicine"). Precision pain medicine, currently an aspirational goal, would consist of empirically based algorithms that determine the optimal treatments, or treatment combinations, for specific patients (ie, targeting the right treatment, in the right dose, to the right patient, at the right time). Answering this question of "what works for whom" will certainly improve the clinical care of patients with pain. It may also support the success of novel drug development in pain, making it easier to identify novel treatments that work for certain patients and more accurately identify the magnitude of the treatment effect for those subgroups. Significant preliminary work has been done in this area, and analgesic trials are beginning to utilize precision pain medicine approaches such as stratified allocation on the basis of prespecified patient phenotypes using assessment methodologies such as quantitative sensory testing. Current major challenges within the field include: 1) identifying optimal measurement approaches to assessing patient characteristics that are most robustly and consistently predictive of inter-patient variation in specific analgesic treatment outcomes, 2) designing clinical trials that can identify treatment-by-phenotype interactions, and 3) selecting the most promising therapeutics to be tested in this way. This review surveys the current state of precision pain medicine, with a focus on drug treatments (which have been most-studied in a precision pain medicine context). It further presents a set of evidence-based recommendations for accelerating the application of precision pain methods in chronic pain research. PERSPECTIVE: Given the considerable variability in treatment outcomes for chronic pain, progress in precision pain treatment is critical for the field. An array of phenotypes and mechanisms contribute to chronic pain; this review summarizes current knowledge regarding which treatments are most effective for patients with specific biopsychosocial characteristics.