Fixed-site high-frequency transcutaneous electrical nerve stimulation for treatment of chronic low back and lower extremity pain

Transcutaneous Electrical Nerve Stimulation Integrated into Pants for the Relief of Postoperative Pain in Hip Surgery Patients: A Randomized Trial

Background

The effect of transcutaneous electrical nerve stimulation (TENS) on pain and impression of change was assessed during a 2.5-hour intervention on the first postoperative days following hip surgery in a randomized, single-blinded, placebo-controlled trial involving 30 patients.

Methods

Mixed-frequency TENS (2 Hz/80 Hz) was administered using specially designed pants integrating modular textile electrodes to facilitate stimulation both at rest and during activity. The treatment outcome was assessed by self-reported pain Numerical Rating Scale (NRS) and Patient Global Impression of Change (PGIC) scores at four time points. The ability to perform a 3-meter walk test and the use of analgesics were also evaluated. Group comparison and repeated-measure analysis were carried out using nonparametric statistics.

Results

The active TENS group exhibited significantly higher PGIC scores after 30 minutes, which persisted throughout the intervention (all p ≤ 0.001). A reduction in NRS appeared after one hour of active TENS, persisting throughout the intervention (all p ≤ 0.05). The median group differences in pain ratings were greater than the minimum clinically important difference, and the analysis of pain trajectories confirmed clinical significance at the individual level. Moreover, patients in the active TENS group were more likely able to perform a 3-meter walk test by the end of the intervention (p = 0.04). Analysis of the opioid-sparing effect of TENS was inconclusive (p = 0.066). No postoperative surgical complications or TENS-related side effects were observed during the study.

Conclusion

Mixed-frequency TENS integrated in pants could potentially be an interesting addition to the arsenal of treatments for multimodal analgesia following hip surgery. This trial is registered with NCT05678101.

Mechanical Affective Touch Therapy for Anxiety Disorders: Feasibility, Clinical Outcomes, and Electroencephalography Biomarkers From an Open-Label Trial

Background

Most external peripheral nerve stimulation devices designed to alter mood states use electrical energy, but mechanical stimulation for activation of somatosensory pathways may be harnessed for potential therapeutic neuromodulation. A novel investigational device for Mechanical Affective Touch Therapy (MATT) was created to stimulate C-tactile fibers through gentle vibrations delivered by piezoelectric actuators on the bilateral mastoid processes.

Methods

22 adults with anxiety disorders and at least moderate anxiety symptom severity enrolled in an open-label pilot trial that involved MATT self-administration using a simple headset at home at least twice per day for 4 weeks. Resting EEG data were acquired before and after a baseline MATT session and again before the final MATT session. Self-report measures of mood and anxiety were collected at baseline, week 2, and week 4, while interoception was assessed pre- and post-treatment.

Results

Anxiety and depressive symptoms improved significantly from baseline to endpoint, and mindfulness was enhanced. EEG metrics confirmed an association between acute MATT stimulation and oscillatory power in alpha and theta bands; symptom changes correlated with changes in some metrics.

Conclusion

Open-label data suggest MATT is a promising non-invasive therapeutic approach to anxiety disorders that warrants further development.

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

Purpose

Fibromyalgia is a chronic condition characterized by widespread pain and interference with daily activities. The aim of this study is to assess the benefit of transcutaneous electrical nerve stimulation (TENS) for persons diagnosed with fibromyalgia.

Patients and Methods

Adults meeting diagnostic criteria for fibromyalgia were randomized in a double-blind trial to receive either an active (n=62) or sham (n=57) wearable TENS device for 3-months. Subjects were classified as having lower or higher pain sensitivity by Quantitative Sensory Testing (QST). Patient Global Impression of Change (PGIC, primary outcome) and secondary efficacy measures including Fibromyalgia Impact Questionnaire (FIQR), Brief Pain Inventory (BPI) and painDETECT questionnaire (PDQ) were assessed at baseline, 6-weeks and 3-months. Treatment effects were determined by a mixed model for repeated measures (MMRM) analysis of the intention-to-treat (ITT) population (N=119). A pre-specified subgroup analysis of pain sensitivity was conducted using an interaction term in the model.

Results

No differences were found between active and sham treatment on PGIC scores at 3-months (0.34, 95% CI [−0.37, 1.04], p=0.351) in the ITT population. However, in subjects with higher pain sensitivity (n=60), PGIC was significantly greater for active treatment compared to sham (1.19, 95% CI [0.24, 2.13], p=0.014). FIQR total score (−7.47, 95% CI [−12.46, −2.48], p=0.003), FIQR pain item (−0.62, 95% CI [−1.17, −0.06], p=0.029), BPI Interference (−0.70, 95% CI [−1.30, −0.11], p=0.021) and PDQ (−1.69, 95% CI [−3.20, −0.18], p=0.028) exhibited significant improvements for active treatment compared to sham in the ITT population. Analgesics use was stable and comparable in both groups.

Conclusion

This study demonstrated modest treatment effects of reduced disease impact, pain and functional impairment from wearable TENS in individuals with fibromyalgia. Subjects with higher pain sensitivity exhibited larger treatment effects than those with lower pain sensitivity. Wearable TENS may be a safe treatment option for people with fibromyalgia.

Clinicaltrials.gov Registration

NCT03714425.

Effectiveness of transcutaneous electrical stimulation combined with artificial tears for the treatment of dry eye: A randomized controlled trial

There is currently no available cure or universally effective treatment for dry eye (DE). The aim of the present study was to investigate the clinical efficacy of transcutaneous electrical stimulation (TES) combined with artificial tears in treating DE. Patients diagnosed with DE were referred for therapy with TES combined with sodium hyaluronate (SH)-containing artificial tears. A total of 52 patients (104 eyes) with DE were enrolled in this randomized controlled trial. The patients were randomized 1:1 to the TES + SH or SH group. The patients in the TES + SH group were treated with 20 sessions (5 sessions per week for 4 weeks), and each session lasted for 20 min. The treatment was continued for 4 weeks in all cases. The Ocular Surface Disease Index (OSDI), tear film breakup time (BUT), Schirmer's I test and corneal fluorescein scores were used to assess treatment efficacy. A total of 90 eyes of 45 patients completed all aspects of the study: 22 patients (44 eyes) in the TES + SH group and 23 patients (46 eyes) in the SH group. There was no statistically significant difference in sex, age or course between the two groups. The mean OSDI scores, BUT, Schirmer's I test and corneal fluorescein scores exhibited a significant improvement in the TES + SH group compared with the SH group after treatment. No serious adverse events were recorded during TES treatment. In conclusion, TES combined with artificial tears appeared to be an effective treatment for DE. Therefore, TES may represent a new therapeutic option with promising potential applications.

The effect of intermittent diet and/or physical therapy in patients with chronic low back pain: A single-blinded randomized controlled trial

BACKGROUND AND PURPOSE

This study aimed to investigate the effect of intermittent diet and/or physical therapy in patients with chronic low back pain.

MATERIALS AND METHODS

Sixty sedentary volunteers with chronic low back pain participated in the study. Body weight and body mass index (BMI) were measured. Pain severity was assessed using Visual Analogue Scale (VAS) and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), while assessment of disability was done using Barthel Index (BI).

RESULTS

The weight and BMI were reduced after treatment with diet only and diet plus physical therapy (p < 0.001). The pain severity was reduced in all the treated groups (p < 0.001), while BI was increased in the group treated with only physical therapy (p < 0.001).

CONCLUSION

The present study indicated that intermittent diet and/or physical therapy are beneficial to patients with chronic low back pain in terms of pain sensation and daily activities.

Remote Analgesic Effects Of Conventional Transcutaneous Electrical Nerve Stimulation: A Scientific And Clinical Review With A Focus On Chronic Pain

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a safe, noninvasive treatment for chronic pain that can be self-administered. Conventional TENS involves stimulation of peripheral sensory nerves at a strong, non-painful level. Following the original gate-control theory of pain, stimulation is typically near the target pain. As another option, remote stimulation may also be effective and offers potential advantages.

OBJECTIVE

This narrative review examines mechanisms underlying the remote analgesic effects of conventional TENS and appraises the clinical evidence.

METHODS

A literature search for English-language articles was performed on PubMed. Keywords included terms related to the location of TENS . Citations from primary references and textbooks were examined for additional articles.

RESULTS

Over 30 studies reported remote analgesic effects of conventional TENS. The evidence included studies using animal models of pain, experimental pain in humans, and clinical studies in subjects with chronic pain. Three types of remote analgesia were identified: at the contralateral homologous site, at sites distant from stimulation but innervated by overlapping spinal segments, and at unrelated extrasegmental sites.

CONCLUSION

There is scientific and clinical evidence that conventional TENS has remote analgesic effects. This may occur through modulation of pain processing at the level of the dorsal horn, in brainstem centers mediating descending inhibition, and within the pain matrix. A broadening of perspectives on how conventional TENS produces analgesia may encourage researchers, clinicians, and medical-device manufacturers to develop novel ways of using this safe, cost-effective neuromodulation technique for chronic pain.

Adding connective tissue manipulation to physiotherapy for chronic low back pain improves pain, mobility, and well-being: a randomized controlled trial

This study aimed to evaluate the effectiveness of connective tissue manipulation (CTM) for improving pain, mobility, and well-being in chronic low back pain (CLBP). Sixty-six patients with CLBP were randomized to three groups: CTM, sham massage (SM) and control groups. The groups got standardized physiotherapy and the related applications 5 days/wk, 3 weeks. Pain intensity, mobility, and well-being (Hospital Anxiety and Depression Scale [HADS], Oswestry Disability Index [ODI], and Short Form-36 [SF-36]) were assessed before and after the applications. Pain, mobility, and disability improved in all groups (P<0.05). There were differences in resting pain, HADS, and SF-36 scores in CTM, resting pain in SM, and SF-36 scores in controls (P<0.05). Activity pain, HADS scores decreased, mobility and physical component of the SF-36 in-creased in CTM compared to SM (P<0.05). Pain, ODI, and HADS scores decreased, mobility and SF-36 increased in CTM, and ODI scores decreased in SM compared to controls (P<0.05). In conclusion, pain intensity during activity and at night and disability decreased, and spinal mobility increased in all groups. However, CTM showed superiority in improving pain, mobility, and well-being in patients with CLBP.

Impact of transcutaneous electrical nerve stimulation on sleep in chronic low back pain: a real-world retrospective cohort study

Objective

The purpose of this study was to determine if transcutaneous electrical nerve stimulation (TENS) improves sleep in chronic low back pain (CLBP).

Background

There is uncertainty over the effectiveness of TENS in CLBP. In most studies, pain intensity has been the primary outcome measure. Although sleep abnormalities are common in CLBP, sleep outcomes have not been evaluated in most studies of TENS effectiveness. Subjective and objective sleep measures are often inconsistent in CLBP, suggesting that perception of sleep and actual sleep may differ.

Methods

This retrospective cohort study evaluated TENS for CLBP over 10 weeks. The source database included demographics, pain characteristics, pain intensity and interference on an 11-point numerical rating scale, adherence and actigraphic sleep data from real-world TENS users. Key inclusion criteria were CLBP with self-reported history of back injury and baseline pain interference with sleep ≥4. Study participants were stratified into improved and unimproved groups based on changes in pain interference with sleep (improved ≥1-point decrease). Actigraphic sleep metrics were compared between the two groups for weeks 1–2 and weeks 9–10.

Results

The inclusion criteria were met by 554 TENS users. There were 282 (50.9%) participants in the improved group and 272 (49.1%) in the unimproved group. The two groups had similar baseline characteristics and high TENS adherence. At the weeks 1–2 assessment, there were no differences among actigraphic sleep. At the weeks 9–10 assessment, there was a difference in total sleep time, with the improved group sleeping 29 minutes longer. In addition, the periodic leg movement (PLM) index was lower in the improved group.

Conclusion

Regular TENS improved self-reported and objective sleep measures in individuals with CLBP. When compared to the unimproved group, the improved group had longer total sleep time and fewer PLMs. Sleep may be an important outcome for TENS effectiveness in CLBP.

Outcome of a High-Frequency Transcutaneous Electrical Nerve Stimulator (hfTENS) Device for Low Back Pain: A Randomized Controlled Trial

OBJECTIVE

This controlled trial examined the benefit of a high-frequency transcutaneous electrical nerve stimulation (hfTENS) device (the Quell, NeuroMetrix, Inc., Waltham, MA, U.S.A.) for patients with chronic low back pain (CLBP).

METHODS

Thirty-five (n = 35) participants were randomly assigned to use the device each day for 3 months (experimental group) and were compared with 33 subjects without the device (treatment-as-usual control group). All patients were instructed to complete baseline questionnaires and were assessed on thresholds of pressure pain and mechanical temporal summation as part of standardized quantitative sensory testing (QST). The subjects also uploaded smartphone applications (apps) for tracking use of the hfTENS and for daily pain assessment. Each participant completed weekly phone interviews, was prompted to complete daily pain app assessments, and was asked to repeat the baseline questionnaires again after 6 weeks and 3 months.

RESULTS

Sixty percent of the subjects were female, 77.9% were Caucasian, and the average age was 46.2 years. Significant reductions in pain intensity (P < 0.01) and activity interference (P < 0.025) and significant improvements in pain catastrophizing (P < 0.025) were noted in the experimental group compared with the control group. No group differences were found on depression, anxiety, or pain-related disability. Older subjects with a longer duration of pain tended to use the hfTENS more often. Subjects who showed greater sensitivity based on QST results revealed increased use of the hfTENS (P < 0.025) and tended to believe that the hfTENS was more helpful in reducing their back pain, but these findings did not reach significance (P = 0.09).

CONCLUSION

These results suggest that hfTENS can have a moderate effect in reducing pain and improving quality of life in low back pain patients. Further trials designed to determine the mechanism of action of the hfTENS are needed.

A Pilot Randomized Sham-Controlled Trial of MC5-A Scrambler Therapy in the Treatment of Chronic Chemotherapy-Induced Peripheral Neuropathy (CIPN)

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) affects 30% to 40% of patients with cancer with long-lasting disability. Scrambler therapy (ST) appeared to benefit patients in uncontrolled trials, so we performed a randomized sham-controlled Phase II trial of ST.

METHODS

The primary end point was "average pain" after 28 days on the Numeric Rating Scale. Each received ten 30-minute sessions of ST on the dermatomes above the painful areas, or sham treatment on the back, typically at L3-5 where the nerve roots would enter the spinal cord. Outcomes included the Brief Pain Inventory (BPI)-CIPN and the EORTC CIPN-20 scale. Patients were evaluated before treatment (day 0), day 10, and days 28, 60, and 90.

RESULTS

Data regarding pain as a primary outcome were collected for 33 of the 35 patients. There were no significant differences between the sham and the "real" ST group at day 10, 28, 60, or 90, for average pain, the BPI, or EORTC CIPN-20. Individual responses were noted during the ST treatment on the real arm, but most dissipated by day 30. There was improvement in the sensory subscale of the CIPN-20 at 2 months in the "real" group (P = .14). All "real" patients wanted to continue treatment if available.

DISCUSSION

We observed no difference between sham and real ST CIPN treatment. Potential reasons include at least the following: ST does not work; the sham treatment had some effect; small sample size with heterogeneous patients; misplaced electrodes on an area of nonpainful but damaged nerves; or a combination of these factors.

Transcutaneous Electrical Nerve Stimulation on Acupuncture Points Improves Myofascial Pain, Moods, and Sleep Quality

PURPOSE

The aim of this study was to evaluate the effects of transcutaneous electrical nerve stimulation at acupuncture points versus trigger points on myofascial pain, moods, and sleep quality.

DESIGN

A randomized controlled study recruited 64 patients with spinal cord injury with myofascial pain.

METHODS

Outcomes of pain, moods, and sleep quality were measured and analyzed by the generalized estimation equation, analysis of covariance, and paired t test. Transcutaneous electrical nerve stimulation was applied for seven consecutive days at Hegu (LI4) and Daling (PC7) acupuncture points or myofascial trigger points.

FINDING

Significant differences were found in pain intensity from Day 3 forward, after controlling for confounders. Significant within-group differences were found in pain, moods, and sleep quality.

CONCLUSIONS

Transcutaneous electrical nerve stimulation at acupuncture and trigger points effectively improved pain, moods, and sleep quality in patients with spinal cord injury with myofascial pain. Acupuncture points had superior improvement in pain intensity and slight improvement in sleep quality than did trigger points.

CLINICAL RELEVANCE

Transcutaneous electrical nerve stimulation at acupuncture points could be applied for improving myofascial pain.

Rationale for electrical parameter determination in external trigeminal nerve stimulation (eTNS) for migraine: A narrative review

Background

Migraine is a primary headache disorder involving dysregulation of central and peripheral pain pathways. Medical treatment is often limited by drug side effects, comorbidities and poor compliance. This makes neuromodulation an ideal option for migraine treatment. Cefaly® is a transcutaneous electrical neurostimulator designed specifically for migraine treatment. It results in external trigeminal nerve stimulation of the supraorbital and supratrochlear nerves. External trigeminal nerve stimulation is effective for acute and preventive migraine treatment and may result in normalization of dysregulated pain pathways.

Objective

Our objective was to provide a narrative review of the neuroanatomical and pathophysiological basis of external trigeminal nerve stimulation for migraine treatment and to provide the rationale behind the choice of the electrical parameters used for external trigeminal nerve stimulation.

Methods

We reviewed external trigeminal nerve stimulation clinical trial publications, basic science neurostimulation literature, publications describing pathophysiological mechanisms in migraine, and documentation used in the application for the Food and Drug Administration approval of external trigeminal nerve stimulation.

Results

The electrical parameters used for external trigeminal nerve stimulation were chosen to maximize safety and efficacy. Critical parameters include generator characteristics, pulse shape, pulse duration, pulse frequency and session duration and frequency. We explain the rationale behind determination of each parameter. There is evidence of dysregulated central and peripheral pathways in migraine and evidence that external trigeminal nerve stimulation may normalize function of these pathways.

Conclusion

External trigeminal nerve stimulation is a safe and effective Food and Drug Administration-approved option for the acute and preventive treatment of migraine. The electrical parameters were optimized specifically for external stimulation of the trigeminal nerve to maximum safety, comfort and efficacy.

Transcutaneous Electrical Nerve Stimulation (TENS) in the Emergency Department for Pain Relief: A Preliminary Study of Feasibility and Efficacy

Introduction

Given the high rates of opioid addiction and overdose in the United States, non-opioid means of treating pain are increasingly needed. Transcutaneous electrical nerve stimulation (TENS) therapy is an effective non-opioid modality for treating pain, but has not yet been routinely used in emergency department (ED) settings. In this study we asked the following questions: Are TENS units a feasible treatment for pain in the ED? How effective are TENS units for the management of pain in a general ED population?

Methods

At our institution, we performed a pilot study using TENS units for pain. Patients in the ED were given, at the discretion of the ED provider, TENS units for the treatment of pain. Patients could be included for acute or chronic pain on whatever part of the body that was safe to use with TENS.

Results

A chart review of patients receiving TENS units in the ED (n=110) revealed that TENS was useful in relieving pain, along with other treatments, in 99% of cases. When surveyed, 83% of patients reported a functional improvement while using the TENS, and 100% of patients would recommend a TENS unit to a family or friend. When surveyed, 100% of ED staff observed that TENS units were effective in treating pain for patients, and 97% would want to use them if they themselves were patients.

Conclusion

Overall, in this small pilot study, TENS units appeared to be effective in our ED for reducing pain, when added to standard treatment. Additional studies are needed to determine which conditions are most responsive to TENS therapy, and the magnitude of pain reduction when used alone.

The role of nonpharmacologic therapies in management of chronic pelvic pain: what to do when surgery fails

PURPOSE OF REVIEW

To provide an update on nonsurgical and nonpharmacologic strategies for the management of chronic pelvic pain (CPP).

RECENT FINDINGS

Effective treatment of patients with CPP requires a multifaceted approach, with thoughtful consideration of surgical, pharmacologic, and nonpharmacologic strategies. Evidence for physical therapy and trigger point injections for treatment of myofascial components of CPP is increasing. Neuromodulation techniques, such as percutaneous tibial nerve stimulation and transcutaneous electrical stimulation, have limited but favorable preliminary data in patients with CPP. Behavioral strategies, such as exercise, cognitive behavioral therapy, and mindfulness, have demonstrated significant improvements in pain, function and quality of life in patients with a variety of chronic pain conditions and are promising avenues for future research in CPP.

SUMMARY

Nonpharmacologic therapies are important adjuncts to surgical and pharmacologic treatment for CPP and should be considered integral to a comprehensive treatment approach.

Effectiveness of fixed-site high-frequency transcutaneous electrical nerve stimulation in chronic pain: a large-scale, observational study

Objective

The objective of this study was to assess the effectiveness of fixed-site high-frequency transcutaneous electrical nerve stimulation (FS-TENS) in a real-world chronic pain sample.

Background

There is a need for nonpharmacological treatment options for chronic pain. FS-TENS improved multisite chronic pain in a previous interventional study. Large observational studies are needed to further characterize its effectiveness.

Methods

This retrospective observational cohort study examined changes in chronic pain measures following 60 days of FS-TENS use. The study data were obtained from FS-TENS users who uploaded their device utilization and clinical data to an online database. The primary outcome measures were changes in pain intensity and pain interference with sleep, activity, and mood on an 11-point numerical rating scale. Dose-response associations were evaluated by stratifying subjects into low (≤30 days), intermediate (31-56 days), and high (≥57 days) utilization subgroups. FS-TENS effectiveness was quantified by baseline to follow-up group differences and a responder analysis (≥30% improvement in pain intensity or ≥2-point improvement in pain interference domains).

Results

Utilization and clinical data were collected from 11,900 people using FS-TENS for chronic pain, with 713 device users meeting the inclusion and exclusion criteria. Study subjects were generally older, overweight adults. Subjects reported multisite pain with a mean of 4.8 (standard deviation [SD] 2.5) pain sites. A total of 97.2% of subjects identified low back and/or lower extremity pain, and 72.9% of subjects reported upper body pain. All pain measures exhibited statistically significant group differences from baseline to 60-day follow-up. The largest changes were pain interference with activity (-0.99±2.69 points) and mood (-1.02±2.78 points). A total of 48.7% of subjects exhibited a clinically meaningful reduction in pain interference with activity or mood. This proportion increased to 57.1% for the high utilization subgroup.

Conclusion

FS-TENS is a practical option for treating multisite chronic pain. The greatest impact is on pain interference with activity and mood. FS-TENS utilization and effectiveness exhibit a dose-response association, suggesting that daily use maximizes pain relief.

Prospective Outcomes of a Pelvic Floor Rehabilitation Program Including Vaginal Electrogalvanic Stimulation for Urinary, Defecatory, and Pelvic Pain Symptoms

OBJECTIVES

This study evaluated our experience after implementing a pelvic floor rehabilitation program including behavioral modification, biofeedback, and vaginal electrogalvanic stimulation (EGS).

METHODS

This prospective cohort study evaluated outcomes of patients with pelvic floor dysfunction (urinary or defecatory dysfunction, pelvic pain/dyspareunia) who underwent pelvic floor rehabilitation. Patients received 4 to 7 sessions (1 every 2 weeks) including biofeedback and concluded with 30 minutes of vaginal EGS. Surveys assessed subjective changes in symptoms; success was evaluated using a 10-point visual analog scale (VAS) at the final session (10 = most successful). Paired comparisons of responses at baseline and final treatment were evaluated.

RESULTS

Ninety-four patients were followed up through therapy completion. Treatment indications included urinary (89.4%), defecatory (33.0%), and pelvic pain or dyspareunia (30.9%); 44.7% of patients had a combination of indications. Among women with urinary symptoms, the percentage reporting leakage decreased from 92.9% to 79.3% (P = 0.001), leakage at least daily decreased from 69.0% to 39.5% (P < 0.001), daily urgency with leakage decreased from 42.7% to 19.5% (P = 0.001), daily urgency without leakage decreased from 41.5% to 18.3% (P < 0.001), and median VAS rating (0 = not at all, 10 = a great deal) of daily life interference decreased from 5 to 1.5 (P < 0.001). The median success ratings were 8, 8, and 7 for treatment of urinary symptoms, pelvic pain/dyspareunia, and bowel symptoms, respectively.

CONCLUSIONS

An aggressive pelvic rehabilitation program including biofeedback with vaginal EGS had a high rate of self-reported subjective success and satisfaction and should be considered a nonsurgical treatment option in patients with pelvic floor dysfunction.

Case report: Percutaneous electrical neural field stimulation in two cases of sympathetically-mediated pain

Background: Fibromyalgia and complex regional pain syndrome (CRPS) are both chronic pain syndromes with pathophysiologic mechanisms related to autonomic nervous system dysregulation and central sensitization.  Both syndromes are considered difficult to treat with conventional pain therapies. Case presentations: Here we describe a female veteran with fibromyalgia and a male veteran with CRPS, both of whom failed multiple pharmacologic, physical and psychological therapies for pain, but responded to percutaneous electrical neural field stimulation (PENFS) targeted at the auricular branches of the cranial nerves. Discussion: While PENFS applied to the body has been previously described for treatment of localized pain, PENFS effects on cranial nerve branches of the ear is not well-known, particularly when used for regional and full-body pain syndromes such as those described here. PENFS of the ear is a minimally-invasive, non-pharmacologic therapy that could lead to improved quality of life and decreased reliance on medication. However, further research is needed to guide clinical application, particularly in complex pain patients.

Efficacy of Auricular Acupressure for Chronic Low Back Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives

To identify the efficacy of auricular acupressure on pain and disability for chronic LBP by systematic review.

Methods

A search of randomized controlled trials was conducted in four English medical electronic databases and three Chinese databases. Two reviewers independently retrieved related studies, assessed the methodological quality, and extracted data with a standardized data form. Meta-analyses were performed using all time-points meta-analysis.

Results

A total of 7 trials met the inclusion criteria, of which 4 had the low risk of bias. The findings of this study showed that, for the immediate effect, auricular acupressure had large, significant effects in improving pain within 12 weeks. As for the follow-up effect, the pooled estimates also showed promising effect at 4-week follow-up after 4-week intervention (standardized mean difference = −1.13, 95% CI (−1.70, −0.56), P < 0.001). But, for the disability level, the therapeutic effect was not significant (mean difference = −1.99, 95% CI (−4.93, 0.95), P = 0.18). No serious adverse effects were recorded.

Conclusions

The encouraging evidence of this study indicates that it is recommended to provide auricular acupressure to patients with chronic low back pain. However, a more accurate estimate of the effect will require further rigorously designed large-scale RCTs on chronic LBP for improving pain and disability.

Transcutaneous electrical nerve stimulator of 5000 Hz frequency provides better analgesia than that of 100 Hz frequency in mice muscle pain model

Transcutaneous electrical nerve stimulators (TENSs) have been proved to be effective in muscle pain management for several decades. However, there is no consensus for the optimal TENS program. Previous research demonstrated that a 100 Hz TENS (L-TENS) provided better analgesia than a conventional TENS (< 5 Hz). However, no research compared a higher-frequency (> 100 Hz) TENS with a 100 Hz TENS. We used a 5000 Hz (5 kHz) frequency TENS (M-TENS) and an L-TENS to compare analgesic effect on a mice skin/muscle incision retraction model. Three groups of mice were used (sham, L-TENS, and M-TENS) and applied with different TENS programs on Day 4 after the mice skin/muscle incision retraction model; TENS therapy was continued as 20 min/d for 3 days. Mice analgesic effects were measured via Von Frey microfilaments with the up-down method. After therapy, mice spinal cord dorsal horn and dorsal root ganglion (DRG) were harvested for cytokine evaluation (tumor necrosis factor-α and interleukin-1β) with the Western blotting method. Our data demonstrated that the M-TENS produced better analgesia than the L-TENS. Cytokine in the spinal cord or DRG all expressed lower than that of the sham group. However, there is no difference in both cytokine levels between TENSs of different frequencies in the spinal cord and DRG. We concluded that the M-TENS produced faster and better mechanical analgesia than the L-TENS in the mice skin/muscle incision retraction model. Those behavior differences were not in accordance with cytokine changes in the spinal cord or DRG.