C2 Nerve Field Stimulation for the Treatment of Fibromyalgia: A Prospective, Double-blind, Randomized, Controlled Cross-over Study

Are OMERACT recommendations followed in clinical trials on fibromyalgia? A systematic review of patient-reported outcomes and their measures

PURPOSE

Patient-Reported Outcomes (PROs) and its measures (PROMs) are key to outcome assessment in Fibromyalgia (FM) trials. The aim of this review was to investigate which domains and instruments were assessed in recent FM trials and to compare them to recommendations by the Outcome Measures in Rheumatology (OMERACT) initiative. In addition, we investigated the overlap with a generic health assessment approach, i.e. eight domains suggested by the Patient-Reported Outcome Measurement Information System® (PROMIS®).

METHODS

In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature search in scientific databases including PubMed, PsycInfo, and Embase was conducted to identify studies that assessed at least two dimensions of health-related quality of life (HRQoL) from 2015 to June 2022. Non-randomized and randomized controlled trials were included in the analysis. We extracted PROs and PROMs used in each study.

RESULTS

From 1845 identified records, 107 records out of 105 studies met the inclusion criteria. Studies investigated 50 PROs using 126 different PROMs. Most frequently assessed domains were pain, depression, fatigue, and anxiety (> 95% of the studies). The disease-specific FIQ was the most frequently applied PROM (82%). Overall, only 9% of the studies covered all domains deemed mandatory by OMERACT. Very few studies covered all eight generic health domains suggested by PROMIS.

CONCLUSION

The majority of trials covered most OMERACT domains or generic PROMIS health domains. There was, however, great variability in the instruments used to assess the domains, which points at a limited degree of standardization in the field.

Greater Occipital Nerve Stimulation Boosts Associative Memory in Older Individuals: A Randomized Trial

Transcutaneous electrical stimulation (tES) is a new approach that aims to stimulate the brain. Recently, we have developed tES approaches to enhance plasticity that modulate cortical activity via the greater occipital nerve (ON) in a “bottom-up” way. Thirty subjects between the ages of 55 and 70 years were enrolled and tested using a double-blind, sham-controlled, and randomized design. Half of the participants received active stimulation, while the other half received sham stimulation. Our results demonstrate that ON-tES can enhance memory in older individuals after one session, with effects persisting up to 28 days after stimulation. The hypothesized mechanism by which ON-tES enhances memory is activation of the locus coeruleus–noradrenaline (LC-NA) pathway. It is likely that this pathway was activated after ON-tES, as supported by observed changes in α-amylase concentrations, a biomarker for noradrenaline. There were no significant or long-lasting side effects observed during stimulation. Clinicaltrial.gov (NCT03467698).

A Systematic Literature Review of Peripheral Nerve Stimulation Therapies for the Treatment of Pain

Objective

To conduct a systematic literature review of peripheral nerve stimulation (PNS) for pain.

Design

Grade the evidence for PNS.

Methods

An international interdisciplinary work group conducted a literature search for PNS. Abstracts were reviewed to select studies for grading. Inclusion/exclusion criteria included prospective randomized controlled trials (RCTs) with meaningful clinical outcomes that were not part of a larger or previously reported group. Excluded studies were retrospective, had less than two months of follow-up, or existed only as abstracts. Full studies were graded by two independent reviewers using the modified Interventional Pain Management Techniques–Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria.

Results

Peripheral nerve stimulation was studied in 14 RCTs for a variety of painful conditions (headache, shoulder, pelvic, back, extremity, and trunk pain). Moderate to strong evidence supported the use of PNS to treat pain.

Conclusion

Peripheral nerve stimulation has moderate/strong evidence. Additional prospective trials could further refine appropriate populations and pain diagnoses.

The effectiveness and safety of electrotherapy in the management of fibromyalgia

Treating fibromyalgia is a challenging task for physicians. With its multifaceted features, fibromyalgia requires a comprehensive management strategy focusing on both the pharmacological and non-pharmacological treatment options. During the last decades, there has been growing evidence regarding the role of electrotherapy in fibromyalgia treatment. In this regard, the present article aimed to review the recent literature on the effectiveness and safety of the electrotherapy in the treatment of fibromyalgia. A literature search was conducted through PubMed/MEDLINE and Scopus databases. Transcutaneous electrical nerve stimulation (TENS), non-invasive brain stimulation (transcranial direct current/magnetic stimulation), and light amplification by stimulated emission of radiation (LASER) emerged as the most commonly examined electrotherapy techniques in fibromyalgia. Currently, there is growing data regarding the effectiveness of electrotherapy in the management of fibromyalgia-related pain. Besides, non-invasive electrotherapy techniques are related to no/minor side effects. Further studies are warranted to identify the optimal treatment protocols for each electrotherapy modality.

Effectiveness of Neurostimulation Technologies for the Management of Chronic Pain: A Systematic Review

OBJECTIVES

To describe the state of the literature for clinical effectiveness of neurostimulation used for the management of chronic pain.

METHODS

A systematic review of spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), peripheral nerve field stimulation (PNFS), and supraorbital transcutaneous electrical nerve stimulation in patients with cancer and noncancer chronic pain was conducted. MEDLINE, Embase, CINAHL, and the Cochrane CENTRAL Register of Controlled Trials were searched, using terms like "electrical stimulation therapy" and "pain management." Direction of effect, consistency across studies, and strength of evidence for effects of neurostimulation on chronic pain were narratively synthesized.

RESULTS

A total of 15 randomized controlled trials (RCTs) examining SCS, 7 RCTs examining PNS/PNFS, and 1 nonrandomized trial examining supraorbital transcutaneous electrical nerve stimulation (TENS) were included. In nine SCS studies, neurostimulation had positive effects on pain. In three studies, neurostimulation did not significantly reduce pain. For PNS/PNFS, five studies found improvements in pain offered by neurostimulation; pain outcomes were not reported in two studies. In the TENS study, neurostimulation reduced headaches per month and medication consumption. Overall, 21 studies were of low or unclear risk of bias, 4 were high risk of bias, and the TENS study was not appropriate for assessment using the Cochrane Risk of Bias tool.

CONCLUSIONS

A robust body of evidence examining SCS and PNS was identified. Only one study for PNFS and TENS was identified; both reported pain reductions. Generally, neurostimulation improved pain control. Future studies should examine the effectiveness of neurostimulation offered early in the trajectory of chronic pain.

Testing the effects of gentle vibrotactile stimulation on symptom relief in fibromyalgia

Background

Sensory disturbances in fibromyalgia extend beyond nociception. It has been proposed that imbalance in the mutual competition between painful input and non-painful sensory activity may, to a significant extent, account for the augmented subjective perception of pain. In this context, non-nociceptive somatosensory stimulation could arguably attenuate fibromyalgia symptoms by restoring the sensory balance. We specifically tested the effect of vibrotactile stimulation on symptom relief in fibromyalgia patients with a randomized, double-blind, sham-controlled, crossover clinical trial.

Methods

Seventy-seven female patients were randomized and data from 63 valid cases were analyzed. Active intervention involved extensive body stimulation with gentle mechanical vibrations administered during 3 h at night for 3 weeks, and the placebo effect was controlled using identical instruments to simulate an alternative treatment option. The primary outcome measure combined pain, fatigue, and complaints of poor cognition.

Results

Vibrotactile stimulation was significantly superior to sham in alleviating fibromyalgia symptoms globally. However, univariate analyses showed that the effect was not universal. Benefits were perceived on unpleasant somatic sensations such as generalized pain and fatigue, but not on poor cognition, anxiety, and depression. Vibrotactile stimulation was notably well tolerated and sleep quality significantly improved despite the fact that vibrations were administered at night.

Conclusions

Results thus provide new evidence that non-nociceptive somatosensory stimulation may favorably act upon altered somatosensory balance in fibromyalgia. From a clinical perspective, both the degree of improvement and the easy application of our proposal would seem to support a potential role for vibrotactile stimulation in the symptomatic treatment of fibromyalgia.

Trial registration

ClinicalTrials.gov registration number NCT03227952. Registered 24 July, 2017.

Adding Prefrontal Transcranial Direct Current Stimulation Before Occipital Nerve Stimulation in Fibromyalgia

OBJECTIVES

Fibromyalgia (FM) is a type of chronic musculoskeletal pain without a clear peripheral origin of nociception, often associated with depression. The underlying pathophysiology involves changes in a functional network that is related to pain and emotional processing in the central nervous system. Transcranial direct current stimulation (tDCS) targeting the dorsolateral prefrontal cortex or the occipital nerve (ON) is a noninvasive neuromodulation technique capable of improving fibromyalgia symptoms. This study aims to test the effect of combining 2 targets of stimulation using tDCS.

MATERIALS AND METHODS

We applied ON-tDCS in isolation or coupled with pre-ONS right-anode bifrontal tDCS and assessed its effect on fibromyalgia using the Fibromyalgia Impact Questionnaire, the Beck Depression Inventory, and Numeric Rating Scale for pain scores. These measures were compared with a sham control group using repeated measures analysis of variance.

RESULTS

The interaction effect of stimulation trials and the protocols of sham versus ON-tDCS were significant for the impact, distress, and pain caused by fibromyalgia (P<0.05). The interaction effect of trials and protocols of sham versus ON-tDCS with bifrontal tDCS was significant for distress (P<0.01), and it showed a trend of improvement for impact and pain (P<0.1). On the basis of the nonsignificant interaction effect of ON-tDCS versus ON-tDCS with bifrontal tDCS (P>0.1), adding bifrontal tDCS was found not to improve the treatment effect of ON-tDCS in any of the tested clinical outcome measures.

DISCUSSION

This study suggests that adding right-anode bifrontal tDCS to ONS has no added benefit in improving fibromyalgia-related symptoms.

High-frequency spinal cord stimulation at 10 kHz for widespread pain: a retrospective survey of outcomes from combined cervical and thoracic electrode placements

OBJECTIVE

To report on the long-term outcomes for patients receiving paraesthesia-free high-frequency spinal cord stimulation (HF10-SCS) at 10 kHz for the treatment of combined upper and lower body neuropathic/nociplastic pain syndromes including chronic widespread pain/fibromyalgia.

MATERIALS AND METHODS

Forty-five patients with widespread (both upper and lower body) neuropathic/nociplastic pain syndromes underwent a trial of combined cervical and thoracic HF10-SCS leads placed over the C2/T2 or C2/T9 vertebral levels, or three leads placed over the C2/T2/T9 vertebral levels. Thirty-eight patients proceeded to permanent implant, resulting in a trial to implant conversion rate of 84.4%. Patients were followed up an average of 2.3 ± 1.7 years post-permanent implant. Patient outcomes were recorded.

RESULTS

A statistically significant reduction of 3.5 ± 1.6 on the 10-point numerical rating scale (NRS) at 2.3 ± 1.7 years post-permanent implant was observed (baseline: 7.1 ± 0.8 vs. follow up: 3.7 ± 1.3) (p ≤ 001). Likewise, a reduction in disability (Roland Morris Disability Questionnaire) was also observed; baseline: 12.3 ± 5.1 vs. follow up: 7.8 ± 5.9. Similar trends were observed in a working capacity, with 20/31 (64.5%) of the work eligible patients employed at follow-up, compared with only 8/31 (25.8%) at baseline. Opioid pain medication use reduced and over 90% of patients were satisfied with their treatment outcome. No long-term adverse events were observed.

CONCLUSIONS

HF10-SCS at 10 kHz provides long-term widespread pain relief when leads are staggered across the cervical and thoracic spine. The improved return to work outcomes and opiate reductions suggest that cost-effectiveness as well as clinical effectiveness may be achieved with this treatment approach.

Occipital Nerve Stimulation

Although the first publications on clinical use of peripheral nerve stimulation for the treatment of chronic pain came out in the mid-1960s, it took 10 years before this approach was used to stimulate the occipital nerves. The future for occipital nerve stimulation is likely to bring new indications, devices, stimulation paradigms, and a decrease in invasiveness. As experience increases, one may expect that occipital nerve stimulation will eventually gain regulatory approval for more indications, most likely for occipital neuralgia, migraines and cluster headaches. This process may require additional studies, at least for approval from the US Food and Drug Administration.

Occipital Nerve Field Transcranial Direct Current Stimulation Normalizes Imbalance Between Pain Detecting and Pain Inhibitory Pathways in Fibromyalgia

Occipital nerve field (OCF) stimulation with subcutaneously implanted electrodes is used to treat headaches, more generalized pain, and even failed back surgery syndrome via unknown mechanisms. Transcranial direct current stimulation (tDCS) can predict the efficacy of implanted electrodes. The purpose of this study is to unravel the neural mechanisms involved in global pain suppression, mediated by occipital nerve field stimulation, within the realm of fibromyalgia. Nineteen patients with fibromyalgia underwent a placebo-controlled OCF tDCS. Electroencephalograms were recorded at baseline after active and sham stimulation. In comparison with healthy controls, patients with fibromyalgia demonstrate increased dorsal anterior cingulate cortex, increased premotor/dorsolateral prefrontal cortex activity, and an imbalance between pain-detecting dorsal anterior cingulate cortex and pain-suppressing pregenual anterior cingulate cortex activity, which is normalized after active tDCS but not sham stimulation associated with increased pregenual anterior cingulate cortex activation. The imbalance improvement between the pregenual anterior cingulate cortex and the dorsal anterior cingulate cortex is related to clinical changes. An imbalance assumes these areas communicate and, indeed, abnormal functional connectivity between the dorsal anterior cingulate cortex and pregenual anterior cingulate cortex is noted to be caused by a dysfunctional effective connectivity from the pregenual anterior cingulate cortex to the dorsal anterior cingulate cortex, which improves and normalizes after real tDCS but not sham tDCS. In conclusion, OCF tDCS exerts its effect via activation of the descending pain inhibitory pathway and de-activation of the salience network, both of which are abnormal in fibromyalgia.

Differential effects of bifrontal and occipital nerve stimulation on pain and fatigue using transcranial direct current stimulation in fibromyalgia patients

Fibromyalgia is a disorder characterized by widespread musculoskeletal pain frequently accompanied by other symptoms such as fatigue. Moderate improvement from pharmacological and non-pharmacological treatments have proposed non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) to the occipital nerve (more specifically the C2 area) or to the dorsolateral prefrontal cortex (DLPFC) as potential treatments. We aimed to explore the effectiveness of repeated sessions of tDCS (eight sessions) targeting the C2 area and DLPFC in reducing fibromyalgia symptoms, more specifically pain and fatigue. Forty-two fibromyalgia patients received either C2 tDCS, DLPFC tDCS or sham procedure (15 C2 tDCS-11 DLPFC tDCS-16 sham). All groups were treated with eight sessions (two times a week for 4 weeks). Our results show that repeated sessions of C2 tDCS significantly improved pain, but not fatigue, in fibromyalgia patients, whereas repeated sessions of DLPFC tDCS significantly improved pain as well as fatigue. This study shows that eight sessions of tDCS targeting the DLPFC have a more general relief in fibromyalgia patients than when targeting the C2 area, suggesting that stimulating different targets with eight sessions of tDCS can lead to benefits on different symptom dimensions of fibromyalgia.

Management of fibromyalgia syndrome in 2016

Fibromyalgia syndrome is a chronic pain disorder and defies definitively efficacious therapy. In this review, we summarize the results from the early treatment research as well as recent research evaluating the pharmacological, interventional and nonpharmacological therapies. We further discuss future directions of fibromyalgia syndrome management; we specifically focus on the issues that are associated with currently available treatments, such as the need for personalized approach, new technologically oriented and interventional treatments, the importance of understanding and harnessing placebo effects and enhancement of patient engagement in therapy.