Repetitive transcranial magnetic stimulation of the prefrontal cortex for fibromyalgia syndrome: a randomised controlled trial with 6-months follow up

Comparative Effectiveness of Noninvasive Brain Stimulation for the Treatment of Pain, Fatigue, and Sleep Quality in Fibromyalgia. A Systematic Review With Network Meta-Analysis

OBJECTIVES

There is tentative evidence to support the analgesic effects of noninvasive brain stimulation (NiBS) in fibromyalgia (FM), but a comprehensive synthesis is lacking. This systematic review with network meta-analysis (NMA) aimed to determine the relative effectiveness of different NiBS techniques, such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) in FM, and to identify the optimal stimulation location and intensity/frequency.

METHODS

Four databases were searched until July 9, 2023 for randomized trials (RCTs) comparing NiBS in FM. Pain was the primary outcome, while fatigue and sleep were secondary outcomes. A frequentist NMA calculated standardized-mean-differences (SMDs) for pain, with pairwise meta-analysis for fatigue and sleep. Bias was assessed with the Cochrane-risk-of-bias-tool (RoB-2.0), and evidence certainty through confidence-in-NMA.

RESULTS

Forty-three RCTs with 2120 participants were included. NMA showed that low frequency (LF)-rTMS (SMD: -1.20, 95% CI: -1.82 to -0.58), dual tDCS (SMD: -0.91, 95% CI: -1.82 to -0.58), and high frequency (HF)-rTMS (SMD: -0.58, 95% CI: -1.00 to -0.17) likely results in a reduction in pain intensity at the end of intervention compared with sham stimulation. For stimulation location, right dorsolateral prefrontal cortex (DLPFC)(SMD: -1.42, 95% CI: -2.69 to -0.15), bilateral DLPFC (SMD: -0.94, 95% CI: -1.82 to -0.05), and left primary motor cortex (M1)(SMD: -0.49, 95% CI: -0.85 to -0.14) likely results in reduction in pain intensity at the end of intervention, with DLPFC maintaining effects in short-term. LF-rTMS over DLPFC (SMD: -1.42, 95% CI: -2.69 to -0.15) and HF-rTMS over M1 (SMD: -0.78, 95% CI: -1.39 to -0.18) likely results in the reduction in pain intensity at the end of intervention, with LF-rTMS over right DLPFC maintaining effects in the short term. NiBS appears to be safe and may reduce fatigue and improve sleep quality.

DISCUSSION

Excitatory stimulation like HF-rTMS over M1 and inhibitory like LF-rTMS over DLPFC may yield better results.

Therapeutic approach to fibromyalgia: a consensus statement on pharmacological and non-pharmacological treatment from the neuropathic pain special interest group of the Italian neurological society

BACKGROUND

Although fibromyalgia is a disabling disease, there is no targeted therapy for specific neurotransmitters or inflammatory mediators. Our aim was to provide neurologists with practical guidance for the management of these difficult patients based on a critical, narrative and non-systematic review of randomized controlled trials (RCTs) from the last 10 years.

METHODS

The members of the Special Interest Group Neuropathic Pain of the Italian Neurological Society evaluated the randomized controlled trials (RCTs) of the last 10 years and answered questions that allow a consensus on the main pharmacological and non-pharmacological approaches.

RESULTS

The neuropathic pain working group agreed on prescribing antiepileptic drugs or antidepressants in the case of comorbidities with anxiety and depression. As a second choice, experts have agreed on the association of antiepileptics and antidepressants, while they disagree with the use of opioids. Medical cannabis and nutraceuticals are promising new treatment options, although more data is needed to prove their efficacy. The neurologists agreed in suggesting physical activity at the first visit, particularly aerobic and strength training. As a second choice, they considered a cognitive behavioral therapy approach to be useful.

CONCLUSIONS

Pharmacologic treatment with antiepileptic drugs and antidepressants in patients with co-occurring anxiety and depression, as well as an early nonpharmacologic approach based primarily on physical activity, may be a useful indication in contemporary neurology clinical practice. Non-pharmacological options, such as cognitive behavioral therapy and non-invasive brain stimulation NIBS, could improve evidence of efficacy and lead to relevant improvement in FM-related disability.

Chronic pain is associated with greater brain entropy in the prefrontal cortex

Chronic pain is a debilitating clinical condition and a severe public health issue that demands to be addressed. Neuroimaging-based techniques have been widely adopted to investigate the neural underpinnings of chronic pain. Despite the efforts the complex nature of pain experience as well as the heterogeneity of chronic pain have made the identification of neuroimaging-based biomarkers extremely challenging. In this study, resting-state fMRI-based brain entropy, a measure reflecting the "irregularity" of brain activity, was adopted as a biomarker of chronic pain by comparing individuals with chronic pain and healthy controls in a sample of middle-to-old-age participants (n > 30,000) drawn from the UK Biobank database. Abnormal brain entropy is associated with altered brain dynamics and may serve as a potential marker of disrupted pain processing in individuals with chronic pain. Compared to healthy controls, individuals with chronic pain exhibited increased brain entropy in a broad set of regions including the frontal, temporal, and occipital lobes, as well as the cerebellum. In addition, individuals with a more distributed chronic pain showed increased brain entropy in occipital lobes. When examining distinct types of chronic pain individually, only participants with headache and pain all over the body showed brain entropy differences compared to a matched sample of healthy controls. Perspective This article investigates the neural substrates of chronic pain using brain entropy, a measure of the randomness and irregularity of brain activity. This measure could potentially aid in the assessment and treatment of chronic pain.

Repetitive transcranial magnetic stimulation for fibromyalgia: are we there yet?

Repetitive transcranial magnetic stimulation (rTMS) has increasingly been used to modify cortical maladaptive plastic changes shown to occur in fibromyalgia (FM) and to correlate with symptoms. Evidence for its efficacy is currently inconclusive, mainly due to heterogeneity of stimulation parameters used in trials available to date. Here, we reviewed the current evidence on the use of rTMS for FM control in the format of a narrative review, in which a systematic dissection of the different stimulation parameters would be possible. We conducted a search in Medline and Embase for controlled trials on rTMS in people with FM with at least 10 participants in each treatment arm, and treatment/follow-up of at least 3 weeks. The search identified 482 abstracts, of which 45 were screened to full review, and 11 met inclusion criteria. Six out of 11 trials were positive. The dorsolateral prefrontal cortex was the target in 218 patients (49.2%), and the primary motor cortex (M1) in 225 (50.8%). Studies targeting M1 at 10 Hz, with stimulation current delivered in the posterior-anterior, were systematically positive, frequently showing that maintenance sessions delivered weekly, and biweekly were able to maintain the analgesic effects seen after daily induction sessions. Studies assessing the effects of rTMS for FM are still marked by heterogeneity in stimulation petameters, choice of primary outcomes, and inclusion criteria. The selection of the stimulation parameters associated with significant analgesic effects is likely to benefit following larger multicenter trials and improve the overall management of pain and associated symptoms in people with FM.

Noninvasive brain stimulation beyond the motor cortex: a systematic review and meta-analysis exploring effects on quantitative sensory testing in clinical pain

BACKGROUND

Noninvasive brain stimulation (NIBS) has been investigated increasingly as a means of treating pain. The effectiveness of NIBS in the treatment of pain has traditionally focused on protocols targeting the primary motor cortex (M1). However, over time, the effectiveness of M1 NIBS has been attributed to effects on interconnected cortical and subcortical sites rather than on M1 itself. Although previous reviews have demonstrated the effectiveness of non-M1 NIBS in improving subjective reports of pain intensity, the neurophysiological mechanisms underlying these effects remain incompletely understood. As chronic pain is associated with pain hypersensitivity and impaired endogenous descending pain modulation, it is plausible that non-M1 NIBS promotes analgesic effects by influencing these processes.

OBJECTIVE

The aim of this systematic review and meta-analysis was therefore to evaluate the effect of NIBS over non-M1 sites on quantitative sensory testing measures in clinical pain populations.

METHODS

A systematic search of electronic databases was conducted from inception to January 2024. Included articles (13 trials, n = 565 participants) were appraised with the Physiotherapy Evidence Database (PEDro) scale and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE), and a random-effects model was used to meta-analyze outcomes where possible.

RESULTS

A small number of studies found that NIBS applied to the dorsolateral prefrontal cortex might improve pain modulation in patients with fibromyalgia and that stimulation of the posterior superior insula and prefrontal cortex could improve pain sensitivity in chronic neuropathic and osteoarthritic pain, respectively. However, findings varied among studies, and there remains a paucity of primary research.

CONCLUSION

This review indicates that current literature does not provide clear evidence that NIBS over non-M1 sites influences pain processing.

STUDY REGISTRATION

PROSPERO (CRD42020201076).

Effect of Neurostimulation on Chronic Pancreatic Pain: A Systematic Review

BACKGROUND

Chronic pancreatic pain is one of the most severe causes of visceral pain, and treatment response is often limited. Neurostimulation techniques have been investigated for chronic pain syndromes once there are pathophysiological reasons to believe that these methods activate descending pain inhibitory systems. Considering this, we designed this systematic literature review to investigate the evidence on neuromodulation techniques as a treatment for chronic pancreatic pain.

MATERIALS AND METHODS

We performed a literature search using the databases MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase until April 2024. The included studies used neurostimulation techniques in participants with chronic pancreatic pain and reported pain-related outcomes, with a focus on pain scales and opioid intake. Two reviewers screened and extracted data, and a third reviewer resolved discrepancies. We assessed the risk of bias using the Jadad scale. The authors then grouped the findings by the target of the neurostimulation, cortex, spinal cord, or peripheral nerves; described the findings qualitatively in the results section, including qualitative data reported by the articles; and calculated effect sizes of pain-related outcomes.

RESULTS

A total of 22 studies were included (7 randomized clinical trials [RCTs], 14 case series, and 1 survey), including a total of 257 clinical trial participants. The two outcomes most commonly reported were pain, measured by the visual analogue scale (VAS), numeric rating scale (NRS), and pressure pain threshold scores, and opioid intake. Two RCTs investigated repetitive transcranial magnetic stimulation (rTMS), showing a reduction of 36% (±16) (d = 2.25; 95% CI, 0.66-3.83) and 27.2% (±24.5%) (d = 2.594; 95% CI, 1.303-3.885) in VAS pain scale. In another clinical trial, transcranial direct-current stimulation (tDCS) and transcranial pulsed current stimulation were not observed to effect a significant reduction in VAS pain (χ2 = 5.87; p = 0.12). However, a complete remission was reported in one tDCS case. Spinal cord stimulation (SCS) and dorsal root ganglion stimulation were performed in a survey and 11 case series, showing major pain decrease and diminished opioid use in 90% of participants after successful implantation; most studies had follow-up periods of months to years. Two noninvasive vagal nerve stimulation (VNS) RCTs showed no significant pain reduction in pain thresholds or VAS (d = 0.916; 95% CI, -0.005 to 1.838; and d = 0.17; -0.86 to 1.20; p = 0.72; respectively). Splanchnic nerve stimulation in one case report showed complete pain reduction accompanied by discontinuation of oral morphine and fentanyl lozenges and a 95% decrease in fentanyl patch use. Two RCTs investigated transcutaneous electrical nerve stimulation (TENS). One found a significant pain reduction effect with the NRS (d = 1.481; 95% CI, 1.82-1.143), and decreased opioid use, while the other RCT did not show significant benefit. Additionally, one case report with TENS showed pain improvement that was not quantitatively measured.

DISCUSSION

The neuromodulation techniques of rTMS and SCS showed the most consistent potential as a treatment method for chronic pancreatic pain. However, the studies have notable limitations, and SCS has had no clinical trials. For VNS, we have two RCTs that showed a non-statistically significant improvement; we believe that both studies had a lack of power issue and suggest a gap in the literature for new RCTs exploring this modality. Additionally, tDCS and TENS showed mixed results. Another important insight was that opioid intake decrease is a common trend among most studies included and that adverse effects were rarely reported. To further elucidate the potential of these neurostimulation techniques, we suggest the development of new clinical trials with larger samples and adequate sham controls.

Effect of neuronavigated repetitive Transcranial Magnetic Stimulation on pain, cognition and cortical excitability in fibromyalgia syndrome

BACKGROUND

Fibromyalgia syndrome is a widespread chronic pain condition identified by body-wide pain, fatigue, cognitive fogginess, and sleep issues. In the past decade, repetitive transcranial magnetic stimulation has emerged as a potential management tool.. In the present study, we enquired whether repetitive transcranial magnetic stimulation could modify pain, corticomotor excitability, cognition, and sleep.

METHODS

Study is a randomized, sham-controlled, double-blind, clinical trial; wherein after randomizing thirty-four fibromyalgia patients into active or sham therapy (n = 17 each), each participant received repetitive transcranial magnetic stimulation therapy. In active therapy was given at 1 Hz for 20 sessions were delivered on dorsolateral prefrontal cortex (1200 pulses, 150 pulses per train for 8 trains); while in sham therapy coil was placed at right angle to the scalp with same frequency. Functional magnetic resonance imaging was used to identify the therapeutic site. Pain intensity, corticomotor excitability, cognition, and sleep were examined before and after therapy.

RESULTS

Baseline demographic and clinical parameters for both active and sham groups were comparable. In comparison to sham, active repetitive transcranial magnetic stimulation showed significant difference in pain intensity (P < 0.001, effect size = 0.29, large effect) after intervention. Other parameters of pain perception, cognition, and sleep quality also showed a significant improvement after the therapy in active therapy group only, as compared to sham.

CONCLUSIONS

Findings suggest that repetitive transcranial magnetic stimulation intervention is effective in managing pain alongside cognition and sleep disturbances in patients of fibromyalgia. It may prove to be an important tool in relieving fibromyalgia-associated morbidity.

Repetitive Transcranial Magnetic Stimulation in Fibromyalgia: Exploring the Necessity of Neuronavigation for Targeting New Brain Regions

Fibromyalgia and osteoarthritis are among the most prevalent rheumatic conditions worldwide. Nonpharmacological interventions have gained scientific endorsements as the preferred initial treatments before resorting to pharmacological modalities. Repetitive transcranial magnetic stimulation (rTMS) is among the most widely researched neuromodulation techniques, though it has not yet been officially recommended for fibromyalgia. This review aims to summarize the current evidence supporting rTMS for treating various fibromyalgia symptoms. Recent findings: High-frequency rTMS directed at the primary motor cortex (M1) has the strongest support in the literature for reducing pain intensity, with new research examining its long-term effectiveness. Nonetheless, some individuals may not respond to M1-targeted rTMS, and symptoms beyond pain can be prominent. Ongoing research aims to improve the efficacy of rTMS by exploring new brain targets, using innovative stimulation parameters, incorporating neuronavigation, and better identifying patients likely to benefit from this treatment. Summary: Noninvasive brain stimulation with rTMS over M1 is a well-tolerated treatment that can improve chronic pain and overall quality of life in fibromyalgia patients. However, the data are highly heterogeneous, with a limited level of evidence, posing a significant challenge to the inclusion of rTMS in official treatment guidelines. Research is ongoing to enhance its effectiveness, with future perspectives exploring its impact by targeting additional areas of the brain such as the medial prefrontal cortex, anterior cingulate cortex, and inferior parietal lobe, as well as selecting the right patients who could benefit from this treatment.

Impact of Repetitive Transcranial Magnetic Stimulation on Cognitive and Psychiatric Dysfunction in Patients with Fibromyalgia: A Double-Blinded, Randomized Clinical Trial

Few randomized controlled trials have reported that repetitive transcranial magnetic stimulation (rTMS) has controversial results for managing multiple domains of fibromyalgia-related symptoms. This work aimed to evaluate the effect of low-frequency rTMS over the right dorsolateral prefrontal area (DLPFC) on the Fibromyalgia Impact Questionnaire (FIQ) concerning psychiatric and cognitive disorders. Forty-two eligible patients with fibromyalgia (FM) were randomized to have 20 sessions of active or sham rTMS (1 Hz, 120% of resting motor threshold with a total of 1200 pules/session) over the right DLPFC. All participants were evaluated at baseline, post sessions, and 3 months after sessions with the FIQ, Hamilton depression, and anxiety rating scales (HDRS and HARS), Montreal Cognitive Assessment (MoCA), Rey Auditory Verbal Learning Test (RAVLT), Tower of London test (TOL), the Trail Making, and Digit Span Tests. Both groups showed improvement in most rating scales at 1 and 3 months follow-up, with greater improvement in the active group, with significant correlation between FIQ cognitive rating scales, including RAVLT and TOL. Twenty sessions of low-frequency rTMS over the right DLPFC can improve FIQ scores regarding the psychiatric and cognitive symptoms of medicated patients with FM to a greater extent than sham. Changes in RAVLT and TOL correlated with changes in FIQ results.

Role of Repetitive Transcranial Magnetic Stimulation in Treatment of Fibromyalgia: A Randomized Controlled Trial

Background and Objective

Fibromyalgia syndrome (FMS) is a chronic disease characterized by widespread, persistent musculoskeletal pain in association with impaired health-related quality of life. Repetitive transcranial magnetic stimulation (rTMS) is an emerging tool for the management of fibromyalgia. There is no standardized protocol of rTMS for the treatment of FMS, and both low- and high-frequency stimulation of the dorsolateral prefrontal cortex (DLPFC) are described in the literature with variable efficacy. The objective of this study was to determine the effectiveness of rTMS in people with fibromyalgia and compare the response of low- and high-frequency stimulation with sham stimulation.

Materials and Methods

This study was a single-blinded, randomized, placebo-controlled trial. Ninety patients with the diagnosis of FMS were randomly allocated into one of the following three groups: low-frequency (1 Hz) group, high-frequency (10 Hz) group, and sham group. Pain, depression, anxiety, and quality of life were measured using the Numerical Pain Rating Scale (NPRS), Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HDRS), and Revised Fibromyalgia Impact Questionnaire (FIQR) immediately following treatment as well as at 1 and 3 months after treatment. The data was statistically analyzed using Statistical Package for the Social Sciences version 23 software. P value < 0.05 was considered statistically significant.

Results

Intergroup analysis revealed a significant improvement in NPRS, HAM-A, HDRS, and FIQR scores in both low- and high- frequency groups immediately following treatment and for 3 months after treatment. No significant difference in the efficacy of low- and high-frequency stimulation was noticed.

Conclusions

rTMS is an effective mode of treatment in people with FMS. Both low and high frequencies of stimulation at DLPFC are equally effective in reducing pain and associated symptoms.

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.

Current Neurostimulation Therapies for Chronic Pain Conditions

PURPOSE OF REVIEW

Neurostimulation treatment options have become more commonly used for chronic pain conditions refractory to these options. In this review, we characterize current neurostimulation therapies for chronic pain conditions and provide an analysis of their effectiveness and clinical adoption. This manuscript will inform clinicians of treatment options for chronic pain.

RECENT FINDINGS

Non-invasive neurostimulation includes transcranial direct current stimulation and repetitive transcranial magnetic stimulation, while more invasive options include spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), dorsal root ganglion stimulation, motor cortex stimulation, and deep brain stimulation. Developments in transcranial direct current stimulation, repetitive transcranial magnetic stimulation, spinal cord stimulation, and peripheral nerve stimulation render these modalities most promising for the alleviating chronic pain. Neurostimulation for chronic pain involves non-invasive and invasive modalities with varying efficacy. Well-designed randomized controlled trials are required to delineate the outcomes of neurostimulatory modalities more precisely.

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.

Beyond the Pain: A Systematic Narrative Review of the Latest Advancements in Fibromyalgia Treatment

Fibromyalgia is a complex chronic pain disorder that significantly impacts the quality of life of affected individuals. The etiology of fibromyalgia remains elusive, necessitating effective treatment options. This review aims to provide an overview of current treatment options for fibromyalgia and highlight recent updates in managing the condition. The methodology employed in this systematic review comprised the following key steps. We conducted a comprehensive search across various databases to identify pertinent studies published between 2000 and 2023. Inclusion criteria were defined to specifically target studies involving adult individuals diagnosed with fibromyalgia, with a focus on both pharmacological and non-pharmacological interventions for managing the condition. The review encompassed a range of study types, including randomized controlled trials, observational studies, and systematic reviews. To ensure the quality of the selected studies, we employed appropriate assessment tools, and data extraction and synthesis adhered to established guidelines. This rigorous approach allowed for a robust analysis of the literature on fibromyalgia management. In the course of our review, it became evident that a spectrum of treatment approaches holds significant promise in the management of fibromyalgia. Specifically, pharmacological interventions, including selective serotonin-norepinephrine reuptake inhibitors, anticonvulsants, cannabinoids, tropisetron, and sodium oxybate, have exhibited substantial potential in alleviating fibromyalgia symptoms. Concurrently, non-pharmacological strategies, such as cognitive-behavioral therapy, exercise regimens, and complementary and alternative therapies, have yielded positive outcomes in improving the condition's management. Recent developments in the field have introduced innovative pharmacological agents like milnacipran and pregabalin, in addition to non-pharmacological interventions like mindfulness-based stress reduction and aquatic exercise, expanding the array of options available to enhance fibromyalgia care and alleviating patient symptoms. Fibromyalgia necessitates a multidisciplinary approach to treatment, encompassing both pharmacological and non-pharmacological interventions. Recent updates in fibromyalgia management offer additional options to alleviate symptoms and improve the quality of life for individuals with fibromyalgia. Healthcare professionals should remain informed about these advancements to provide evidence-based care, addressing the complex symptoms associated with fibromyalgia and enhancing patient outcomes.

Overweight Impairs Postural Control of Female Night Workers

Objectives  To verify the relationships between sleep duration (Total Sleep Time - TST) and postural control of female night workers before and after shift. As well as, to verify if there is an influence of the body mass index (BMI) on the postural control of these female workers before and after shift. Methods  A total of 14 female night workers (mean age: 35.0 ± 7.7 years) were evaluated. An actigraph was placed on the wrist to evaluate the sleep-wake cycle. The body mass and height were measured, and BMI was calculated. Postural control was evaluated by means of a force platform, with eyes opened and eyes closed before and after the 12-hour workday. Results  There was an effect of the BMI on the velocity and the center of pressure path with eyes opened before ( t  = 2.55, p  = 0.02) and after ( t  = 4.10, p  < 0.01) night work. The BMI impaired the velocity and the center of pressure path with eyes closed before ( t  = 3.05, p  = 0.01; t  = 3.04, p  = 0.01) and after ( t  = 2.95, p  = 0.01; t  = 2.94, p  = 0.01) night work. Furthermore, high BMI is associated with female workers' postural sway ( p  < 0.05). Conclusion  Therefore, high BMI impairs the postural control of female night workers, indicating postural instability before and after night work.

EEG Beta functional connectivity decrease in the left amygdala correlates with the affective pain in fibromyalgia: A pilot study

Fibromyalgia (FM) is a major chronic pain disease with prominent affective disturbances, and pain-associated changes in neurotransmitters activity and in brain connectivity. However, correlates of affective pain dimension lack. The primary goal of this correlational cross-sectional case-control pilot study was to find electrophysiological correlates of the affective pain component in FM. We examined the resting-state EEG spectral power and imaginary coherence in the beta (β) band (supposedly indexing the GABAergic neurotransmission) in 16 female patients with FM and 11 age-adjusted female controls. FM patients displayed lower functional connectivity in the High β (Hβ, 20-30 Hz) sub-band than controls (p = 0.039) in the left basolateral complex of the amygdala (p = 0.039) within the left mesiotemporal area, in particular, in correlation with a higher affective pain component level (r = 0.50, p = 0.049). Patients showed higher Low β (Lβ, 13-20 Hz) relative power than controls in the left prefrontal cortex (p = 0.001), correlated with ongoing pain intensity (r = 0.54, p = 0.032). For the first time, GABA-related connectivity changes correlated with the affective pain component are shown in the amygdala, a region highly involved in the affective regulation of pain. The β power increase in the prefrontal cortex could be compensatory to pain-related GABAergic dysfunction.

Efficacy of High-Frequency Repetitive Transcranial Magnetic Stimulation at 10 Hz in Fibromyalgia: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this review was to systematically assess the effectiveness of 10-Hz repetitive transcranial magnetic stimulation (rTMS) in fibromyalgia.

DATA SOURCES

We searched PubMed, Cochrane Library, Embase, Web of Science, and Ovid databases as of November 6, 2021.

STUDY SELECTION

The inclusion criteria for this review were randomized controlled trials of 10-Hz rTMS for fibromyalgia, exploring the effects of 10-Hz rTMS on pain, depression, and quality of life in patients with fibromyalgia.

DATA EXTRACTION

Data extraction was performed independently by 2 evaluators according to predefined criteria, and the quality of the included literature was assessed using the Cochrane Bias Risk Assessment Tool. The measurement outcomes include visual analog scale, Hamilton Depression Rating Scale, and Fibromyalgia Impact Questionnaire, and so on.

DATA SYNTHESIS

A total of 488 articles were screened, and the final 7 selected high-quality articles with 217 patients met our inclusion criteria. Analysis of the results showed that high-frequency transcranial magnetic stimulation at 10 Hz was significantly associated with reduced pain compared with sham stimulation in controls (standardized mean difference [SMD]=-0.72; 95% confidence interval [CI], -1.12 to -0.33; P<.001; I²=46%) and was able to improve quality of life (SMD=-0.70; 95% CI, -1.00 to -0.40; P<.001; I²=15%) but not improve depression (SMD=-0.23; 95% CI, -0.50 to 0.05; P=.11; I²=33%). In addition, a subgroup analysis of pain conducted based on stimulation at the primary motor cortex and dorsolateral prefrontal cortex showed no significant difference (SMD=-0.72; 95% CI, -1.12 to -0.33; P=.10; I²=62%).

CONCLUSIONS

Overall, 10-Hz rTMS has a significant effect on analgesia and improved quality of life in patients with FMS but did not improve depression.

Evidence from Indian studies on safety and efficacy of therapeutic transcranial magnetic stimulation across neuropsychiatric disorders- A systematic review and meta-analysis

Repetitive transcranial magnetic stimulation (rTMS) is potentially effective as an augmentation strategy in the treatment of many neuropsychiatric conditions. Several Indian studies have been conducted in this regard. We aimed to quantitatively synthesize evidence from Indian studies assessing efficacy and safety of rTMS across broad range of neuropsychiatric conditions. Fifty two studies- both randomized controlled and non-controlled studies were included for a series of random-effects meta-analyses. Pre-post intervention effects of rTMS efficacy were estimated in "active only" rTMS treatment arms/groups and "active vs sham" (sham-controlled) studies using pooled Standardized Mean Differences (SMDs). The outcomes were 'any depression', depression in unipolar/bipolar depressive disorder, depression in obsessive compulsive disorder (OCD), depression in schizophrenia, schizophrenia symptoms (positive, negative, total psychopathology, auditory hallucinations and cognitive deficits), obsessive compulsive symptoms of OCD, mania, craving/compulsion in substance use disorders (SUDs) and migraine (headache severity and frequency). Frequencies and odds ratios (OR) for adverse events were calculated. Methodological quality of included studies, publication bias and sensitivity assessment for each meta-analyses was conducted. Meta-analyses of "active only" studies suggested a significant effect of rTMS for all outcomes, with moderate to large effect sizes, at both end of treatment as well as at follow-up. However, except for migraine (headache severity and frequency) with large effect sizes at end of treatment only and craving in alcohol dependence where moderate effect size at follow-up only, rTMS was not found to be effective for any outcome in the series of "active vs sham" meta-analyses. Significant heterogeneity was seen. Serious adverse events were rare. Publication bias was common and the sham controlled positive results lost significance in sensitivity analysis. We conclude that rTMS is safe and shows positive results in 'only active' treatment groups for all the studied neuropsychiatric conditions. However, the sham-controlled evidence for efficacy is negative from India.

Conclusion

rTMS is safe and shows positive results in "only active" treatment groups for all the studied neuropsychiatric conditions. However, the sham-controlled evidence for efficacy is negative from India.

Non-invasive brain stimulation and pain neuroscience education in the cognitive-affective treatment of chronic low back pain: Evidence and future directions

Chronic low back pain (CLBP) is among the leading causes of disability worldwide. Beyond the physical and functional limitations, people's beliefs, cognitions, and perceptions of their pain can negatively influence their prognosis. Altered cognitive and affective behaviors, such as pain catastrophizing and kinesiophobia, are correlated with changes in the brain and share a dynamic and bidirectional relationship. Similarly, in the presence of persistent pain, attentional control mechanisms, which serve to organize relevant task information are impaired. These deficits demonstrate that pain may be a predominant focus of attentional resources, leaving limited reserve for other cognitively demanding tasks. Cognitive dysfunction may limit one's capacity to evaluate, interpret, and revise the maladaptive thoughts and behaviors associated with catastrophizing and fear. As such, interventions targeting the brain and resultant behaviors are compelling. Pain neuroscience education (PNE), a cognitive intervention used to reconceptualize a person's pain experiences, has been shown to reduce the effects of pain catastrophizing and kinesiophobia. However, cognitive deficits associated with chronic pain may impact the efficacy of such interventions. Non-invasive brain stimulation (NIBS), such as transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) has been shown to be effective in the treatment of anxiety, depression, and pain. In addition, as with the treatment of most physical and psychological diagnoses, an active multimodal approach is considered to be optimal. Therefore, combining the neuromodulatory effects of NIBS with a cognitive intervention such as PNE could be promising. This review highlights the cognitive-affective deficits associated with CLBP while focusing on current evidence for cognition-based therapies and NIBS.

Advances in Non-Invasive Neuromodulation

PURPOSE OF REVIEW

Pain medicine is rapidly expanding. The gap in treatment for patients with chronic pain in between traditional conservative therapy and major invasive surgery is closing. Neuromodulation is one therapeutic area that has continued to show promise for treatment of chronic pain. Our aim is to review updates in non-invasive neuromodulation (NIN) techniques as an adjunct for various chronic pain conditions.

RECENT FINDINGS

Overall, the literature suggests that NIN techniques such as tCDS, TMS, TENS, tVNS, and HIFUS/LIFUS have utility in treating various types of chronic pain and have a promising future. There is a better understanding of the mechanistic basis for pain relief from NIN, as well as refinement in technology improving NIN therapy success. Future studies will need to focus on continuing to refine protocols for optimal benefit from NIN as well as implementing larger RCTs to improve the quality of data being generated in the field.

Systematic Review and Meta-Analysis of High-Frequency rTMS over the Dorsolateral Prefrontal Cortex .on Chronic Pain and Chronic-Pain-Accompanied Depression

The effect of high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) on the dorsolateral prefrontal cortex (DLPFC) can relieve chronic pain and accompanying depressive symptoms. However, in recent years, some high-quality studies have challenged this view. Therefore, it is necessary to update the data and analyze the effects of HF rTMS on the DLPFC on chronic pain and accompanying depression. We performed a systematic review and meta-analysis to evaluate the effect of HF rTMS on the DLPFC on chronic pain and accompanying depression. We searched PubMed, Medline, Web of Science, and Cochrane through September 2021. The search strings searched were : "pain" AND ("TMS" OR "transcranial magnetic stimulation") AND "prefrontal cortex". The inclusion criteria according to PICOS was as follows: P, patient with chronic pain; I, HF (≥5 Hz) rTMS on the DLPFC; C, included a sham treatment condition; O, pain indicators; S, pre-/poststudies, crossover, or parallel-group. We extracted the pain and accompanying depression evaluation indicators. The short-term analgesic effect of HF rTMS over the left DLPFC is not significant (WMD = 0.34, 95% CI: [-1.60, 2.28]) but has a significant mid-term and long-term analgesic effect on chronic pain (WMD = -0.50, 95% CI: [-0.99, -0.01]; WMD = -1.10, 95% CI: [-2.00, -0.19], respectively). HF rTMS over the DLPFC can effectively alleviate the depressive symptoms of patients with chronic pain (WMD = -0.83, 95% CI: [-3.01, 1.36]). Thus, HF rTMS on the left DLPFC can relieve chronic pain and accompanying depressive symptoms.

Modulation of the nociceptive flexion reflex by conservative therapy in patients and healthy people: a systematic review and meta-analysis

ABSTRACT

The nociceptive flexion reflex (NFR) is a spinally mediated withdrawal response and is used as an electrophysiological marker of descending modulation of spinal nociception. Chemical and pharmacological modulation of nociceptive neurotransmission at the spinal level has been evidenced by direct effects of neurotransmitters and pharmacological agents on the NFR. Largely unexplored are, however, the effects of nonpharmacological noninvasive conservative interventions on the NFR. Therefore, a systematic review and meta-analysis was performed and reported following the PRISMA guidelines to determine whether and to what extent spinal nociception measured through the assessment of the NFR is modulated by conservative therapy in patients and healthy individuals. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using the predefined inclusion criteria. Risk of bias was investigated according to Version 2 of the Cochrane risk-of-bias assessment tool for randomized trials. The evidence synthesis for this review was conducted in accordance with the Grading of Recommendations Assessment, Development and Evaluation. Thirty-six articles were included. Meta-analyses provided low-quality evidence showing that conservative therapy decreases NFR area and NFR magnitude and moderate-quality evidence for increases in NFR latency. This suggests that conservative interventions can exert immediate central effects by activating descending inhibitory pathways to reduce spinal nociception. Such interventions may help prevent and treat chronic pain characterized by enhanced spinal nociception. Furthermore, given the responsiveness of the NFR to conservative interventions, the NFR assessment seems to be an appropriate tool in empirical evaluations of treatment strategies.PROSPERO registration number: CRD42020164495.

Scrambler Therapy for Chronic Pain after Burns and Its Effect on the Cerebral Pain Network: A Prospective, Double-Blinded, Randomized Controlled Trial

Chronic pain is common after burn injuries, and post-burn neuropathic pain is the most important complication that is difficult to treat. Scrambler therapy (ST) is a non-invasive modality that uses patient-specific electrocutaneous nerve stimulation and is an effective treatment for many chronic pain disorders. This study used magnetic resonance imaging (MRI) to evaluate the pain network-related mechanisms that underlie the clinical effect of ST in patients with chronic burn-related pain. This prospective, double-blinded, randomized controlled trial (ClinicalTrials.gov: NCT03865693) enrolled 43 patients who were experiencing chronic neuropathic pain after unilateral burn injuries. The patients had moderate or greater chronic pain (a visual analogue scale (VAS) score of ≥5), despite treatment using gabapentin and other physical modalities, and were randomized 1:1 to receive real or sham ST sessions. The ST was performed using the MC5-A Calmare device for ten 45 min sessions (Monday to Friday for 2 weeks). Baseline and post-treatment parameters were evaluated subjectively using the VAS score for pain and the Hamilton Depression Rating Scale; MRI was performed to identify objective central nervous system changes by measuring the cerebral blood volume (CBV). After 10 ST sessions (two weeks), the treatment group exhibited a significant reduction in pain relative to the sham group. Furthermore, relative to the pre-ST findings, the post-ST MRI evaluations revealed significantly decreased CBV in the orbito-frontal gyrus, middle frontal gyrus, superior frontal gyrus, and gyrus rectus. In addition, the CBV was increased in the precentral gyrus and postcentral gyrus of the hemisphere associated with the burned limb in the ST group, as compared with the CBV of the sham group. Thus, a clinical effect from ST on burn pain was observed after 2 weeks, and a potential mechanism for the treatment effect was identified. These findings suggest that ST may be an alternative strategy for managing chronic pain in burn patients.

Low-energy Pulsed Electromagnetic Field Therapy Reduces Pain in Fibromyalgia: A Randomized Single-blind Controlled Pilot Study

OBJECTIVES

Fibromyalgia symptoms have a significant impact on the quality of life and respond poorly to medications. It has been hypothesized that the use of low-energy pulsed electromagnetic field (PEMF) induces neuroprotective effects that may interfere with pain perception. We explored the efficacy of PEMF in patients affected by fibromyalgia.

METHODS

Twenty-one females (median age 59 years, interquartile range [IQR] 16.5) affected by fibromyalgia were randomized to receive pulsed electromagnetic field-triple energy pain treatment (PEMF-TEPT) or placebo at T0 and at 4 weeks and 8 weeks. Fibromyalgia impact questionnaire (FIQ), widespread pain index (WPI), visual analog score (VAS) pain, symptom severity (SS) scale, and short form 36 (SF-36) health survey questionnaire have been evaluated.

RESULTS

Patients in the PEMF-TEPT group had a significantly higher reduction of WPI compared to placebo (mean difference -12.90 ± standard deviation [SD] 5.32 vs. -1.91 ± 4.55, difference in difference [DD] of -10.99; P < 0.001), of SS score (-4.10 ± 4.85 vs. -2.00 ± 2.32; DD = -2.1; P < 0.05), of VAS pain (-48 ± 30.75 vs. -16.82 ± 23.69; DD = -31.18; P < 0.01). They also reported a higher improvement of FIQ and SF-36, albeit not reaching statistical significance.

CONCLUSION

In our pilot controlled study, PEMF-TEPT appeared to be safe and improved fibromyalgia symptoms.

Cortical stimulation for chronic pain: from anecdote to evidence

Epidural stimulation of the motor cortex (eMCS) was devised in the 1990's, and has now largely supplanted thalamic stimulation for neuropathic pain relief. Its mechanisms of action involve activation of multiple cortico-subcortical areas initiated in the thalamus, with involvement of endogenous opioids and descending inhibition toward the spinal cord. Evidence for clinical efficacy is now supported by at least seven RCTs; benefits may persist up to 10 years, and can be reasonably predicted by preoperative use of non-invasive repetitive magnetic stimulation (rTMS). rTMS first developed as a means of predicting the efficacy of epidural procedures, then as an analgesic method on its own right. Reasonable evidence from at least six well-conducted RCTs favors a significant analgesic effect of high-frequency rTMS of the motor cortex in neuropathic pain (NP), and less consistently in widespread/fibromyalgic pain. Stimulation of the dorsolateral frontal cortex (DLPFC) has not proven efficacious for pain, so far. The posterior operculo-insular cortex is a new and attractive target but evidence remains inconsistent. Transcranial direct current stimulation (tDCS) is applied upon similar targets as rTMS and eMCS; it does not elicit action potentials but modulates the neuronal resting membrane state. tDCS presents practical advantages including low cost, few safety issues, and possibility of home-based protocols; however, the limited quality of most published reports entails a low level of evidence. Patients responsive to tDCS may differ from those improved by rTMS, and in both cases repeated sessions over a long time may be required to achieve clinically significant relief. Both invasive and non-invasive procedures exert their effects through multiple distributed brain networks influencing the sensory, affective and cognitive aspects of chronic pain. Their effects are mainly exerted upon abnormally sensitized pathways, rather than on acute physiological pain. Extending the duration of long-term benefits remains a challenge, for which different strategies are discussed in this review.

Efficacy of Repetitive Transcranial Magnetic Stimulation in Fibromyalgia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This article aimed to investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in fibromyalgia. The PubMed, Medline, Cochrane Library, and Web of Science databases were searched for articles published through 14 August 2021. We enrolled only randomized controlled trials. The Cochrane Collaboration risk of bias tool was used for quality assessment. Outcomes were analyzed as standardized mean differences (SMDs) with 95% CIs. The beta coefficient and p value were adopted for meta-regression. We included 18 studies comprising 643 participants. A significant reduction in disease influence, as measured by the Fibromyalgia Impact Questionnaire, was observed (SMD, −0.700, 95% CI, −1.173 to −0.228), and the reduction was larger in older patients (β = −0.1327, p = 0.008). The effect persisted at least two weeks after the final treatment session (SMD, −0.784, 95% CI, −1.136 to −0.432). Reductions in pain, depression, and anxiety were discovered, which persisted for at least two weeks after the last intervention. The effects on pain and depression remained significant up to one and a half months after the final session. No serious adverse events were reported by the included articles. In conclusion, our systematic review and meta-analysis revealed that rTMS is safe and effective for managing multiple domains of fibromyalgia-related symptoms and older patients may have a stronger treatment effect. Larger randomized controlled trials with sufficient male populations are warranted to confirm our findings, detect rare adverse events, and determine the optimal stimulation parameters.

Repetitive transcranial magnetic stimulation for fibromyalgia patients: A Systematic Review with Meta-Analysis

OBJECTIVE

Fibromyalgia is a poorly understood pain syndrome. Repetitive transcranial magnetic stimulation is a noninvasive brain stimulation therapy and is commonly applied for the management of fibromyalgia. However, controversy regarding its efficacy remains. Therefore, a meta-analysis was conducted to evaluate the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for fibromyalgia syndrome.

METHOD

Four medical databases and one physiotherapy database were screened for randomized controlled trials. A systematic review and meta-analysis was performed. Numerical Pain Rating Scale (NPRS), Beck Depression Inventory (BDI), Hospital Anxiety and Depression Scale (HADS) anxiety score, Pain Catastrophizing Scale (PCS), Fatigue Severity Scale (FSS), Short Form-36 general health survey mental score, and Fibromyalgia Impact Questionnaire (FIQ) were set as outcome measures.

RESULTS

Analysis of 14 studies and 433 participants indicated that rTMS exerted more favorable effects on the NPRS than sham rTMS after treatment (standardized mean difference = -0.49, 95% confidence interval = -0.86 to - 0.13, P = 0.008, I2 = 68%) and FIQ (standardized mean difference = -0.50, 95% confidence interval = -0.75 to - 0.25, P = 0.0001, I2 = 28%). However, the BDI, FSS, PCS, mood index, and HADS scores showed no significant difference compared with sham rTMS after treatment. The mean methodological quality of included studies was an acceptable score of 8.5 based on the PEDro scale, suggesting the validity of our conclusions.

CONCLUSION

This study demonstrated that rTMS relieved pain and enhanced quality of life of patients with fibromyalgia; however, it did not improve anxiety, depression, and other symptoms based on current reports.

Neuromodulation for Pain: A Comprehensive Survey and Systematic Review of Clinical Trials and Connectomic Analysis of Brain Targets

BACKGROUND

Chronic pain is a debilitating condition that imposes a tremendous burden on health-care systems around the world. While frontline treatments for chronic pain involve pharmacological and psychological approaches, neuromodulation can be considered for treatment-resistant cases. Neuromodulatory approaches for pain are diverse in both modality and target and their mechanism of action is incompletely understood.

OBJECTIVES

The objectives of this study were to (i) understand the current landscape of pain neuromodulation research through a comprehensive survey of past and current registered clinical trials (ii) investigate the network underpinnings of these neuromodulatory treatments by performing a connectomic mapping analysis of cortical and subcortical brain targets that have been stimulated for pain relief.

METHODS

A search for clinical trials involving pain neuromodulation was conducted using 2 major trial databases (ClinicalTrials.gov and the International Clinical Trials Registry Platform). Trials were categorized by variables and analyzed to gain an overview of the contemporary research landscape. Additionally, a connectomic mapping analysis was performed to investigate the network connectivity patterns of analgesic brain stimulation targets using a normative connectome based on a functional magnetic resonance imaging dataset.

RESULTS

In total, 487 relevant clinical trials were identified. Noninvasive cortical stimulation and spinal cord stimulation trials represented 49.3 and 43.7% of this count, respectively, while deep brain stimulation trials accounted for <3%. The mapping analysis revealed that superficial target connectomics overlapped with deep target connectomics, suggesting a common pain network across the targets.

CONCLUSIONS

Research for pain neuromodulation is a rapidly growing field. Our connectomic network analysis reinforced existing knowledge of the pain matrix, identifying both well-described hubs and more obscure structures. Further studies are needed to decode the circuits underlying pain relief and determine the most effective targets for neuromodulatory treatment.

High-frequency rTMS over the dorsolateral prefrontal cortex on chronic and provoked pain: A systematic review and meta-analysis

BACKGROUND

High-frequency rTMS over the dorsolateral prefrontal cortex (DLPFC) has demonstrated mixed effects on chronic and provoked pain.

OBJECTIVES/METHODS

In this study, a meta-analysis was conducted to characterise the potential analgesic effects of high-frequency rTMS over the DLPFC on both chronic and provoked pain.

RESULTS

A total of 626 studies were identified in a systematic search. Twenty-six eligible studies were included for the quantitative review, among which 17 modulated chronic pain and the remaining investigated the influence on provoked pain. The left side DLPFC was uniformly targeted in the chronic pain studies. While our data identified no overall effect of TMS across chronic pain conditions, there was a significant short-term analgesia in neuropathic pain conditions only (SMD = -0.87). In terms of long-lasting analgesia, there was an overall pain reduction in the midterm (SMD = -0.53, 24.6 days average) and long term (SMD = -0.63, 3 months average) post DLPFC stimulation, although these effects were not observed within specific chronic pain conditions. Surprisingly, the number of sessions was demonstrated to have no impact on rTMS analgesia. In the analysis of provoked pain, our data also indicated a significant analgesic effect following HF-rTMS over the DLPFC (SMD = -0.73). Importantly, we identified a publication bias in the studies of provoked pain but not for chronic pain conditions.

CONCLUSIONS

Overall, our findings support that HF-DLPFC stimulation is able to induce an analgesic effect in chronic pain and in response to provoked pain. These results highlight the potential of DLPFC-rTMS in the management of certain chronic pain conditions and future directions are discussed to enhance the potential long-term analgesic effects.

Repetitive transcranial magnetic stimulation (rTMS) versus transcranial direct current stimulation (tDCS) in the management of patients with fibromyalgia: A randomized controlled trial

OBJECTIVES

The aim of this study was to compare the effects of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on pain and quality of life in patients with fibromyalgia.

METHODS

Thirty participants were randomized into two groups of 15 patients, to receive 3 sessions of either high-frequency (10 Hz) rTMS or 2 mA, 20 min anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex (DLPFC) over 1 week. Pain was assessed using a Visual Analog Scale (VAS) before treatment, immediately after treatment, 6 and 12 weeks later. Quality of life was evaluated using the Revised Fibromyalgia Impact Questionnaire (FIQR) and psychiatric symptoms were measured using the Depression Anxiety Stress Scale-21 Item (DASS-21) before treatment, and 6 and 12 weeks after treatment.

RESULTS

For the VAS there was a significant time-group interaction, showing that the behavior of two groups differed regarding changes of VAS in favor of the RTMS group (df = 1.73, F = 4.80, p = <0.016). Time-group interaction effect on DASS-21 and FIQR was not significant. 66.6% of patients in rTMS group and 26.6% of patients in tDCS group experienced at least a 30% reduction of VAS from baseline to last follow-up (p = 0.028).

DISCUSSION

With the methodology used in this study, both rTMS and tDCS were safe modalities and three sessions of rTMS over DLPFC had greater and longer lasting analgesic effects compared to tDCS in patients with FM. However, considering the limitations of this study, further studies are needed to explore the most effective modality.

Association between Chronic Pain and Alterations in the Mesolimbic Dopaminergic System

Chronic pain (pain lasting for >3 months) decreases patient quality of life and even occupational abilities. It can be controlled by treatment, but often persists even after management. To properly control pain, its underlying mechanisms must be determined. This review outlines the role of the mesolimbic dopaminergic system in chronic pain. The mesolimbic system, a neural circuit, delivers dopamine from the ventral tegmental area to neural structures such as the nucleus accumbens, prefrontal cortex, anterior cingulate cortex, and amygdala. It controls executive, affective, and motivational functions. Chronic pain patients suffer from low dopamine production and delivery in this system. The volumes of structures constituting the mesolimbic system are known to be decreased in such patients. Studies on administration of dopaminergic drugs to control chronic pain, with a focus on increasing low dopamine levels in the mesolimbic system, show that it is effective in patients with Parkinson's disease, restless legs syndrome, fibromyalgia, dry mouth syndrome, lumbar radicular pain, and chronic back pain. However, very few studies have confirmed these effects, and dopaminergic drugs are not commonly used to treat the various diseases causing chronic pain. Thus, further studies are required to determine the effectiveness of such treatment for chronic pain.

Neuronavigation based 10 sessions of repetitive transcranial magnetic stimulation therapy in chronic migraine: an exploratory study

INTRODUCTION

Chronic migraine is a disease of altered cortical excitability. Repetitive transcranial magnetic stimulation provides a novel non-invasive method to target the nociceptive circuits in the cortex. Motor cortex is one such potential target. In this study, we targeted the left motor cortex using fMRI-guided neuronavigation.

MATERIALS AND METHODS

Twenty right-handed patients were randomized into real and sham rTMS group. Baseline subjective pain assessments were done using visual analog scale (VAS) and questionnaires: State-Trait Anxiety Inventory, Becks Depression Inventory, and Migraine Disability Assessment (MIDAS) questionnaire. Objectively, pain was assessed by means of thermal pain thresholds using quantitative sensory testing. For corticomotor excitability parameters, resting motor thresholds and motor-evoked potentials were mapped. For rTMS total, 600 pulses in 10 trains at 10 Hz with an intertrain interval of 60 s were delivered in each session. Ten such sessions were given 5 days per week over 2 consecutive weeks. The duration of each session was 10 min. Real rTMS was administered at 70% of Resting MT. All the tests were repeated post-intervention and after 1 month of follow-up. There are no studies reporting the use of fMRI-based TMS for targeting the motor cortex in CM patients.

RESULTS

We observed a significant reduction in the mean VAS rating, headache frequency, and MIDAS questionnaire in real rTMS group which was maintained after 1 month of follow-up.

CONCLUSION

Ten sessions of fMRI-based rTMS over the left motor cortex may provide long-term pain relief in CM, but further studies are warranted to confirm our preliminary findings.