Fibromyalgia: from pathophysiology to therapy

Amitriptyline and duloxetine attenuate activities of superficial dorsal horn neurons in a rat reserpine-induced fibromyalgia model

Fibromyalgia (FM) is an intractable disease with a chief complaint of chronic widespread pain. Amitriptyline (AMI) and duloxetine (DLX), which are antidepressant drugs, have been reported to ameliorate pain in patients with FM and pain-related behaviors in several rodent models of FM. However, the mechanisms of action of AMI and DLX are not yet fully understood. Here, we examined the effects of these drugs on the responsiveness of superficial dorsal horn (SDH) neurons in the spinal cord, using a rat FM model developed by injecting a biogenic amine depleter (reserpine). Extracellular recordings of SDH neurons in vivo demonstrated that bath application of AMI and DLX at concentrations of 0.1-1.0 mM on the dorsal surface of the spinal cord markedly suppressed spontaneous discharge and von Frey filament-evoked mechanical firing in SDH neurons. The suppression induced by the drugs was noted in a concentration-dependent manner and the suppressive effects resolved after washing the spinal cord surface. These results show that SDH neurons are the site of action for AMI and DLX in a rat reserpine-induced FM model. Spinal mechanisms may underlie the therapeutic effects of these drugs in patients with FM.

Retrospective Analysis of Fibromyalgia: Exploring the Interplay Between Various Triggers and Fibromyalgia's Severity

OBJECTIVES

This study aimed to explore the diverse etiological factors associated with fibromyalgia (FM), including trauma, stress, infections, and head injuries, and investigate their potential correlation with FM severeness manifestation, aiming to discern FM subgroups.

METHODS

The study was a retrospective analysis, conducted with data of 182 FM patients. Each patient's medical history was analyzed to identify a primary etiological event preceding FM. Following this, correlations were examined between each etiology group and different measurements, such as the impact of FM on overall function, widespread pain, depression, anxiety, and cognitive impairments. Cluster analysis was conducted to distinguish between groups of symptoms and functioning.

RESULTS

Contrary to the initial hypothesis, no direct association between a specific trigger and symptom manifestation was identified. However, cluster analyses revealed 2 distinct profiles based on symptom severity. Emotional trauma emerged as a potential contributor to heightened symptom severity, impacting overall function and cognitive abilities.

DISCUSSION

Emotional trauma and stress are crucial factors exacerbating FM symptoms, highlighting the importance of managing these elements in FM patients. This study underscores the complexity of FM, necessitating a nuanced understanding of its etiology and symptomatology. We recommend a multidisciplinary treatment approach that includes assessing and addressing chronic stress and trauma and incorporating stress management interventions to improve patient outcomes.

The effect of the EXOPULSE Mollii Suit on pain and fibromyalgia-related symptoms-A randomized sham-controlled crossover trial

BACKGROUND

Fibromyalgia pain and related symptoms are poorly managed by approved pharmacological and alternative interventions. This trial aimed to evaluate the effects of the EXOPULSE Mollii Suit-a multisite transcutaneous electrical nerve stimulation device-on fibromyalgia pain, fatigue, affective symptoms, disease impact, and quality of life.

METHODS

Adult patients with fibromyalgia were enrolled. Phase 1 implied a randomized, sham-controlled, cross-over, double-blind trial, applying daily 1 h sessions of active or sham intervention, over 2 weeks (2-week washout). In the open-label phase 2, all patients received daily active intervention for 4 weeks. Comparisons on pain, fatigue, disease impact, affective symptoms, quality of life, clinical impression, and comfort ratings were performed using Friedman, Wilcoxon signed rank, and Chi2 tests.

RESULTS

Thirty-three patients completed the study (93.9% female, mean age: 51.3 years). Pain (primary endpoint assessed via a visual analog scale) was significantly reduced after the active (pre-active: 6.9 ± 1.4, post-active: 5.9 ± 1.8, pre-sham: 6.8 ± 1.4, post-sham: 6.6 ± 1.5) versus the sham intervention (X2 = 10.60, p = 0.014). This was also the case of other secondary endpoints (i.e., fatigue, anxiety, and disease impact), except depression and quality of life. The Clinical Global Impression of Change (CGI-C) was significantly different between the active and sham intervention periods (X2 p = 0.035), and the different proportions of categories were as follows: 'worsening' (sham: 18.2% vs. active: 0.0%), 'improvement' (sham: 48.5% vs. active 63.6%) or 'no change (sham: 33.3% vs. active 36.4%) respectively. After phase 2, significant positive effects were observed for most of the outcomes, and 78.8% of patients reported improvement according to CGI-C.

CONCLUSIONS

This study suggests the clinical benefits of the EXOPULSE Mollii Suit in alleviating pain and fibromyalgia-related fatigue, emotional symptoms, and disease impact. It is worth noting that the study has several limitations related to the low number of participants, the short-term analysis of effects in the first blinded and controlled phase, and the open-label nature of phase 2. Future studies with a larger cohort and longer protocol treatment are needed, to further confirm the current results, and evaluate the long-term effects of this technique.

SIGNIFICANCE

Patients with fibromyalgia suffer from pain as well as fatigue, sleep impairment, emotional disturbances, and altered quality of life. Transcutaneous electrical nerve stimulation might help manage those symptoms, but the available systems are limited by the fact that they could be applied at best over two sites. This randomized controlled study is the first to apply a multi-site transcutaneous electrical nerve stimulation device, the EXOPULSE Mollii Suit, with significant effects on fibromyalgia pain and related symptoms.

Executive functions and functioning in women with fibromyalgia

BACKGROUND

 Fibromyalgia (FM) is a chronic condition characterized by widespread pain that is associated with sleep, emotional, and cognitive disturbances, including in executive functions (EFs).

OBJECTIVE

 To investigate the relationship between EFs and functionality in women with FM.

METHODS

 The study included 17 women with FM, aged between 30 and 59 years, with no history of neurological disease. The EFs were assessed using the Digit Span Subtest (DS), Five Digit Test, Trail Making Test (TMT), Corsi Block-Tapping Task, Hayling Test (HT), and Verbal Fluency Task. Functionality was evaluated through the Fibromyalgia Impact Questionnaire. The Beck Depression Inventory, Hamilton Anxiety Rating Scale, and Brief Pain Inventory were used to measure depression, anxiety, and pain, which were controlled in the statistical analyses.

RESULTS

 The FM patients showed longer response latency on the HT and TMT. They made fewer errors on part B of the HT, and they performed worse on the DS backward and on the Corsi Block-Tapping Task forward and backward. There were moderate correlations in the expected direction between performance on the Corsi Block-Tapping Task backward and interference at work, as well as between the time to complete part B of the Trail Making Test - B (TMT-B) and fatigue. An unexpected relationship was found between errors on part B of the HT and interference at work.

CONCLUSION

 The results suggest lower efficiency in processes such as inhibitory control and cognitive flexibility, difficulties in working memory and non-executive processes such as processing speed. Even with pain, anxiety, and depression controlled, some relationships between EFs and functionality were observed, indicating that these symptoms do not fully explain this relationship. We suggest that cognition, particularly EFs, and broader measures of functionality be considered in the evaluation of FM.

Impact of migraine and fibromyalgia on temporomandibular disorder: A retrospective study on pain, psychological factors and quality of life

OBJECTIVES

This study assessed the impact of migraine and fibromyalgia (FM) in TMD patients, focusing on pain, anxiety, depression, and quality of life (QoL). Additionally, we investigated how these variables relate to the total number of comorbidities to gain insights into their interactions.

METHODS

A retrospective data collection was conducted during January 2016 to December 2022, involving 409 adult TMD patients. TMD patients were categorised into four groups: those without comorbidity (TMD-only) and those with comorbid migraine and/or fibromyalgia (TMD + MG, TMD + FM and TMD + MG + FM). Quantitative variables were compared among them. Linear regression was used to analyse the associations between these variables.

RESULTS

Most of study population were women (79%) with a mean age of 44.43 years. TMD + MG patients reported longer pain duration, higher pain scores and greater pain interference compared with TMD-only patients. Similarly, TMD + FM patients had higher pain intensity than patients with TMD only. Both the TMD + MG and TMD + FM groups had higher levels of anxiety, depression, and health impairment compared with patients with TMD only. Patients with all three pain conditions (TMD + MG + FM) experienced the longest pain duration, highest pain intensity, psychological distress, and impaired QoL. The result showed positive associations between pain outcomes, psychological measures, pain's impact on QoL, and the number of comorbidities and a negative association between overall health states and the number of comorbidities.

CONCLUSIONS

These findings underscore the importance of considering the presence of comorbidities and addressing physical and psychological aspects in the management of TMD patients.

Hyperbaric oxygen therapy vs. pharmacological intervention in adults with fibromyalgia related to childhood sexual abuse: prospective, randomized clinical trial

Fibromyalgia syndrome (FMS) is a chronic pain syndrome characterized by disruptions in pain processing within the central nervous system. It exhibits a high prevalence among patients with a history of traumatic experiences, notably childhood sexual abuse (CSA). This study compared the efficacy of hyperbaric oxygen therapy (HBOT) to the current pharmacological standard of care for individuals suffering from CSA-related FMS. Forty-eight participants diagnosed with FMS and a history of CSA were randomly assigned to either the HBOT group (60 sessions of 100% oxygen at 2 ATA for 90 min, with air breaks every 5 min) or the medication (MED) group (FDA-approved medications, Pregabalin and Duloxetine). The primary endpoint was the Fibromyalgia impact questionnaire (FIQ) score, while secondary endpoints encompassed emotional status and daily functioning questionnaires, as well as pain thresholds and conditioned pain modulation tests. Brain activity was evaluated through single photon emission computed tomography (SPECT). Results revealed a significant group-by-time interaction for the FIQ score favoring HBOT over MED (p < 0.001), with a large effect size (Cohen's d = - 1.27). Similar findings were observed in emotional symptoms and functional measures. SPECT imaging demonstrated an increase in activity in pre-frontal and temporal brain areas, which correlated with symptoms improvement. In conclusion, HBOT exhibited superior benefits over medications in terms of physical, functional, and emotional improvements among FMS patients with a history of CSA. This associated with increased activity in pre-frontal and temporal brain areas, highlighting the neuroplasticity effect of HBOT.

TMS in combination with a pain directed intervention for the treatment of fibromyalgia - A randomized, double-blind, sham-controlled trial

BACKGROUND

Fibromyalgia Syndrome (FMS) is a highly prevalent condition, that causes chronic pain and severe reduction in quality of life and productivity, as well as social isolation. Despite the significant morbidity and economic burden of FMS, current treatments are scarce.

OBJECTIVE

To investigate whether stimulation of ACC -mPFC activity by dTMS enhances a pain-directed psychotherapeutic intervention.

METHODS

19 FMS patients were randomised to receive either 20 sessions of dTMS or sham stimulation, each followed by a pain-directed psychotherapeutic intervention. With the H7 HAC coil or sham stimulation, we targeted the ACC -mPFC; specific brain areas that play a central role in pain processing. Clinical response to treatment was assessed with the McGill Pain Questionnaire Short Form (SF-MPQ), the Visual Analogue Fibromyalgia Impact Questionnaire, the Brief Pain Inventory questionnaire, and the Hamilton Depression Rating Scale.

RESULTS

DTMS treatment was safe and well tolerated by FMS patients. A significant decrease in the combined sensory and affective pain dimensions was specifically demonstrated in the dTMS cohort, as measured by the SF-MPQ (Significant group × time interaction [F(2, 32) = 3.51, p < .05,ηp2 = 0.18]; No significant changes were found in depressive symptoms in both the dTMS and sham groups.

CONCLUSION

Our results suggest that a course of dTMS combined with a pain-directed psychotherapeutic intervention can alleviate pain symptoms in FMS patients. Beyond clinical possibilities, future studies are needed to substantiate the innovative hypothesis that it is not dTMS alone, but rather dTMS-induced plasticity of pain-related networks, that enables the efficacy of pain-directed psychotherapeutic interventions.

Saffron (Crocus sativus) and its constituents for pain management: A review of current evidence

Pain can become a chronic and deliberating experience with a significant burden. In preclinical and clinical studies, Saffron (Crocus sativus L.) has shown analgesic activities. Considering the unsatisfactory results of current therapeutic management for chronic pain conditions, we aimed to review saffron's analgesic activity and underlying mechanisms. Saffron showed antinociceptive activities in formalin-, carrageenan-, and capsaicin-induced experimental pain models. Saffron analgesic activities affected several targets, including ion channels of nociceptors; the adrenergic system and central histaminic system; inhibition of inflammatory pathways, apoptotic pathways, and oxidative stress; regulation of NO pathway, and the endocannabinoid system. Clinical studies showed analgesia of Saffron in rheumatoid arthritis, after-pain following childbirth, dysmenorrhea, and fibromyalgia. Our literature review showed that saffron can be beneficial as an adjunct therapy to commonly used analgesics in practice, particularly in chronic pain conditions.

Sensory Profiling in Classical Ehlers-Danlos Syndrome: A Case-Control Study Revealing Pain Characteristics, Somatosensory Changes, and Impaired Pain Modulation

Pain is one of the most important yet poorly understood complaints in heritable connective tissue disorders (HCTDs) caused by monogenic defects in extracellular matrix molecules. This is particularly the case for the Ehlers-Danlos syndrome (EDS), paradigm collagen-related disorders. This study aimed to identify the pain signature and somatosensory characteristics in the rare classical type of EDS (cEDS) caused by defects in type V or rarely type I collagen. We used static and dynamic quantitative sensory testing and validated questionnaires in 19 individuals with cEDS and 19 matched controls. Individuals with cEDS reported clinically relevant pain/discomfort (Visual Analogue Scale ≥5/10 in 32% for average pain intensity the past month) and worse health-related quality of life. An altered somatosensory profile was found in the cEDS group with higher (P = .04) detection thresholds for vibration stimuli at the lower limb, indicating hypoesthesia, reduced thermal sensitivity with more (P < .001) paradoxical thermal sensations (PTSs), and hyperalgesia with lower pain thresholds to mechanical (P < .001) stimuli at both the upper and lower limbs and cold (P = .005) stimulation at the lower limb. Using a parallel conditioned pain modulation paradigm, the cEDS group showed significantly smaller antinociceptive responses (P-value .005-.046) suggestive of impaired endogenous pain modulation. In conclusion, individuals with cEDS report chronic pain and worse health-related quality of life and present altered somatosensory perception. This study is the first to systematically investigate pain and somatosensory characteristics in a genetically defined HCTD and provides interesting insights into the possible role of the ECM in the development and persistence of pain. PERSPECTIVE: Chronic pain compromises the quality of life in individuals with cEDS. Moreover, an altered somatosensory perception was found in the cEDS group with hypoesthesia for vibration stimuli, more PTSs, hyperalgesia for pressure stimuli, and impaired pain modulation.

Is Fibromyalgia a Fashionable Diagnosis or a Medical Mystery?

Despite its prevalence, there is no clear-cut diagnostic path or treatment paradigm for fibromyalgia; this can lead to a multiplicity of symptoms and comorbid conditions that complicate care. "Overlapping symptoms" describe conditions that can occur concomitantly with fibromyalgia and include migraine, irritable bowel syndrome, obesity, and pelvic pain syndromes. A variety of pharmacologic and nonpharmacologic treatments are available for fibromyalgia, but treatment is best personalized for an individual and recognizes potential comorbidities. Opioids are not the recommended front-line treatment, cannabinoids hold promise but with limitations and nonpharmacologic options, such as aerobic or resistance exercise and cognitive behavior therapy, can play a very important but often underestimated role. Amitriptyline appears to be safe and effective in treating six of the main fibromyalgia domains: pain, disturbed sleep, fatigue, affective symptoms, functional limitations, and impaired cognition ("fibro fog"). Very low-dose naltrexone (2.5-4.5 mg) may offer analgesic and anti-inflammatory benefits to fibromyalgia patients, but further studies are needed. Fibromyalgia can be a devastating and debilitating condition for patients, and clinicians are challenged with its diagnosis and treatment as well. Further research as well as compassionate approaches to offering personalized care to those with fibromyalgia are required.

Nutraceuticals for Fibromyalgia and Neuropathic Pain

Both neuropathic pain and fibromyalgia are horrific painful conditions arising due to impairment in the somatosensory nervous system and the musculoskeletal system, respectively. They share some common symptoms like hyperalgesia, allodynia, insomnia, cognitive deficits, and mood disturbances. It is believed that fibromyalgia is the consequence of dysfunction of the central nervous system, autonomic nervous system, imbalance in neurotransmitters, and psychological and emotional stress. Henceforth, these pain syndromes have become a major challenge for healthcare professionals due to their complex etiology and poor availability and effectiveness of the drugs. Notably, the available synthetic drugs possess serious side effects including physical dependence and tolerance. Therefore, researchers are now seeking natural-based therapy for modulating chronic pain conditions. This chapter has been written with the intention of exploring the beneficial effects of various nutraceuticals including herbal dietary supplements in neuropathic pain and fibromyalgia.

Effects of the TENS device, Exopulse Mollii Suit, on pain related to fibromyalgia: An open-label study

Fibromyalgia is characterized by diffuse and chronic pain, that is often only partially alleviated by the available pharmacological treatments. Therefore, nonpharmacological interventions such as transcutaneous electrical stimulation (TENS) are highly needed to improve the quality of life of this population. However, the classical TENS devices offer a limited number of electrodes and are not adapted to this diffuse painful condition. For these reasons, we aimed to assess the effects of a new TENS device, the Exopulse Mollii Suit, that can stimulate up to 40 muscle groups integrated into pants and jackets and connected to a control unit. We report the data of 50 patients who received one session of active stimulation (pulse intensity 2 mA, and pulse frequency 20 Hz). Pain intensity was evaluated by means of the visual analogue scale (VAS), before (T0) and after the session (T1), and 24 h later (T24). Compared to baseline scores, a significant decrease in VAS was observed after the session (p<0.001), and 24 h later (p<0.001). T1 scores were significantly lower than T24 scores (p<0.001). Therefore, this new system seems to exert analgesic effects whose mechanisms primarily evoke the theory of "gate control". The effects were transient and started to decrease the following day, highlighting the need for additional studies to better evaluate the long-term effects of this intervention on pain, mood, and quality of life.

Pain Biomarkers in Fibromyalgia Syndrome: Current Understanding and Future Directions

Fibromyalgia is a complex and heterogeneous clinical syndrome, mainly characterized by the presence of widespread pain, possibly associated with a variety of other symptoms. Fibromyalgia can have an extremely negative impact on the psychological, physical and social lives of people affected, sometimes causing patients to experience dramatically impaired quality of life. Nowadays, the diagnosis of fibromyalgia is still clinical, thus favoring diagnostic uncertainties and making its clear identification challenging to establish, especially in primary care centers. These difficulties lead patients to undergo innumerable clinical visits, investigations and specialist consultations, thus increasing their stress, frustration and even dissatisfaction. Unfortunately, research over the last 25 years regarding a specific biomarker for the diagnosis of fibromyalgia has been fruitless. The discovery of a reliable biomarker for fibromyalgia syndrome would be a critical step towards the early identification of this condition, not only reducing patient healthcare utilization and diagnostic test execution but also providing early intervention with guideline-based treatments. This narrative article reviews different metabolite alterations proposed as possible biomarkers for fibromyalgia, focusing on their associations with clinical evidence of pain, and highlights some new, promising areas of research in this context. Nevertheless, none of the analyzed metabolites emerge as sufficiently reliable to be validated as a diagnostic biomarker. Given the complexity of this syndrome, in the future, a panel of biomarkers, including subtype-specific biomarkers, could be considered as an interesting alternative research area.

A systematic review and meta-analysis of voxel-based morphometric studies of fibromyalgia

Objective

Although neuroimaging investigations have revealed significant changes in brain structure in fibromyalgia (FM) patients, these findings are inconsistent. The current study conducted a systematic review and meta-analysis of voxel-based morphometric studies in order to comprehend those alterations in brain structure in FM patients.

Methods

Voxel-based morphometric (VBM) studies published up to January 17, 2023 were searched in the Web of Science, PubMed, EMBASE, Cochrane Library (CENTRAL), China National Knowledge Infrastructure (CNKI), Chongqing VIP, Wanfang Database. Two independent researchers carried out study screening, quality assessment, clinical data and neuroimaging data extraction. The whole-brain voxel-based gray matter (GM) data of FM patients were collected from eligible studies, and meta-analyzed using anisotropic effect size-signed differential mapping (AES-SDM).

Results

Twelve researches were included in this study, including 289 FM patients (mean age: 47.36 years) and 272 HS (mean age: 47.34 years). According to the meta-analysis, FM patients had increased GM in the right postcentral gyrus and left angular gyrus, and decreased GM in the right cingulate gyrus, right paracingulate gyrus, left cerebellum, and left gyrus rectus.

Conclusion

Our study suggests that fibromyalgia patients have altered gray matter in several brain regions that are involved in affective, cognitive functions, and in motor adaptations to pain processing.

Sensory profiling in classical Ehlers-Danlos syndrome: a case-control study revealing pain characteristics, somatosensory changes, and impaired pain modulation

Pain is one of the most important, yet poorly understood complaints in heritable connective tissue disorders (HCTD) caused by monogenic defects in extracellular matrix molecules. This is particularly the case for Ehlers-Danlos syndromes (EDS), paradigm collagen-related disorders. This study aimed to identify the pain signature and somatosensory characteristics in the rare classical type of EDS (cEDS) caused by defects in type V or rarely type I collagen. We used static and dynamic quantitative sensory testing and validated questionnaires in 19 individuals with cEDS and 19 matched controls. Individuals with cEDS reported clinically relevant pain/discomfort (VAS ≥5/10 in 32% for average pain intensity the past month) and worse health -related quality of life. Altered sensory profile was found in the cEDS group with higher (p=0.04) detection thresholds for vibration stimuli at the lower limb indicating hypoesthesia, reduced thermal sensitivity with more (p<0.001) paradoxical thermal sensations, and hyperalgesia with lower pain thresholds to mechanical (p<0.001) stimuli at both the upper and lower limbs and to cold (p=0.005) stimulation at the lower limb. Using a parallel conditioned pain paradigm, the cEDS group showed significantly smaller antinociceptive responses (p-value between 0.005 and 0.046) suggestive of impaired endogenous central pain modulation. In conclusion, Individuals with cEDS report chronic pain and worse health-related quality of life, and present altered somatosensory perception. This study is the first to systematically investigate pain and somatosensory characteristics in a genetically defined HCTD and provides interesting insights on the possible role of the ECM in the development and persistence of pain.

"INTEGRO INTEGRated Psychotherapeutic InterventiOn" on the Management of Chronic Pain in Patients with Fibromyalgia: The Role of the Therapeutic Relationship

Fibromyalgia (FM) is a chronic disease characterized by a heterogeneous set of physical and psychological conditions. The chronic experience of disability felt by patients and the impact on quality of life (QoL) of the disease may worsen the cognitive reappraisal ability and contribute to maintaining an altered pain modulation mechanism. This paper presents the study protocol of an INTEGRated psychotherapeutic interventiOn on the management of chronic pain in patients with fibromyalgia (INTEGRO). The aim of the study is to investigate the efficacy of an integrated psychotherapeutic intervention focused on pain management on QoL and pain perception, in a pilot sample of 45 FM patients with idiopathic chronic pain. The contribution of perceived therapeutic relationship (alliance) and physiological attunement, in both the patient and therapist, will be considered as possible mediators of intervention efficacy. Attachment dimensions, traumatic experiences, difficulties in emotion regulation, mindfulness attitude and psychophysiological profile will also be considered as covariates. The objectives are to evaluate longitudinally if patients will experience an increase in QoL perception (primary endpoint), pain-managing self-efficacy and emotion-regulation abilities as well as a reduction in pain intensity (secondary endpoints), considering the mediating role of perceived therapeutic alliance and physiological attunement in both the patient and therapist.

Effectiveness of aquatic therapy on sleep in persons with fibromyalgia. A meta-analysis

CONTEXT

Fibromyalgia syndrome (FMS) is a chronic musculoskeletal condition characterized by persistent, widespread pain, myofascial tenderness, negative affect, fatigue, memory problems and sleep disturbances.

OBJECTIVE

To summarize the evidence of the effects of aquatic therapy on sleep quality in patients with FMS.

METHODS

This systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols 2020 (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO), whit the registration number CRD42021249982. Cochrane library, Medline (PubMed), Science Direct Web of Science (WOS), Scopus, and PEDro were searched from inception until September 2021. The search included only randomized clinical trials.

RESULTS

Of the 7711 studies identified in the initial search, a total of 7 trials (361 participants) satisfied the eligibility criteria. Finally, a meta-analysis was conducted with 6 studies (311 participants). The overall pooled effect favored aquatic therapy interventions in improving sleep quality in patients with FMS (pooled MD, -2.05; 95% CI, -4.35 to 0.25).

CONCLUSIONS

The results of this systematic review and meta-analysis provide evidence that aquatic therapy improved sleep quality in patients with FMS. This study highlights the importance of aquatic therapy for sleep. Nonetheless, although an aquatic therapy intervention may represent a good option to improve sleep, given the low number of studies the evidence should be taken with caution.

Efficacy and safety of hyperbaric oxygen therapy for fibromyalgia: a systematic review and meta-analysis

OBJECTIVE

To investigate the efficacy and safety of hyperbaric oxygen therapy (HBOT) for fibromyalgia (FM).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, Web of Science, VIP (China Science and Technology Journal Database), CNKI (China National Knowledge Infrastructure) and WanFang database were searched from from inception to 22 October 2022.

ELIGIBILITY CRITERIA

We included clinical trials (randomised controlled and non-randomised controlled trials) of HBOT for FM.

DATA EXTRACTION AND SYNTHESIS

Two researchers independently screened the literature, extracted data and evaluated the quality of the included studies, with disagreements resolved by a third researcher. The Cochrane Collaboration checklists and the Methodological Index for Non-randomised Studies were used to assess the risk of bias. Meta-analysis was performed by RevMan V.5.4.1 software. Random effect models were used for meta-analysis.

RESULTS

Nine studies were included in this review, with a total of 288 patients. For pain assessment, we combined the results of the Visual Analogue Scale and Widespread Pain Index. The results showed that HBOT could relieve the pain of FM patients compared with the control intervention (standardised mean difference=-1.56, 95% CI (-2.18 to -0.93), p<0.001, I 2=51%). Most included studies reported that HBOT ameliorated tender points, fatigue, multidimensional function, patient global and sleep disturbance in FM. Adverse events occurred in 44 of 185 patients (23.8%). Twelve patients (6.5%) withdrew because of adverse reactions. No serious adverse events or complications were observed.

CONCLUSIONS

HBOT might have a positive effect in improving pain, tender points, fatigue, multidimensional function, patient global and sleep disturbance in FM, with reversible side effects. Low pressure (less than 2.0 atmospheric absolute) may be beneficial to reduce adverse events in FM. Further studies should be carried out to evaluate the optimal protocol of HBOT in FM.

PROSPERO REGISTRATION NUMBER

CRD42021282920.

The Safety and Efficacy of Low-Dose Naltrexone in Patients with Fibromyalgia: A Systematic Review

Fibromyalgia (FM) is a chronic pain sensitivity syndrome characterized by diffuse musculoskeletal pain and many other systemic manifestations. Low-dose naltrexone (LDN) has been increasingly used as an off-label treatment option in FM. However, current evidence on the safety and efficacy of LDN in patients with FM is not well known. To systematically assess the current evidence on the safety and efficacy of LDN use in the treatment of FM. A comprehensive bibliographic search was conducted on EBM Reviews - Cochrane Central Register of Controlled Trials, EBM Reviews - Cochrane Database of Systematic, Embase, Ovid MEDLINE(R) and Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions and Scopus databases in September 2022. Inclusion criteria were articles that were published in English, focusing on clinical trials involving LDN for the treatment of FM. Two reviewers independently screened and extracted the data. A qualitative analysis was used due to the high methodological heterogeneity between studies. The electronic search produced 805 articles. After applying the inclusion criteria, 9 articles (one RCT, two case reports, two case series, and four pilot trials) were selected for evaluation. LDN intervention protocols, study designs, and follow-up periods were different among the included studies. Overall, LDN was found to be effective in the symptomatic management of FM, and of the 78% of included studies that evaluated for safety, no severe adverse events were reported. Proving the efficacy and safety of low-dose naltrexone is a future possibility based on current study data, but the level of scientific evidence is limited. Future well-designed trials with large sample sizes are required.

Effects of strength training in fibromyalgia on balance, neuromuscular performance, and symptomatic analysis: a 12-week study protocol

Fibromyalgia affects skeletal muscles presenting with muscle stiffness, pain, and fatigue. The exercise practice is wellstabilized and suggested for the reduction of symptoms. However, there are some gaps in the literature related to balance and neuromuscular performance in a strength training protocol. The aim of this study is to structure a protocol to verify the effects of strength training applied over a short period, on balance, neuromuscular performance, and fibromyalgia symptoms. Additionally, we intend to analyze the effects of a short period of cessation of training. Participants will be recruited through flyers, internet advertisements, clinical referrals, health professionals, and email outreach. Volunteers will be randomly assigned to the control group or experimental group. Before the training period, symptoms (Fibromyalgia Impact Questionnaire, Visual Analog Scale), balance (force plate), and neuromuscular performance (medicine ball throw and vertical jump) will be assessed. Participants in the experimental group will perform strength training twice a week (50 min each), on alternate days, for 8 weeks (16 sessions). Then, 4 weeks of detraining will be completed. This training program will be carried out online, using real-time videos, and the participants will be divided into two groups with different schedules. The Borg scale will be used to monitor perceived effort in each session. There is a gap in the literature about exercise prescriptions for fibromyalgia. The supervised online intervention enables a wide range of participation. The strength exercises used (without the use of external materials and/or machines) and load (few repetitions per set) represent a novelty to training programming. Moreover, this training program respects the limitations and individuality of the volunteers, providing exercise adaptations. With positive results, the present protocol could be an easy-to-apply guideline with clear instructions on the details related to exercise prescription. Also, ensure the effectiveness of a low-cost and feasible treatment, especially for fibromyalgia patients.

Clinical trial registration

https://clinicaltrials.gov/, identifier: NCT05646641.

Bipolar Spectrum Symptoms in Patients with Fibromyalgia: A Dimensional Psychometric Evaluation of 120 Patients

BACKGROUND

Fibromyalgia Syndrome (FMS) is characterized by chronic widespread pain, fatigue, unrefreshing sleep and cognitive dysfunction. Depressive and manic symptoms are often reported in FMS patients' history. The aim of this study was to evaluate the prevalence of bipolar spectrum symptoms (BSS) and to correlate these with quality of life (QoL) scores and antidepressant treatment.

METHODS

From October 2017 to July 2018, a battery of QoL questionnaires (FIQ, PSQI and SF-12) was administered to 120 FMS patients after a clinical examination. The MOODS-SR lifetime questionnaire was then remotely administered to the patients included in the study.

RESULTS

The presence of depressive and manic lifetime symptoms was found, in line with the results of the available literature. A correlation was found between the history of depressive symptoms and the severity of FIQ and SF-12 scores. Despite a low statistical strength, a trend toward a correlation between a history of manic symptoms and SNRI treatment was detected.

CONCLUSIONS

The correlation between the MOOD-depressive domains and poor QoL is in line with the available literature. Further studies are needed to corroborate these findings and to elucidate the relationship between manic symptoms and SNRI treatment.

Fibromyalgia: epidemiology and risk factors, a population-based case-control study in Damascus, Syria

Background

Fibromyalgia is a chronic disease with a high burden. We aim to be the first to investigate the prevalence of fibromyalgia (FM) in Syria and assess its risk factors.

Methods

A self-reported questionnaire was distributed to the public to identify fibromyalgia patients using the American College of Rheumatology (ACR) 2010 modified criteria. Identified cases were matched using age with controls free from rheumatic disorders that were randomly sampled from the same population.

Results

Out of 2966 participants, 350 (11.8%) satisfied the diagnostic criteria. Of these, only 29 (8.2%) were previously diagnosed by a physician, 239 (68.3%) were females, and 69 (19.71%) were diagnosed with depression. Female sex (OR = 1.31), diagnosis of major depressive disorder (OR = 2.62), irritable bowel syndrome (OR = 1.8), and Restless legs syndrome (OR = 1.72) were associated with a higher likelihood of fibromyalgia.

Conclusion

Our study revealed one of the highest prevalence rates of fibromyalgia ever reported in the general population. Efforts must be intensified to increase awareness about this disease in Syrian society as well as among healthcare providers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00294-8.

Resting-state functional connectivity predicts motor cortex stimulation-dependent pain relief in fibromyalgia syndrome patients

MRI-based resting-state functional connectivity (rsFC) has been shown to predict response to pharmacological and non-pharmacological treatments for chronic pain, but not yet for motor cortex transcranial magnetic stimulation (M1-rTMS). Twenty-seven fibromyalgia syndrome (FMS) patients participated in this double-blind, crossover, and sham-controlled study. Ten daily treatments of 10 Hz M1-rTMS were given over 2 weeks. Before treatment series, patients underwent resting-state fMRI and clinical pain evaluation. Significant pain reduction occurred following active, but not sham, M1-rTMS. The following rsFC patterns predicted reductions in clinical pain intensity after the active treatment: weaker rsFC of the default-mode network with the middle frontal gyrus (r = 0.76, p < 0.001), the executive control network with the rostro-medial prefrontal cortex (r = 0.80, p < 0.001), the thalamus with the middle frontal gyrus (r = 0.82, p < 0.001), and the pregenual anterior cingulate cortex with the inferior parietal lobule (r = 0.79, p < 0.001); and stronger rsFC of the anterior insula with the angular gyrus (r =  - 0.81, p < 0.001). The above regions process the attentional and emotional aspects of pain intensity; serve as components of the resting-state networks; are modulated by rTMS; and are altered in FMS. Therefore, we suggest that in FMS, the weaker pre-existing interplay between pain-related brain regions and networks, the larger the pain relief resulting from M1-rTMS.

Effect of different types of exercise in adult subjects with fibromyalgia: a systematic review and meta-analysis of randomised clinical trials

Exercise has been recommended for fibromyalgia treatment. However, doubts related to exercise benefits remain unclear. The objective of this study was to summarise, through a systematic review with meta-analysis, the available evidence on the effects of aerobic, resistance and stretching exercise on pain, depression, and quality of life. Search was performed using electronic databases Pubmed and Cochrane Library. Studies with interventions based on aerobic exercise, resistance exercise and stretching exercise published until July 2020 and updated in December 2021, were identified. Randomized controlled trials and meta-analyses involving adults with fibromyalgia were also included. Eighteen studies were selected, including a total of 1184 subjects. The effects were summarised using standardised mean differences (95% confidence intervals) by random effect models. In general, aerobic exercise seems to reduce pain perception, depression and improves quality of life; it also improves mental and physical health-related quality of life. Resistance exercise decreases pain perception and improves quality of life and moreover improves the physical dimension of health-related quality of life. It was also observed that resistance exercise appears to have a non-significant positive effect on depression and the mental dimension of health-related quality of life. Studies revealed that stretching exercise reduces the perception and additionally improves quality of life and health-related quality of life. However, a non-significant effect was observed on depression. We conclude that exercise may be a way to reduce depression, and pain and improve the quality of life in adult subjects with fibromyalgia and should be part of the treatment for this pathology.

Serum netrin-1 and netrin receptor levels in fibromyalgia and osteoarthritis

Objectives: This study aims to define serum levels of netrin-1 and netrin receptors in patients with fibromyalgia (FM) and osteoarthritis (OA).

Patients and methods: This cross-sectional study was conducted with a total of 150 female participants (mean age: 47.2±16.1 years; range, 18 to 89 years) at Fırat University between June 2016 and December 2016. The participants were evaluated in three groups: the FM group with 50 patients, the OA group with 50 patients, and the control group, which included 50 healthy volunteers. Netrin-1, netrin receptors (DCC, UNC5B, and UNC5D), interleukin (IL)-6, IL-10, and IL-17 levels were analyzed by the enzyme-linked immunosorbent assay from the serum samples of the participants.

Results: The level of serum netrin-1 was significantly lower in the FM group than in the control and OA groups (p<0.01 and p<0.001, respectively). However, the difference between patients with OA and healthy controls in terms of netrin-1 was not statistically significant (p>0.05). In addition, serum levels of netrin receptors and cytokines in the FM group were similar to the control group (p>0.05). However, serum DCC, UNC5D, IL-6, and IL-10 levels were higher in the OA group compared to the control group (p<0.001, p<0.05, p<0.01, and p<0.001, respectively).

Conclusion: Serum netrin-1 level is suppressed in FM, which suggests that netrin-1 is influential in FM pathogenesis.

Effects of different protocols of physical exercise on fibromyalgia syndrome treatment: systematic review and meta-analysis of randomized controlled trials

Physical exercise has been used as a form of treatment for fibromyalgia, however, the results indicate the need for further investigations on the effect of exercise on different symptoms. The aim of the study was to synthesize and analyse studies related to the effect of exercise in individuals with fibromyalgia and provide practical recommendations for practitioners and exercise professionals. A search was carried out in the Web of Science, PubMed, and Scopus databases in search of randomized clinical trials (RCT) written in English. A meta-analysis was performed to determine the effectiveness of different types of exercise on the fibromyalgia impact questionnaire (FIQ), and the protocol period and session duration on the pain outcome. Eighteen articles were eligible for a qualitative assessment and 16 were included in the meta-analysis. The exercise showed large evidence for the association with a reduction in the FIQ (SMD - 0.98; 95% CI - 1.49 to - 0.48). Protocols between 13 and 24 weeks (SMD - 1.02; 95% CI - 1.53 to - 0.50), with a session time of less than 30 min (SMD - 0.68 95% CI - 1.26 to - 0.11) or > 30 min and < 60 min (SMD - 1.06; 95% CI - 1.58 to - 0.53) presented better results. Better results were found after combined training protocols and aerobic exercises. It is suggested that exercise programs lasting 13-24 weeks should be used to reduce pain, and each session should last between 30 and 60 min. In addition, the intensity should always be carried out gradually and progressively.PROSPERO registration number CRD42020198151.

A comparative study of heart rate variability and physical fitness in women with moderate and severe fibromyalgia

The aim of this study was to compare the physical fitness and cardiac autonomic activity among women with moderate and severe fibromyalgia (FM) and healthy women. This study included 35 women with FM (age: 46.2±8.9 years) and 17 healthy women (age: 44.3±9.9 years). Participants with FM were divided into moderate FM (n=15) and severe FM (n=20) according to the total score obtained in FM impact questionnaire. The heart rate variability was monitored using a portable cardiac monitor with participants resting in supine position during 10 min. Thereafter, the participants performed the chair sit and reach test, the chair stand test, and the 6-min walk test to measure the lower-body flexibility, lower-body muscle strength, and cardiorespiratory fitness, respectively. The lower-body muscle strength and cardiorespiratory fitness were both reduced in moderate and severe FM compared to healthy women (P<0.01), with greater reduction in severe FM when compared to moderate FM (P<0.05). In addition, the parasympathetic indexes of heart rate variability were all similarly decreased in both moderate and severe FM, when compared to healthy women (P<0.05). The cardiac parasympathetic activity is similarly decreased in women with both moderate and severe FM in comparison to healthy women, despite a greater physical deconditioning in severe FM.

Clinical Effects of Repetitive Transcranial Magnetic Stimulation of the Motor Cortex Are Associated With Changes in Resting-State Functional Connectivity in Patients With Fibromyalgia Syndrome

In this double-blinded, sham-controlled, counterbalanced, and crossover study, we investigated the potential neuroplasticity underlying pain relief and daily function improvements following repetitive transcranial magnetic stimulation of the motor cortex (M1-rTMS) in fibromyalgia syndrome (FMS) patients. Specifically, we used magnetic resonance imaging (MRI) to examine changes in brain structural and resting-state functional connectivity (rsFC) that correlated with improvements in FMS symptomology following M1-rTMS. Twenty-seven women with FMS underwent real and sham treatment series, each consisting of 10 daily treatments of 10Hz M1-rTMS over 2 weeks, with a washout period in between. Before and after each series, participants underwent anatomical and resting-state functional MRI scans and questionnaire assessments of FMS-related clinical pain and functional and psychological burdens. The expected reductions in FMS-related symptomology following M1-rTMS occurred with the real treatment only and correlated with rsFC changes in brain areas associated with pain processing and modulation. Specifically, between the ventromedial prefrontal cortex and the M1 (t = -5.54, corrected P = .002), the amygdala and the posterior insula (t = 5.81, corrected P = .044), and the anterior and posterior insula (t = 6.01, corrected P = .029). Neither treatment significantly changed brain structure. Therefore, we provide the first evidence of an association between the acute clinical effects of M1-rTMS in FMS and functional alterations of brain areas that have a significant role in the experience of chronic pain. Structural changes could potentially occur over a more extended treatment period. PERSPECTIVE: We show that the neurophysiological mechanism of the improvement in fibromyalgia symptoms following active, but not sham, rTMS applied to M1 involves changes in resting-state functional connectivity in sensory, affective and cognitive pain processing brain areas, thus substantiating the essence of fibromyalgia syndrome as a treatable brain-based disorder.

Bioactive Compounds for Fibromyalgia-like Symptoms: A Narrative Review and Future Perspectives

Fibromyalgia (FM) is a prevalent, chronic condition without a cure or reliable therapy. The etiopathogenesis of this syndrome is ambiguous, which has heightened the challenge of discovering treatments to minimize patients’ painful symptoms. FM is characterized by diffuse musculoskeletal pain usually accompanied by functional pain syndromes, such as fatigue, sleep disturbances, cognitive difficulties, and mood issues. Currently available treatment options for FM are limited. Recent studies have suggested a potential role for dietary bioactive compounds in FM management. We performed a narrative review to evaluate the existing evidence regarding the dietary bioactive compounds for FM, and we proposed molecular mechanisms on this topic. The inclusion criteria were (i) human, in vivo, or in vitro studies, (ii) studies related to the effect of bioactive compounds on FM-like symptoms, (iii) peer-reviewed literature, and (iv) publications until February 2022 in PubMed and Google Scholar. Exclusion criteria were (i) study designs using CCI, SNI, or SNL models because they are more NP models rather than FM models, and (ii) studies published in a language other than English. Keywords were dietary bioactive compounds, fibromyalgia, cell, animals, humans. Here, we report the effects of commonly consumed bioactive compounds (capsaicin, ginger, curcumin, n-3 PUFA, grape seed extract, naringin, and genistein) on FM-like symptoms in cellular, animal, and human studies. Cellular studies demonstrated that these bioactive compounds reduce pro-inflammatory production and increase antioxidant capacity of neurons or myoblasts that regulate apoptosis/cell survival. Animal studies showed that these regularly consumed bioactive compounds have an effect on FM-like symptoms, as evidenced by decreased pain hypersensitivity and fatigue as well as improved social behaviors. Further studies are warranted to allow meaningful comparison and quantification of the efficacy of these bioactive compounds on FM-like symptoms across studies, in terms of actual changes in antioxidant capacity, pain hypersensitivity, fatigue, and social behaviors. To date, human studies regarding the efficacy of these bioactive compounds on FM-like symptoms are limited and inconclusive. Our review identifies this important knowledge gap and proposes that the development and use of improved preclinical FM models are needed, particularly concerning the usage of female animals to better mimic FM pathophysiology and symptomatology.

Nociceptive chemical hypersensitivity in the spinal cord of a rat reserpine-induced fibromyalgia model

The pathological mechanisms of fibromyalgia (FM) are largely unknown. Recently, a rat reserpine-induced pain model showing exaggerated pain-related behaviors to mechanical and thermal stimuli has been used in FM research. However, the model has not been fully characterized. Here, we investigated nociceptive hypersensitivity to chemical stimuli and its spinal mechanisms to further characterize the model. The rat model was induced by administering reserpine to the nervous system. Nociceptive behaviors to chemical stimuli were quantified using the formalin pain test, and neuronal activation of the stimuli was examined using spinal c-Fos immunohistochemistry and electrophysiological recordings of superficial dorsal horn (SDH) neurons. The duration of pain-related behaviors was prolonged in both phases I (0-5min) and II (10-60min) and the interphase; and the number of c-Fos-immunoreactive nuclei increased in laminae I-II, III-IV, and V-VI at the spinal segments L3-L5 on the side ipsilateral to the formalin injection, and these factors were significantly and positively correlated. The action potentials of SDH neurons induced by formalin injection were markedly increased in rats treated with reserpine. These results demonstrate that pain-related behaviors are facilitated by noxious chemical stimuli in a rat reserpine-induced FM model, and that the behavioral hypersensitivity is associated with hyperactivation of SDH neurons.

Multiple Chemical Sensitivity

Multiple Chemical Sensitivity (MCS), a condition also known as Chemical Sensitivity (CS), Chemical Intolerance (CI), Idiopathic Environmental Illness (IEI) and Toxicant Induced Loss of Tolerance (TILT), is an acquired multifactorial syndrome characterized by a recurrent set of debilitating symptoms. The symptoms of this controversial disorder are reported to be induced by environmental chemicals at doses far below those usually harmful to most persons. They involve a large spectrum of organ systems and typically disappear when the environmental chemicals are removed. However, no clear link has emerged among self-reported MCS symptoms and widely accepted objective measures of physiological dysfunction, and no clear dose-response relationship between exposure and symptom reactions has been observed. In addition, the underlying etiology and pathogenic processes of the disorder remain unknown and disputed, although biologic and psychologic hypotheses abound. It is currently debated whether MCS should be considered a clinical entity at all. Nevertheless, in the last few decades MCS has received considerable scientific and governmental attention in light of the many persons reporting this illness. In this review, we provide a general overview of the history, definition, demographics, prevalence, and etiologic challenges in defining and understanding MCS.

Structural and functional thalamocortical connectivity study in female fibromyalgia

Dysfunctional thalamocortical interactions have been suggested as putative mechanisms of ineffective pain modulation and also suggested as possible pathophysiology of fibromyalgia (FM). However, it remains unclear which specific thalamocortical networks are altered and whether it is related to abnormal pain perception in people with FM. Here, we conducted combined vertex-wise subcortical shape, cortical thickness, structural covariance, and resting-state functional connectivity analyses to address these questions. FM group exhibited a regional shape deflation of the left posterior thalamus encompassing the ventral posterior lateral and pulvinar nuclei. The structural covariance analysis showed that the extent of regional deflation of the left posterior thalamus was negatively covaried with the left inferior parietal cortical thickness in the FM group, whereas those two regions were positively covaried in the healthy controls. In functional connectivity analysis with the left posterior thalamus as a seed, FM group had less connectivity with the periaqueductal gray compared with healthy controls, but enhanced connectivity between the posterior thalamus and bilateral inferior parietal regions, associated with a lower electrical pain threshold at the hand dorsum (pain-free point). Overall, our findings showed the structural thalamic alteration interacts with the cortical regions in a functionally maladaptive direction, leading the FM brain more responsive to external stimuli and potentially contributing to pain amplification.

Intensive Multicomponent Fibromyalgia Treatment: A Translational Study to Evaluate Effectiveness in Routine Care Delivery

OBJECTIVE

The current study was designed to evaluate the translation of clinical trial outcomes and clinical guidelines for the treatment of fibromyalgia (FM) into an intensive multicomponent clinical program embedded in routine care delivery. The study aimed to assess the adaptation of these recommended strategies into routine clinical care while evaluating their effectiveness and durability in improving functional status and level of distress in a large clinical sample of FM patients.

METHODS

Four hundred eighty-nine patients with FM completed a 2-day program that incorporated best practice recommendations for the treatment of FM. Patients completed the Fibromyalgia Impact Questionnaire-Revised, the Center for Epidemiologic Studies Depression Scale, and the Pain Catastrophizing Scale at admission to the program and at follow-up on average 5 months posttreatment.

RESULTS

Significant improvements were seen in functional status (p < 0.0001), depressive symptoms (p < 0.0001), and pain catastrophizing (p < 0.0001) after participation in the intensive multicomponent treatment program.

CONCLUSIONS

The present study shows that an intensive multicomponent treatment program embedded in routine care delivery is effective in significantly improving functional status and psychological distress in a large sample of FM patients. The significant improvements were durable and maintained at follow-up.

Could ferritin, vitamin B12, and vitamin D play a role in the etiopathogenesis of fibromyalgia syndrome?

Introduction. Fibromyalgia syndrome (FS) comprises general body pain, sleep disturbances, and fatigue. Vitamin B₁₂ (VB), vitamin D (VD), and iron deficiencies lead to similar complaints. First, this study aimed to evaluate the VB, VD, and ferritin levels of patients with FS. Second, it aimed to investigate whether there was a relationship between these parameters and FS severity. Material and methods. The study included 58 female patients with FS and 58 healthy females as a control group. The patients completed the Fibromyalgia Impact Questionnaire (FIQ), Visual Analog Scale (VAS), fatigue questionnaire, Pittsburgh sleep quality scale, and the Short Form-36 (SF-36). This study examined the VD, VB, and ferritin levels of the patient and control groups. Results. The VB (240.0 [110.0-394.0] vs 291.0 [210.0-609.0] pg/ml, p<0.001), VD (12.5 [3.0-45.0] vs 20.0 [5.0-54.0] ng/ml, p=0.013), and ferritin levels (21.2 [4.0-86.0] vs 32.0 [7.1-120.0], ng/ml, p=0.009) of the FS patients were determined to be significantly lower than those of the control group. A negative correlation was determined between the number of tender points and VB, VD, and ferritin levels. In the regression analysis, we found low ferritin levels (odds ratio [OR] 1.036, 95% confidence interval [CI] 1.015-1.058, p<0.001) and VB (OR 1.010, CI 1.002-1.018, p=0.010) to be an independent risk factor for FS. Conclusions. There may be a relationship between VB, VD, and ferritin levels and the number of tender points in patients with FS. Levels of iron and VB may play a vital role in FS etiopathogenesis. However, VD levels may not be a risk factor for FS etiopathogenesis.

Carotid Arterial Stiffness and Cardiometabolic Profiles in Women with Fibromyalgia

Background: The present study aimed to evaluate the association between FM and cardiometabolic risk factors and carotid arterial stiffness in FM patients. Methods: The cardiometabolic risk profile was defined based on the Adult Treatment Panel III panel. Carotid intimal media thickness (cIMT) and arterial stiffness were assessed using high-resolution ultrasonography. Multivariate logistic analysis was performed to estimate the association between FM and cardiometabolic risk factors. We used a general linear regression to compare the cIMT and carotid beta-index between the participants with and without FM. Pearson’s coefficient was calculated to evaluate the potential correlation between cardiometabolic risk profiles, cIMT, and arterial stiffening in FM. Results: FM participants showed a higher risk of central obesity (odds ratio [OR] = 3.21, 95% confidence interval [CI] 1.49, 6.91), high triglyceride (OR = 4.73, 95% CI 2.29, 9.79), and impaired fasting glucose (IFG) (OR = 4.27, 95% CI 2.07, 8.81) compared to the control group. The FM group exhibited higher beta-index values than the control group (p = 0.003). Although IFG and triglyceride glucose index showed a tendency to correlate with the beta-index, statistical significance was not observed. Conclusions: FM was associated with an increased risk of central obesity, high triglyceride levels, and IFG. Furthermore, advanced arterial stiffness of the carotid artery was observed in FM, which might be correlated with insulin resistance.

Contemporary English Pain Descriptors as Detected on Social Media Using Artificial Intelligence and Emotion Analytics Algorithms: Cross-sectional Study

BACKGROUND

Pain description is fundamental to health care. The McGill Pain Questionnaire (MPQ) has been validated as a tool for the multidimensional measurement of pain; however, its use relies heavily on language proficiency. Although the MPQ has remained unchanged since its inception, the English language has evolved significantly since then. The advent of the internet and social media has allowed for the generation of a staggering amount of publicly available data, allowing linguistic analysis at a scale never seen before.

OBJECTIVE

The aim of this study is to use social media data to examine the relevance of pain descriptors from the existing MPQ, identify novel contemporary English descriptors for pain among users of social media, and suggest a modification for a new MPQ for future validation and testing.

METHODS

All posts from social media platforms from January 1, 2019, to December 31, 2019, were extracted. Artificial intelligence and emotion analytics algorithms (Crystalace and CrystalFeel) were used to measure the emotional properties of the text, including sarcasm, anger, fear, sadness, joy, and valence. Word2Vec was used to identify new pain descriptors associated with the original descriptors from the MPQ. Analysis of count and pain intensity formed the basis for proposing new pain descriptors and determining the order of pain descriptors within each subclass.

RESULTS

A total of 118 new associated words were found via Word2Vec. Of these 118 words, 49 (41.5%) words had a count of at least 110, which corresponded to the count of the bottom 10% (8/78) of the original MPQ pain descriptors. The count and intensity of pain descriptors were used to formulate the inclusion criteria for a new pain questionnaire. For the suggested new pain questionnaire, 11 existing pain descriptors were removed, 13 new descriptors were added to existing subclasses, and a new Psychological subclass comprising 9 descriptors was added.

CONCLUSIONS

This study presents a novel methodology using social media data to identify new pain descriptors and can be repeated at regular intervals to ensure the relevance of pain questionnaires. The original MPQ contains several potentially outdated pain descriptors and is inadequate for reporting the psychological aspects of pain. Further research is needed to examine the reliability and validity of the revised MPQ.

Dysfunctional eating behavior in fibromyalgia and its association with serum biomarkers of brain plasticity (BDNF and S100B): an exploratory study

OBJECTIVE

To assess disordered eating, hunger and satiety perceptions in women with fibromyalgia (FM) compared to healthy controls (HC) and their association with biomarkers of brain plasticity (brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100B)).

METHODS

Cross-sectional exploratory study. The sample included FM (n = 20) and HC (n = 19), matched to age and waist perimeter. Dysfunctional eating was assessed through the Three Factor Eating Questionnaire and Eating Disorders Examination with a questionnaire. Hunger and satiety levels were rated by a Numerical Scale. Serum leptin, S100B and BDNF were analyzed.

RESULTS

The MANCOVA analysis showed that the mean of Emotional Eating rates was 30.65% higher in FM compared to HC (p = 0.015). Eating, shape and weight concerns were 77.77%, 57.14% and 52.22% higher in FM (p = <0.001) compared to HC, respectively. Moreover, the FM group reported higher scores for feeling of hunger "[5.2 (±2.9) vs. 4.8 (±2.0); p = 0.042] and lower scores for satiety [7.0 (±1.7) vs. 8.3 (±1.0); p = 0.038]. In the FM group, serum BDNF was negatively associated with hunger (r = - 0.52; p = 0.02), while S100B was positively associated with hunger scores (r = 0.463; p = 0.004).

CONCLUSION

The present findings support the hypothesis that the association between FM and obesity can be mediated by a hedonistic pathway. Further research is needed.

Neuronal Sensitization and Synaptic Facilitation in the Superficial Dorsal Horn of a Rat Reserpine-induced Pain Model

Chronic widespread pain is one of the important issues to be solved in medical practice. Impaired spinal descending pain inhibitory system due to decreased monoamine neurotransmitters is assumed to cause nociceptive hypersensitivities in chronic painful conditions like that described in patients with fibromyalgia (FM). However, response behaviors and synaptic transmission of the spinal dorsal horn neurons in response to reserpine remain to be clarified. Here we examined the activities of superficial dorsal horn (SDH) neurons, as well as excitatory and inhibitory postsynaptic inputs to SDH neurons, using a putative rat model of FM that was established by injecting reserpine. Extracellular recordings in vivo revealed that SDH neurons were sensitized to mechanical stimulation applied to the neurons' receptive fields, and the mechanically sensitized neurons were spontaneously more active. The sensitizing effect was evident 1 day and 3 days after the reserpine treatment, but subsided 5 days after the treatment or later. Using patch-clamp recordings in vivo, spontaneous excitatory postsynaptic currents (sEPSCs) to SDH neurons were found to increase in the pain model, while spontaneous inhibitory postsynaptic currents (sIPSCs) to SDH neurons decreased. These results demonstrate that the SDH neurons were strongly sensitized in response to the reserpine treatment, and that increased excitatory and decreased inhibitory postsynaptic inputs could be responsible for the spinal nociceptive hypersensitivity in the putative FM model.

The challenge of differentiating fibromyalgia from small-fiber neuropathy in clinical practice

Fibromyalgia and small fibre neuropathy are two diseases leading to chronic widespread pain, and it is difficult to differentiate them in order to provide appropriate care. In this review, we will describe the pathophysiological and clinical differences between fibromyalgia and small fibre neuropathy. In fibromyalgia, pain is increased by dysregulation of central pain processing while small fibre neuropathy pain is related to loss or dysfunction of intraepidermal small nerve fibres. Higher pain intensity; stabbing pain and paraesthesia; allodynia; dry eyes/mouth; changed pattern or sweating on body; skin colour alterations/modifications; reduced hair/nail growth on lower extremities; warm or cold hypoesthesia could be more common in small fibre neuropathy whereas headache or temporo-mandibular disorder point toward fibromyalgia. Length-dependent distribution of pain is common in small fibre neuropathy but can also affect the whole body. Anxiety or depression are common in these two diseases, but post-traumatic stress disorder and physical or sexual abuse in childhood or adulthood suggest fibromyalgia. Inflammatory disease or musculoskeletal disease is frequently reported with fibromyalgia whereas metabolic disorders (especially diabetes mellitus), neurotoxic exposure, Sjogren's syndrome, sarcoidosis, HIV are the main diseases associated with small fibre neuropathy. Skin biopsy, quantitative sensory testing, laser evoked potentials, confocal corneal microscopy or electrochemical skin conductance can help to discriminate between fibromyalgia and small fibre neuropathy.

Higher Pain Sensitivity Predicts Efficacy of a Wearable Transcutaneous Electrical Nerve Stimulation Device for Persons With Fibromyalgia: A Randomized Double-Blind Sham-Controlled Trial

OBJECTIVES

This study investigated the efficacy of a transcutaneous electrical nerve stimulation (TENS) device (Quell®) for persons with symptoms due to fibromyalgia (FM).

MATERIALS AND METHODS

One hundred nineteen (N = 119) subjects were randomly assigned to use an active (N = 62) or sham (N = 57) TENS for three months. All subjects completed baseline questionnaires and were administered quantitative sensory testing (QST). Subjects completed the Patients' Global Impression of Change (PGIC, primary outcome measure) and other mailed questionnaires (secondary outcome measures) at six weeks and three months.

RESULTS

The subjects averaged 50.4 ± 13.5 years of age, 93.3% were female, and 79.8% were Caucasian. Most showed benefit from using the TENS, but no differences between groups were found on the primary outcome measure after three months (active 3.87 ± 1.85, sham 3.73 ± 1.80, 95% confidence interval [CI] [-0.60, 0.88], p = 0.707). Those with more hypersensitivity showed most improvement on the PGIC at six weeks (0.22, 95% CI [0.01, 0.43], p = 0.042) and three months (0.20, 95% CI [0.00, 0.41], p = 0.049) and among those with higher sensitivity based on QST, the active TENS group showed the most benefit with TENS compared with the sham treatment (1.20, 95% CI [0.22, 2.18], p = 0.017). No TENS-related serious adverse events were reported. Subjects in the sham group correctly identified their treatment 87.5% of the time, while, surprisingly, subjects in the active group correctly identified their treatment only 17.4% of the time.

CONCLUSION

This study found no differences between those who were exposed to maximal-frequency active stimulation or minimal-frequency sham stimulation from a wearable TENS in reducing FM-related symptoms. However, those with greater hypersensitivity showed most benefit from TENS. Additional studies to help determine the role individual differences play in the use of TENS in managing FM-related symptoms are needed.

Mapping of predictors of the disengagement of the descending inhibitory pain modulation system in fibromyalgia: an exploratory study

BACKGROUND

The main symptoms of fibromyalgia comprise diffuse pain, disability, depressive symptoms, catastrophizing, sleep disruption and fatigue, associated with dysfunction of the descending pain-modulating system (DPMS).

OBJECTIVES

We aimed to identify patterns of main symptoms of fibromyalgia and neuroplasticity biomarkers (i.e. brain-derived neurotrophic factor (BDNF) and S100B protein) in non-responders to the conditioned pain modulation task (CPM-task) induced by immersion of hand in cold water (0-1°C). Furthermore, we evaluated if these patterns predict responsiveness to CPM-task.

METHODS

This cross-sectional study included 117 women with fibromyalgia ((n = 60) non-responders and (n = 57) responders), with age ranging from 30 to 65 years old. We analysed changes in numerical pain scale (NPS-10) during the CPM-task using a standardized protocol.

RESULTS

A hierarchical multivariate logistic regression analysis was used to construct a propensity score-adjusted index to identify non-responders compared to responders to CPM-task. The following variables were retained in the models: analgesic use four or more times per week, heat pain threshold (HPT), poor sleep quality, pain catastrophizing, serum levels of BDNF, number of psychiatric diagnoses and the impact of symptoms of fibromyalgia on quality of life. Receiver operator characteristics (ROC) analysis showed non-responders can be discriminated from responders by a composite index of more frequent symptoms of fibromyalgia and neuroplasticity markers (area under the curve (AUC) = 0.83, sensitivity = 100% and specificity = 98%).

CONCLUSION

Patterns of fibromyalgia symptoms and neuroplasticity markers may be helpful to predict responsiveness to the CPM-task which might help personalize treatment and thereby contribute to the care of patients with fibromyalgia.

Neural therapy for fibromyalgia: Myth or improving quality of life?

BACKGROUND

Fibromyalgia is a common rheumatic disease, which is thought to be a neuroendocrine dysregulation disorder. Patients' quality of life (QOL) is severely affected by this disease. Though neural therapy, as a treatment option, attempts to correct the underlying neuroendocrine dysfunction, yet there is no proven evidence of its effect on this disease. The present study aimed to evaluate the effectiveness of neural therapy on pain and functionality in patients with fibromyalgia.

METHODS

The study was a 1-year retrospective cohort study and held in physical medicine and rehabilitation clinics. A total of 60 female patients diagnosed with fibromyalgia were included. Sixty female patients with fibromyalgia were included in this study. Patients were divided into two groups; the first group (n = 30) received neural therapy, the second group (n = 30) received conventional physical therapy and each of the two groups received the same home exercise (stretching, strengthening and aerobic exercises) programme for four weeks. The primer outcomes were visual analogue scale (VAS), Short Form-36 (SF-36) and Fibromyalgia Impact Questionnaire (FIQ) scores after the treatment.

RESULTS

The social functioning score exhibited a significant improvement only in the intra-group comparison of the neural therapy group (P < .001). However, after treatment, the VAS, FIQ and all the SF-36 parameters, except role limitations because of physical health, were detected to be significantly improved in the neural therapy group compared with the exercise group (P < .001).

CONCLUSIONS

Neural therapy may be an effective alternative treatment for improving the QOL in patients with fibromyalgia.

Medical cannabis for the treatment of fibromyalgia syndrome: a retrospective, open-label case series

BACKGROUND

The use of cannabis for treating fibromyalgia syndrome (FMS) has not been comprehensively investigated. Thus, we have assessed the efficacy and adverse events (AEs) of short- and long-term medical cannabis (MC) treatment for FMS.

METHODS

Data were obtained from medical reports archived in the pain clinic of Ponderano (Italy; retrospective study). FMS patients, who were resistant to conventional therapy, received licensed MC with various Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content, as powdered whole flowers (decoction or vaporization) or oil extracts. Demographic and clinical parameters, including Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), Hospital Anxiety and Depression Scale, Widespread Pain Index (WPI), Severity Score (SyS), and side effects, were obtained after 1, 3, and 12 months. Data were analyzed with Wilcoxon signed-rank tests for paired data.

RESULTS

Thirty-eight patients were included. Thirty, 18, and 12 patients continued therapy for 1, 3, and 12 months, respectively. Significant improvements (p < 0.01) were observed in NRS, ODI, WPI, and SyS at 1 month; in NRS, ODI, and WPI at 3 months; and in NRS, ODI, and SyS at 12 months. Therapy was interrupted by 17 patients (48.6%) owing to nonserious AEs according to the FDA. The most common side effects were mental confusion (37%), dizziness (14%), nausea/vomiting (14%), and restlessness/irritation (14%). The median daily dose of milled flowers administered as THC-dominant MC and hybrid MC (with similar THC/CBD ratio) was 200 mg/day and 400 mg/day, respectively. After 3 months of titration, the median content of THC administered with THC-dominant MC cultivars was 46.2 mg, and of THC + CBD administered as a hybrid MC cultivar, was 23.6 mg + 38 mg. At 3 months, median THC content administered in the oil extract of the THC-dominant MC cultivars was 9.7 mg, while that of THC + CBD administered in the oil extract of the hybrid MC cultivars was 1.8 mg + 2 mg.

CONCLUSIONS

MC may represent an alternative treatment for patients with FMS who are unresponsive to conventional therapy. However, its application may be limited by the incidence of nonserious AEs.

The role of lifetime stressors in adult fibromyalgia: systematic review and meta-analysis of case-control studies

BACKGROUND

Fibromyalgia is a chronic condition characterised by widespread musculoskeletal pain. Although accumulating evidence suggests that exposure to stressful events increases the risk for this complex disorder, this is the first meta-analysis to compare the impact of a full range of lifetime stressors (e.g. physical trauma through to emotional neglect) on adult fibromyalgia.

METHODS

This review was performed in accordance with PRISMA guidelines. Random-effects models examined associations between different stressor exposures and fibromyalgia status with meta-regression investigating the effects of publication year and study quality on effect sizes.

RESULTS

Nineteen studies were included in the meta-analysis. Significant associations with fibromyalgia status were observed for all six exposure types examined: odds ratios (OR) were highest for physical abuse (OR 3.23, 95% confidence interval 1.99-5.23) and total abuse (3.06, 1.71-5.46); intermediate for sexual abuse (2.65, 1.85-3.79) and smaller for medical trauma (1.80, 1.19-2.71), other lifetime stressors (1.70, 1.31-2.20), and emotional abuse (1.52, 1.27-1.81). Results were not significantly changed when childhood, as opposed to adult, exposures were used in studies that reported both. Meta-regression analyses demonstrated no effect of publication year or study quality on effect sizes.

CONCLUSIONS

This study confirmed a significant association between stressor exposure and adult fibromyalgia with the strongest associations observed for physical abuse. Limitations related to current available literature were identified; we provide several suggestions for how these can be addressed in future studies. Stressors are likely to be one of many risk factors for fibromyalgia which we argue is best approached from a biopsychosocial perspective.

Quantitative response of healthy muscle following the induction of capsaicin: an exploratory randomized controlled trial

Background

Myofascial pain syndrome (MPS) is a prevalent chronic pain disorder primarily characterized by myofascial trigger points (MTrPs). There is limited knowledge on the pathophysiology and mechanisms underlying MTrP and its development. Research has previously demonstrated the identification of MTrPs using ultrasound and vibration sonoelastography, although there is some contradictory evidence regarding if MTrPs present as hyper or hypoechoic regions. Electromyography (EMG) investigations of MTrP have demonstrated that MTrPs are usually located proximal to innervation zones where the peak surface EMG signals are obtained from. Central sensitization has been proposed as the primary mechanism underlying MTrP development. Central sensitization is associated with hyperexcitability of neuronal responses to normal or noxious stimuli. There is a need for a study that measures ultrasound image textural changes and motor unit activity responses in the muscle following sensitization. The purpose of this study is to determine whether sensitizing healthy muscle using capsaicin induces a regional change in image texture variables within the specific and surrounding muscles, as well as the motor unit frequency and amplitude changes that accompany them. This is an exploratory trial that aims to provide preliminary evidence on whether central sensitization is a direct cause of taut band and MTrP development.

Methods

Ethical approval was obtained from the University Health Network (UHN) Research Ethics Board. This proposed study is a single centered, factorial, randomized placebo-controlled trial with two independent variables, depth of capsaicin application and dose of capsaicin, for a total of six treatment arms and three control treatment groups.

Discussion

This will be the first study that assesses the B-mode ultrasound image texture of induced sensitized muscles and will provide more evidence on muscle motor unit activity and regional changes of central sensitization. Findings from this study may support one of few hypotheses proposed delineating the involvement of central sensitization in the development of trigger points.

Trial registration

National Institutes of Health ClinicalTrials.gov NCT03944889. Registered on May 07, 2019

Assessing our approach to diagnosing Fibromyalgia

Introduction: Fibromyalgia represents the most prevalent of the group of conditions that are known as central sensitivity syndromes. Approximately 2-5% of the adult population in the United States is affected by Fibromyalgia. This pain amplification syndrome has an enormous economic impact as measured by work absenteeism, decreased work productivity, disability and injury compensation, and over-utilization of healthcare resources. Multiple studies have shown that early diagnosis of this condition can improve patient outlook, and redirect valuable health care resources toward more appropriate targeted therapy. Efforts have been made toward improving diagnostic accuracy through updated criteria. Areas Covered: Reviewed here are 1) reasons for the need for more accurate diagnosis of Fibromyalgia, (2) a review of the evolution of Fibromyalgia to current times, and (3) the proliferation of currently available diagnostic criteria and problems related to each of them. From initial literature review until October 2020, PubMed, Embase, and Scopus were searched for applicable literature. Expert Opinion: A discussion of ongoing efforts to obtain a biomarker to enhance diagnostic accuracy concludes this review. A need to include rheumatologists as part of the care team of patients with Fibromyalgia is emphasized.

Neuromagnetic Amygdala Response to Pain-Related Fear as a Brain Signature of Fibromyalgia

INTRODUCTION

Fibromyalgia (FM) is a chronic pain condition characterized by impaired emotional regulation. This study explored the brain response to pain-related fear as a potential brain signature of FM.

METHODS

We used a conditioned fear task and magnetoencephalography to record pain-related fear responses in patients with FM. Two blocks of 30 fear responses were collected to compute the response strength in the first block and the strength difference between the first and second blocks (fear habituation). These measurements were investigated for their clinical relevance and compared with measurements obtained from healthy controls and patients with chronic migraine (CM), a different chronic pain condition often comorbid with FM.

RESULTS

Pain-related fear clearly activated the bilateral amygdala and anterior insula in patients with FM (n = 52), patients with CM (n = 50), and the controls (n = 30); the response strength in the first block was consistent across groups. However, fear habituation in the right amygdala decreased in the FM group (vs. CM and control groups, both p ≤ 0.001, no difference between CM and control groups). At the 3-month follow-up, the patients with FM reporting < 30% improvement in pain severity (n = 15) after pregabalin treatment exhibited lower fear habituation in the left amygdala at baseline (vs. ≥ 30% improvement, n = 22, p = 0.019). Receiver operating characteristic analysis confirmed that amygdala fear habituation is a suitable predictor of diagnosis and treatment outcomes of FM (area under the curve > 0.7).

CONCLUSIONS

Amygdala activation to pain-related fear is maladaptive and linked to treatment outcomes in patients with FM. Because the aberrant amygdala response was not observed in the CM group, this response is a potential brain signature of FM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT02747940.

Fatigue, depression, and pain in multiple sclerosis: How neuroinflammation translates into dysfunctional reward processing and anhedonic symptoms

Fatigue, depression, and pain affect the majority of multiple sclerosis (MS) patients, which causes a substantial burden to patients and society. The pathophysiology of these symptoms is not entirely clear, and current treatments are only partially effective. Clinically, these symptoms share signs of anhedonia, such as reduced motivation and a lack of positive affect. In the brain, they are associated with overlapping structural and functional alterations in areas involved in reward processing. Moreover, neuroinflammation has been shown to directly impede monoaminergic neurotransmission that plays a key role in reward processing. Here, we review recent neuroimaging and neuroimmunological findings, which indicate that dysfunctional reward processing might represent a shared functional mechanism fostering the symptom cluster of fatigue, depression, and pain in MS. We propose a framework that integrates these findings with a focus on monoaminergic neurotransmission and discuss its therapeutic implications, limitations, and perspectives.

Linking Nonrestorative Sleep and Activity Interference Through Pain Catastrophizing and Pain Severity: An Intraday Process Model Among Individuals With Fibromyalgia

Nonrestorative sleep is a key diagnostic feature of the musculoskeletal pain disorder fibromyalgia and is robustly associated with poor physical functioning, including activity interference. However, the mechanisms through which nonrestorative sleep elicits activity interference among individuals with fibromyalgia at the within-person level remain unclear. The present study tested the following 3-path mediation model, using data gathered from a 21-day electronic daily diary in 220 individuals with fibromyalgia: previous night nonrestorative sleep → morning pain catastrophizing → afternoon pain severity → end-of-day activity interference. Results of multilevel structural equation modeling supported the 3-path mediation model. Previous night's nonrestorative sleep and morning pain catastrophizing were also directly related to end-of-day activity interference. Previous night nonrestorative sleep did not significantly predict afternoon pain severity while controlling for the effect of morning pain catastrophizing. Greater nonrestorative sleep during the previous night and a higher level of morning pain catastrophizing appear to serve as risk factors for experiencing greater daily pain and activity interference later in the day. These findings point to the potential utility of targeted interventions that improve both sleep quality and pain catastrophizing to help individuals with chronic pain engage in important daily activities despite experiencing pain. PERSPECTIVE: This study provides a better understanding of how nonrestorative sleep is associated with daily activity interference among individuals with fibromyalgia. An intervention that targets attenuating nonrestorative sleep and pain catastrophizing may help improve daily physical functioning of this population.