Elevated cerebrospinal fluid levels of substance P in patients with the fibromyalgia syndrome

Effects of Tryptophan and Physical Exercise on the Modulation of Mechanical Hypersensitivity in a Fibromyalgia-like Model in Female Rats

Though the mechanisms are not fully understood, tryptophan (Trp) and physical exercise seem to regulate mechanical hypersensitivity in fibromyalgia. Here, we tested the impact of Trp supplementation and continuous low-intensity aerobic exercise on the modulation of mechanical hypersensitivity in a fibromyalgia-like model induced by acid saline in female rats. Twelve-month-old female Wistar rats were randomly divided into groups: [control (n = 6); acid saline (n = 6); acid saline + exercise (n = 6); acid saline + Trp (n = 6); and acid saline + exercise + Trp (n = 6)]. Hypersensitivity was caused using two intramuscular jabs of acid saline (20 μL; pH 4.0; right gastrocnemius), 3 days apart. The tryptophan-supplemented diet contained 7.6 g/hg of Trp. The three-week exercise consisted of progressive (30-45 min) treadmill running at 50 to 60% intensity, five times (Monday to Friday) per week. We found that acid saline induced contralateral mechanical hypersensitivity without changing the levels of Trp, serotonin (5-HT), and kynurenine (KYN) in the brain. Hypersensitivity was reduced by exercise (~150%), Trp (~67%), and its combination (~160%). The Trp supplementation increased the levels of Trp and KYN in the brain, and the activity of indoleamine 2,3-dioxygenase (IDO), and decreased the ratio 5-HT:KYN. Exercise did not impact the assessed metabolites. Combining the treatments reduced neither hypersensitivity nor the levels of serotonin and Trp in the brain. In conclusion, mechanical hypersensitivity induced by acid saline in a fibromyalgia-like model in female rats is modulated by Trp supplementation, which increases IDO activity and leads to improved Trp metabolism via the KYN pathway. In contrast, physical exercise does not affect mechanical hypersensitivity through brain Trp metabolism via either the KYN or serotonin pathways. Because this is a short study, generalizing its findings warrants caution.

Pharmacological Treatment of Fibromyalgia Syndrome: A Practice-Based Review

PURPOSE OF REVIEW

Fibromyalgia Syndrome (FMS) is a complex chronic pain condition characterized by widespread musculoskeletal pain and numerous other debilitating symptoms. The purpose of this review is to provide a comprehensive overview, based on everyday clinical practice, of the drugs presently employed in the treatment of FMS.

RECENT FINDINGS

The treatment of FMS is based on a multimodal approach, with pharmacologic treatment being an essential pillar. The drugs used include tricyclic antidepressants, serotonin and noradrenaline reuptake inhibitors, other antidepressants, anticonvulsants, myorelaxants, and analgesics. The effectiveness of these medications varies, and the choice of drug often depends on the specific symptoms presented by the patient. Many drugs tend to either address only some domains of the complex FMS symptomatology or have a limited effect on pain. Each treatment option comes with potential side effects and risks that necessitate careful consideration. It may be beneficial to divide patients into clinical subpopulations, such as FMS with comorbid depression, for more effective treatment. Despite the complexities and challenges, the pharmacological treatment remains a crucial part for the management of FMS. This review aims to guide clinicians in prescribing pharmacological treatment to individuals with FMS.

Neurokinin1 - cholinergic receptor mechanisms in the medial Septum-Dorsal hippocampus axis mediates experimental neuropathic pain

The neurokinin-1 receptors (NK1Rs) in the forebrain medial septum (MS) region are localized exclusively on cholinergic neurons that partly project to the hippocampus and the cingulate cortex (Cg), regions implicated in nociception. In the present study, we explored the hypothesis that neurotransmission at septal NK1R and hippocampal cholinergic mechanisms mediate experimental neuropathic pain in the rodent chronic constriction injury model (CCI). Our investigations showed that intraseptal microinjection of substance P (SP) in rat evoked a peripheral hypersensitivity (PH)-like response in uninjured animals that was attenuated by systemic atropine sulphate, a muscarinic-cholinergic receptor antagonist. Conversely, pre-emptive destruction of septal cholinergic neurons attenuated the development of PH in the CCI model that also prevented the expression of cellular markers of nociception in the spinal cord and the forebrain. Likewise, anti-nociception was evoked on intraseptal microinjection of L-733,060, an antagonist at NK1Rs, and on bilateral or unilateral microinjection of the cholinergic receptor antagonists, atropine or mecamylamine, into the different regions of the dorsal hippocampus (dH) or on bilateral microinjection into the Cg. Interestingly, the effect of L-733,060 was accompanied with a widespread decreased in levels of CCI-induced nociceptive cellular markers in forebrain that was not secondary to behaviour, suggesting an active modulation of nociceptive processing by transmission at NK1R in the medial septum. The preceding suggest that the development and maintenance of neuropathic nociception is facilitated by septal NK1R-dH cholinergic mechanisms which co-ordinately affect nociceptive processing in the dH and the Cg. Additionally, the data points to a potential strategy for pain modulation that combines anticholinergics and anti-NKRs.

Proteomics in Patients with Fibromyalgia Syndrome: A Systematic Review of Observational Studies

PURPOSE OF REVIEW

Fibromyalgia syndrome (FMS) is a disease of unknown pathophysiology, with the diagnosis being based on a set of clinical criteria. Proteomic analysis can provide significant biological information for the pathophysiology of the disease but may also reveal biomarkers for diagnosis or therapeutic targets. The present systematic review aims to synthesize the evidence regarding the proteome of adult patients with FMS using data from observational studies.

RECENT FINDINGS

An extensive literature search was conducted in MEDLINE/PubMed, CENTRAL, and clinicaltrials.gov from inception until November 2022. The study protocol was published in OSF. Two independent reviewers evaluated the studies and extracted data. The quality of studies was assessed using the modified Newcastle-Ottawa scale adjusted for proteomic research. Ten studies fulfilled the protocol criteria, identifying 3328 proteins, 145 of which were differentially expressed among patients with FMS against controls. The proteins were identified in plasma, serum, cerebrospinal fluid, and saliva samples. The control groups included healthy individuals and patients with pain (inflammatory and non-inflammatory). The most important proteins identified involved transferrin, α-, β-, and γ-fibrinogen chains, profilin-1, transaldolase, PGAM1, apolipoprotein-C3, complement C4A and C1QC, immunoglobin parts, and acute phase reactants. Weak correlations were observed between proteins and pain sensation, or quality of life scales, apart from the association of transferrin and a2-macroglobulin with moderate-to-severe pain sensation. The quality of included studies was moderate-to-good. FMS appears to be related to protein dysregulation in the complement and coagulation cascades and the metabolism of iron. Several proteins may be dysregulated due to the excessive oxidative stress response.

Psoriasis and Fibromyalgia: A Systematic Review

Psoriasis is a chronic inflammatory cutaneous condition characterized by several comorbidities, including musculoskeletal disorders. While the association with psoriatic arthritis has been widely addressed in literature, the aim of the present systematic review was to identify all available evidence on the relationship between psoriasis and fibromyalgia, a musculoskeletal syndrome primarily characterized by chronic widespread pain. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and MedLine and Web of Science (WOS) databases were searched for literature up to March 2023. After the removal of duplicate records, a total of 11 articles were deemed eligible for inclusion in a qualitative synthesis. Our results suggested that psoriatic patients had a higher prevalence of fibromyalgia (8-30%), with a very high impact on symptoms of psoriasis. Moreover, fibromyalgic patients had a slightly increased prevalence of psoriasis (2.2-6.7%) compared to the control groups. Finally, several studies demonstrated the substantial impact of fibromyalgia on psoriatic outcome measures in patients with concomitant psoriatic arthritis. In conclusion, available data support a potential interplay between psoriasis and fibromyalgia, but further research is encouraged in this area.

Alpha Calcitonin Gene-related Peptide, Neuropeptide Y, and Substance P as Biomarkers for Diagnosis and Disease Activity and Severity in Multiple Sclerosis

BACKGROUND

Alpha calcitonin gene-related peptide (aCGRP), neuropeptide Y (NPY), and substance P (SP) are neuropeptides that have emerged recently as potent immunomodulatory factors with potential as novel biomarkers and therapeutic targets in multiple sclerosis (MS).

OBJECTIVE

The study aimed to detect serum levels of aCGRP, NPY, and SP in MS patients versus healthy controls and their association with disease activity and severity.

METHODS

Serum levels were measured in MS patients and age and sex-matched healthy controls using ELISA.

RESULTS

We included 67 MS patients: 61 relapsing-remitting MS (RR-MS) and 6 progressive MS (PR-MS), and 67 healthy controls. Serum NPY level was found to be lower in MS patients than in healthy controls (p < 0.001). Serum aCGRP level was higher in PR-MS compared to RR-MS (p = 0.007) and healthy controls (p = 0.001), and it positively correlated with EDSS (r = 0.270, p = 0.028). Serum NPY level was significantly higher in RR-MS and PR-MS than in healthy controls (p < 0.001 and p = 0.001, respectively), and it was lower in patients with mild or moderate/severe disease than in healthy controls (p < 0.001). Significant inverse correlations were found between SP level and MS disease duration (r = -0.279, p = 0.022) and duration of current DMT (r = -0.315, p = 0.042).

CONCLUSION

Lower serum levels of NPY were revealed in MS patients compared to healthy controls. Since serum levels of aCGRP are significantly associated with disease activity and severity, it is a potential disease progression marker.

Myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia are indistinguishable by their cerebrospinal fluid proteomes

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and fibromyalgia have overlapping neurologic symptoms particularly disabling fatigue. This has given rise to the question whether they are distinct central nervous system (CNS) entities or is one an extension of the other.

MATERIAL AND METHODS

To investigate this, we used unbiased quantitative mass spectrometry-based proteomics to examine the most proximal fluid to the brain, cerebrospinal fluid (CSF). This was to ascertain if the proteome profile of one was the same or different from the other. We examined two separate groups of ME/CFS, one with (n = 15) and one without (n = 15) fibromyalgia.

RESULTS

We quantified a total of 2083 proteins using immunoaffinity depletion, tandem mass tag isobaric labelling and offline two-dimensional liquid chromatography coupled to tandem mass spectrometry, including 1789 that were quantified in all the CSF samples. ANOVA analysis did not yield any proteins with an adjusted p value <.05.

CONCLUSION

This supports the notion that ME/CFS and fibromyalgia as currently defined are not distinct entities.Key messageME/CFS and fibromyalgia as currently defined are not distinct entities.Unbiased quantitative mass spectrometry-based proteomics can be used to discover cerebrospinal fluid proteins that are biomarkers for a condition such as we are studying.

Fibromyalgia: Could hyperbaric oxygen therapy make the difference? Our experience

Fibromyalgia is a rare disease, difficult to diagnose and to treat. We think that hyperbaric oxygen therapy could improve its signs and symptoms although more evidences have to be accumulated.

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.

Psychoeducation for Fibromyalgia Syndrome: A Systematic Review of Emotional, Clinical and Functional Related-Outcomes

Fibromyalgia Syndrome (FMS) is a chronic condition of widespread pain accompanied by several symptoms such as stiffness, fatigue, sleep problems, depression, anxiety, and cognitive deficits. To date, there is no specific treatment for FMS. The European League Against Rheumatism, and the majority of the international recommendations for managing FMS, has claimed psychoeducational intervention as the first step in FMS treatment for adequate symptoms management. However, scientific studies in this regard are scarce, diverse, and with contradictory findings. Results integration from analogous studies could provide a clear presentation of the real clinical value of psychoeducation in FMS. Therefore, the current systematic review aims at exploring the effect of psychoeducation on emotional, clinical, and functional symptoms of FMS patients and encourages researchers towards psychoeducation's procedure optimization and systematization. The systematic review was conducted according to the guidelines of the Cochrane Collaboration and PRISMA statements. The selected articles were evaluated using the Cochrane risk of bias (ROB) assessment tool. The selected articles were extracted from PubMed, Scopus, and Web of Science databases. The literature search identified 11 studies eligible for the systematic review. The ROB evaluation revealed that 2 of the 11 studies showed a low quality, the other 2 had a moderate quality, and the remaining 7 studies exhibited a high quality. Results showed that psychoeducation is generally included as an important first therapeutic step in multicomponent treatments for FMS. Moreover, psychoeducation generally seems to be quite beneficial in reducing emotional (i.e., number of days feeling emotionally well, general anxiety, depression levels, etc.) and clinical symptoms (levels of fatigue, morning stiffness, pain intensity, etc.), as well as increasing functional status (i.e., general physical function, morning fatigue, stiffness, etc.). Despite that psychoeducation´s clinical benefits are highlighted, there is scarce amount of research on psychoeducation beyond its usefulness as part of multicomponent treatments.

Microglia polarization in nociplastic pain: mechanisms and perspectives

Nociplastic pain is the third classification of pain as described by the International Association for the Study of Pain (IASP), in addition to the neuropathic and nociceptive pain classes. The main pathophysiological mechanism for developing nociplastic pain is central sensitization (CS) in which pain amplification and hypersensitivity occur. Fibromyalgia is the prototypical nociplastic pain disorder, characterized by allodynia and hyperalgesia. Much scientific data suggest that classical activation of microglia in the spinal cord mediates neuroinflammation which plays an essential role in developing CS. In this review article, we discuss the impact of microglia activation and M1/M2 polarization on developing neuroinflammation and nociplastic pain, besides the molecular mechanisms engaged in this process. In addition, we mention the impact of microglial modulators on M1/M2 microglial polarization that offers a novel therapeutic alternative for the management of nociplastic pain disorders. Illustrating the mechanisms underlying microglia activation in central sensitization and nociplastic pain. LPS lipopolysaccharide, TNF-α tumor necrosis factor-α, INF-γ Interferon gamma, ATP adenosine triphosphate, 49 P2Y12/13R purinergic P2Y 12/13 receptor, P2X4/7R purinergic P2X 4/7 receptor, SP Substance P, NK-1R Neurokinin 1 receptor, CCL2 CC motif ligand 2, CCR2 CC motif ligand 2 receptor, CSF-1 colony-stimulating factor 1, CSF-1R colony-stimulating factor 1 receptor, CX3CL1 CX3C motif ligand 1, CX3XR1 CX3C motif ligand 1 receptor, TLR toll-like receptor, MAPK mitogen-activated protein kinases, JNK jun N-terminal kinase, ERK extracellular signal-regulated kinase, iNOS Inducible nitric oxide synthase, IL-1β interleukin-1β, IL-6 interleukin-6, BDNF brain-derived neurotrophic factor, GABA γ-Aminobutyric acid, GABAR γ-Aminobutyric acid receptor, NMDAR N-methyl-D-aspartate receptor, AMPAR α-amino-3-hydroxy-5-methyl-4-isoxazolepropi-onic acid receptor, IL-4 interleukin-4, IL-13 interleukin-13, IL-10 interleukin-10, Arg-1 Arginase 1, FGF fibroblast growth factor, GDNF glial cell-derived neurotrophic factor, IGF-1 insulin-like growth factor-1, NGF nerve growth factor, CD Cluster of differentiation.

Cannabinoids and the endocannabinoid system in fibromyalgia: A review of preclinical and clinical research

Characterised by chronic widespread musculoskeletal pain, generalised hyperalgesia, and psychological distress, fibromyalgia (FM) is a significant unmet clinical need. The endogenous cannabinoid system plays an important role in modulating both pain and the stress response. Here, we appraise the evidence, from preclinical and clinical studies, for a role of the endocannabinoid system in FM and the therapeutic potential of targeting the endocannabinoid system. While many animal models have been used to study FM, the reserpine-induced myalgia model has emerged as perhaps the most translatable to the clinical phenotype. Inhibition of fatty acid amide hydrolase (FAAH) has shown promise in preclinical studies, ameliorating pain- and anxiety-related behaviour . Clinically, there is evidence for alterations in the endocannabinoid system in patients with FM, including single nucleotide polymorphisms and increased levels of circulating endocannabinoids and related N-acylethanolamines. Single entity cannabinoids, cannabis, and cannabis-based medicines in patients with FM show promise therapeutically but limitations in methodology and lack of longitudinal studies to assess efficacy and tolerability preclude the current recommendation for their use in patients with FM. Gaps in the literature that warrant further investigation are discussed, particularly the need for further development of animal models with high validity for the multifaceted nature of FM, balanced studies to eliminate sex-bias in preclinical research, and ultimately, better translation between preclinical and clinical research.

Oxidative Stress in Fibromyalgia: From Pathology to Treatment

Fibromyalgia (FM) is characterized by chronic widespread musculoskeletal pain associated with sleep problems, fatigue, depression, and anxiety. The persistence of pain, impairment of cognitive function, and negative impact on the psychological state have caused a detrimental effect on the patients' quality of life. However, to date, the treatment and mechanisms of this disease are yet to be established. Oxidative stress might play a critical role in FM pathophysiology. Increased levels of prooxidative factors such as nitric oxide, lipid peroxidation, and mitophagy can cause pain sensitization in fibromyalgia. Numerous studies have supported the hypothesis of beneficial antioxidative effects in FM. Due to the lack of effective therapy for fibromyalgia, many treatments are sought to reduce pain and fatigue and improve patients' quality of life. This manuscript discusses the impact of various antioxidative procedures that can diminish fibromyalgia symptoms, such as hyperbaric oxygen therapy, modification of dietary habits, and physical activity.

Knowledge Mapping of Acupuncture for Fibromyalgia from 1990 to 2022: A Bibliometric Analysis

Background

Fibromyalgia is a rheumatic disease with no specific laboratory markers and is insensitive to hormonal drugs and nonsteroidal anti-inflammatory drugs commonly used to treat rheumatism. Guidelines recommend that non-pharmacological therapy should be the first-line treatment for fibromyalgia. Since the publication of the first diagnostic criteria for fibromyalgia in 1990, studies on acupuncture for fibromyalgia have been reported periodically. This study aims to explore the intellectual landscape of acupuncture for fibromyalgia since 1990, and to identify research trends and fronts in this field.

Methods

The Web of Science Core Collection Database was searched for publications on acupuncture for fibromyalgia from 1990 to 2022. VOSviewer and CiteSpace were used to analyze the annual publication, countries, institutions, authors and cited authors, journals and cited journals, references and keywords.

Results

A total of 280 publications were retrieved, and the number of publications showed an overall upward trend. The United States was the most productive country. China Medical University was the institution with the most publications. Lin Yi-wen was the most prolific author, while Wolfe was the most cited author. Evidence-Based Complementary and Alternative Medicine was the journal in which most of the research was published, while Pain was the most cited journal. An article by Wolfe (1990) had the most citations, but an article by Crofford (2001) had the highest centrality. The four most frequently used keywords in the included articles were mechanism, spinal cord, activation and sensitivity.

Conclusion

Acupuncture can effectively relieve pain in patients with fibromyalgia and improve accompanying symptoms such as anxiety and depression. However, the design of clinical trials still needs to be optimized to better verify the efficacy of acupuncture on various clinical symptoms of fibromyalgia. Exploring the central analgesic mechanism of acupuncture on fibromyalgia is also the focus research direction now and future.

Advances in the management of fibromyalgia: what is the state of the art?

INTRODUCTION

Fibromyalgia (FM) is a chronic pain syndrome associated with fatigue, insomnia, dyscognition, and emotional distress. Critical illness mechanisms include central sensitization to nociceptive and non-nociceptive stimuli often resulting in hypersensitivity to all sensory input.

AREAS COVERED

The clinical presentation of FM can vary widely and therefore requires therapies tailored to each patient's set of symptoms. This manuscript examines currently prescribed therapeutic approaches supported by empirical evidence as well as promising novel treatments. Although pharmacological therapy until now has been only moderately effective for FM symptoms, it represents a critical component of every treatment plan.

EXPERT OPINION

Currently approved pharmacological therapies for FM symptoms have limited but proven effectiveness. Novel therapies with cannabinoids and naltrexone appear promising. Recent functional imaging studies of FM have discovered multiple brain network abnormalities that may provide novel targets for mechanism-based therapies. Future treatment approaches, however, need to improve more than clinical pain but also other FM domains like fatigue, insomnia, and distress.

Antihistamine promotes electroacupuncture analgesia in healthy human subjects: A pilot study

Background and aim

We have previously reported that histamine H₁ receptor antagonists facilitate electroacupuncture (EA) analgesia in experimental animals. In this pilot study, we sought to determine whether the histamine H₁ receptor antagonist dexchlorpheniramine (DCPA) facilitates EA analgesia in healthy human subjects.

Experimental procedure

Forty healthy subjects aged 20–30 years were randomly allocated to 1 of 4 groups: (1) sham EA at acupoints Zusanli (ST36) and Yanglingquan (GB34) (sham EA; n = 10); (2) EA at ST36 and GB34 (n = 10); (3) EA at ST36 and GB34 plus low-dose DCPA (2 mg, n = 10); (4) EA at ST36 and GB34 plus high-dose DCPA (4 mg, n = 10). Before and after acupuncture treatment, pain thresholds were determined by transcutaneous electrical stimuli on the glabrous skin of the left upper arm.

Results

After the acupuncture session, subjects in the EA plus high-dose DCPA group had a significantly higher pain threshold elevation compared with the other 3 study groups. The change from baseline in pain threshold in the EA plus high-dose DCPA group was significantly greater than the change in pain threshold with EA only, indicating that DCPA 4 mg facilitated EA analgesia.

Conclusion

The results suggest that combining H₁ receptor antagonist treatment with EA appears to relieve pain to a greater extent compared with EA alone. This study is registered with ClinicalTrials.gov (https://clinicaltrials.gov/), number NCT03805035 (https://clinicaltrials.gov/ct2/show/NCT03805035).

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Histamine H₁ receptor antagonist treatment appears to augment the pain-relieving effects of EA in healthy subjects.

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EA increased the pain thresholds in EA treated groups.

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Combination of EA and high-dose of DCPA further increased pain thresholds.

The use of Pilates for pain control in patients with fibromyalgia

Abstract Introduction: Although the Pilates method is commonly used to treat fibromyalgia (FM) in clinical practice, research is scarce, and little is known about its real effectiveness in pain management. Objective: Systematically review the literature to determine whether Pilates affects pain control in FM patients. Methods: The PubMed, Science Direct, PEDro and Cochrane databases were searched to identify randomized controlled trials that investigated the effects of Pilates in individuals diagnosed with FM. The descriptors used were: “pilates based exercise” OR “pilates training” OR “pilates exercise” OR “pilates” AND “fibromyalgia.” Independent reviewers performed abstract/full-text screening, data extraction, and methodological quality assessments using the PEDro scale. Results: The search identified 646 potential articles, four of which were used in the analysis. The Pilates method had positive effects on pain control, physical function, quality of life and biopsychosocial factors such as stress and depression in individuals with FM in four studies. However, improvement in these parameters did not differ between intervention groups in three studies. Additionally, the control group showed no significant improvement for the same parameters in one study. The PEDro scale scores of the studies ranged from 6 to 8 points. Conclusion: Evidence suggests that Pilates influences pain control in individuals with FM, and is more effective than no intervention or minimal intervention in the treatment of FM.

Enhanced sensory conduction in primary fibromyalgia: a case–control pilot study

Background

This study aimed to test the changes in the conduction properties of peripheral nerves in patients with primary fibromyalgia (FM). Thirty patients with FM and sixteen healthy controls participated in this study. Visual analogue scale (VAS) for pain severity, pain duration, Widespread Pain Index (WPI), Symptom Severity (SS) scale, Hamilton depression rating scale, Taylor’s manifest anxiety scale, and Fibromyalgia Impact Questionnaire (FIQR) were used for measurement of psychiatric comorbidities and quality of life for each patient. Routine motor and sensory nerve conduction studies of both median, ulnar, common peroneal, posterior tibial, and sural nerves were measured for all study participants.

Results

We found statistically significant increase in Sensory Conduction Velocity (SCV), Sensory Nerve Action Potential (SNAP) amplitude, and decrease in Sensory Latency (SL) in patients with FM compared to controls. There were no significant changes in motor nerve conduction between patients and controls. Regression analysis showed a significant relation between WPI and both SCV and SL especially in nerves of upper limbs. However, no significant relation between SCV and SL and other presumed predictors including VAS for pain severity, pain duration, SS scale, FIQR, and psychiatric comorbidities. Patients with FM suffered more depression and anxiety than controls.

Conclusions

We found enhanced conductivity of the sensory rather than the motor nerves in patients with FM. To our knowledge, this is the first study to describe these sensory changes which may add further evidence of peripheral sensitization in patients with FM.

The Role of Nutrient Supplementation in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

The multifaceted clinical presentation of fibromyalgia (FM) supports the modern understanding of the disorder as a more global condition than one simply affecting pain sensation. The main pharmacologic therapies used clinically include anti-epileptics and anti-depressants. Conservative treatment options include exercise, myofascial release, psychotherapy, and nutrient supplementation.

METHODS

Narrative review.

RESULTS

Nutrient supplementation is a broadly investigated treatment modality as numerous deficiencies have been linked to FM. Additionally, a proposed link between gut microbiome patterns and chronic pain syndromes has led to studies investigating probiotics as a possible treatment. Despite positive results, much of the current evidence regarding this topic is of poor quality, with variable study designs, limited sample sizes, and lack of control groups.

CONCLUSIONS

The etiology of FM is complex, and has shown to be multi-factorial with genetics and environmental exposures lending influence into its development. Preliminary results are promising, however, much of the existing evidence regarding diet supplementation is of poor quality. Further, more robust studies are needed to fully elucidate the potential of this alternative therapeutic option.

Prevalence of Patients Affected by Fibromyalgia in a Cohort of Women Underwent Mammography Screening

Fibromyalgia is a widespread condition which is currently underdiagnosed; therefore we conceived this study in order to assess whether a diagnostic suspicion may be assumed during widespread screening procedures, so that patients for which a reasonable diagnostic suspicion exist may be redirected towards rheumatologic evaluation. We analyzed a sample of 1060 patients, all of whom were female and undergoing standard breast cancer screening procedures, and proceeded to evaluate the level of pain they endured during mammographic exam. We also acquired a range of other information which we related to the level of pain endured; we suggested a rheumatologic examination for those patients who endured the highest level of pain and then we evaluated how many patients in this subgroup were actually diagnosed with fibromyalgia. Out of the 1060 patients who participated to our study, 139 presented level 4 pain intensity; One patient did not go for rheumatologic examination; the remaining 138 underwent rheumatologic evaluation, and 50 (36%, 28-44, 95% CI) were diagnosed with fibromyalgia. Our study shows that assessing the level of pain endured by patients during standard widespread screening procedures may be an effective asset in deciding whether or not to suggest specialist rheumatologic evaluation for fibromyalgia.

MAO-A Inhibition by Metaxalone Reverts IL-1β-Induced Inflammatory Phenotype in Microglial Cells

Experimental and clinical studies have suggested that several neurological disorders are associated with the occurrence of central nervous system neuroinflammation. Metaxalone is an FDA-approved muscle relaxant that has been reported to inhibit monoamine oxidase A (MAO-A). The aim of this study was to investigate whether metaxalone might exert antioxidant and anti-inflammatory effects in HMC3 microglial cells. An inflammatory phenotype was induced in HMC3 microglial cells through stimulation with interleukin-1β (IL-1β). Control cells and IL-1β-stimulated cells were subsequently treated with metaxalone (10, 20, and 40 µM) for six hours. IL-1β stimulated the release of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), but reduced the anti-inflammatory cytokine interleukin-13 (IL-13). The upstream signal consisted of an increased priming of nuclear factor-kB (NF-kB), blunted peroxisome proliferator-activated receptor gamma (PPARγ), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression. IL-1β also augmented MAO-A expression/activity and malondialdehyde levels and decreased Nrf2 mRNA expression and protein levels. Metaxalone decreased MAO-A activity and expression, reduced NF-kB, TNF-α, and IL-6, enhanced IL-13, and also increased PPARγ, PGC-1α, and Nrf2 expression. The present experimental study suggests that metaxalone has potential for the treatment of several neurological disorders associated with neuroinflammation.

Spanish Translation and Cultural Adaptation of the Fibromyalgia Knowledge Questionnaire

INTRODUCTION

Fibromyalgia (FM) translates into a reduction in the quality of life of people who suffer from it, being a chronic disease of unknown etiology. One of the most widespread treatments includes the combination of patient education, along with other components. At the educational level, the Fibromyalgia Knowledge Questionnaire (FKQ) is a tool that assesses knowledge of fibromyalgia.

OBJECTIVE

To obtain the translation and cultural adaptation of the FKQ questionnaire into Spanish, as well as its readability, in addition to knowing the relationship between knowledge of the disease and the level of disability.

METHOD

In phase one, a translation-back translation and an evaluation of the readability of the questionnaire was carried out from INFLESZ, while in phase two, the questionnaire was passed to women with FM to detect their knowledge of the disease. A total of 49 women participated, with a mean age of 54.48 years.

RESULTS

The Spanish version of the FKQ questionnaire was rated by the participants in all its items as "clear and understandable". The readability obtained by the questionnaire was similar to its original version, with both totals being in the "normal" range, following the INFLESZ ranges. Regarding the patients' knowledge about FM, the component in which the highest score was obtained was physical activity (80% correct), while the one that obtained the worst score was knowledge about medication (50% correct). In addition, an inverse correlation was obtained between the FKQ and the FIQ (Fibromyalgia Impact Questionnaire) (r = -0.438; p < 0.01).

CONCLUSIONS

The FKQ has been translated and culturally adapted, obtaining a correct understanding by the participants, as well as a degree of readability similar to the original questionnaire. Furthermore, it was obtained that, the lower the level of knowledge of the sick person, the greater the disability.

Nutritional Supplements for the Treatment of Neuropathic Pain

Neuropathic pain affects 7-10% of the population and is often ineffectively and incompletely treated. Although the gold standard for treatment of neuropathic pain includes tricyclic antidepressants (TCAs), serotonin-noradrenaline reuptake inhibitors, and anticonvulsants, patients suffering from neuropathic pain are increasingly turning to nonpharmacologic treatments, including nutritional supplements for analgesia. So-called "nutraceuticals" have garnered significant interest among patients seeking to self-treat their neuropathic pain with readily available supplements. The supplements most often used by patients include vitamins such as vitamin B and vitamin D, trace minerals zinc and magnesium, and herbal remedies such as curcumin and St. John's Wort. However, evidence surrounding the efficacy and mechanisms of these supplements in neuropathic pain is limited, and the scientific literature consists primarily of preclinical animal models, case studies, and small randomized controlled trials (RCTs). Further exploration into large randomized controlled trials is needed to fully inform patients and physicians on the utility of these supplements in neuropathic pain. In this review, we explore the basis behind using several nutritional supplements commonly used by patients with neuropathic pain seen in rheumatology clinics.

Neurophysiological mechanisms of chiropractic spinal manipulation for spine pain

Together, neck pain and back pain are the first cause of disability worldwide, accounting for more than 10% of the total years lived with disability. In this context, chiropractic care provides a safe and effective option for the management of a large proportion of these patients. Chiropractic is a healthcare profession mainly focused on the spine and the treatment of spinal disorders, including spine pain. Basic studies have examined the influence of chiropractic spinal manipulation (SM) on a variety of peripheral, spinal and supraspinal mechanisms involved in spine pain. While spinal cord mechanisms of pain inhibition contribute at least partly to the pain-relieving effects of chiropractic treatments, the evidence is weaker regarding peripheral and supraspinal mechanisms, which are important components of acute and chronic pain. This narrative review highlights the most relevant mechanisms of pain relief by SM and provides a perspective for future research on SM and spine pain, including the validation of placebo interventions that control for placebo effects and other non-specific effects that may be induced by SM. SIGNIFICANCE: Spinal manipulation inhibits back and neck pain partly through spinal segmental mechanisms and potentially through peripheral mechanisms regulating inflammatory responses. Other mechanisms remain to be clarified. Controls and placebo interventions need to be improved in order to clarify the contribution of specific and non-specific effects to pain relief by spinal manipulative therapy.

The amino-terminal heptapeptide of the algesic substance P provides analgesic effect in relieving chronic neuropathic pain

Of painful conditions, somatic pain of acute nociceptive origin can be effectively managed clinically, while neuropathic pain of chronic neuropathy origin is difficult to control. For molecules involved in pain sensation, substance P (SP) is algesic, exacerbating painful sensation, while its amino-terminal fragment, heptapeptide SP(1-7), confers biological activities different from its full-length parent neuropeptide precursor. We previously demonstrated SP(1-7) interaction with pain processing to alleviate chronic pain. Here we evaluated SP(1-7) and its C-terminal amidated analogue SP(1-7)amide, together with SP and opioid agonist DAMGO. We tested mouse behaviors of both acute somatic pain in tail-flick latency assay, and neuropathic pain in sciatic nerve injury model of chronic constriction injury (CCI). DAMGO produced dose-dependent analgesia for somatic pain as expected, so did both SP(1-7) and its analogue SP(1-7)amide, while SP yielded the opposite effect of algesia, in a phenomenon we termed 'contrintus', meaning 'opposite from within' to denote that two peptides of the same origin (SP and its metabolic fragment SP(1-7)) produced opposite effects. In CCI model, DAMGO showed a general reduction in allodynia sensitivity for both nerve-injured and normal paws, without selective effect for neuropathic pain, consistent with clinical observation that opioids are less effective for chronic neuropathic pain. On the other hand, both SP(1-7) and SP(1-7)amide displayed dose-dependent anti-allodynia effect that is selective for neuropathic pain. These findings suggest that SP(1-7) and its analogue may be useful for developing pharmaceuticals to treat neuropathic pain.

Low-Dose Dextromethorphan for the Treatment of Fibromyalgia Pain: Results from a Longitudinal, Single-Blind, Placebo-Controlled Pilot Trial

Objective

Fibromyalgia (FM) is a debilitating chronic pain condition with few treatment options. Central sensitization and neuroinflammation have been forwarded as models of FM pathophysiology, both of which indicate dextromethorphan (DXM) as a potential treatment. DXM is an NMDA-receptor antagonist and microglial modulator with anti-neuroinflammatory properties at low doses. It is available for clinical use but has not been tested as a treatment for FM at low dosages. This study evaluated the effectiveness of DXM in treating FM-associated symptoms.

Methods

In a single-blind, placebo-controlled trial, 14 women meeting the 2010 American College of Rheumatology criteria for FM received a placebo for five weeks, followed by 20 mg DXM for ten weeks, while providing daily symptom reports on a 0–100 scale. Pain and physical activity were the primary and secondary outcomes, respectively. Daily symptom ratings during the last four weeks of placebo were contrasted with ratings during the last four weeks of the active treatment using generalized estimating equations (GEE).

Results

DXM was well tolerated, and treatment adherence was high. Baseline pain was reduced by at least 20% in six participants. Self-reported daily pain and physical activity in the entire cohort were not significantly different between the placebo and DXM conditions, and the primary hypotheses were not supported. Exploratory analyses using the entire placebo and DXM data showed that pain was significantly lower in the DXM condition than in the placebo condition (b=−9.933, p=0.013).

Discussion

A strong clinical effect of DXM was not observed at the 20mg/day dosage.

The Search for Biomarkers in Fibromyalgia

Fibromyalgia is the most common of the central sensitivity syndromes affecting 2–5% of the adult population in the United States. This pain amplification syndrome has enormous societal 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 healthcare resources towards more appropriate targeted therapy. Efforts have been made towards improving diagnostic accuracy through updated criteria. The search for biomarkers for diagnosis and verification of Fibromyalgia is an ongoing process. Inadequacies with current diagnostic criteria for this condition have fueled these efforts for identification of a reproducible marker that can verify this disease in a highly sensitive, specific and reproducible manner. This review focuses on areas of research for biomarkers in fibromyalgia and suggests that future efforts might benefit from approaches that utilize arrays of biomarkers to identify this disorder that presents with a diverse clinical phenotype.

Fibromyalgia Pain and Depression: An Update on the Role of Repetitive Transcranial Magnetic Stimulation

Fibromyalgia is a musculoskeletal pain of different parts of the body, which is also associated with fatigue, lack of sleep, cognition deficits, family history, gender bias, and other disorders such as osteoarthritis and rheumatoid arthritis. It is generally initiated after trauma, surgery, infection, or stress. Fibromyalgia often coexists with several other conditions or disorders such as temporomandibular joint disorders, bowel and bladder syndrome, anxiety, depression, headaches, and interstitial cystitis. While there is no permanent cure for fibromyalgia, some interventions are available with multiple side effects. rTMS (repetitive transcranial magnetic stimulation), a noninvasive management strategy is used widely for various pain-related etiologies including fibromyalgia in both the laboratory and clinical settings. In this Review, we discuss the role and mechanism of action of rTMS in fibromyalgia patients and on associated comorbidities including anxiety, pain, depression, neurotransmitter alterations, sleep disorders, and overall quality of life of the patients suffering from this chronic problem. We also provide an update on the rTMS application in the clinical trials of fibromyalgia patients and prospective management therapy for multiple problems that these patients suffer.

The Impact of Tinnitus on Fibromyalgia

Objective

Fibromyalgia (FM) is a disorder characterized by chronic diffuse pain and enhanced pain response to stimuli and is caused by central sensitization Tinnitus also is related to central sensitization So we investigated the impact of tinnitus on FM.

Methods

We included 22 FM patients with tinnitus and 25 FM patients without tinnitus We assessed a range of symptoms using the Widespread Pain Index; Symptom Severity Score scale; Visual Analogue Scale of pain; and the Korean versions of the Fibromyalgia Impact Questionnaire (FIQ), the Insomnia Severity Index, and the Short-form Health Survey (SF-36) Information about the severity of tinnitus in FM patients was evaluated using the Korean version of the Tinnitus Handicap Questionnaire (THQ-K).

Results

There were significant differences between the group that had mild tinnitus (THQ<38) and the group that had moderate-to-severe tinnitus (THQ≥38) for FIQ score (p=0025) and for the physical functioning (p=0003), social functioning (p=0035), and mental health (p=0017) components of the SF-36 Also, after dividing patients into 2 groups according to insomnia severity, significant differences were observed in FIQ score (p=0002) and in body pain (p=0001), general health (p=0008), vitality (p=0003), social functioning (p=0003), role limitation due to emotional condition (p=0001), and mental health (p<0001) components of the SF-36.

Conclusion

The FM patients with severe tinnitus had more functional impairments and lower quality of life than those with mild tinnitus Severe insomnia also was accompanied by worse health status and lower quality of life.

Fibromyalgia: practical considerations for oral health care providers

Fibromyalgia is a syndrome characterized by chronic pain in the skeletal system accompanied by stiffness, sleep disturbance, fatigue, and psychiatric problems, such as anxiety and depression. Fibromyalgia commonly affects orofacial health, presenting with a variety of oral manifestations, including temporomandibular disorder, xerostomia, glossodynia, and dysgeusia. Therefore, oral healthcare providers need to be aware of this clinical entity to effectively manage oral symptoms and provide proper oral self-care modification and education on the nature of fibromyalgia. This review focuses on the epidemiology, pathophysiology, clinical manifestation, diagnosis, orofacial concerns, and treatment of fibromyalgia.

Impact of Acupuncture Intervention on the Pain Intensity of Patients Treated at a Tertiary Hospital in Brazil

BACKGROUND

Nowadays, in western societies, acupuncture is widely used over the control of pain and this analgesic approach is still the most studied aspect of acupuncture. Several studies have shown that most patients go through a significant pain decrease soon after the first sessions of acupuncture.

OBJECTIVES

This research has as a goal the evaluation on the effect of acupuncture treatment regarding the relief of pain intensity of different etiologies, through the visual analog scale.

METHODS

This research constitutes a retrospective, descriptive study, carried out with 449 patients attended in the Institute Hospital de Base of the Federal District, in Brasilia city- Brazil. Every data was gathered from our own form, with detailed clinical history which included age, marital status, work activity, reason for referral to acupuncture, main and secondary complaints, pain intensity evaluated by the Visual Analog Scale (VAS), number of sessions completed and drug therapy. All data was organized in the Microsoft Excel and processed in the Statistical Package for the Social Sciences (SPSS), version 20.0.

RESULTS

Regarding the main complaint, the mean pain decreased from 7.3 (initial VAS) to 3.2 (final VAS), a reduction that meant more than 50% relief in pain intensity. This 50% reduction in initial pain was also observed in secondary complaints (initial VAS = 6.5 and final VAS = 3.1).

CONCLUSIONS

The results of this research suggest that acupuncture treatment was effective in relieving pain intensity, providing a 50% reduction on the visual analogue scale, in relation to painful complaints of different etiologies.

Is hypovitaminosis D associated with fibromyalgia? A systematic review

CONTEXT

Recent findings have suggested a high prevalence of vitamin D deficiency or insufficiency in fibromyalgia (FM) patients despite the lack of clinical and pathophysiological evidence.

OBJECTIVE

A systematic review was conducted to examine the association between vitamin D status and FM, including the effect of vitamin D supplementation.

DATA SOURCE

PubMed, LILACS, Scopus, SciELO, Cochrane, and EMBASE were searched, from January 2000 to July 2018, using the descriptors "Fibromyalgia" and "Vitamin D."

STUDY SELECTION

Trials including FM patients in whom vitamin D levels were assessed were eligible for inclusion.

DATA EXTRACTION

Data comprised age, gender, country, aims, bias, diagnosis criteria, cutoff point, and status of vitamin D, together with FM symptoms and vitamin D supplementation protocol.

RESULTS

A total of 26 articles were selected. Most of the studies were found to present unreliable control groups and small samples. Experimental data on vitamin D supplementation indicated improvement in certain FM symptoms.

CONCLUSION

Prevalence of hypovitaminosis D in the FM population and the cause-effect relationship were inconclusive. Nevertheless, vitamin D supplementation may be considered as a co-adjuvant in FM therapy.

Key Milestones Contributing to the Understanding of the Mechanisms Underlying Fibromyalgia

The promulgation of the American College of Rheumatology (ACR) 1990 criteria for fibromyalgia (FM) classification has significantly contributed to an era of increased research into mechanisms that underlie the disorder. The previous emphasis on putative peripheral nociceptive mechanisms has advanced to identifying of changes in central neural networks that modulate pain and other sensory processes. The influences of psychosocial factors on the dynamic and complex neurobiological mechanisms involved in the fibromyalgia clinical phenotype are now better defined. This review highlights key milestones that have directed knowledge concerning the fundamental mechanisms contributing to fibromyalgia.

The Antiallodynic Effect of Nefopam on Vincristine-Induced Neuropathy in Mice

Background

Chemotherapy-induced neuropathic pain is a disabling condition following cancer treatment. Vincristine has more neurotoxicity than other vinca alkaloid agents. This study evaluated the correlation of different doses of nefopam with antiallodynic effects in a mouse vincristine neuropathy model.

Methods

A peripheral neuropathic mouse model was made by intraperitoneal injection of vincristine (0.1 mg/kg/day; 5-day-on, 2-day-off schedule over 12 days). After the development of allodynia, mice were injected intraperitoneally with 0.9% normal saline (NS group) or various doses (10, 30, 60 mg/kg) of nefopam (Nefopam group). We examined allodynia using von Frey hairs pre-administration and at 30, 60, 90, 120, 180, 240 mins, and 24 hrs after drug administration. We also measured the neurokinin-1 receptor concentrations in the spinal cord to confirm the antiallodynic effect of nefopam after drug administration.

Results

The peripheral neuropathic mouse model showed prominent mechanical allodynia. Intraperitoneal nefopam produced a clear dose-dependent increase in paw withdrawal threshold compared with pre-administration values and versus the NS group. The concentration of neurokinin-1 receptor was significantly decreased in the Nefopam group (P<0.05).

Conclusion

Intraperitoneally administered nefopam yielded a dose-dependent attenuation of mechanical allodynia and decreased neurokinin-1 receptor concentration, suggesting that the neurokinin-1 receptor is involved in the antiallodynic effects of nefopam in vincristine neuropathy.

An investigation of serum irisin levels and inflammatory markers in fibromyalgia syndrome

OBJECTIVE:

In the present study, we aimed to compare serum irisin levels in patients with fibromyalgia syndrome (FMS) and healthy control subjects and also investigate the relationship between irisin, disease activity and inflammation markers in patients.

METHODS:

A total of 84 women, including 48 patients who were diagnosed with FMS and 36 healthy controls, were included in this study. The demographic characteristics of the patients and control group were recorded. VAS for pain and the Fibromyalgia Impact Questionnaire for the assessment of the physical function of the patients, SF36 was used for quality of life, and accompanying Beck Depression Inventory to assess depression was used. Blood samples were taken for analysis that irisin, and inflammatory markers of the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), high-sensitivity C-reactive protein (hs-CRP) and neutrophil/lymphocyte ratio (NLO). Serum irisin levels were determined using the Enzyme-Linked Immunosorbent Assay (ELISA) method.

RESULTS:

Serum irisin level of the patients with FMS had no significant differences compared with the healthy control group. When we compared the values of ESR, CRP, hsCRP, NLO with FMS patients and healthy controls, there was no significant difference found between them (p>0.05). There was no significant correlation between inflammatory markers and level of serum irisin (p>0.05). In patients, there was no significant correlation between inflammatory markers and level of serum irisin (p>0.05).

CONCLUSION:

Irisin, which is a myokine, was determined to have no significant role in the pathogenesis of FMS. Irisin had no association with disease activity and inflammatory markers. Also, the inflammation hypothesis was not supported, which suggested in FMS.

The gadolinium hypothesis for fibromyalgia and unexplained widespread chronic pain

Fibromyalgia (FM) is a chronic, painful, heterogeneous, and common disorder carrying a substantial socio-economical burden. It lacks effective cures and its aetiology is still unknown. There exists evidence for central and peripheral neurological contribution to the symptoms but grasping the real source of abnormal nervous system sensitization remains an ongoing challenge. There exists an association between an injury/trauma and the onset of the symptoms, but a causal relationship has not been yet sufficiently supported by scientific evidence. I postulate a role for gadolinium-based contrast agents and retention of gadolinium in the body. This conjecture breaks the hypothesis of a direct role for a physical injury/trauma per se in favour of an indirect one by the subsequent diagnostic procedures. It creates a new link between retention of gadolinium in the body and painful conditions as FM and unexplained chronic widespread pain reported after a trauma, surgery, or medical illness. Experimental evidence demonstrates possible retention of gadolinium species in human body, still lacking conclusive answers on their pathological consequences. Notwithstanding, there exist some initial data that report unexplained chronic widespread pain and symptoms of FM in those patients: they are suggestive for pathological consequences associated with gadolinium retention. Besides clear compelling symptoms overlapping, biochemical findings are provided to sustain the hypothesis of a role for gadolinium in the disease process focusing on neurotransmitters, endogenous metal cations, cytokines, and muscle tissue. Experimental findings strongly support the hypothesis of impairment at the cellular, intracellular, and systemic levels in FM. And these data are highly compatible with collateral effects associated with the interference of the gadolinium ion and its pharmaceutical chelates into biochemical pathways in vivo. The hypothesis presented in this article, along with the support of scientific evidence, links FM and unexplained chronic widespread pain reported after a trauma, surgery, or medical illness to retention of gadolinium in the body. If the hypothesis is confirmed, it could improve diagnosis and prevention, while providing a ground for development of new treatments.

Effects of an Extract of Salmon Milt on Symptoms and Serum TNF and Substance P in Patients With Fibromyalgia Syndrome

PURPOSE

The aim of this study was to evaluate the effects of a dietary supplement containing primarily an extract of salmon's milt (semen) on symptoms and blood levels of proinflammatory molecules in patients with fibromyalgia syndrome (FMS), a chronic, painful musculoskeletal disease without a distinct pathogenesis or treatment. We recently reported increased serum levels of the proinflammatory molecules substance P (SP) and tumor necrosis factor (TNF) in patients with FMS as compared to those in normal controls.

METHODS

This prospective, open-label study was conducted in patients with FMS (n = 87; 80 women, 7 men; age range, 18-80 years) selected from 2 clinical centers in Spain. Patients were administered the supplement and were evaluated at weeks 1 (before treatment), 4, 8, and 12 (end of treatment) for clinical parameters of functioning, fatigue, and pain, as well as overall impression. Patients were directed to take 1 capsule per day in the morning for the first 4 weeks, followed by 1 capsule in the morning and 1 capsule in the evening for the remaining 8 weeks. Differences in symptom scores in patients with FMS between weeks 1 and weeks 4, 8, and 12 were evaluated using ANOVA. Blood was obtained and serum separated in patients with FMS at 1 and 12 weeks and in a separate population of healthy controls (n = 20; 15 women, 5 men; age range, 25-65 years). Serum levels of SP and TNF were measured in patients with FMS at 1 and 12 weeks and in healthy controls by ELISA. TNF and SP levels in patients with FMS were compared between weeks 1 and 12, as well as between patients with FMS and untreated controls, using the Mann-Whitney U test.

FINDINGS

Clinical parameters of functioning, fatigue, and pain, as well as overall impression, were improved significantly at 4 weeks as compared to 1 week and remained unchanged for the duration of the study (all, P < 0.0001). Serum TNF and SP levels were significantly elevated at 1 week in patients with FMS compared to controls and were decreased significantly at 12 weeks as compared to 1 week (all, P < 0.0001).

IMPLICATIONS

Our findings indicate that this dietary supplement may significantly improve symptoms in patients with FMS. This is the first time to our knowledge that any molecule has been reported to be associated with a reduction in serum SP level. Consequently, the supplement or its hypothesized main active ingredient, spermine, may be developed as a novel treatment approach to FMS or other neuroinflammatory conditions. ClinicalTrials.gov identifier: NCT03911882.

Fibromyalgia as a Predictor of Complex Regional Pain Syndrome After Distal Radius Fracture

Background: Complex regional pain syndrome (CRPS) can be a devastating complication following extremity injury, but risk factors are not well understood. The purpose of this study was to investigate the association between fibromyalgia and the development of CRPS after distal radius fracture. Methods: The PearlDiver Medicare database was queried using International Classification of Diseases, 9th Revision (ICD-9) and Current Procedural Terminology (CPT) codes for diagnoses and treatments of distal radius fractures. Patients were separated into fibromyalgia and control cohorts, and the prevalence of CRPS was measured at 3, 6, 9, and 12 months from the date of injury or procedure. Demographic factors, treatment modality, and comorbid conditions were analyzed by multivariable logistic regression to reduce confounding and identify additional risk factors. Results: Database queries yielded 853 186 patients diagnosed or treated for distal radius fracture, with 6% having previous diagnosis of fibromyalgia. The prevalence of CRPS following distal radius fracture was increased at 3, 6, 9, and 12 months in the fibromyalgia cohort compared with the control c, with a 1-year incidence of 0.51% compared with 0.20% (odds ratio [OR], 2.54, P < .001). Multivariable logistic regression supported the association, with estimated OR of 2.0 (P < .001). In addition, female gender, surgical or manipulative treatment, and anxiety were positively associated with CRPS, and age >65, diabetes, and heart failure were negatively associated. Conclusions: While the basis of the association between fibromyalgia and CRPS is unknown, our data suggest that it could serve as a useful predictor of CRPS risk, promoting increased vigilance for CRPS symptoms and earlier recognition and treatment, thereby improving patient outcomes.

Ion Channels Involved in Substance P-Mediated Nociception and Antinociception

Substance P (SP), an 11-amino-acid neuropeptide, has long been considered an effector of pain. However, accumulating studies have proposed a paradoxical role of SP in anti-nociception. Here, we review studies of SP-mediated nociception and anti-nociception in terms of peptide features, SP-modulated ion channels, and differential effector systems underlying neurokinin 1 receptors (NK1Rs) in differential cell types to elucidate the effect of SP and further our understanding of SP in anti-nociception. Most importantly, understanding the anti-nociceptive SP-NK1R pathway would provide new insights for analgesic drug development.

The GC-MS metabolomics signature in patients with fibromyalgia syndrome directs to dysbiosis as an aspect contributing factor of FMS pathophysiology

INTRODUCTION

Fibromyalgia syndrome (FMS) is a chronic pain syndrome. Previous analyses of untargeted metabolomics data indicated altered metabolic profile in FMS patients.

OBJECTIVES

We report a semi-targeted explorative metabolomics study on the urinary metabolite profile of FMS patients; exploring the potential of urinary metabolite information to augment existing medical diagnosis.

METHODS

All cases were females. Patients had a medical history of persistent FMS (n = 18). Control groups were first-generation family members of the patients (n = 11), age-related individuals without indications of FMS (n = 10), and healthy, young (18-22 years) individuals (n = 41). The biofluid investigated was early morning urine samples. Data generation was done through gas chromatography-mass spectrometry (GC-MS) analysis and data processing and analyses were performed using Matlab, R, SPSS and SAS software.

RESULTS

Quantitative analysis revealed the presence of 196 metabolites. Unsupervised and supervised multivariate analyses distinguished all three control groups and the FMS patients, which could be related to 14 significantly increased metabolites. These metabolites are associated with energy metabolism, digestion and metabolism of carbohydrates and other host and gut metabolites.

CONCLUSIONS

Overall, urinary metabolite profiles in the FMS patients suggest: (1) energy utilization is a central aspect of this pain disorder, (2) dysbiosis seems to prevail in FMS patients, indicated by disrupted microbiota metabolites, supporting the model that microbiota may alter brain function through the gut-brain axis, with the gut being a gateway to generalized pain, and (3) screening of urine from FMS is an avenue to explore for adding non-invasive clinical information for diagnosis and treatment of FMS.

Nanotechnology: A Promising New Paradigm for the Control of Pain

Objective

The objective of this article is to critically review both preclinical and clinical studies that focus on the use of nanotechnology for both acute and chronic pain management, surveying both diagnostic and therapeutic applications. The article also provides information on nanotechnology for pain practitioners, so that they may better understand how this technology works and how it may be applied to their day-to-day clinical practice.

Study Design

Narrative review.

Methods

The Pubmed NCBI and EMBASE databases were utilized to review published reports of in vivo and clinical studies that focus on using nanotechnology for pain management applications in both the acute and chronic pain settings.

Results

Articles were screened by title, abstract, and full article review. They were then analyzed by specific clinical indications, and appropriate data were presented based on a critical analysis of those articles.

Conclusions

As the development of nanomedical applications in acute and chronic pain management continues, medical practitioners should consider their growing potential to enhance the care of patients who are consistently living with pain. Current barriers to implementation include manufacturing scale-up for commercial viability, long-term nanoparticle toxicity considerations, and high cost for successful passage through clinical trials. These challenges will need to be overcome with ongoing translational research efforts in collaboration with industry and government bodies such as the Food and Drug Administration (FDA).

The Role of Complementary and Alternative Medicine Treatments in Fibromyalgia: a Comprehensive Review

PURPOSE OF REVIEW

Fibromyalgia is a complex chronic pain syndrome that can have debilitating consequences for affected patients. When compared to the general population, patients with fibromyalgia experience lowered mechanical and thermal pain thresholds, altered temporal summation of painful stimuli, and higher than normal pain ratings for known noxious stimuli.

RECENT FINDINGS

There is no definitive cure for fibromyalgia and treatment primarily focuses on both symptom management and improving patient quality of life. This treatment strategy involves a comprehensive multidisciplinary approach consisting of lifestyle modifications, pharmacologic measures, and other complementary approaches including but not limited to acupuncture, yoga, tai chi, and meditation. This manuscript will discuss the diagnosis and treatment of fibromyalgia, as well as complementary and alternative therapies that should be considered by healthcare providers.

Decline of substance P levels after stress management with cognitive behaviour therapy in women with the fibromyalgia syndrome

Background and aims

Substance P (CSF-SP) is known to be elevated in females with fibromyalgia syndrome (FMS). The aims of this study were to evaluate the effect of cognitive behaviour therapy (CBT) on plasma SP levels in women with FMS and to find possible clinical behavioural correlates to plasma SP level changes.

Methods

Forty-eight women with FMS were randomly allocated into two groups. Group 1 received the CBT treatment intervention over the course of 6 months while group 2 was waitlisted. CBT was given with a protocol developed to diminish stress and pain. After 6 months, group 2 was given the same CBT treatment as well. All were followed up 1 year after the start of CBT treatment. This approach allowed for two analytical designs – a randomised controlled trial (RCT) (n=24 vs. n=24) and a before-and-after treatment design (n=48). All women were repeatedly evaluated by the West Haven-Yale Multidimensional Pain Inventory (MPI) and three other psychometric questionnaires and plasma SP was analysed.

Results

In the RCT design, the plasma SP level was 8.79 fmol/mL in both groups at the start of the trial, after adjustment for initial differences. At the end of the RCT, the plasma SP level was 5.25 fmol/mL in the CBT intervention group compared to 8.39 fmol/mL in the control group (p=0.02). In the before-and-after design, the plasma SP was reduced by 33% (p<0.01) after CBT, but returned to the pre-treatment level at follow-up 1 year after the start of CBT treatment. Plasma SP was associated with the MPI dimensions experienced “support from spouses or significant others” and “life control”.

Conclusions

Plasma SP might be a marker of the effect of CBT in FMS associated with better coping strategies and reduced stress rather than a biochemical marker of pain.

Exposure to Cold Unmasks Potential Biomarkers of Fibromyalgia Syndrome Reflecting Insufficient Sympathetic Responses to Stress

OBJECTIVES

Fibromyalgia syndrome (FMS) is a chronically painful condition whose symptoms are widely reported to be exacerbated by stress. We hypothesized that female patients with FMS differ from pain-free female controls in their sympathetic responses, a fact that may unmask important biomarkers and factors that contribute to the etiology of FMS.

MATERIALS AND METHODS

In a pilot study, blood pressure (BP), skin temperature, thermogenic activity, circulating glucose, and pain sensitivity of 13 individuals with FMS and 11 controls at room temperature (24°C) were compared with that after exposure to cold (19°C).

RESULTS

When measured at 24°C, BP, skin temperature, blood glucose, and brown adipose tissue (BAT) activity, measured using F-fluorodeoxyglucose positron-emission tomography/computed tomography, did not differ between controls and individuals with FMS. However, after cold exposure (19°C), BP and BAT activity increased in controls but not in individuals with FMS; skin temperature on the calf and arm decreased in controls more than in individiuals with FMS; and circulating glucose was lower in individiuals with FMS than in controls. Pain sensitivity did not change during the testing interval in response to cold.

DISCUSSION

The convergence of the effect of cold on 4 relatively simple measures of thermogenic, cardiovascular, and metabolic activity, each regulated by sympathetic activity, strongly indicate that individuals with FMS have impaired sympathetic responses to stress that are observable and highly significant even when measured in extraordinarily small sample populations. If insufficient sympathetic responses to stress are linked to FMS, stress may unmask and maximize these potential clinical biomarkers of FMS and be related to its etiology.

Salivary beta-endorphin and substance P are not biomarkers of neuropathic chronic pain propensity

Objective

The pathophysiology of chronic pain is complex, with most of our knowledge being derived from preclinical studies. The search for biomarkers mirroring the pathophysiology of chronic pain is ongoing, and there is an increasing interest in saliva as a diagnostic tool. Given what is known about salivary substance P and salivary gland innervation, we hypothesized that salivary substance P and/or beta-endorphin might reflect the basal activity of these neuropeptides in the central nervous system, thereby perhaps mirroring a general propensity to chronic pain. Based on this overall hypothesis, our aim was to compare salivary levels of these neuropeptides in chronic neuropathic pain patients with healthy controls. An additional aim was to relate salivary levels to plasma levels.

Materials and methods

We compared salivary concentrations of beta-endorphin and substance P in 14 chronic neuropathic pain patients with concentrations in 18 healthy controls using a Luminex technology kit. Salivary-to-plasma quotients were also calculated.

Results

We found no significant difference between the groups' salivary concentrations of substance P and beta-endorphin. No correlation was found between salivary and plasma concentrations of each neuropeptide, which we hypothesize might point to local production of beta-endorphin and/or substance P in the salivary glands. Given high substance P salivary-to-plasma quotients, such a local production seems more likely for substance P than for beta-endorphin.

Conclusions

Propensity to neuropathic chronic pain was not substantiated by our analysis of salivary levels of substance P and/or beta-endorphin. However, we report salivary-to-plasma quotients that give potentially important physiological insight about these neuropeptides.