Neuroimaging of Fibromyalgia

Assessment of the therapeutic potential of lutein and beta-carotene nanodispersions in a rat model of fibromyalgia

Fibromyalgia (FM) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and cognitive impairment. Despite the availability of various treatment options, FM remains a challenging condition to manage. In the present study, we investigated the efficacy of formulated nanodispersions of lutein and beta-carotene in treating FM-related symptoms induced by reserpine in female Wistar rats. Several techniques have been implemented to assess this efficacy at various levels, including biochemical, bioelectrical, and behavioral. Namely, oxidative stress markers, monoamine levels, electrocorticography, pain threshold test, and open field test were conducted on control, FM-induced, and FM-treated groups of animals. Our results provided compelling evidence for the efficacy of carotenoid nanodispersions in treating FM-related symptoms. Specifically, we found that the dual action of the nanodispersion, as both antioxidant and antidepressant, accounted for their beneficial effects in treating FM. With further investigation, nano-carotenoids and particularly nano-lutein could potentially become an effective alternative treatment for patients with FM who do not respond to current treatment options.

Evaluating the Effect of Delayed Diagnosis on Disease Outcome in Fibromyalgia: A Multi-Center Cross-Sectional Study

Background

The impact of delayed diagnosis (DD) on fibromyalgia (FM) patients' symptomatology and disease outcome has not yet been systematically studied.

Objective

To analyze the predictors of DD and the influence of DD on FM aggravation and disease evaluation measures.

Methods

370 FM patients were interviewed prospectively for this study. The following information was obtained: DD, widespread pain index (WPI), symptom severity scale (SSS), polysymptomatic distress scale (PDS) scale (SSS + WPI), and tender points. We identified three groups of patients: early diagnosis (ED: 2 years; 83 patients), late diagnosis (LD: > 2-7 years; 198 patients), and very late diagnosis (VLD: > 7 years; 89 patients).

Results

The patients' average age was 33.9 (9.8) years, and 79% were female. The SSS, PDS, and tender point means were 7.8 (1.6), 16.46 (4.1), and 14.31 (2.3), respectively. The correlation between DD and SSS (r = 0.14), the PDS scale (r = 0.37), and FM tender points (r = 0.16) was significant, but not with WPI (r = 0.06). When the three groups were examined, the SSS mean was 7.54 (1.6), 7.73 (1.4), and 8.25 (1.7), respectively (P 0.008), while the PDS mean was 15 (3.8), 15.95 (3.8), and 18.96 (4.4), respectively (P 0.008). (P 0.001).

Conclusion

Early FM diagnosis is associated with lower SSS, total severity scale, and FM tender points, indicating a less severe condition.

The Role of Vitamin D in the Management of Chronic Pain in Fibromyalgia: A Narrative Review

INTRODUCTION

Fibromyalgia (FM) is a complex disorder characterized primarily by chronic, widespread musculoskeletal pain. Currently, the Food and Drug Administration (FDA) has approved the use of three medications to treat FM: pregabalin, duloxetine, and milnacipran. The pharmaceutical intervention has lacked consistent pain relief among all patients. Therefore, the investigation into alternative treatment options has grown in interest. This narrative review aims to evaluate the evidence regarding vitamin D for the treatment of FM.

METHODS

Narrative review.

RESULTS

Low serum vitamin D has been linked to various chronic pain states. An association between vitamin D deficiency and FM has been reported but is controversial in the literature. Some studies have documented the beneficial effects of vitamin D supplementation on reducing pain symptoms and improving the overall quality of life in those with FM. Despite these positive findings, many of the studies regarding this topic lack adequate power to make substantial conclusions about the effects of vitamin D on FM.

CONCLUSION

Existing studies provide promising results. However, additional high-quality data on vitamin D supplementation is needed before recommendations for pain management can be made. Vitamin D supplementation is inexpensive, has minimal side effects, and can benefit FM patients regardless of its efficacy in pain control. Additionally, high-quality studies are warranted to fully elucidate the potential of vitamin D to manage chronic pain in FM.

Cationic liposome-encapsulated carotenoids as a potential treatment for fibromyalgia in an animal model

The present study investigated the efficacy of cationic liposome-encapsulated carotenoids (lutein or beta-carotene) as a treatment in an animal model of fibromyalgia (FM). Preparation and characterization of the nano-sized cationic liposomal carotenoids have been carried out. FM has been induced in the experimental animals via successive subcutaneous reserpine injection (1 mg/kg). Animals were divided into four groups; control, reserpinized (Res), reserpinized and cationic liposomal lutein-treated (Res + CL-Lut), and reserpinized and liposomal beta-carotene-treated (Res + CL-Bc). Levels of norepinephrine (NE), dopamine (DA), and serotonin (5-HT), and oxidative stress markers (MDA, H₂O₂, NO, and GSH) were determined in the brain's cortical tissue of the different groups of animals. Furthermore, the spectral analysis of the electrocorticogram (ECoG) was carried out. Animal behavior was tested for different animal groups. Results showed a significant reduction in monoamines, an elevation of oxidative stress markers, a shift in the ECoG frequency band power, and a change in pain threshold of the reserpinized animals. A return to a non-significant difference from the control values of all the measured parameters has been obtained after two weeks of cationic liposomal carotenoid preparations treatment. The present findings shed more light on the validity of the reserpine model of FM and provide evidence for the antidepressant, antioxidant, and anti-nociceptive potential of the cationic liposomal carotenoids. The present results proofed that the natural product preparations on a nano-sized scale could be a good alternative to the pharmacological interventions for FM treatment.

Specialized, pro-resolving mediators as potential therapeutic agents for alleviating fibromyalgia symptomatology

OBJECTIVE

To present a hypothesis on a novel strategy in the treatment of fibromyalgia (FM).

DESIGN

A narrative review.

SETTING

FM as a disease remains a challenging concept for numerous reasons, including undefined etiopathogenesis, unclear triggers and unsuccessful treatment modalities. We hypothesize that the inflammatome, the entire set of molecules involved in inflammation, acting as a common pathophysiological instrument of gut dysbiosis, sarcopenia, and neuroinflammation, is one of the major mechanisms underlying FM pathogenesis. In this setup, dysbiosis is proposed as the primary trigger of the inflammatome, sarcopenia as the peripheral nociceptive source, and neuroinflammation as the central mechanism of pain sensitization, transmission and symptomatology of FM. Whereas neuroinflammation is highly-considered as a critical deleterious element in FM pathogenesis, the presumed pathogenic roles of sarcopenia and systemic inflammation remain controversial. Nevertheless, sarcopenia-associated processes and dysbiosis have been recently detected in FM individuals. The prevalence of pro-inflammatory factors in the cerebrospinal fluid and blood has been repeatedly observed in FM individuals, supporting an idea on the role of inflammatome in FM pathogenesis. As such, failed inflammation resolution might be one of the underlying pathogenic mechanisms. In accordance, the application of specialized, inflammation pro-resolving mediators (SPMs) seems most suitable for this goal.

CONCLUSIONS

The capability of various SPMs to prevent and attenuate pain has been repeatedly demonstrated in laboratory animal experiments. Since SPMs suppress inflammation in a manner that does not compromise host defense, they could be attractive and safe candidates for the alleviation of FM symptomatology, probably in combination with anti-dysbiotic medicine.

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 juvenile fibromyalgia syndrome (JFMS): a poorly defined disorder

Juvenile fibromyalgia syndrome (JFMS) is a chronic condition characterized by symptoms of chronic diffuse musculoskeletal pain and multiple painful tender points on palpation. It is often accompanied by fatigue, disorders of sleep, chronic headaches, irritable bowel syndrome, and subjective soft tissue swelling. The complexity of the presenting clinical picture in JPFS has not been sufficiently defined in the literature. Similarities to adult fibromyalgia syndrome in JFMS are often difficult to compare, because many of the symptoms are "medically unexplained" and often overlap frequently with other medical conditions. However, a valid diagnosis of JFMS often decreases parents' anxiety, reduces unnecessary further investigations, and provides a rational framework for a management plan. The diagnostic criteria proposed by Yunus and Masi in 1985 to define JFMS were never validated or critically analyzed. In most cases, the clinical diagnosis is based on the history, the physical examination that demonstrates general tenderness (muscle, joints, tendons), the absence of other pathological conditions that could explain pain and fatigue, and the normal basic laboratory tests. Research and clinical observations defined that JFMS may have a chronic course that impacts the functional status and the psychosocial development of children and adolescents. This paper briefly reviews the existing knowledge on JFMS focusing on the diagnosis, clinical and the epidemiological characteristics in children and adolescents for better understanding of this disorder.

Controversies and challenges in fibromyalgia: a review and a proposal

Fibromyalgia (FM) is the most commonly encountered chronic widespread pain (CWP) condition in rheumatology. In comparison to inflammatory arthritis (IA), it can seem ill defined with no clear understanding of the pathology and therefore no specific targeted treatment. This inevitably raises controversies and challenges. However, this is an outdated view perpetuated by poor teaching of pain at undergraduate and postgraduate levels, and the perennial problem of advances in relevant cross-speciality knowledge penetrating speciality silos. Research has provided a better understanding of the aetiopathology and FM is now regarded as a centralized pain state. Effective treatment is possible utilizing a multidisciplinary approach combining nonpharmacologic and pharmacologic treatments rooted in a biopsychosocial model. This article will provide a review of the mechanisms, diagnosis and treatment of FM, focus on some ongoing contentious issues and propose a change to the diagnostic terminology.

QT dispersion and P wave dispersion in patients with fibromyalgia

OBJECTIVE

Fibromyalgia (FM) is a chronic disease characterized by widespread pain. Somatic complaints associated with the cardiovascular system, such as chest pain and palpitations, are frequently seen in FM patients. P and QT dispersions are simple and inexpensive measurements reflecting the regional heterogeneity of atrial and ventricular repolarization, respectively. QT dispersion can cause serious ventricular arrhythmias. The aim of the present study was to evaluate QT dispersion and P wave dispersion in patients with FM.

MATERIAL AND METHODS

The study involved 48 FM patients who fulfilled the established criteria and 32 healthy controls (HC). A standard 12-lead electrocardiogram was performed on all participants. QT dispersion was defined as the difference between the longest and the shortest QT intervals. Similarly, the differences between the shortest and longest P waves were defined as P wave dispersion.

RESULTS

The QT dispersion and corrected QT dispersion were shorter in the FM group compared with the HC group (p<0.001 for both). In terms of the P wave dispersion value, there was no significant difference between the FM and HC groups (p=0.088).

CONCLUSION

Longer QT and P wave dispersions are not problems in patients with FM. Therefore, it may be concluded that fibromyalgia does not include an increased risk of atrial and/or ventricular arrhythmias.

α-Terpineol, a monoterpene alcohol, complexed with β-cyclodextrin exerts antihyperalgesic effect in animal model for fibromyalgia aided with docking study

The anti-hyperalgesic effect of the complex containing α-terpineol (αTPN) and β-cyclodextrin (βCD) was analyzed in a non-inflammatory chronic muscle pain model, as well as its mechanism of action through docking study for a possible interaction with receptors. The αTPN-βCD complex was prepared and characterized through the thermogravimetry/derivate thermogravimetry (TG/DTG), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The model of chronic muscle pain was induced by two injections of pH 4.0 saline (20 μl) into the left gastrocnemius 5 days apart. After confirming hyperalgesia, male mice were treated with αTPN-βCD (25, 50 or 100 mg/kg; p.o.) or vehicle (saline 0.9%, p.o.) daily for 10 days. 1 h after the mechanical hyperalgesia, motor performance was evaluated. In addition, the systemic administration of naloxone and ondansetron tested the analgesic effect on the active opioid and serotonin receptors, respectively. The characterization tests indicated that αTPN was efficiently incorporated into βCD. The oral treatment with αTPN-βCD, at all doses tested, produced a significant (p < 0.001) decrease in the mechanical hyperalgesia, without causing any alteration in the force and in motor performance. This analgesic effect was reversed by the systemic administration of naloxone or ondansetron. These findings are corroborated by the docking study described in the present study, which verified a possible interaction of αTPN-βCD with opioid (MU, Kappa, Delta) and 5-HT receptors. Thus, it can be concluded that αTPN-βCD reduced the hyperalgesia followed by the chronic muscle pain model, probably evoked by the descending inhibitory pain system, specifically by opioid and serotoninergic receptors.

Music reduces pain and increases resting state fMRI BOLD signal amplitude in the left angular gyrus in fibromyalgia patients

Music reduces pain in fibromyalgia (FM), a chronic pain disease, but the functional neural correlates of music-induced analgesia (MIA) are still largely unknown. We recruited FM patients (n = 22) who listened to their preferred relaxing music and an auditory control (pink noise) for 5 min without external noise from fMRI image acquisition. Resting state fMRI was then acquired before and after the music and control conditions. A significant increase in the amplitude of low frequency fluctuations of the BOLD signal was evident in the left angular gyrus (lAnG) after listening to music, which in turn, correlated to the analgesia reports. The post-hoc seed-based functional connectivity analysis of the lAnG showed found higher connectivity after listening to music with right dorsolateral prefrontal cortex (rdlPFC), the left caudate (lCau), and decreased connectivity with right anterior cingulate cortex (rACC), right supplementary motor area (rSMA), precuneus and right precentral gyrus (rPreG). Pain intensity (PI) analgesia was correlated (r = 0.61) to the connectivity of the lAnG with the rPreG. Our results show that MIA in FM is related to top-down regulation of the pain modulatory network by the default mode network (DMN).

Chemobrain: a critical review and causal hypothesis of link between cytokines and epigenetic reprogramming associated with chemotherapy

One consequence of modern cancer therapy is chemotherapy related cognitive dysfunction or "chemobrain", the subjective experience of cognitive deficits at any point during or following chemotherapy. Chemobrain, a well-established clinical syndrome, has become an increasing concern because the number of long-term cancer survivors is growing dramatically. There is strong evidence that correlates changes in peripheral cytokines with the development of chemobrain in commonly used chemotherapeutic drugs for different types of cancer. However, the mechanisms by which these cytokines elicit change in the central nervous system are still unclear. In this review, we hypothesize that the administration of chemotherapy agents initiates a cascade of biological changes, with short-lived alterations in the cytokine milieu inducing persistent epigenetic alterations. These epigenetic changes lead to changes in gene expression, alterations in metabolic activity and neuronal transmission that are responsible for generating the subjective experience of cognition. This speculative but testable hypothesis should help to gain a comprehensive understanding of the mechanism underlying cognitive dysfunction in cancer patients. Such knowledge is critical to identify pharmaceutical targets with the potential to prevent and treat cancer-treatment related cognitive dysfunction and similar disorders.

Brain imaging in fibromyalgia

Fibromyalgia is a primary brain disorder or a result of peripheral dysfunctions inducing brain alterations, with underlying mechanisms that partially overlap with other painful conditions. Although there are methodologic variations, neuroimaging studies propose neural correlations to clinical findings of abnormal pain modulation in fibromyalgia. Growing evidences of specific differences of brain activations in resting states and pain-evoked conditions confirm clinical hyperalgesia and impaired inhibitory descending systems, and also demonstrate cognitive-affective influences on painful experiences, leading to augmented pain-processing. Functional data of neural activation abnormalities parallel structural findings of gray matter atrophy, alterations of intrinsic connectivity networks, and variations in metabolites levels along multiple pathways. Data from positron-emission tomography, single-photon-emission-computed tomography, blood-oxygen-level-dependent, voxel-based morphometry, diffusion tensor imaging, default mode network analysis, and spectroscopy enable the understanding of fibromyalgia pathophysiology, and favor the future establishment of more tailored treatments.

High-dose thiamine improves the symptoms of fibromyalgia

Living with fibromyalgia means living with chronic pain, fatigue, sleep disorders and other associated key symptoms. To date, pharmacotherapy generally produces modest benefits. Some observations indicate that the large majority of symptoms of fibromyalgia could be the clinical manifestation of a mild thiamine deficiency due to a dysfunction of the active transport of thiamine from the blood to the mitochondria or to enzymatic abnormalities. Between June and July 2011, we recruited three female patients affected by fibromyalgia. We proceeded with the study of the patients' history, a physical examination, an evaluation of chronic widespread pain using the Visual Numeric Scale and an evaluation of the fatigue using the Fatigue Severity Scale were also performed. The levels of thiamine and thiamine pyrophosphate in the blood were determined. After the therapy with high doses of thiamine, in the patients, there was an appreciable improvement of the symptoms.

Do patients with fibromyalgia show abnormal neural responses to the observation of pain in others?

Chronic widespread pain is a hallmark of fibromyalgia (FM). Previous neuroimaging studies have reported that the pain neuro-matrix in patients with FM showed augmented activation in response to actual pain. However, the effect of observing pain in others among patients with FM remains poorly understood. Both healthy female control subjects (n=24) and female patients with FM (n=23) underwent functional magnetic resonance imaging while observing a series of color pictures depicting others' hands and feet being injured, and a matched set of control pictures that did not show any painful events. Compared with healthy subjects, patients with FM showed a smaller neural response to pain-related versus neutral stimuli in several neural regions, including the thalamus, anterior cingulate cortex, dorsolateral prefrontal cortex, pre- and post-central gyrus, and supplementary motor area. In contrast to augmented pain processing in response to actual experimental pain, patients with FM did not show an enhanced pain response but generally showed lesser activation in cortical regions known to play a role in processing of pain. These hemodynamic alterations observed in patients with FM suggest that patients with chronic pain may empathize less with others in pain, possibly in order to lessen arousal and aversive self-oriented emotions.

Clinical overview of fibromyalgia

Fibromyalgia (FM) is a complex disorder that affects up to 5% of the general population worldwide, more frequently in women than in men. In addition to chronic widespread pain, patients with FM usually experience other characteristic symptoms, including fatigue, disturbed sleep, stiffness, reduced functioning, dyscognition, and depressed mood. Many patients also have comorbid conditions such as depression, irritable bowel syndrome, temporomandibular disorder, or migraine. Although the etiology of FM remains unclear, evidence suggests that biologic, genetic, and environmental factors are involved. The variability of symptoms and the frequency of comorbidities among patients with FM make this a difficult disorder to diagnose. Diagnosis may be further complicated by the stigmatization of this disorder among treatment providers, the health insurance industry, and the general population. Treating chronic pain disorders such as FM can be time consuming and costly, and other issues such as polypharmacy, treatment adherence, and access to treatment often need to be addressed. The aim of this article is to provide physicians with a general overview of FM, including a brief review of the pathophysiology that explains the biologic and genetic bases of this disorder. Also included is a synopsis of new diagnostic criteria and other useful diagnostic tools and a discussion of various treatment challenges and strategies.

Fibromyalgia syndrome: etiology, pathogenesis, diagnosis, and treatment

Fibromyalgia syndrome is mainly characterized by pain, fatigue, and sleep disruption. The etiology of fibromyalgia is still unclear: if central sensitization is considered to be the main mechanism involved, then many other factors, genetic, immunological, and hormonal, may play an important role. The diagnosis is typically clinical (there are no laboratory abnormalities) and the physician must concentrate on pain and on its features. Additional symptoms (e.g., Raynaud's phenomenon, irritable bowel disease, and heat and cold intolerance) can be associated with this condition. A careful differential diagnosis is mandatory: fibromyalgia is not a diagnosis of exclusion. Since 1990, diagnosis has been principally based on the two major diagnostic criteria defined by the ACR. Recently, new criteria have been proposed. The main goals of the treatment are to alleviate pain, increase restorative sleep, and improve physical function. A multidisciplinary approach is optimal. While most nonsteroidal anti-inflammatory drugs and opioids have limited benefit, an important role is played by antidepressants and neuromodulating antiepileptics: currently duloxetine (NNT for a 30% pain reduction 7.2), milnacipran (NNT 19), and pregabalin (NNT 8.6) are the only drugs approved by the US Food and Drug Administration for the treatment of fibromyalgia. In addition, nonpharmacological treatments should be associated with drug therapy.

Decreased intrinsic brain connectivity is associated with reduced clinical pain in fibromyalgia

OBJECTIVE

A major impediment to the development of novel treatment strategies for fibromyalgia (FM) is the lack of an objective marker that reflects spontaneously reported clinical pain in patients with FM. Studies of resting-state intrinsic brain connectivity in FM have demonstrated increased insular connectivity to the default mode network (DMN), a network whose activity is increased during nontask states. Moreover, increased insular connectivity to the DMN was associated with increased spontaneous pain levels. However, as these analyses were cross-sectional in nature, they provided no insight into dynamic changes in connectivity or their relationship to variations in self-reported clinical pain. The purpose of this study was to evaluate longitudinal changes in the intrinsic brain connectivity of FM patients treated with nonpharmacologic interventions known to modulate pain levels in this patient population, and to test the hypothesis that the reduction of DMN-insula connectivity following therapy would correlate with diminished pain.

METHODS

Seventeen FM patients underwent resting-state functional magnetic resonance imaging at baseline and following 4 weeks of a nonpharmacologic intervention to diminish pain. Intrinsic DMN connectivity was evaluated using probabilistic independent components analysis. Longitudinal changes in intrinsic DMN connectivity were evaluated by paired analysis, and correlations between longitudinal changes in clinical pain and changes in intrinsic DMN connectivity were investigated by multiple linear regression analysis. Changes in clinical pain were assessed with the short form of the McGill Pain Questionnaire (SF-MPQ).

RESULTS

Clinical pain as assessed using the sensory scale of the SF-MPQ was reduced following therapy (P=0.02). Intrinsic DMN connectivity to the insula was reduced, and this reduction correlated with reductions in pain (corrected P<0.05).

CONCLUSION

Our findings suggest that intrinsic brain connectivity can be used as a candidate objective marker that reflects changes in spontaneous chronic pain within individual FM patients. We propose that intrinsic connectivity measures could potentially be used in either research or clinical settings as a complementary, more objective outcome measure for use in FM.

Central nervous system reorganization in a variety of chronic pain states: a review

Chronic pain can develop from numerous conditions and is one of the most widespread and disabling health problems today. Unfortunately, the pathophysiology of chronic pain in most of these conditions, along with consistently effective treatments, remain elusive. However, recent advances in neuroimaging and neurophysiology are rapidly expanding our understanding of these pain syndromes. It is now clear that substantial functional and structural changes, or plasticity, in the central nervous system (CNS) are associated with many chronic pain syndromes. A group of cortical and subcortical brain regions, often referred to as the "pain matrix," often show abnormalities on functional imaging studies in persons with chronic pain, even with different pain locations and etiologies. Changes in the motor and sensory homunculus also are seen. Some of these CNS changes return to a normal state with resolution of the pain. It is hoped that this knowledge will lead to more effective treatments or even new preventative measures. The purpose of this article is to review recent advances in the understanding of the CNS changes associated with chronic pain in a number of clinical entities encountered in the field of physical medicine and rehabilitation. These clinical entities include nonspecific low back pain, fibromyalgia, complex regional pain syndrome, postamputation phantom pain, and chronic pain after spinal cord injury.

FMRI reveals abnormal central processing of sensory and pain stimuli in ill Gulf War veterans

Many veterans chronically ill from the 1991 Gulf War exhibit symptoms of altered sensation, including chronic pain. In this study of 55 veterans of a Construction Battalion previously examined in 1995-1996 and 1997-1998, brain activation to innocuous and noxious heat stimuli was assessed in 2008-2009 with a quantitative sensory testing fMRI protocol in control veterans and groups representing three syndrome variants. Testing outside the scanner revealed no significant differences in warm detection or heat pain threshold among the four groups. In the fMRI study, Syndrome 1 and Syndrome 2, but not Syndrome 3, exhibited hypo-activation to innocuous heat and hyper-activation to noxious heat stimuli compared to controls. The results indicate abnormal central processing of sensory and painful stimuli in 2 of 3 variants of Gulf War illness and call for a more comprehensive study with a larger, representative sample of veterans.

Fibromyalgia: a primer for the anesthesia community

PURPOSE OF REVIEW

The present review is intended to give an overview of fibromyalgia for the anesthesiologist. While the basics of the treatment of fibromyalgia are included, the intent is to provide context to discuss the potential implications in perioperative management.

RECENT FINDINGS

Research continues to demonstrate that fibromyalgia patients have neurophysiologic abnormalities that alter sensory perception, including lower levels of central neurotransmitters associated with the inhibition of pain and higher levels those that facilitate pain. While comorbid mood disorders are more common in fibromyalgia patients, studies have shown that fibromyalgia symptoms are not explained by depression alone. In the last year, the American College of Rheumatology established a new self-report questionnaire for the diagnosis of fibromyalgia in lieu of the previously required tender point examination plus self-report questionnaire. This questionnaire allows for the study of the severity of sensitivity and symptomatology on a continuum, which is termed 'fibromyalgianess'. Some new concepts in the treatment have been proposed, including sodium oxybate, transcranial magnetic stimulation, and web-based cognitive behavioral therapy.

SUMMARY

The impact of fibromyalgia on anesthesia care is not known. Years of quality research have clearly demonstrated multiple pathophysiologic changes that could impact anesthesia care and future study is needed.

The science of fibromyalgia

Fibromyalgia (FM) is a common chronic widespread pain disorder. Our understanding of FM has increased substantially in recent years with extensive research suggesting a neurogenic origin for the most prominent symptom of FM, chronic widespread pain. Neurochemical imbalances in the central nervous system are associated with central amplification of pain perception characterized by allodynia (a heightened sensitivity to stimuli that are not normally painful) and hyperalgesia (an increased response to painful stimuli). Despite this increased awareness and understanding, FM remains undiagnosed in an estimated 75% of people with the disorder. Clinicians could more effectively diagnose and manage FM if they better understood its underlying mechanisms. Fibromyalgia is a disorder of pain processing. Evidence suggests that both the ascending and descending pain pathways operate abnormally, resulting in central amplification of pain signals, analogous to the "volume control setting" being turned up too high. Patients with FM also exhibit changes in the levels of neurotransmitters that cause augmented central nervous system pain processing; levels of several neurotransmitters that facilitate pain transmission are elevated in the cerebrospinal fluid and brain, and levels of several neurotransmitters known to inhibit pain transmission are decreased. Pharmacological agents that act centrally in ascending and/or descending pain processing pathways, such as medications with approved indications for FM, are effective in many patients with FM as well as other conditions involving central pain amplification. Research is ongoing to determine the role of analogous central nervous system factors in the other cardinal symptoms of FM, such as fatigue, nonrestorative sleep, and cognitive dysfunction.

Intersection of chronic pain treatment and opioid analgesic misuse: causes, treatments, and policy strategies

Treating chronic pain in the context of opioid misuse can be very challenging. This paper explores the epidemiology and potential treatments for chronic pain and opioid misuse and identifies educational and regulation changes that may reduce diversion of opioid analgesics. We cover the epidemiology of chronic pain and aberrant opioid behaviors, psychosocial influences on pain, pharmacological treatments, psychological treatments, and social treatments, as well as educational and regulatory efforts being made to reduce the diversion of prescription opioids. There are a number of ongoing challenges in treating chronic pain and opioid misuse, and more research is needed to provide strong, integrated, and empirically validated treatments to reduce opioid misuse in the context of chronic pain.

Prevalence of myofascial trigger points in fibromyalgia: the overlap of two common problems

With the objective evidence of their existence, myofascial trigger points (MTrPs) contribute to an increasing number of chronic regional and widespread pain conditions. The widespread spontaneous pain pattern in fibromyalgia (FM) is a summation of multiple regional pains due to active MTrPs. A regional pain in FM is from local active MTrPs and/or referred from remote active MTrPs. Positive tender points specified in FM are MTrPs, either active or latent. Manual stimulation of active MTrPs located in the muscles in different body regions completely reproduced overall spontaneous FM pain pattern. Active MTrPs as tonic peripheral nociceptive input contribute tremendously to the initiation and maintenance of central sensitization, to the impairment of descending inhibition, to the increased excitability of motor units, and to the induction of sympathetic hyperactivity observed in FM. The considerable overlap of MTrPs and FM in pain characteristics and pathophysiology suggests that FM pain is largely due to MTrPs.

Improving the recognition and diagnosis of fibromyalgia

Fibromyalgia (FM) is a chronic widespread pain disorder often seen in primary care practices. Advances in the understanding of FM pathophysiology and clinical presentation have improved the recognition and diagnosis of FM in clinical practice. Fibromyalgia is a clinical diagnosis based on signs and symptoms and is appropriate for primary care practitioners to make. The hallmark symptoms used to identify FM are chronic widespread pain, fatigue, and sleep disturbances. Awareness of common mimics of FM and comorbid disorders will increase confidence in establishing a diagnosis of FM.