Chronic widespread pain—the need for a standard definition

Pain patterns and their association with psychological measures among people accessing an online pain management program

AIM

This study aimed to explore the association between the distribution of pain sites and psychosocial measures at baseline of patients enrolled in an online MPMP.

PATIENTS

This study analyzed baseline data from adults (N = 2002) enrolled in the 'Reboot Online' pain program.

METHODS

Participants completed measures of Pain Self-Efficacy Questionnaire (PSEQ), Tampa Scale for Kinesiophobia (TSK), Pain Disability Index (PDI), Patient Health Questionnaire (PHQ-9), and Kessler Psychological Distress Scale (K-10). Pain was categorized by the number of body regions affected: 1, 2, 3, >3. One-way ANOVA tests examined psychosocial measure differences across these groups.

RESULTS

The majority of participants had multisite pain, with multisite pain showing significantly worse psychosocial outcome measures (p < .05) compared to those with a single pain site, except for kinesiophobia, which was consistently high across groups.

CONCLUSION

Most online participants reported multisite pain, with multisite pain associated with poorer baseline psychosocial outcome measures, excluding kinesiophobia. The pattern of pain should be considered when developing and implementing online programs.

What has brain diffusion magnetic resonance imaging taught us about chronic primary pain: a narrative review

ABSTRACT

Chronic pain is a pervasive and debilitating condition with increasing implications for public health, affecting millions of individuals worldwide. Despite its high prevalence, the underlying neural mechanisms and pathophysiology remain only partly understood. Since its introduction 35 years ago, brain diffusion magnetic resonance imaging (MRI) has emerged as a powerful tool to investigate changes in white matter microstructure and connectivity associated with chronic pain. This review synthesizes findings from 58 articles that constitute the current research landscape, covering methods and key discoveries. We discuss the evidence supporting the role of altered white matter microstructure and connectivity in chronic primary pain conditions, highlighting the importance of studying multiple chronic pain syndromes to identify common neurobiological pathways. We also explore the prospective clinical utility of diffusion MRI, such as its role in identifying diagnostic, prognostic, and therapeutic biomarkers. Furthermore, we address shortcomings and challenges associated with brain diffusion MRI in chronic primary pain studies, emphasizing the need for the harmonization of data acquisition and analysis methods. We conclude by highlighting emerging approaches and prospective avenues in the field that may provide new insights into the pathophysiology of chronic pain and potential new therapeutic targets. Because of the limited current body of research and unidentified targeted therapeutic strategies, we are forced to conclude that further research is required. However, we believe that brain diffusion MRI presents a promising opportunity for enhancing our understanding of chronic pain and improving clinical outcomes.

Exploring signs of central sensitization in adolescents with hypermobility Spectrum disorder or hypermobile Ehlers-Danlos syndrome

BACKGROUND

Hypermobility Spectrum Disorder (HSD) and Hypermobile Ehlers-Danlos Syndrome (hEDS) are two overlapping heritable connective tissue disorders characterized by joint hypermobility, chronic pain, impaired body perception, and musculoskeletal symptoms. Central sensitization has been proposed as a plausible explanation for symptoms like widespread pain, fatigue, mood disorders, and sleep disturbances in patients with HSD/hEDS.

OBJECTIVE

The aim of this study was to investigate signs of central sensitization, including exercise-induced hypoalgesia (EIH), and fatigue severity in adolescents with HSD/hEDS.

METHODS

In this prospective, experimental, case-control study, thirty-seven adolescents with HSD/hEDS and 47 healthy adolescents (all aged 13-17 years) were included. Pressure pain thresholds (PPTs) were measured at four muscle groups using a pressure algometer. EIH was evaluated by measuring PPTs on two muscle groups immediately after an exercise test on a bicycle ergometer. Participants also completed questionnaires on fatigue and cognitive/emotional factors.

RESULTS

The study demonstrated significantly lower PPTs in four different muscle groups in adolescents with HSD/hEDS compared to the healthy control group. Both groups achieved a significantly higher PPTs after exercise in the muscle involved in the activity. Adolescents with HSD/hEDS reported higher fatigue levels and more cognitive/emotional difficulties than the control group.

CONCLUSION

Adolescents with HSD/hEDS showed generalized hyperalgesia measured through PPTs at different body sites. EIH was partly affected in adolescents with HSD/hEDS, presenting as unchanged pain sensitivity in the remote muscle. Pain should be considered as a phenomenon that is influenced by different biopsychosocial factors, including possible central sensitization, which increase its complexity.

SIGNIFICANCE STATEMENT

This study breaks new ground by showing signs of central sensitization, including diminished EIH, in adolescents with HSD or hEDS. Given that exercise is a key element in pain management, these findings offer valuable insights when developing treatment plans for adolescents with HSD or hEDS.

Chronic Widespread Pain

OBJECTIVE

This article reviews the potential etiologies of chronic widespread pain syndromes and outlines a practical approach to the management of patients with these disorders.

LATEST DEVELOPMENTS

Recent updates to diagnostic criteria for primary chronic widespread pain syndromes have allowed for more effective diagnosis. Fibromyalgia is the most common presentation of chronic widespread pain, and the concept of nociplastic pain has been used to describe pain that is related to altered processing of pain sensory pathways. Research studies have provided a better understanding of the pathophysiology of the central augmentation that occurs in patients with nociplastic pain and fibromyalgia.

ESSENTIAL POINTS

Primary chronic widespread pain and fibromyalgia have established diagnostic criteria in which chronic pain involves multiple defined regions and occurs for longer than 3 months. Evaluation of chronic widespread pain should be directed by the clinical presentation. Neurologic disease can present with chronic widespread pain but is accompanied by associated signs and symptoms. Patients with chronic widespread pain benefit from effective communication that validates concerns, provides an understandable explanation of the presenting symptoms, and sets realistic expectations in outcomes using a comprehensive multimodal care plan.

Body awareness and cognitive behavioral therapy for multisite musculoskeletal pain: patients` experiences with group rehabilitation

BACKGROUND

An extended group program called Mind and Body (MB), based on body awareness exercises and cognitive behavioral therapy (CBT), was offered to a subgroup of patients who had completed their traditional outpatient multidisciplinary rehabilitation and were motivated for further treatment.

PURPOSE

To explore how patients with multisite musculoskeletal pain experienced participation in the MB program with respect to usefulness, meaningfulness, behavioral changes, and transferability to daily life and work.

METHOD

The study is rooted in the phenomenological tradition. Individual, semi-structured interviews were performed with eight patients aged 29-56 years. The data were analyzed using systematic text condensation.

RESULTS

Two main themes emerged: 1) New knowledge provided increased body awareness, new ways of thinking, and acceptance of one's own situation. This theme reflected how new knowledge and MB coping strategies were useful in the process of changing problematic thoughts, increasing body awareness, and facilitating acceptance; and 2) Implementing new habits and strategies in daily life revealed how demanding it was to alter behavior, a process that unfolded over time.

CONCLUSION

A combination of body awareness exercises and cognitive coping strategies was described as helpful in further improving function and coping with pain and stress in daily life and work.

Prevalence of chronic pain and chronic widespread pain among subjects with heart failure in the general population: The HUNT study

BACKGROUND

Pain in chronic heart failure (HF) is a significant but often unrecognized symptom. Characteristics of pain in subjects with HF are largely undescribed. The study aimed to address a knowledge gap in the relationship between HF and pain by investigating the prevalence of chronic pain and chronic widespread pain (CWP) among subjects with HF.

METHODS

Population data from the HUNT3 study in Norway (2006-2008, n = 50,802) was used. HF was measured by self-report. CWP was defined as having pain in both sides of the body, pain in the upper and lower limbs, and axial pain for at least 3 months in the last year. Associations between HF and CWP and HF and moderate to high pain intensity were analysed with logistic regression.

RESULTS

Among subjects with HF in the general population, the prevalence of chronic pain was 67.8%, 20.7% had CWP, and 58.8% had moderate to high intensity pain. Compared to participants with cardiovascular disease but not HF, the odds of both CWP (OR = 1.6; 95% CI: 1.3-2.0) and moderate to high intensity pain (OR = 1.3; 95% CI: 1.3-1.8) were higher among participants with HF-controlled for age, sex, body mass index, and comorbidity.

CONCLUSIONS

Our study confirmed the high prevalence of pain among HF subjects. This pain could not be explained by comorbidity or sociodemographic factors, which are relevant for clinical and research purposes. Pain management should not be restricted to cardiac-related pain but to chronic pain in general.

SIGNIFICANCE

This epidemiological study corroborates previous studies reporting a high prevalence of pain in the HF-population. We found that the relationship between HF, CWP, and pain intensity could not be explained by comorbidity or sociodemographic factors, illustrating the burden of chronic pain related to HF. Our results expand the understanding of pain in HF and highlight the need to identify and manage chronic pain among individuals with HF, as widespread pain adds to the symptom burden in individuals with HF.

Exercise Training for Chronic Pain: Available Evidence, Current Recommendations, and Potential Mechanisms

Chronic pain conditions pose a significant global burden of disability, with epidemiological data indicating a rising incidence. Exercise training is commonly recommended as a standalone or complementary approach for managing various chronic pain conditions like low back pain, osteoarthritis, rheumatoid arthritis, fibromyalgia syndrome, and neuropathic pain. Regardless of the specific condition or underlying cause (e.g., autoimmune disease, chronic inflammation), exercise training consistently leads to moderate to large reductions in pain. Moreover, exercise yields numerous benefits beyond pain alleviation, including small-to-moderate improvements in disability, quality of life, and physical function. Despite its efficacy, there is a lack of comprehensive research delineating the optimal intensity, duration, and type of exercise for maximal benefits; however, evidence suggests that sustained engagement in regular exercise or physical activity is necessary to achieve and maintain reductions in both clinical pain intensity ratings and the level that pain interferes with activities of daily living. Additionally, the precise mechanisms through which exercise mitigates pain remain poorly understood and likely vary based on the pathophysiological mechanisms underlying each condition.

Role of Vagus Nerve Stimulation in the Treatment of Chronic Pain

Vagus nerve stimulation (VNS) can modulate vagal activity and neuro-immune communication. Human and animal studies have provided growing evidence that VNS can produce analgesic effects in addition to alleviating refractory epilepsy and depression. The vagus nerve (VN) projects to many brain regions related to pain processing, which can be affected by VNS. In addition to neural regulation, the anti-inflammatory property of VNS may also contribute to its pain-inhibitory effects. To date, both invasive and noninvasive VNS devices have been developed, with noninvasive devices including transcutaneous stimulation of auricular VN or carotid VN that are undergoing many clinical trials for chronic pain treatment. This review aimed to provide an update on both preclinical and clinical studies of VNS in the management for chronic pain, including fibromyalgia, abdominal pain, and headaches. We further discuss potential underlying mechanisms for VNS to inhibit chronic pain.

Pain Widespreadedness, and Not Primary Pain Location, is Associated With Comorbid Symptoms in Children With Chronic Pain

OBJECTIVES

Pediatric chronic pain represents heterogeneous diagnoses; often, primary pain location informs research classifications and treatment. In contrast, recent research has highlighted the role of widespread pain and this perspective has been adopted in assessments in specialty pediatric pain clinics. The lack of direct comparison between these 2 methods of categorizing pediatric chronic pain may hinder the adoption of evidence-based practices across the spectrum of care. Therefore, this study aimed to compare whether primary pain location or pain widespreadedness is more informative for pain-related symptoms in pediatric chronic pain.

METHODS

Youth (n=223) between the ages of 8 to 23 years (M=15.93, SD=2.11, 83% female) completed surveys upon intake at the pediatric chronic pain clinic. Free-text entries of primary pain location were coded into categories: headache, abdominal pain, and musculoskeletal pain. Additional domains assessed included widespread pain, pain interference, kinesiophobia, catastrophizing, anxiety, depression, sleep, and fatigue.

RESULTS

Differences based on primary pain location only emerged for kinesiophobia, F(2150)=8.20, P<0.001, with the highest scores among those with musculoskeletal pain. In contrast, controlling for sex, age, and pain intensity, pain widespreadedness was associated with pain interference, pain catastrophizing, fatigue, anxiety, and depression (P<0.05).

DISCUSSION

Pain widespreadedness was more consistently associated with pain-related outcomes among pediatric chronic pain patients than primary pain location, and body maps may be useful in determining a nociplastic pain mechanism to inform treatment. Improved assessment of pediatric pain mechanisms may help advance more precise treatment delivery.

Chronic musculoskeletal pain: traps and pitfalls in classification and management of a major global disease burden

Mary-Ann Fitzcharles et al. propose to introduce "regional fibromyalgia" as a new diagnosis. This commentary summarizes why this term is misleading but nonetheless the article may pave the way towards useful concepts for myofascial pains.

Prevalence and municipal variation in chronic musculoskeletal pain among independent older people: data from the Japan Gerontological Evaluation Study (JAGES)

BACKGROUND

Urbanization and population aging may affect prevalence of chronic pain from various causes. This cross-sectional study aimed to investigate the prevalence of chronic musculoskeletal pain, including some subtypes, in independent Japanese older people, and whether population density and population aging rate explained prevalence and differences in pain levels between municipalities.

METHODS

We analyzed data from 12,883 independent older people living in 58 municipalities who completed mailed questionnaires and did not need support for daily living. We identified three types of pain: "chronic musculoskeletal pain" lasting ≥ 3 months (overall and in each part of the body), "chronic widespread-type pain" in the spinal and peripheral area, and "chronic multisite pain" in at least three sites. The latter two were measured using new definitions. These types of pain are correlated with depressive symptoms and we therefore examined the construct validity of the definitions by comparing the Geriatric Depression Scale score. We also used analysis of covariance to compare the prevalence of these three types of pain between municipalities. Odds ratios, median odds ratios, and the municipal variance in prevalence of chronic musculoskeletal pain were estimated by Bayesian multilevel logistic regression analysis using the Markov Chain Monte Carlo method.

RESULTS

The construct validity of the definitions of chronic widespread-type pain and chronic multisite pain was confirmed. The prevalence of the three types of pain (chronic musculoskeletal, widespread, and multisite pain) was 39.0%, 13.9%, and 10.3%, respectively. Chronic musculoskeletal pain showed a higher prevalence among older people and women. Individuals in underpopulated, suburban, or metropolitan areas tended to have more pain than those in urban areas, but this was not statistically significant (odds ratio [95% credible interval] 1.15 [0.86-1.51], 1.17 [0.93-1.43], 1.17 [0.94-1.46]). Population density and population aging rate did not explain the differences between municipalities.

CONCLUSIONS

The prevalence of chronic musculoskeletal pain was consistent with previous global reports. Areas with overpopulation and depopulation tended to have higher pain prevalence, but population density and population aging rate did not explain municipal variance. Further research is needed to identify other factors that contribute to regional variance.

Adults with unilateral lower-limb amputation: greater spatial extent of pain is associated with worse adjustment, greater activity restrictions, and less prosthesis satisfaction

OBJECTIVES

This study's primary purpose was to determine if the extent of bodily pain, as evaluated with pain body diagrams, is associated with prosthetic-related activity restrictions, adjustment, and satisfaction among adults with a major unilateral lower-limb amputation. A secondary objective was to evaluate between-days, test-retest reliability for pain body diagrams among adults with lower-limb amputation.

METHODS

Adults with a lower-limb amputation that occurred ≥1 year prior participated in an online, cross-sectional research study. Outcome measures included pain body diagrams and the Trinity Amputation and Prosthesis Experience Scales-Revised, which evaluates post-amputation activity restrictions, psychosocial adjustment, and prosthesis satisfaction. Linear regression modeling was used to evaluate associations between the number of painful body regions and prosthetic outcomes, after considering covariates (alpha ≤ 0.010). A subset of participants recompleted pain body diagrams to evaluate between-days, test-retest reliability.

RESULTS

Data from 74 participants (n = 32 female; n = 42 transtibial-level; n = 27 traumatic etiology) were available. Beyond covariates (i.e., age, sex, amputation level), the total number of painful body regions was significantly associated with all Trinity Amputation and Prosthesis Experience Scales-Revised subscales (p < 0.001-0.006), with the exception of Social Adjustment (p = 0.764). The total number of painful body regions explained 14.5, 11.8, 11.6, and 7.4% of the variance in Functional Satisfaction with the Prosthesis, Adjustment to Limitation, General Adjustment, and Activity Restriction, respectively. In a subset (n = 54), test-retest reliability for total number of painful body regions per body diagrams was good [intraclass correlation coefficient (ICC)3,1 = 0.84].

CONCLUSIONS

A greater number of painful body regions is associated with greater activity restriction, worse adjustment, and lower prosthesis satisfaction, supporting the need to enhance post-amputation pain management and both amputated- and secondary-site pain prevention.

ETHICAL COMMITTEE NUMBER

IRB #1611862.

Repetitive Transcranial Magnetic Stimulation of the Primary Motor Cortex beyond Motor Rehabilitation: A Review of the Current Evidence

Transcranial magnetic stimulation (TMS) has emerged as a novel technique to stimulate the human brain through the scalp. Over the years, identifying the optimal brain region and stimulation parameters has been a subject of debate in the literature on therapeutic uses of repetitive TMS (rTMS). Nevertheless, the primary motor cortex (M1) has been a conventional target for rTMS to treat motor symptoms, such as hemiplegia and spasticity, as it controls the voluntary movement of the body. However, with an expanding knowledge base of the M1 cortical and subcortical connections, M1-rTMS has shown a therapeutic efficacy that goes beyond the conventional motor rehabilitation to involve pain, headache, fatigue, dysphagia, speech and voice impairments, sleep disorders, cognitive dysfunction, disorders of consciousness, anxiety, depression, and bladder dysfunction. In this review, we summarize the latest evidence on using M1-rTMS to treat non-motor symptoms of diverse etiologies and discuss the potential mechanistic rationale behind the management of each of these symptoms.

Leptin promoter methylation in female patients with painful multisomatoform disorder and chronic widespread pain

Background

Different functional somatic syndromes (FSS), fibromyalgia (FMS) and other unexplained painful conditions share many common clinical traits and are characterized by troubling and functionally disabling somatic symptoms. Chronic pain is most frequently reported and at the center of patients’ level of disease burden. The construct of multisomatoform disorder (MSD) allows to subsume severely impaired patients suffering from FSS, FMS and other unexplained painful conditions to be examined for common underlying processes. Altered leptin levels and a pathological response of the HPA-axis as a result of chronic stress and childhood trauma have been suggested as one of the driving factors of disease development and severity. Previous studies have demonstrated that methylation of the leptin promoter can play a regulatory role in addiction. In this study, we hypothesized that methylation of the leptin promoter is influenced by the degree of childhood traumatization and differs between patients with MSD and controls. A cohort of 151 patients with MSD and 149 matched healthy volunteers were evaluated using clinical and psychometric assessment while methylation level analysis of the leptin promoter was performed using DNA isolated from whole blood.

Results

In female controls, we found CpG C-167 to be negatively correlated with leptin levels, whereas in female patients CpG C-289, C-255, C-193, C-167 and methylation cluster (C-291 to C-167) at putative bindings sites for transcription factors Sp1 and c/EBPalpha were negatively correlated with leptin levels. Methylation levels were significantly lower in female patients CpG C-289 compared with controls. When looking at female patients with chronic widespread pain methylation levels were significantly lower at CpG C-289, C-255 and methylation cluster (C-291 to C-167).

Conclusion

Our findings support the hypothesis that epigenetic regulation of leptin plays a role in the regulation of leptin levels in patients with MSD. This effect is more pronounced in patients with chronic widespread pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01235-5.

Differences and similarities among questionnaires to assess pain status in chronic widespread pain population: a quantitative analysis

Objective

In clinical practice, multiple questionnaires are often used as part of the diagnosis of chronic widespread pain. Body Surface Area (BSA), Visual Analogue Scale (VAS), Fibromyalgia Diagnostic Criteria (FDC) and Central Sensitization Inventory (CSI) have all been used as screening tools to assess pain status in individuals with widespread pain. However, substantial overlap can be observed among these commonly employed questionnaires. This study aimed to quantitatively determine the most independent and dependent clinical characteristics obtained through these questionnaires and to examine potential redundancies.

Methods

Seventy-nine participants with widespread pain, 61 females and 18 males, from a chronic pain outpatient clinic were recruited. The FDC, BSA, VAS and the CSI were measured for all participants. A principal component analysis (PCA) using a varimax rotation was used to determine which clinical measures represented separate constructs of widespread pain. This was followed by a regression analysis to assess redundancy between the constructs and related pain characteristics.

Results

The identified three-component PCA solution was characterized by (1) the FDC and CSI score, (2) the VAS score and (3) the BSA score. This indicates that the BSA and the VAS scores capture independent patient information. From the regression analysis, the FDC and CSI scores shared approximately 80% of the variance, indicative of substantial overlap between scores.

Conclusion

Our findings demonstrated that BSA and VAS scores were independent clinical measures of widespread chronic pain, while the FDC and CSI scores were not independent, were highly correlated and provided redundant information. Clinicians should continue using both the BSA and VAS; however, either only FDC or CSI will be beneficial during clinical assessment of widespread chronic pain.

Comparison of chronic widespread pain prevalence with different criteria in two cohorts of rheumatoid arthritis

Objective

This study aims to investigate chronic widespread pain with the 1990 (CWP1990) and 2019 (CWP2019) definitions 6 years after the onset of rheumatoid arthritis (RA), in one patient cohort with tight controls and one conventional cohort, and factors associated with reporting CWP1990 and CWP2019, respectively.

Methods

A cohort of 80 RA patients with monthly visits to the physician the first 6 months was compared to a cohort of 101 patients from the same clinic with conventional follow-up. Both cohorts had early RA (< 13 months). The prevalence of CWP1990 and the more stringent CWP2019 were in a 6-year follow-up investigated with a questionnaire, including a pain mannequin and a fear-avoidance beliefs questionnaire.

Results

In the tight control cohort, 10% reported CWP2019 after 6 years compared to 23% in the conventional cohort (p = 0.026). There was no difference when using the CWP1990 definition (27% vs 31%, p = 0.546). When adjusted for important baseline data, the odds ratio for having CWP2019 was 2.57 (95% CI 1.02–6.50), in the conventional group compared to the tight control group (p = 0.046). A high level of fear-avoidance behaviour towards physical activity was associated with CWP2019, OR 10.66 (95% CI 1.01–112.14), but not with CWP1990 in the tight control cohort.

Conclusion

A more stringent definition of CWP identifies patients with a more serious pain condition, which potentially could be prevented by an initial tight control management. Besides tight control, caregivers should pay attention to fear-avoidance behaviour and tailor treatment.

Key Points

• CWP2019 is a more stringent definition of chronic widespread pain and identifies patients with a more serious pain condition.

• Patients with a serious pain condition could be helped by frequent follow-ups.

• This study suggests that a special attention of fear-avoidance behaviour towards physical activity in patients with RA is needed.

Animal models of fibromyalgia: What is the best choice?

Fibromyalgia (FM) is a complex syndrome, with an indefinite aetiology and intricate pathophysiology that affects 2 - 3% of the world population. From the beginning of the 2000s, experimental animal models have been developed to mimic clinical FM and help obtain a better understanding of the relevant neurobiology. These animal models have enabled a broad study of FM symptoms and mechanisms, as well as new treatment strategies. Current experimental FM models include the reserpine-induced systemic depletion of biogenic amines, muscle application of acid saline, and stress-based (cold, sound, or swim) approaches, among other emerging models. FM models should: (i) mimic the cardinal symptoms and complaints reported by FM patients (e.g., spontaneous nociception, muscle pain, hypersensitivity); (ii) mimic primary comorbidities that can aggravate quality of life and lead to worse outcomes (e.g., fatigue, sleep disturbance, depression, anxiety); (iii) mimic the prevalent pathological mechanisms (e.g., peripheral and central sensitization, inflammation/neuroinflammation, change in the levels of the excitatory and inhibitory neurotransmitters); and (iv) demonstrate a pharmacological profile similar to the clinical treatment of FM. However, it is difficult for any one of these models to include the entire spectrum of clinical FM features once even FM patients are highly heterogeneous. In the past six years (2015 - 2020), a wide range of experimental FM studies has amounted to the literature reinforcing the need for an updated review. Here we have described, in detail, several approaches used to experimentally study FM, with a focus on recent studies in the field and in previously less discussed mechanisms. We highlight each model's challenges, limitations, and future directions, intending to help preclinical researchers establish the correct experimental FM model to use depending on their goals.

Chronic cancer and non-cancer pain and opioid-induced hyperalgesia share common mechanisms: neuroinflammation and central sensitization

Neuroinflammation, a peculiar form of inflammation that occurs in response to noxious stimuli in peripheral and central nervous system (CNS), consists in altered vascular permeability followed by leukocyte recruitment and activation in the inflamed tissue, release of inflammatory mediators including cytokines and chemokines, and finally in the activation of microglia and astrocytes in the spinal cord and CNS. This phenomenon mediates and even worsen the inflammatory pain in many painful states and is responsible for central sensitization leading to pain chronicity. We describe the major neuroinflammatory mechanisms shared by cancer and non-cancer pain. Particular attention is given to two different chronic inflammatory painful diseases such as the complex regional pain syndrome and the rheumatoid arthritis as prototypes of neuroinflammatory diseases (gliopathies). In addition, we describe the complexity of tumor microenvironment, their main cellular components (tumor cells, tumor infiltrating leukocytes and sensory neurons) and their reciprocal interactions that characterize different forms and intensity of cancer pain. We also hypothesize that one type of cancer pain, the breakthrough pain, can be attributable to receptor-mediated interaction of opioids with tumor cells and intratumoral leukocytes. Surprisingly, long-term opioid treatment shares the same neuroinflammatory potential responsible for the chronicity of both cancer and non-cancer pain; thus, resulting in paradoxical worsening rather than relieving pain. This paradox has upset the world of pain therapy, with neuroinflammation now being a main target of emerging therapies.

Two sides on the fibromyalgia coin: physical pain and social pain (invalidation)

Although fibromyalgia (FM) has been traditionally defined by the extent of physical pain sites alongside other non-pain symptoms, recent evidence has highlighted the importance of social dimension in definition of pain perception. Social pain or invalidation, which denotes painful feeling following social conflicts or misunderstanding about illness legitimacy, is an important but ignored issue in the FM lexicon. While physical and social pain seem to be different and separate entities, we hypothesize that they are completely intertwined with indistinct borders in FM. Accumulating emergent neuroscience and behavioral evidence highlights the overlapping of physical and social pain in different painful conditions. However, this overlapping seems to reach its maximum in FM. This review sheds more light on the tight interconnectivity between physical and social pain in FM from the perspective of intuitional commonalities, clinical aspects, and shared neural pathways. The conceptualization of FM as an integrative physical-social pain paradigm will move us closer to necessitating the incorporation of social pain in future models of FM diagnosis and management. Key Points • Considering of social pain as one key concept is relatively mute in FM literature. • Overlapping of physical and social pain seems to be unique in FM due to its nature. • Acknowledging social pain in the FM lexicon could shift the paradigm of diagnosis and management of FM patients.

Decreased Chronic Widespread Pain on Nonworking Days Might Help Differentiate Work-Related Musculoskeletal Disorders From Fibromyalgia: A Cross-Sectional Study of Working Females

Objectives

This study aims to investigate whether fibromyalgia (FM) and work-related musculoskeletal disorders can be differentiated in working females by comparing their pain on nonworking and working days.

Patients and methods

The study included 142 female workers (mean age 30.0±6.5 years; range, 18 to 50 years) from five different work areas: 27 factory workers, 27 janitors, 25 data automation employees, 31 nurses, and 32 physiotherapists. Demographic characteristics were recorded. FM was diagnosed according to 2016 criteria of the American College of Rheumatology. The extended version of the Nordic Musculoskeletal Questionnaire was used to evaluate the participants’ musculoskeletal complaints and the severity of their pain. Pain was assessed with visual analog scale (VAS) scores on working and nonworking days. Differences in the participants’ VAS-Pain on working and nonworking days were compared. Sensitivity, specificity, receiver operating characteristic (ROC) curve and area under the curve (AUC) were used.

Results

Of the 142 working females, 32 (22.5%) were diagnosed with FM. There was a significant difference in nonworking day VAS-Pain scores between the FM patients and the work-related musculoskeletal disorder patients (p<0.001). Analysis of ROC curve for VAS-Pain difference scores yielded AUC of 0.860 (95% confidence interval=0.774–0.945) (p<0.001). ROC analysis identified 1.5 centimeters of VAS-Pain difference score as the cut-point for differentiating work-related musculoskeletal disorders and FM resulting in sensitivity of 97% and specificity of 96%. FM patients had significantly higher rates of positive answers to “visit health professionals,” “take medication,” and “sick leave” questions compared to patients with work-related musculoskeletal disorders (p<0.001).

Conclusion

The amount of the decrease in pain on nonworking days may help differentiate work-related musculoskeletal disorders from FM in working females. Therefore, evaluating pain on nonworking days may help clinicians diagnose and treat FM correctly.

The Association of Pain Phenotype with Neuromuscular Impairments and Mobility Limitations Among Older Primary Care Patients: A Secondary Analysis of the Boston Rehabilitative Impairment Study of the Elderly

BACKGROUND

Clarifying the relationship between pain phenotypes and physical function in older adults may enhance screening and treatment for functional decline in primary care settings.

OBJECTIVE

To investigate the association of more severe pain phenotypes with neuromuscular impairments or mobility limitations among older community-dwelling primary care patients.

DESIGN

Cross-sectional analysis.

SETTING

The Boston Rehabilitative Impairment Study of the Elderly.

PARTICIPANTS

Adults aged 65 years or older.

METHODS

We counted the number of musculoskeletal pain locations (none, single site, multisite, or widespread) using the McGill Pain Questionnaire and identified pain intensity tertiles using the Brief Pain Inventory. Neuromuscular attributes (trunk extensor muscle endurance, and leg speed, strength, strength asymmetry, and range of motion) and mobility (Short Physical Performance Battery [SPPB]) were assessed with performance-based measures. Additionally, self-reported mobility was measured on the Late Life Function and Disability Instrument (LLFDI). For neuromuscular attributes and LLFDI, scores in the lowest tertile indicated neuromuscular impairment or mobility limitations, respectively. For SPPB, a score <7 (of 12) indicated severe mobility limitations.

RESULTS

Among 430 participants (mean age = 77) most were female (68%), white (83%), and had either multisite (50%) or widespread (14%) pain. After adjusting for baseline characteristics, widespread pain (compared to none) was associated with slow leg speed (adjusted odds ratio, 95% confidence interval: aOR = 2.33, 1.03-5.27), limited ankle range of motion (aOR = 2.15, 1.03-4.47) and mobility limitations on LLFDI (aOR = 3.85, 1.81-8.19). Being in the highest pain intensity tertile, versus lowest tertile, was associated with poor trunk extensor muscle endurance (aOR = 2.49, 1.41-4.39), limited ankle range of motion (aOR = 2.15, 1.25-3.71), and mobility limitations on SPPB (aOR = 2.56, 1.45-4.52), and LLFDI (aOR = 4.70, 2.63-8.40).

CONCLUSIONS

Among ambulatory, older primary care patients, more severe pain phenotypes are associated with neuromuscular impairments identified on physical testing and mobility limitations on validated measures.

Revised chronic widespread pain criteria: development from and integration with fibromyalgia criteria

Background and aims

Persons with chronic widespread pain (CWP) have poor medical outcomes and increased mortality. But there are no universally accepted criteria for CWP or of methods to assess it. The most common criteria come from the 1990 American College of Rheumatology (ACR) fibromyalgia (FM) criteria, but that method (WP1990) can identify CWP with as few as three pain sites, and in subjects with wide differences in illness severity. Recently, to correct WP1990 deficiencies, the 2016 fibromyalgia criteria provided a modified CWP definition (WP2016) by dividing the body into five regions of three pain sites each and requiring a minimum of four regions of pain. Although solving the geographic problem of pain distribution, the problem of just how many pain sites (pain diffuseness) are required remained a problem, as WP2016 required as few as four painful sites. To better characterize CWP, we compared four CWP definitions with respect to symmetry, extent of pain sites and association with clinical severity variables.

Methods

We characterized pain in 40,960 subjects, including pain at 19 individual sites and five pain regions, and calculated the widespread pain index (WPI) and polysymptomatic distress scales (PDS) from epidemiology, primary care and rheumatology databases. We developed and evaluated a new definition for CWP, (WP2019), defined as pain in four or five regions and a pain site score of at least seven of 15 sites. We also tested a definition based on the number of painful sites (WPI ≥ 7).

Results

In rheumatology patients, WP1990 and WPI ≥ 7 classified patients with <4 regions as WSP. CWP was noted in 51.3% by WP1990, 41.7% by WP2016, 37.6% of WPI ≥ 7 and 33.9% by WP2019. 2016 FM criteria was satisfied in WP1990 (51.1%), WP2016 (63.3%), WPI ≥ 7 (69.0%) and WP2019 (76.6%). WP2019 positive patients had more severe clinical symptoms compared with WP1990, WP2016 and WPI ≥ 7, and similar to but less than FM 2016 positive patients. In stepwise fashion, scores for functional disability, visual analog scale fatigue and pain, WPI, polysymptomatic distress score and Patient Health Questionnaire 15 (PHQ-15) worsened from WP1990 through WP2016, WPI ≥ 7 and WP2019.

Conclusions

WP2019 combines the high WPI scores of WPI ≥ 7 and the symmetry of WP2016, and is associated with the most abnormal clinical scores. The WP1990 does not appear to be an effective measure. We suggest that CWP can be better defined by combining 4-region pain and a total pain site score ≥7 (WP2019). This definition provides a simple, unambiguous measure that is suitable for clinical and research use as a standalone diagnosis that is integrated with fibromyalgia definitions.

Implications

Definitions of CWP in research and clinic care are arbitrary and have varied, and different definitions of CWP identify different sets of patients, making a universal interpretation of CWP uncertain. In addition, CWP is a mandatory component of some fibromyalgia criteria. Our study provides quantitative data on the differences between CWP definitions and their criteria, allowing better understanding of research results and a guide to the use of CWP in clinical care.

Motivational Non-directive Resonance Breathing as a Treatment for Chronic Widespread Pain

Chronic widespread pain (CWP) is one of the most difficult pain conditions to treat due to an unknown etiology and a lack of innovative treatment design and effectiveness. Based upon preliminary findings within the fields of motivational psychology, integrative neuroscience, diaphragmatic breathing, and vagal nerve stimulation, we propose a new treatment intervention, motivational non-directive (ND) resonance breathing, as a means of reducing pain and suffering in patients with CWP. Motivational ND resonance breathing provides patients with a noninvasive means of potentially modulating five psychophysiological mechanisms imperative for endogenously treating pain and increasing overall quality of life.

Psychological therapies for chronic widespread pain and fibromyalgia syndrome

Psychological factors such as adverse childhood experiences, traumatic life events, interpersonal conflicts and psychological distress play an important role in the predisposition, onset and severity of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS). Therefore, psychological therapies might have the potential to reduce disability as well as symptom and economic burden in patients with CWP and FMS. Recent interdisciplinary guidelines have suggested different strengths of recommendation for psychological therapies for FMS. The aims of this narrative review are to summarise: • Mechanisms of actions. • Evidence on efficacy, tolerability and safety. • Knowledge gaps and needs for future research of psychological therapies for CWP and FMS for non-mental health professionals.

Chronic widespread pain patients show disrupted cortical connectivity in default mode and salience networks, modulated by pain sensitivity

Purpose: The remodeling of functional neuronal connectivity in chronic widespread pain (CWP) patients remains largely unexplored. This study aimed to investigate functional connectivity in CWP patients in brain networks related to chronic pain for changes related to pain sensitivity, psychological strain, and experienced pain.

Patients and methods: Functional connectivity strength of the default mode network (DMN) and the salience network (SN) was assessed with functional magnetic resonance imaging. Between-group differences were investigated with an independent component analysis for altered connectivity within the whole DMN and SN. Then, changes in connectivity between nodes of the DMN and SN were investigated with the use of a seed-target analysis in relation to the covariates clinical pain intensity, pressure pain sensitivity, psychological strain, and as an effect of experienced experimental cuff-pressure pain.

Results: CWP patients showed decreased connectivity in the inferior posterior cingulate cortex (PCC) in the DMN and increased connectivity in the left anterior insula/superior temporal gyrus in the SN when compared to controls. Moreover, higher pain sensitivity in CWP when compared to controls was related to increased connectivity within the SN (between left and right insula) and between SN and DMN (between right insula and left lateral parietal cortex).

Conclusion: This study shows that connectivity within the DMN was decreased and connectivity within the SN was increased for CWP. Furthermore, we present a novel finding of interaction of pain sensitivity with SN and DMN-SN functional connectivity in CWP.

The interplay between sleeplessness and high-sensitivity C-reactive protein on risk of chronic musculoskeletal pain: longitudinal data from the Tromsø Study

Study Objectives

To examine independent associations of sleeplessness and high-sensitivity C-reactive protein (hsCRP) with risk of chronic musculoskeletal pain, and to explore the joint effect of sleeplessness and hsCRP on risk of chronic musculoskeletal pain.

Methods

A population-based prospective study of 3214 women and 3142 men (mean age: 55.4, range: 32–87) without severe chronic musculoskeletal pain and with hsCRP ≤ 10 mg/L at baseline in 2007–2008. Modified Poisson regression was used to calculate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for any chronic musculoskeletal pain and chronic widespread pain (CWP) at follow-up in 2015–2016 associated with self-reported sleeplessness and hsCRP at baseline.

Results

Compared with persons without sleeplessness, women and men reporting often/or always sleeplessness had RRs of CWP of 2.53 (95% CI: 1.94–3.29) and 2.48 (95% CI: 1.63–3.77), respectively. There was no clear association between hsCRP and risk of any chronic musculoskeletal pain or CWP. Joint effect analyses using persons without sleeplessness and with a hsCRP < 1.00 mg/L as the reference gave RRs for chronic musculoskeletal pain of 1.73 (95% CI: 1.26–2.37) for those with often/always sleeplessness and hsCRP < 1.00 mg/L; 1.01 (95% CI: 0.78–1.32) for those without sleeplessness and hsCRP ≥3.00 mg/L; and 2.47 (95% CI: 1.79–3.40) if they had both often/always sleeplessness and hsCRP ≥ 3.00 mg/L. The corresponding RRs for CWP were 1.89 (95% CI: 1.27–2.83), 0.96 (95% CI: 0.68–1.37), and 2.83 (95% CI: 1.91–4.20), respectively.

Conclusions

These results suggest that there is an interplay between sleeplessness and hsCRP on risk of any chronic musculoskeletal pain and CWP.

Chronic Widespread Pain in a tertiary pain clinic: classification overlap and use of a patient generated quality of life instrument

Background and aims This study has two main aims: (1) To explore the overlap between classification criteria in patients with Chronic Widespread Pain (CWP) and (2) To explore the use of the Patient Generated Index (PGI) as a quality of life (QoL) measure in this patient group. Methods Patients with Widespread Pain (ICD-11: pain in four or more out of five bodily regions, i.e. the four quadrants and axially) in a tertiary pain outpatient clinic were assessed according to classification criteria for Fibromyalgia [FM, American College of Rheumatology (ACR) criteria of 1990, 2010, 2011 and 2016], Chronic Fatigue Syndrome [CFS, Fukuda, Canada and International Consensus Criteria (ICC)] and Bodily Distress Syndrome (BDS). Furthermore, patients completed the PGI to assess QoL, and electronic questionnaires including demographic variables and standardised patient-reported outcome measures (PROMs). Results All patients (n=33) fulfilled the criteria for musculoskeletal type single-organ BDS, 81.8% met the 2016 modified criteria for FM, 30.3% met the Canada criteria for CFS and 24.2% met the criteria for multi-organ type BDS. There was substantial agreement between the 2016 and the 2011 and 2010 criteria sets for FM compared to the 1990 criteria (κ=0.766 and 0.673 compared to 0.279). Patients generally scored low on the PGI, indicating poor QoL (mean PGI 28.9, SD 19.8, range 0-100). Conclusions Our findings support the use of the term musculoskeletal type single-organ BDS to describe patients with CWP and the 2016 revision of the FM criteria. The PGI provides useful clinical information which is not captured by standardised PROMs. Implications The terminology of CWP has become less ambiguous as the new ICD-11 is closely related to the generalised pain criterion of the modified 2016 FM definition. Studies based on the 1990 classification criteria for FM should not be directly compared to studies based on later criteria set. The PGI may be a supplement to other measurements to portray patients' individual concerns in patients with complex symptom disorders.

Empirical Grouping of Pain Zones in Fibromyalgia: A Preliminary Study

OBJECTIVES

Widespread pain is important for the diagnosis of fibromyalgia (FM). For this purpose, the sum of pain regions obtained from a topographical distribution has been used to compute a Widespread Pain Index (WPI), but there is no empirical basis for choosing the regions. The aim of this study was to find an empirical distribution of the pain regions.

MATERIALS AND METHODS

We evaluated 228 female patients with FM. They completed the Fibromyalgia Survey Questionnaire, Fibromyalgia Impact Questionnaire (FIQ), Combined Index of Severity in Fibromyalgia (ICAF), and Short Form-36 Health Survey. The pain regions of the WPI were grouped by the topographical distribution (WPIR) and compared with a new empirical distribution (WPIE) obtained through exploratory factor analysis. A decision- tree analysis was conducted to identify the optimal algorithm for selecting pain regions related to the severity of FM.

RESULTS

The WPIE has a normal distribution compared with the WPIR. It also shows higher correlations with FM severity. From the factor analysis, 4 factors explain 48.5% of the variance. Two factors (emotional and physical) can conform to the decision-tree analysis using the dependent variables FIQ and ICAF. These factors are very congruent with the cutoff points previously proposed for FIQ and ICAF. The emotional factor is the first in the decision-tree.

DISCUSSION

WPIE has a normal distribution and shows better predictive qualities than WPIR. The emotional factor is conceptualized as emotional because of the relative importance of the right hemisphere in negative emotions and pain. The physical factor could be responsible for the decreased ability to coordinate left-right stepping.

Does association of opioid use with pain and function differ by fibromyalgia or widespread pain status?

Many consider chronic opioid therapy (COT) to be ineffective for fibromyalgia, but empirical evidence is limited. Among patients identified as initiating COT, we examined whether fibromyalgia was associated with different relationships of opioid use to pain and activity interference outcomes 12 months later. We obtained electronic data on diagnoses and opioid prescriptions. We obtained patient self-report data, including pain and activity interference measures, at baseline, 4 months, and 12 months. Among 1218 patients, 429 (35%) met our definition of fibromyalgia. Patients with and without fibromyalgia who had intermittent/lower-dose or regular/higher-dose opioid use at 12 months had similar 12-month pain intensity scores. However, among patients with minimal/no opioid use at 12 months, 12-month pain intensity was greater for those with fibromyalgia (adjusted mean = 5.15 [95% confidence interval, 4.80-5.51]; 0-10 scale) than for those without (4.44 [4.15-4.72]). Similar patterns were observed for 12-month activity interference. Among patients who discontinued opioids by 12 months, those with fibromyalgia were more likely to report bothersome side effects and less likely to report pain improvement as important reasons for discontinuation (P < 0.05). In sum, at 12 months, among patients who had discontinued opioids or used them minimally, those with fibromyalgia had worse outcomes and were less likely to have discontinued because of pain improvement. Among patients continuing COT, pain and activity interference outcomes were worse than those of patients with minimal/no opioid use and did not differ for those with fibromyalgia vs those with diverse other chronic pain conditions.

Chronic pain in multiple sclerosis: A 10-year longitudinal study

BACKGROUND AND PURPOSE

Pain is a common symptom associated with multiple sclerosis (MS), and has lasting effects on an individual's functional capacity and quality of life. A wide range of prevalence rates of pain (between 23% and 90%)have been reported in MS and this is mainly due to the methodological differences amongst the studies such as variability in patient sources, method of sampling and the definition of pain used. Chronic pain in MS, defined as pain lasting for greater than 3-6 months, can have a significant impact on their biopsychosocial health, including negative impact on activities of daily living, relationships and social participation. The long-term course of MS-related pain and its impact in an Australian cohort over a 7-year period has been investigated earlier. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period.

METHODS

This was a prospective longitudinal study conducted at the Rehabilitation Department of Royal Melbourne Hospital (RMH), a tertiary referral hospital in Victoria and Australia. The source of participants was from the RMH MS database and contains detailed MS patient information including demographic data, diagnosis details (using McDonald's criteria), pain characteristics. Structured face-face interviews and validated measures were used, which include the visual analogue scale (VAS); chronic pain grade (CPG); the assessment of quality of life (AQoL) and the carer strain index (CSI). The mean age of the participants (n=70) was 55.3 years and majority (70%) were female.

RESULTS

The mean age of the participants (n=70) was 55.3 years and majority (70%) were female. The findings show that over time (10 years), participants report having greater bilateral bodily pain and greater description of pain as 'worse as it could be'. Pain types were similar to 7-years follow-up but remained higher than baseline. There was a significant deterioration in quality of life in those with more severe CPG over time. Almost half of the participants 31 (44%) required care either from a private carer, institution or from a family member. Although fear of taking medications and side effects were common barriers to treatment for pain, there was an increase in the use of pharmacological treatment over time and an increase in the use of healthcare services, mainly neurologists and general practitioners.

CONCLUSIONS

The pain measures reported by the participants were similar to those at the 7-year follow-up except there was a greater representation of bilateral pain locations (limb, trunk and facial pain) compared to baseline and 7-year follow-up. At 10-year follow-up, more participants used medications compared to 7-year follow-up and there was an increase in the use of health professionals at the 10-year follow-up. At the 10-year follow up QoL of the participants deteriorated significantly and more participants had progressed to higher CPG III and CPG IV. This study demonstrates that chronic pain is a significant issue over time in MS, with clinical and health implications, impact on quality of life, disability and healthcare utilization.

IMPLICATIONS

Greater awareness of chronic pain in pwMS, cognitive classifications and an interdisciplinary approach is required to improve long-term patient outcomes and well-being.

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.

Clear differences in cerebrospinal fluid proteome between women with chronic widespread pain and healthy women - a multivariate explorative cross-sectional study

Introduction

Frequent chronic local pain can develop into chronic widespread pain (CWP). The spread of pain is correlated with pain intensity, anxiety, and depression, conditions that ultimately lead to a poor quality of life. Knowledge is incomplete about CWP’s etiology, although it has been suggested that both central hyperexcitability and/or a combination with peripheral factors may be involved. Cerebrospinal fluid (CSF) could act as a mirror for the central nervous system as proteins are signal substances that activate the formation of algesics and control nociceptive processes. To this end, this study investigates the CSF protein expression in women with CWP and in female healthy controls.

Materials and methods

This study included 12 female patients with CWP diagnosed according to the American College of Rheumatology criteria with 13 healthy age- and sex-matched pain-free subjects. All subjects went through a clinical examination and answered a health questionnaire that registered sociodemographic and anthropometric data, pain characteristics, psychological status, and quality of life rating. CSF was collected by lumbar puncture from each subject. Two-dimensional gel electrophoresis in combination with mass spectrometry was used to analyze the CSF proteome. This study identifies proteins that significantly discriminate between the two groups using multivariate data analysis (MVDA) (i.e., orthogonal partial least squares discriminant analysis [OPLS-DA]).

Results

There were no clinically significant levels of psychological distress and catastrophization presented in subjects with CWP. MVDA revealed a highly significant OPLS-DA model where 48 proteins from CSF explained 91% (R²) of the variation and with a prediction of 90% (Q²). The highest discriminating proteins were metabolic, transport, stress, and inflammatory.

Conclusion

The highest discriminating proteins (11 proteins), according to the literature, are involved in apoptotic regulations, anti-inflammatory and anti-oxidative processes, the immune system, and endogenous repair. The results of this explorative study may indicate the presence of neuro-inflammation in the central nervous system of CWP patients. Future studies should be larger and control for confounders and determine which alterations are unspecific/general and which are specific changes.

Are persons with fibromyalgia or other musculoskeletal pain more likely to report hearing loss? A HUNT study

BACKGROUND

Leading theories about the pathogenesis of fibromyalgia focus on central nervous dysregulation or sensitization, which can cause altered perception. There is growing evidence that fibromyalgia involves altered perception not only of pain, but also other sensory stimuli. On this basis, we investigated whether individuals with fibromyalgia are more likely to report subjective loss of hearing, adjusted for audiometrically measured loss of hearing, compared to persons without any musculoskeletal pain disorders. In addition, we studied persons with other musculoskeletal pain than fibromyalgia and persons who did not have any musculoskeletal pain.

METHODS

The study includes 44 494 persons from the second health survey in Nord-Trøndelag (HUNT2) who had undergone audiometry and answered a comprehensive questionnaire that mapped fibromyalgia, musculoskeletal pain at various sites and subjective hearing loss. Respondents with other musculoskeletal pain problems than fibromyalgia were divided into two groups with respectively localized and widespread musculoskeletal pain. Data were analyzed with logistic regression models adjusting for age, education, anxiety, depression and hearing thresholds.

RESULTS

In adjusted analysis, individuals with fibromyalgia had increased likelihood to report subjective hearing loss, compared to persons without fibromyalgia or other musculoskeletal pain (OR 4.578, 95% CI 3.622-5.787 and OR 4.523, 95% CI 3.077-6.647 in women and men). Furthermore, people with local and widespread musculoskeletal pain not diagnosed with fibromyalgia, also had increased likelihood to report subjective hearing loss, compared to people with no musculoskeletal pain. This relationship was greater for widespread pain than for localized pain (OR 1.915, 95% CI 1.627-2.255, and 1.796, 95% CI 1.590-2.029, in women and men with local musculoskeletal pain and OR 3.073, 95% CI 2.668-3.539, OR 3.618, 95% CI 3.225-4.058, in women and men with widespread pain, respectively).

CONCLUSIONS

Our findings are consistent with the hypothesis that fibromyalgia is related to a general dysregulation of the central nervous system. The same might also be the case for other local and, in particular, other widespread, musculoskeletal pain.

2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria

OBJECTIVES

The provisional criteria of the American College of Rheumatology (ACR) 2010 and the 2011 self-report modification for survey and clinical research are widely used for fibromyalgia diagnosis. To determine the validity, usefulness, potential problems, and modifications required for the criteria, we assessed multiple research reports published in 2010-2016 in order to provide a 2016 update to the criteria.

METHODS

We reviewed 14 validation studies that compared 2010/2011 criteria with ACR 1990 classification and clinical criteria, as well as epidemiology, clinical, and databank studies that addressed important criteria-level variables. Based on definitional differences between 1990 and 2010/2011 criteria, we interpreted 85% sensitivity and 90% specificity as excellent agreement.

RESULTS

Against 1990 and clinical criteria, the median sensitivity and specificity of the 2010/2011 criteria were 86% and 90%, respectively. The 2010/2011 criteria led to misclassification when applied to regional pain syndromes, but when a modified widespread pain criterion (the "generalized pain criterion") was added misclassification was eliminated. Based on the above data and clinic usage data, we developed a (2016) revision to the 2010/2011 fibromyalgia criteria. Fibromyalgia may now be diagnosed in adults when all of the following criteria are met: CONCLUSIONS: The fibromyalgia criteria have good sensitivity and specificity. This revision combines physician and questionnaire criteria, minimizes misclassification of regional pain disorders, and eliminates the previously confusing recommendation regarding diagnostic exclusions. The physician-based criteria are valid for individual patient diagnosis. The self-report version of the criteria is not valid for clinical diagnosis in individual patients but is valid for research studies. These changes allow the criteria to function as diagnostic criteria, while still being useful for classification.