The IASP classification of chronic pain for ICD-11: chronic primary pain

Treating neuropathic pain and comorbid affective disorders: Preclinical and clinical evidence

INTRODUCTION

Neuropathic pain (NP) significantly impacts quality of life and often coexists with affective disorders such as anxiety and depression. Addressing both NP and its psychiatric manifestations requires a comprehensive understanding of therapeutic options. This study aimed to review the main pharmacological and non-pharmacological treatments for NP and comorbid affective disorders to describe their mechanisms of action and how they are commonly used in clinical practice.

METHODS

A review was conducted across five electronic databases, focusing on pharmacological and non-pharmacological treatments for NP and its associated affective disorders. The following combination of MeSH and title/abstract keywords were used: "neuropathic pain," "affective disorders," "depression," "anxiety," "treatment," and "therapy." Both animal and human studies were included to discuss the underlying therapeutic mechanisms of these interventions.

RESULTS

Pharmacological interventions, including antidepressants, anticonvulsants, and opioids, modulate neural synaptic transmission to alleviate NP. Topical agents, such as capsaicin, lidocaine patches, and botulinum toxin A, offer localized relief by desensitizing pain pathways. Some of these drugs, especially antidepressants, also treat comorbid affective disorders. Non-pharmacological techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and photobiomodulation therapy, modulate cortical activity and have shown promise for NP and mood disorders.

CONCLUSIONS

The interconnection between NP and comorbid affective disorders necessitates holistic therapeutic strategies. Some pharmacological treatments can be used for both conditions, and non-pharmacological interventions have emerged as promising complementary approaches. Future research should explore novel molecular pathways to enhance treatment options for these interrelated conditions.

Transforaminal pulsed radiofrequency and epidural steroid injection on chronic lumbar radiculopathy: A prospective observational study from a tertiary care hospital in Vietnam

BACKGROUND

Lumbosacral radicular syndrome (LRS) is probably the most frequent neuropathic pain syndrome, exaggerating medical and economy burden on developing countries, such as Vietnam. As a result, the urgence to find an approach which is both affordable and effective always puts great demand on medical researchers.

OBJECTIVES

Evaluate the effectiveness of transforaminal pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) and epidural steroid injection (ESI) in management of chronic lumbosacral radiculopathy.

METHODS

Seventy-six patients with chronic radicular pain were performed transforaminal PRF + ESI by neurosurgeons. Demographic characteristics and surgical outcomes were recorded on admission, pre-procedural and post-procedural for 1-month, 3-month, 6-month and 12-month follow-up. Primary outcome was measured by using Visual Analogue Scale (VAS), Oswestry disability index (ODI) and Straight Leg Raising Test (SLRT). Secondary outcome was subjectively collected based on short assessment of patients' satisfaction (SAPS).

RESULTS

Patients who received transforaminal PRF and ESI showed significant improvements on all three evaluation tools (VAS, ODI, SLRT), compared to that before treatment (p<0.001). Pain relief was achievable and long-lasting, which met patients' expectation. No significant complications were observed for 12 months follow-up.

CONCLUSION

Transforaminal PRF combined with ESI in management of lumbosacral radiculopathy should be a good method of choice for its effectiveness and safety in management of pain.

A multi-ancestry genetic study of pain intensity in 598,339 veterans

Chronic pain is a common problem, with more than one-fifth of adult Americans reporting pain daily or on most days. It adversely affects the quality of life and imposes substantial personal and economic costs. Efforts to treat chronic pain using opioids had a central role in precipitating the opioid crisis. Despite an estimated heritability of 25-50%, the genetic architecture of chronic pain is not well-characterized, in part because studies have largely been limited to samples of European ancestry. To help address this knowledge gap, we conducted a cross-ancestry meta-analysis of pain intensity in 598,339 participants in the Million Veteran Program, which identified 126 independent genetic loci, 69 of which are new. Pain intensity was genetically correlated with other pain phenotypes, level of substance use and substance use disorders, other psychiatric traits, education level and cognitive traits. Integration of the genome-wide association studies findings with functional genomics data shows enrichment for putatively causal genes (n = 142) and proteins (n = 14) expressed in brain tissues, specifically in GABAergic neurons. Drug repurposing analysis identified anticonvulsants, β-blockers and calcium-channel blockers, among other drug groups, as having potential analgesic effects. Our results provide insights into key molecular contributors to the experience of pain and highlight attractive drug targets.

Post stroke pain: Is there under-diagnosis in Black versus White patients?

Stroke incidence is higher and stroke outcomes are poorer in Black patients compared to White patients. Poststroke pain, however, is not a well understood stroke outcome. Using the National Institutes of Health All of Us Research Program database, we hypothesized that the dataset would demonstrate proportionately higher relative risk of poststroke pain in the Black poststroke patient population compared to the White poststroke patient population. However, our analysis showed that Black stroke patients were diagnosed with poststroke pain at a similar rate as White stroke patients. As our results are not consistent with other poststroke outcomes in the literature, this study identifies a potentially underdiagnosed patient population, highlighting the need for further research.

Examining the Association Between Objective Physical Activity and Momentary Pain: A Systematic Review of Studies Using Ambulatory Assessment

Chronic pain (CP) is a debilitating and increasingly common health condition that adversely impacts function, including physical activity (PA). Research using ambulatory assessment (AA) methods (eg, ecological momentary assessment, actigraphy) offers promise for elucidating the relationship between momentary pain and objective PA in CP populations. This study aimed to systematically review articles assessing the association between momentary pain and PA in adults with CP as measured using AA and to make recommendations for the measurement and study of this relationship. Five databases were systematically searched, and 13 unique records (N = 768) met the inclusion criteria. CP conditions included mixed/nonspecific CP (k = 3), low back pain (k = 2), fibromyalgia (k = 1), unspecified arthritis (k = 1), and hip/knee osteoarthritis (k = 6). The average age of participants across studies was 55.29 years, and the majority identified as women (60.68%) and White (83.16%). All studies measured objective PA via actigraphy, and momentary pain with either a diary/log or ratings on an actigraph. Studies varied in the quantification of PA (ie, activity counts, step count, moderate-vigorous PA), statistical method (ie, correlation, regression, multilevel modeling), and inclusion of moderators (eg, pain acceptance). Studies reported mixed results for the pain-PA relationship. This heterogeneity suggests that no summarizing conclusions can be drawn about the pain-PA relationship without further investigation into its complex nuances. More within-person and exploratory examinations that maximize the richness of AA data are needed. A greater understanding of this relationship can inform psychotherapeutic and behavioral recommendations to improve CP outcomes. PERSPECTIVE: This article presents a systematic review of the literature on the association between momentary pain and PA in adults with CP as measured using AA methods. A better understanding of this nuanced relationship could help elucidate areas for timely intervention and may inform clinical recommendations to improve CP outcomes. PROSPERO REGISTRATION NUMBER: CRD42023389913.

The Adaptive, Pain Sensitive, and Global Symptoms Clusters: Evidence from a Patient-Based Study

OBJECTIVES

The largest epidemiologic study conducted about painful temporomandibular disorders (pTMDs) to date identified 3 clusters of individuals with similar symptoms-adaptive, pain sensitive, and global symptoms-which hold promise as a means of personalizing pain care. Our goal was to compare the clinical and psychological characteristics that are consistent with a pTMD clinical examination among patients who are seeking care and assigned to the different clusters.

METHODS

This cross-sectional study used data from the medical records of patients attending Duke Innovative Pain Therapies between August 2017 and April 2021 who received a pTMD diagnosis (i.e., myalgia) and consented to have their data used for research. Data included orofacial and pain-related measures, dental features, and psychological measures. We used the Rapid OPPERA Algorithm to assign clusters to patients and multinomial regression to determine the likelihood (odds ratios [OR] and 95% confidence intervals [CI]) of being assigned to the pain sensitive or global symptoms cluster attributed to each measure.

RESULTS

In total, 131 patients were included in this study and assigned a cluster: adaptive (n = 54, 41.2%), pain sensitive (n = 49, 37.4%), and global symptoms (n = 28, 21.4%). The PS cluster displayed greater numbers of temporomandibular joint sites (OR, 1.29; 95% CI, 1.01 to 1.65) and masticatory (1.48; 1.19 to 1.83) and cervical (1.23; 1.09 to 1.39) muscles with pain evoked by palpation. The GS cluster displayed greater scores of pain catastrophizing (1.04; 1.01 to 1.06) and perceived stress (1.23; 1.03 to 1.46) and was more likely to report persistent pain (16.23; 1.92 to 137.1) of higher impact (1.43; 1.14 to 1.80).

CONCLUSION

Our findings support that care-seeking patients with pTMDs who are assigned to the GS cluster display a poorer psychological profile, even though those assigned to the PS cluster display more measures consistent with orofacial pain. Findings also establish the PS cluster as a group that does not display psychological comorbidities despite being hypersensitive.

KNOWLEDGE TRANSFER STATEMENT

This study informs clinicians that patients seeking care for painful temporomandibular disorders, in specific cases of myalgia, can be classified into 1 of 3 groups that display unique profiles of symptoms. Most importantly, it emphasizes the importance of examining patients with painful temporomandibular disorders in a holistic manner that includes assessing symptoms of psychological distress. Patients with greater psychological distress will likely benefit from multidisciplinary treatment strategies that may include psychological treatments.

How do we explain painful non-traumatic knee conditions to adolescents? A multiple-method study to develop credible explanations

BACKGROUND

Perceived diagnostic uncertainty can leave adolescents confused about their condition and impede their ability to understand "what's wrong with me". Our aim is to develop credible explanations about the condition for adolescents suffering from non-traumatic knee pain.

METHODS

This multiple-method study integrated findings from two systematic literature searches of qualitative and quantitative studies, an Argumentative Delphi with international experts (n = 16) and think-aloud interviews with adolescents (n = 16). Experts provided feedback with arguments on how to communicate credible explanations to meet adolescents' needs; we analysed feedback using thematic analysis. The explanations were tailored based on the adolescent end-users' input.

RESULTS

We screened 3239 titles/abstracts and included 16 papers exploring diagnostic uncertainty from adolescents' and parents' perspectives. Five themes were generated: (1) understanding causes and contributors to the pain experience, (2) feeling stigmatized for having an invisible condition, (3) having a name for pain, (4) controllability of pain, and (5) worried about something being missed. The Argumentative Delphi identified the following themes: (1) multidimensional perspective, (2) tailored to adolescents, (3) validation and reassurance, and (4) careful wording. Merging findings from the systematic search and the Delphi developed three essential domains to address in credible explanations: "What is non-traumatic knee pain and what does it mean?", "What is causing my knee pain?" and "How do I manage my knee pain?"

CONCLUSIONS

Six credible explanations for the six most common diagnoses of non-traumatic knee pain were developed. We identified three domains to consider when tailoring credible explanations to adolescents experiencing non-traumatic knee pain.

SIGNIFICANCE

This study provides credible explanations for the six most common diagnoses of non-traumatic knee pain. Additionally, we identified three key domains that may need to be addressed to reduce diagnostic uncertainty in adolescents suffering from pain complaints. Based on our findings, we believe that clinicians will benefit from exploring adolescents' own perceptions of why they experience pain and perceived management strategies, as this information might capture important clinical information when managing these young individuals.

Musculoskeletal pain affects the age of retirement and the risk of work cessation among older people

OBJECTIVES

Many people with chronic pain cannot work, while working despite chronic pain is linked to absenteeism and presenteeism and a host of other deleterious effects. This disproportionately affects older adults, who are closer to retirement, while the exact relationship between pain and work cessation as well as retirement among older adults is not known. We explore longitudinally the relationship between chronic pain and the risk of ceasing work and entering retirement.

METHODS

Data from 1156 individuals 50 years or older living in England taking part in the English Longitudinal Study of Ageing were used in this study. Cox proportional hazards regression analyses were used to examine the nature of the relationship between musculoskeletal pain and work cessation as well as retirement longitudinally over the course of fourteen years.

RESULTS

Suffering from frequent musculoskeletal pain was associated with an increased risk of ceasing work and retiring at an earlier age, as did work dissatisfaction, higher perceived social status, female gender, and not receiving the recognition they felt they deserved in their job. Severity of depressive symptoms, psychosocial job demands, decision authority, and social support did not influence the age at which participants reported work cessation or retirement.

CONCLUSIONS

Frequent musculoskeletal pain may increase the risk of earlier work exit and earlier retirement. Further research should establish the mechanisms and decision making involved in leaving the workforce in people with frequent musculoskeletal pain.

Sexual Orientation/Gender Identity Discrimination and Chronic Pain in Children: A National Study

INTRODUCTION

This study provides national estimates of parental perceived child sexual orientation or gender minority (SGM) discrimination and examines associations between SGM discrimination and chronic pain in children.

METHODS

Cross-sectional analysis of the 2020 and 2021 National Survey of Children's Health (N=47,213). Caregivers of children ages 6-17 years old reported whether their child had ever been treated or judged unfairly (i.e., discrimination) because of their SGM identity. Chronic pain in children was defined as frequent or chronic difficulty with repeated or chronic physical pain during the past 12 months, as reported by caregivers. Weighted prevalence estimates for discrimination were calculated for the whole sample and sociodemographic subgroups. Associations between SGM discrimination and chronic pain were estimated using multivariable Poisson regression models adjusting for sociodemographic factors. Analyses were conducted 2022-2023.

RESULTS

Within this nationally representative sample, parents reported 1.4% (95% CI 1.2%-1.6%) of children have experienced SGM-related discrimination. The prevalence was higher among adolescents, females at birth, and those living in suburban areas. Children who experienced discrimination had a higher prevalence of chronic pain (20.2%) compared to those who did not (7.0%, p<0.0001), with an adjusted prevalence rate ratio of 2.0 (95% CI 1.5-2.5, p<0.0001).

CONCLUSIONS

Based on parent report, about 0.6 million children in the U.S. have experienced SGM-based discrimination; these children are twice as likely to have chronic pain. Findings highlight the importance of assessment and intervention for chronic pain in children who may experience marginalization and discrimination due to their sexual orientation and gender identity.

Life course socioeconomic status, chronic pain, and the mediating role of allostatic load: findings from the midlife in the United States

Introduction

Low socioeconomic status (SES) has been linked to chronic pain (CP); however, the mechanisms by which SES over the life course influences downstream CP outcomes remain unclear.

Methods

This study utilizes data from the Midlife in the United States (MIDUS) survey, a prospective sample of community-dwelling individuals (N=781), to investigate the chain of risk additive model of SES in relation to CP. Additionally, the study examines the mediating role of allostatic load (AL) in the relationship between life course SES and CP. Confirmatory factor analysis was employed to capture the multidimensionality of life course SES and path analysis was used to examine the direct and indirect effects on CP. AL was computed by quartile-based summation and by latent class analysis.

Results

Results indicated lower SES in MIDUS 2 was associated with greater high-interference CP odds in MIDUS 3 (OR=1.069, 95% CI=1.006-1.136, P < 0.05) and no association was found between distal SES and levels of CP interference. Similarly, no significant relationship was observed between SES and the number of CP locations. Additionally, no additive effects of SES were found, and AL did not present mediation effects on the association between life course SES and CP.

Discussion

The present study emphasizes the importance of directly proximal effects of SES on CP, underscoring the need for equitable distribution of health resources and the implementation of policies focused on diminishing socioeconomic inequalities. Further research is needed to examine alternative pathways by which proximal SES impact CP.

Elaboration and validation of a novelty nomogram for the prognostication of anxiety susceptibility in individuals suffering from low back pain

Low back pain (LBP) constitutes a distressing emotional ordeal and serves as a potent catalyst for adverse emotional states, notably anxiety. We dedicated to discerning methodologies for identifying patients who are predisposed to heightened levels of anxiety and pain. A self-assessment questionnaire was administered to patients afflicted with LBP. The pain scores were subjected to analysis in conjunction with anxiety scores, and a clustering procedure was executed using the scientific k-means methodology. Subsequently, six machine learning algorithms, including Logistics Regression (LR), K-Nearest Neighbor (KNN), Decision Tree (DT), Support Vector Machine (SVM), Random Forest (RF), and Extreme Gradient Boosting (XGB), were employed. Next, five pertinent variables were identified, namely Age, Course, Body Mass Index (BMI), Education, and Marital status. Furthermore, a LR model was utilized to construct a nomogram, which was subsequently subjected to assessment for discrimination, calibration, and evaluation of its clinical utility. As a result, 599 questionnaires were valid (effective rate: 99 %). The correlation analysis revealed a significant association between anxiety and pain scores (r = 0.31, P < 0.001). LBP patients could be divided into two clusters, Cluster1 had higher pain scores (P < 0.05) and SAS scores (P < 0.001). The proposed nomogram demonstrated an area under the receiver operating characteristics curve (ROC) of 0.841 (95 %CI: 0.804-0.878) and 0.800 (95 %CI: 0.733-0.867) in the training and test groups, respectively. Briefly, the established nomogram has demonstrated remarkable proficiency in discerning individuals afflicted with LBP who are at a heightened risk of experiencing anxiety.

The changes of blood-based inflammatory biomarkers after non-pharmacologic interventions for chronic low back pain: a systematic review

BACKGROUND

Chronic low back pain (CLBP) is a prevalent and debilitating condition, leading to significant challenges to both patients and the governmental healthcare system. Non-pharmacologic interventions have received increasing attention as potential strategies to alleviate chronic low back pain and improve patient outcomes. The aim of this systematic review was to comprehensively assess the changes in blood inflammatory biomarkers after non-pharmacologic interventions for CLBP patients, thus trying to understand the complex interactions between non-pharmacologic interventions and inflammatory biomarker changes in CLBP.

METHODS

A thorough search (from January 1st, 2002 to October 5th, 2022) of PubMed, Medline (platform Web of Science), and the Cochrane Library (platform Wiley Online Library) were conducted, and inclusion criteria as well as exclusion criteria were refined to selection of the studies. Rigorous assessments of study quality were performed using RoB 2 from Cochrane or an adaptation of the Downs and Black checklist. Data synthesis includes alterations in inflammatory biomarkers after various non-pharmacologic interventions, including exercise, acupressure, neuro-emotional technique, and other modalities.

RESULTS

Thirteen primary studies were included in this systematic review, eight randomized controlled trials, one quasi-randomized trial, and four before-after studies. The interventions studied consisted of osteopathic manual treatment (one study), spinal manipulative therapy (SMT) (three studies), exercise (two studies), yoga (two studies) and acupressure (two studies), neuro-emotional technique (one study), mindfulness-based (one study) and balneotherapy study (one study). Four studies reported some changes in the inflammatory biomarkers compared to the control group. Decreased tumor necrosis factor-alpha (TNF-α) after osteopathic manual treatment (OMT), neuro-emotional technique (NET), and yoga. Decreased interleukin (IL)-1, IL-6, IL-10, and c-reactive protein (CRP) after NET, and increased IL-4 after acupressure. Another five studies found changes in inflammatory biomarkers through pre- and post-intervention comparisons, indicating improvement outcomes after intervention. Increased IL-10 after balneotherapy; decreased TNF-α, IL-1β, IL-8, Interferon-gamma, interferon-γ-induced protein 10-γ-induced protein 10 after exercise; decreased IL-6 after exercise and SMT; decreased CRP and chemokine ligand 3 after SMT.

CONCLUSION

Results suggest a moderation of inflammatory biomarkers due to different non-pharmacologic interventions for CLBP, generally resulting in decreased pro-inflammatory markers such as TNF-α and IL-6 as well as increased anti-inflammatory markers such as IL-4, thus revealing the inhibition of inflammatory processes by different non-pharmacologic interventions. However, a limited number of high-quality studies evaluating similar interventions and similar biomarkers limits the conclusion of this review.

Can we achieve pain stratification in musculoskeletal conditions? Implications for clinical practice

In the last few years there has been an increased appreciation that pain perception in rheumatic and musculoskeletal diseases (RMDs) has several mechanisms which include nociceptive, inflammatory, nociplastic and neuropathic components. Studies in specific patient groups have also demonstrated that the pain experienced by people with specific diagnoses can present with distinctive components over time. For example, the pain observed in rheumatoid arthritis has been widely accepted to be caused by the activation of nociceptors, potentiated by the release of inflammatory mediators, including prostaglandins, leukotrienes and cytokine networks in the joint environment. However, people with RA may also experience nociplastic and neuropathic pain components, particularly when treatments with disease modifying anti-rheumatic drugs (DMARDs) have been implemented and are insufficient to control pain symptoms. In other RMDs, the concept of pain sensitisation or nociplastic pain in driving ongoing pain symptoms e.g. osteoarthritis and fibromyalgia, is becoming increasingly recognised. In this review, we explore the hypothesis that pain has distinct modalities based on clinical, pathophysiological, imaging and genetic factors. The concept of pain stratification in RMD is explored and implications for future management are also discussed.

"The mere imagination scares me"-evidence for fear responses during mental imagery of pain-associated interoceptive sensations in adolescents with chronic pain

ABSTRACT

According to the bio-informational theory of emotion by Lang, mental imagery of fearful stimuli activates physiological and behavioural response systems, even in the absence of sensory input. We investigated whether instructed mental imagery of pain-associated (not painful) interoceptive sensations entails a threat value and elicits increased startle response, skin conductance level (SCL), and heart rate (HR) indicative of defensive mobilization in adolescents with chronic pain. Additionally, self-reported measures (fear, fear of pain, desire to avoid) were assessed. Adolescents (11-18 years) with chronic headache (CH, n = 46) or chronic abdominal pain (CAP, n = 29) and a control group (n = 28) were asked to imagine individualized pain-associated, neutral and standardized fear scripts. During pain-associated compared with neutral imagery, both pain groups showed higher mean HR, with CH also showing higher HR reactivity, while HR acceleration was not observed within control group. In contrast, during pain-associated compared with neutral imagery, startle response magnitude and SCL remained unchanged in all groups. Additionally, overall levels in self-reports were higher during pain-associated compared with neutral imagery, but significantly more pronounced in the pain groups compared with the control group. Results suggest that the mere imagination of pain-associated sensations elicits specific autonomic fear responses accompanied by increased self-reported fear in adolescents with chronic pain. The specific modulation of heart rate shed new light on our understanding of multimodal fear responses in adolescents with chronic pain and may help to refine paradigms to decrease fear of interoceptive sensations in chronic pain.

Sex differences in visceral sensitivity and brain activity in a rat model of comorbid pain: a longitudinal study

ABSTRACT

Temporomandibular disorder (TMD) and irritable bowel syndrome (IBS) are 2 chronic overlapping pain conditions (COPCs) that present with significant comorbidity. Both conditions are more prevalent in women and are exacerbated by stress. While peripheral mechanisms might contribute to pain hypersensitivity for each individual condition, mechanisms underlying the comorbidity are poorly understood, complicating pain management when multiple conditions are involved. In this study, longitudinal behavioral and functional MRI-based brain changes have been identified in an animal model of TMD-like pain (masseter muscle inflammation followed by stress) that induces de novo IBS-like comorbid visceral pain hypersensitivity in rats. In particular, data indicate that increased activity in the insula and regions of the reward and limbic systems are associated with more pronounced and longer-lasting visceral pain behaviors in female rats, while the faster pain resolution in male rats may be due to increased activity in descending pain inhibitory pathways. These findings suggest the critical role of brain mechanisms in chronic pain conditions and that sex may be a risk factor of developing COPCs.

Pain as a disease in the new International Classification of Diseases (ICD-11): Latin American expert consensus

Aims: Pain diagnoses in the 10th version of the International Classification of Diseases (ICD-10) did not adequately support the current management of pain. Therefore, we aimed to review the new 11th revision (ICD-11) in order to analyze its usefulness for the management, coding, research and education of chronic pain from a Latin American perspective. Methods: The Latin American Federation of Associations for the Study of Pain convened a meeting of pain experts in Lima, Peru. Pain specialists from 14 Latin American countries attended the consensus meeting. Results: In ICD-11, chronic pain is defined as pain that persists or recurs longer than 3 months and is subdivided into seven categories: chronic primary pain and six types of chronic secondary pain. Chronic primary pain is now considered a disease in itself, and not a mere symptom of an underlying disease. Conclusion: The novel definition and classification of chronic pain in ICD-11 is helpful for better medical care, research and health statistics. ICD-11 will improve chronic pain management in Latin American countries, for both the pain specialist and the primary care physician.

Application of a Clinical Approach to Diagnosing Primary Pain: Prevalence and Correlates of Primary Back and Neck Pain in a Community Physiatry Clinic

Chronic back or neck pain (CBNP) can be primary (nociplastic or neuroplastic; without clear peripheral etiology) or secondary (to nociceptive or neuropathic causes). Expanding on available models of nociplastic pain, we developed a clinic-ready approach to diagnose primary/nociplastic pain: first, a standard physical exam and review of imaging to rule out secondary pain; and second, a detailed history of symptom presentation to rule in primary pain. We trained a physician who evaluated 222 patients (73.9% female, age M = 59.6) with CBNP; patients separately completed pain and psychosocial questionnaires. We estimated the prevalence of primary CBNP and explored biomedical, imaging, and psychological correlates of primary CBNP. Although almost all patients (97.7%) had at least 1 spinal anomaly on imaging, the diagnostic approach estimated that 88.3% of patients had primary pain, 5.0% had secondary pain, and 6.8% had mixed pain. Patients with primary pain were more likely than the other 2 groups of patients (combined as "non-primary pain") to report certain functional conditions, central sensitization, and features such as sensitivity to light touch, spreading pain, and pain worsening with stress; however, no difference was detected in depression, anxiety, and pain catastrophizing between those with primary and nonprimary pain. These findings are consistent with prior estimates that 85 to 90% of CBNP is "nonspecific." Further research is needed to validate and perhaps refine this diagnostic approach, which holds the potential for better outcomes if patients are offered treatments targeted to primary pain, such as pain neuroscience education and several emerging psychological therapies. PERSPECTIVE: We developed an approach to diagnose chronic primary pain, which was applied in a physiatry clinic to 222 patients with CBNP. Most patients (88.3%) had primary pain, despite almost universal anomalies on spinal imaging. This diagnostic approach can guide educational and psychological treatments tailored for primary pain.

Analysis of Clinical Characteristics and Neuropeptides in Patients with Dry Eye with and without Chronic Ocular Pain after FS-LASIK

INTRODUCTION

Chronic ocular pain, particularly prevalent in patients with dry eye disease and post-femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) surgery, presents with unclear clinical characteristics and an undefined pathogenesis. In this study, we aimed to compare clinical characteristics and tear neuropeptide concentrations in patients with dry eye disease (DED) with and without chronic ocular pain following FS-LASIK, and investigate correlations between ocular pain, clinical characteristics, and tear neuropeptide levels.

METHODS

Thirty-eight post-FS-LASIK patients with DED were assigned to two groups: those with chronic ocular pain and those without chronic ocular pain. Dry eye, ocular pain, and mental health-related parameters were evaluated using specific questionnaires and tests. The morphology of corneal nerves and dendritic cells (DCs) was evaluated by in vivo confocal microscopy. Function of corneal innervation was evaluated by corneal sensitivity. Concentrations of tear cytokines (interleukin [IL]-6, IL-23, IL-17A, and interferon-γ) and neuropeptides (α-melanocyte-stimulating hormone, neurotensin, β-endorphin, oxytocin, and substance P [SP]) were measured using the Luminex assay.

RESULTS

Most patients with chronic ocular pain experienced mild to moderate pain; the most common types included stimulated pain (provoked by wind and light), burning pain, and pressure sensation. More severe dry eye (P < 0.001), anxiety symptoms (P = 0.026), lower Schirmer I test values (P = 0.035), lower corneal nerve density (P = 0.043), and more activated DCs (P = 0.041) were observed in patients with ocular pain. Tear concentrations of SP and oxytocin were significantly higher in patients with ocular pain (P = 0.001, P = 0.021, respectively). Furthermore, significant correlations were observed among ocular pain severity, SP, and anxiety levels.

CONCLUSIONS

Patients with DED after FS-LASIK who have chronic ocular pain show more severe ocular and psychological discomfort and higher tear levels of neuropeptides. Furthermore, ocular pain severity is correlated with tear SP levels.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05600985.

Prediction of duloxetine efficacy in addition to self-management in painful temporomandibular disorders: A randomised, placebo-controlled clinical trial

BACKGROUND

Conditioned pain modulation (CPM) is a potential predictor of treatment response that has not been studied in temporomandibular disorders (TMD).

OBJECTIVES

We conducted a randomised, double-blind, placebo-controlled trial (RCT) of duloxetine in addition to self-management (SM) strategies to investigate its efficacy to reduce pain intensity in painful TMD patients. Moreover, we investigated whether baseline CPM would predict the duloxetine efficacy to reduce TMD pain intensity.

METHODS

Eighty participants were randomised to duloxetine 60 mg or placebo for 12 weeks. The primary outcomes were the change in the pain intensity from baseline to week-12 and CPM-sequential paradigm at baseline. Safety, physical and emotional functioning outcomes were also evaluated.

RESULTS

Of 80 participants randomised, 78 were included in intention-to-treat analysis. Pain intensity decreased for SM-duloxetine and SM-placebo but did not differ between groups (p = .82). A more efficient CPM was associated with a greater pain intensity reduction regardless of the treatment group (p = .035). Physical and emotional functioning did not differ between groups, but adverse events (p = .014), sleep impairment (p = .003) and catastrophizing symptoms (p = .001) were more prevalent in SM-duloxetine group.

CONCLUSION

This study failed to provide evidence of a beneficial effect of adding duloxetine to SM strategies for treatment of painful TMD. Nonetheless, this RCT has shown the feasibility of applying pain modulation assessment to predict short-term treatment response in painful TMD patients, which confirms previous finds that CPM evaluation may serve a step forward in individualising pain treatment.

Understanding How Patients With Lumbar Radiculopathy Make Sense of and Cope With Their Symptoms

Lumbar radiculopathy, characterized by pain radiating along a nerve root, significantly diminishes the quality of life due to its neuropathic nature. Patients' understanding of their illness and the coping strategies they employ directly influence how they manage their condition. Understanding these illness representations from the patient's perspective is crucial for healthcare providers seeking to optimize treatment outcomes. This study adopted a qualitative interpretive/constructive paradigm to explore this dynamic. A qualitative evidence synthesis approach, utilizing best-fit framework synthesis for data extraction, was applied to analyze primary qualitative studies focused on patient experiences with lumbar radiculopathy. Using SPiDER (Sample, Phenomenon of interest, Design, Evaluation, Research type) to guide the search strategy, extracted data was mapped against the Common-Sense Model of Self-Regulation (CSM) framework. Sixteen studies, with moderate to minor methodological quality concerns, were included in the analysis. Data mapping across CSM domains generated 14 key review findings. Results suggest that patients with high-threat illness representations often exhibit maladaptive coping behaviors (e.g., activity avoidance) driven by emotional responses. In contrast, problem-solving techniques appear to contribute to positive outcomes (e.g., exercise adherence and effective self-management) in patients who perceive their condition as less threatening. These findings highlight the potential benefits of interventions designed to reduce perceived threat levels and enhance self-efficacy in patients with lumbar radiculopathy, leading to improved self-management and ultimately better health outcomes.

Is nociplastic pain, a new pain category, associated with biochemical, hematological, and inflammatory parameters?

OBJECTIVE

The aim of the study was to evaluate the relationship between biochemical, hematological, and inflammatory parameters and pain in patients with nociplastic pain.

METHODS

In this cross-sectional study, a total of 8632 patients, aged between 20 and 65, were evaluated according to the nociplastic pain diagnosis criteria determined by IASP. Excluding individuals who did not meet the criteria for nociplastic pain, the study included a total of 660 participants. The biochemical, hematological, and inflammatory parameters of all individuals were examined. The pain levels of the patients were assessed using the Visual Analogue Scale (VAS). The patients were categorized based on nociplastic pain types and pain regions for evaluation.

RESULTS

In this study, the female gender was more prevalent both in all nociplastic pain categories and in all pain region groups (p < 0.05). In the nociplastic pain categories, it was observed that vitamin D levels were lower in patients with chronic widespread pain, while ferritin and C-reactive protein levels were higher in patients with chronic primary musculoskeletal pain. Among patients with chronic widespread pain with low hemoglobin and/or ferritin levels, the Visual Analog Scale activity score was higher. For patients with chronic widespread pain and low vitamin D levels and/or high erythrocyte sedimentation rate levels, the Visual Analog Scale rest score was higher. In patients with fibromyalgia and high parathyroid hormone levels, the Visual Analog Scale activity score was higher. For patients with fibromyalgia and high Neutrophil/Lymphocyte ratio levels, the Visual Analog Scale rest score was higher. In patients with chronic primary musculoskeletal pain and high erythrocyte sedimentation rate and/or C-reactive protein levels, the Visual Analog Scale activity score was higher. While vitamin B12 levels were found to be lower in patients with widespread pain, no significant relationship was identified between electrolytes, other blood count results, and nociplastic pain.

CONCLUSION

In our study, it was observed that levels of vitamin D in individuals with nociplastic pain were low, while erythrocyte sedimentation rate, C-reactive protein, and Neutrophil/Lymphocyte ratio were high, and hemoglobin and ferritin levels were elevated. Furthermore, these findings were found to be associated with both the presence of pain and the severity of pain assessed using the visual analog scale.

Valproate attenuates somatic hyperalgesia induced by orofacial inflammation combined with stress through inhibiting spinal IL-6 and STAT1 phosphorylation

Temporomandibular disorder (TMD) and fibromyalgia syndrome (FMS) may present as comorbid conditions, but treatment options are ineffective. The purpose of this study was to investigate whether valproate (VPA) attenuates somatic hyperalgesia induced by orofacial inflammation combined with stress, which represents a model of pain associated with TMD and FMS comorbidity, and to explore the potential mechanisms. The results showed that VPA inhibited somatic hyperalgesia induced by orofacial inflammation combined with stress, and down-regulated the interleukin-6 (IL-6) expression in the L4-L5 spinal dorsal horn of female rats. The anti-nociceptive effect of VPA was blocked by single or 5 consecutive day intrathecal administration of recombinant rat IL-6. Orofacial inflammation combined with stress up-regulated the ratio of phosphorylated signal transducer and activator of transcription 1 (p-STAT1) to STAT1 (p-STAT1/STAT1) in the spinal cord. VPA did not affect the STAT1 expression, while it down-regulated the ratio of p-STAT1/STAT1. The expression of STAT3 and the ratio of p-STAT3/STAT3 were not affected by orofacial inflammation combined with stress and VPA treatment. Intrathecal administration of exogenous IL-6 up-regulated the ratio of p-STAT1/STAT1. These data indicate that VPA attenuated somatic hyperalgesia induced by orofacial inflammation combined with stress via inhibiting spinal IL-6 in female rats, and the mechanism may involve the alteration of activation status of spinal STAT1. Thus, VPA may be a new candidate analgesic that targets IL-6 and STAT1 for the treatment of pain associated with the comorbidity of TMD and FMS.

Psychological/behavioral interventions for emerging adults with chronic pain

Background

Emerging adults, of whom significant numbers report chronic pain, are characterized as having unique needs and challenges. Psychological/behavioral treatments found to be beneficial for reducing pain outcomes in children and adults are understudied in emerging adults. Following a systematic review of the literature, our objective is to report on quantitative studies of psychological/behavioral interventions for chronic pain in emerging adults.

Method

We conducted a search of six databases (Cochrane Central Register of Controlled Trials, Google Scholar, ProQuest, PsycINFO, PubMed, and Web of Science) and reference sections in dissertations and systematic reviews to 4/29/2023. Keywords and phrases were search term combinations of "chronic/persistent pain", "emerging/young adults," and "intervention/treatment" using Boolean logic.

Results

Our review resulted in identifying 37 articles, of which 2 duplicates were removed, and 31 were further excluded by a screening process based on various inclusionary and exclusionary criteria. The search yielded four studies on psychological/behavioral interventions (yoga, acceptance and commitment therapy and relaxation), all of which positively affected the pain experience and/or pain-related outcomes. These studies presented issues in design such as not being blinded or randomized, having a small sample size, and potential confounds that were not reported or examined.

Discussion

The low number of studies reveals a large gap in the literature and is a call-to-action to further expand our understanding of effective and safer psychological/behavioral therapies for chronic pain in emerging adults. Successful pain management during this developmental phase may help young adults achieve positive trajectories for personal, occupational, relational, and health aspects of their lives.

Social cognition abilities in patients with primary and secondary chronic pain

Previous evidence suggested that chronic pain is characterized by cognitive deficits, particularly in the social cognition domain. Recently, a new chronic pain classification has been proposed distinguishing chronic primary pain (CPP), in which pain is the primary cause of patients' disease, and chronic secondary pain (CSP), in which pain is secondary to an underlying illness. The present study aimed at investigating social cognition profiles in the two disorders. We included 38 CPP, 43 CSP patients, and 41 healthy controls (HC). Social cognition was assessed with the Ekman-60 faces test (Ekman-60F) and the Story-Based Empathy Task (SET), whereas global cognitive functioning was measured with the Montreal Cognitive Assessment (MoCA). Pain and mood symptoms, coping strategies, and alexithymia were also evaluated. Correlations among clinical pain-related measures, cognitive performance, and psychopathological features were investigated. Results suggested that CSP patients were impaired compared to CPP and HC in social cognition abilities, while CPP and HC performance was not statistically different. Pain intensity and illness duration did not correlate with cognitive performance or psychopathological measures. These findings confirmed the presence of social cognition deficits in chronic pain patients, suggesting for the first time that such impairment mainly affects CSP patients, but not CPP. We also highlighted the importance of measuring global cognitive functioning when targeting chronic pain disorders. Future research should further investigate the cognitive and psychopathological profile of CPP and CSP patients to clarify whether present findings can be generalized as disorder characteristics.

NMDA Receptors Regulate Oxidative Damage in Keratinocytes during Complex Regional Pain Syndrome in HaCaT Cells and Male Rats

Complex regional pain syndrome (CRPS), a type of primary chronic pain, occurs following trauma or systemic disease and typically affects the limbs. CRPS-induced pain responses result in vascular, cutaneous, and autonomic nerve alterations, seriously impacting the quality of life of affected individuals. We previously identified the involvement of keratinocyte N-methyl-d-asparagic acid (NMDA) receptor subunit 2 B (NR2B) in both peripheral and central sensitizations in CRPS, although the mechanisms whereby NR2B functions following activation remain unclear. Using an in vivo male rat model of chronic post-ischemia pain (CPIP) and an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) cell model, we discovered that oxidative injury occurs in rat keratinocytes and HaCaT cells, resulting in reduced cell viability, mitochondrial damage, oxidative damage of nucleotides, and increased apoptosis. In HaCaT cells, OGD/R induced increases in intracellular reactive oxygen species levels and disrupted the balance between oxidation and antioxidation by regulating a series of antioxidant genes. The activation of NMDA receptors via NMDA exacerbated these changes, whereas the inhibition of the NR2B subunit alleviated them. Co-administration of ifenprodil (an NR2B antagonist) and NMDA (an NMDA receptor agonist) during the reoxygenation stage did not result in any significant alterations. Furthermore, intraplantar injection of ifenprodil effectively reversed the altered gene expression that was observed in male CPIP rats, thereby revealing the potential mechanisms underlying the therapeutic effects of peripheral ifenprodil administration in CRPS. Collectively, our findings indicate that keratinocytes undergo oxidative injury in CRPS, with NMDA receptors playing regulatory roles.

Identification of unique genomic signatures in patients with fibromyalgia and chronic pain

Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread pain. The pathophysiology of fibromyalgia is not clearly understood and there are no specific biomarkers available for accurate diagnosis. Here we define genomic signatures using high throughput RNA sequencing on 96 fibromyalgia and 93 control cases. Our findings revealed three major fibromyalgia-associated expression signatures. The first group included 43 patients with a signature enriched for gene expression associated with extracellular matrix and downregulation of RhoGDI signaling pathway. The second group included 30 patients and showed a profound reduction in the expression of inflammatory mediators with an increased expression of genes involved in the CLEAR signaling pathway. These results suggest defective tissue homeostasis associated with the extra-cellular matrix and cellular program that regulates lysosomal biogenesis and participates in macromolecule clearance in fibromyalgia. The third group of 17 FM patients showed overexpression of pathways that control acute inflammation and dysfunction of the global transcriptional process. The result of this study indicates that FM is a heterogeneous and complex disease. Further elucidation of these pathways will lead to the development of accurate diagnostic markers, and effective therapeutic options for fibromyalgia.

Small fibre pathology, small fibre symptoms and pain in fibromyalgia syndrome

A proportion of people with fibromyalgia demonstrate small fibre pathology (SFP). However, it is unclear how SFP directly relates to pain phenomenology. Thirty-three individuals with FMS and ten healthy volunteers underwent assessment of SFP and sensory phenotyping using corneal confocal microscopy, validated questionnaires and quantitative sensory testing (QST). Corneal nerve fibre length was used to stratify participants with fibromyalgia into with SFP [SFP+] and without SFP [SFP-]. SFP was detected in 50% of the fibromyalgia cohort. Current pain score and QST parameters did not differ between SFP+ and SFP-. Mechanical pain sensitivity (MPS) demonstrated a significant gain-of-function in the SFP- cohort compared to healthy-volunteers (p = 0.014, F = 4.806, η2 = 0.22). Further stratification revealed a cohort without structural SFP but with symptoms compatible with small fibre neuropathy symptoms and a significant gain in function in MPS (p = 0.020 Chi-square). Additionally, this cohort reported higher scores for both depression (p = 0.039, H = 8.483, η2 = 0.312) and anxiety (p = 0.022, F = 3.587, η2 = 0.293). This study confirms that SFP is present in a proportion of people with fibromyalgia. We also show that in a proportion of people with fibromyalgia, small fibre neuropathy symptoms are present in the absence of structural SFP. Greater mechanical pain sensitivity, depression and anxiety are seen in these individuals.

Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing: A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial

Chronic primary low back pain (CPLBP) refers to low back pain that persists over 3 months, that cannot be explained by another chronic condition, and that is associated with emotional distress and disability. Previous studies have shown that spinal manipulative therapy (SMT) is effective in relieving CPLBP, but the underlying mechanisms remain elusive. This randomized placebo-controlled dual-blind mixed experimental trial (NCT05162924) aimed to investigate the efficacy of SMT to improve CPLBP and its underlying mechanisms. Ninety-eight individuals with CPLBP and 49 controls were recruited. Individuals with CPLBP received SMT (n = 49) or a control intervention (n = 49), 12 times over 4 weeks. The primary outcomes were CPLBP intensity (0-100 on a numerical rating scale) and disability (Oswestry Disability Index). Secondary outcomes included pressure pain thresholds in 4 body regions, pain catastrophizing, Central Sensitization Inventory, depressive symptoms, and anxiety scores. Individuals with CPLBP showed widespread mechanical hyperalgesia (P < .001) and higher scores for all questionnaires (P < .001). SMT reduced pain intensity compared with the control intervention (mean difference: -11.7 [95% confidence interval, -11.0 to -12.5], P = .01), but not disability (P = .5). Similar mild to moderate adverse events were reported in both groups. Mechanical hyperalgesia at the manipulated segment was reduced after SMT compared with the control intervention (P < .05). Pain catastrophizing was reduced after SMT compared with the control intervention (P < .05), but this effect was not significant after accounting for changes in clinical pain. Although the reduction of segmental mechanical hyperalgesia likely contributes to the clinical benefits of SMT, the role of pain catastrophizing remains to be clarified. PERSPECTIVE: This randomized controlled trial found that 12 sessions of SMT yield greater relief of CPLBP than a control intervention. These clinical effects were independent of expectations, and accompanied by an attenuation of hyperalgesia in the targeted segment and a modulation of pain catastrophizing.

Mind-Body Training: A Plausible Strategy against Osteomuscular Chronic Pain-A Systematic Review with Meta-Analysis

(1) Background: Chronic pain, which affects more than one in five adults worldwide, has a negative impact on the quality of life, limiting daily activities and generating absences from work. The aim of the present review is to analyze the efficacy of mind-body therapies as therapeutic strategies for patients with chronic pain. (2) Methods: A systematic review with a meta-analysis was carried out, searching PubMed, Scopus, and Web of Science databases using specific keywords. We selected studies that included mind-body therapies as the primary intervention for older adults with chronic pain. The methodological quality of the articles was assessed using the PEDro scale. (3) Results: Of the 861 studies identified, 11 were included in this review, all of which employed different mind-body therapies as an intervention. The selected studies measured chronic pain as the main variable. (4) Conclusions: This review highlights the value of mind-body exercises in reducing chronic pain in older adults, suggesting their integration as a non-pharmacological therapeutic alternative that improves the quality of life, promoting a holistic approach to pain management.

Unraveling the Complex Web of Fibromyalgia: A Narrative Review

Fibromyalgia is a complex and often misunderstood chronic pain disorder. It is characterized by widespread musculoskeletal pain, fatigue, and heightened sensitivity, and has evolved in diagnostic criteria and understanding over the years. Initially met with skepticism, fibromyalgia is now recognized as a global health concern affecting millions of people, with a prevalence transcending demographic boundaries. The clinical features and diagnosis of fibromyalgia encompass a range of symptoms beyond pain, including sleep disturbances and cognitive difficulties. This study emphasizes the importance of a comprehensive evaluation for accurate diagnosis, considering the shift from tender point reliance to a more holistic approach. Etiology and pathophysiology involve genetic predisposition, neurotransmitter dysregulation, central sensitization, and immune system involvement. Risk factors such as gender, age, family history, and comorbid conditions contribute to susceptibility. The impact on quality of life is profound, affecting physical and social aspects, often accompanied by mood disorders. Management approaches include pharmacological interventions, non-pharmacological therapies, lifestyle modifications, and alternative treatments. This study also delves into emerging research, exploring advances in neurobiological understanding, brain imaging, genetic markers, glutamate modulation, cannabinoids, gut microbiome, and digital health tools for fibromyalgia management. Overall, this study provides a nuanced and up-to-date overview of the complexities surrounding fibromyalgia, aiming to enhance understanding and support for individuals grappling with this challenging condition.

Targeting TRPV1 for Cancer Pain Relief: Can It Work?

Chronic intractable pain affects a large proportion of cancer patients, especially those with metastatic bone disease. Blocking sensory afferents for cancer pain relief represents an attractive alternative to opioids and other drugs acting in the CNS in that sensory nerve blockers are not addictive and do not affect the mental state of the patient. A distinct subpopulation of sensory afferents expresses the capsaicin receptor TRPV1. Intrathecal resiniferatoxin, an ultrapotent capsaicin analog, ablates TRPV1-expressing nerve endings exposed to the cerebrospinal fluid, resulting in permanent analgesia in women with cervical cancer metastasis to the pelvic bone. High-dose capsaicin patches are effective pain killers in patients with chemotherapy-induced peripheral neuropathic pain. However, large gaps remain in our knowledge since the mechanisms by which cancer activates TRPV1 are essentially unknown. Most important, it is not clear whether or not sensory denervation mediated by TRPV1 agonists affects cancer progression. In a murine model of breast cancer, capsaicin desensitization was reported to accelerate progression. By contrast, desensitization mediated by resiniferatoxin was found to block melanoma growth. These observations imply that TRPV1 blockade for pain relief may be indicated for some cancers and contraindicated for others. In this review, we explore the current state of this field and compare the analgesic potential of TRPV1 antagonism and sensory afferent desensitization in cancer patients.

Medical Cannabis Use and Inflammatory Cytokines and Chemokines Among Adult Chronic Pain Patients

Background: Utilizing cannabis as a therapeutic option for chronic pain (CP) has increased significantly. However, data regarding the potential immunomodulatory effects of cannabis in CP patients remain scarce. We aimed at exploring the relationship between cannabis use and inflammatory cytokines and chemokines among a cohort of CP patients. Methods: Adult patients with a CP diagnosis and medical authorization of cannabis were enrolled. Patients completed validated clinical questionnaires and self-reported the effectiveness of cannabis for symptom management. Patients' blood and cannabis samples were analyzed for the presence of four major cannabinoids, two major cannabinoid metabolites, 29 different cytokines/chemokines, and cortisol. The multivariable linear regression model was used to identify cannabis and patient factors associated with immune markers. Results: Fifty-six patients (48±15 years; 64% females) were included, with dried cannabis (53%) being the most common type of cannabis consumed. Seventy percent of products were considered delta-9-tetrahydrocannabinol (Δ9-THC)-dominant. The majority of patients (96%) self-reported effective pain management, and 76% reported a significant decrease in analgesic medication usage (p≤0.001). Compared with males, female patients had higher plasma levels of cannabidiol (CBD), cannabidiolic acid, Δ9-THC, and 11-hydroxy-Δ9-tetrahydrocannabinol but lower concentrations of delta-9-tetrahydrocannabinolic acid and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH). Females had significantly lower eotaxin levels (p=0.04) in comparison to male patients. The regression analysis indicated that high cannabis doses were related to increased levels of interleukin (IL)-12p40 (p=0.02) and IL-6 (p=0.01), whereas female sex was associated with decreased eotaxin (p≤0.01) concentrations. Blood CBD levels were associated with lower vascular endothelial growth factor (p=0.04) concentrations, and THC-COOH was a factor related to decreased tumor necrosis factor alpha (p=0.02) and IL-12p70 (p=0.03). Conclusion: This study provides further support for the patient-perceived effectiveness of cannabis in managing CP symptoms and reducing analgesic medication consumption. The results suggest a potential sex difference in metabolizing cannabinoids, and the varying immune marker concentrations may support a possible immunomodulatory effect associated with patient sex and cannabis product type. These preliminary findings provide grounds for further validation using larger, well-designed studies with longer follow-up periods.

Clinical features of chronic primary pain in individuals presenting painful temporomandibular disorder and comorbidities

BACKGROUND

The diagnosis of chronic primary pain (CPP), according to the recently released International Classification of Disease (ICD-11) criteria, refers to conditions with complex aetiologies. CPP is characterized by specific clinical features such as generalized sensory hypersensitivity and widespread pain, and is associated with functional disability and emotional distress.

OBJECTIVE

This study investigated clinical features of CPP in individuals with painful temporomandibular disorders (TMD) and comorbidities (fibromyalgia, migraine and/or tension-type headache).

METHODS

This cross-sectional study was conducted with a sample of 129 individuals. Painful TMD, fibromyalgia and primary headaches were evaluated based on well-established international criteria. Generalized sensory hypersensitivity was assessed using psychophysical tests. Symptoms of anxiety and depression were assessed by the Generalized Anxiety Disorder-7 and Patient Health Questionnaire-9. The Central Sensitization Inventory was applied to assess central sensitization-related symptoms and the Pittsburg Sleep Quality Index to evaluate the quality of sleep. The presence of widespread pain was assessed using a body map. The sample was stratified into three groups: control (n = 25), TMD-painful TMD only (n = 35) and TMD + Cm-painful TMD and comorbidities (n = 69). Statistical analysis was performed using one-way ANOVA, chi-squared test and ANCOVA, considering gender as a covariate (α = .05).

RESULTS

Compared to controls, individuals presenting painful TMD and comorbidities showed lower pressure pain thresholds in all evaluated areas (p ≤ .012) and a higher number of painful areas in the body (p = .001). They presented more symptoms of anxiety (p = .040) and depression (p = .018), and a higher score in the Central Sensitization Inventory (p ≤ .006) than the other groups.

CONCLUSION

Individuals with painful TMD and comorbidities presented more clinical features of CPP compared to those affected by TMD only.

An update on the pharmacotherapeutic options for complex regional pain syndrome

INTRODUCTION

Complex regional pain syndrome (CRPS) is a rare and painful condition that has a wide range of triggering factors, often traumatic, and can present various clinical manifestations. The lack of knowledge about the underlying mechanisms has led to numerous treatment approaches, both conservative and surgical, which work through different mechanisms of action.

AREAS COVERED

In this review, the authors explore the key aspects of CRPS, including definition, diagnostic criteria, pitfalls, pathogenic hypotheses, and treatment strategies with a focus on pharmacotherapy. The review was based on a comprehensive search of the literature using PubMed, while also considering international guidelines for managing CRPS.

EXPERT OPINION

Based on the available evidence, pharmacological interventions appear to be effective in treating CRPS, especially when they target peripheral mechanisms, specifically nociceptive inflammatory pain, and when administered early in the course of the disease. However, there is still a lack of reliable evidence regarding the effects of drugs on central mechanisms of chronic pain in CRPS. In our expert opinion, drug therapy should be initiated as soon as possible, particularly in warm CRPS patient clusters, to prevent significant functional limitations, psychological distress, and negative impacts on individuals' social and economic well-being.

Sensitivity and Specificity of a Neuropathic Screening Tool (Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, S-LANSS) in Adolescents With Moderate-Severe Chronic Pain

Neuropathic screening tools improve recognition of neuropathic pain in adults. Although utilized in pediatric populations, the sensitivity, specificity and methodology of screening tool delivery have not been compared in children. We evaluated the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) in adolescents (10-18 years) referred to a tertiary pediatric pain clinic. History and examination by specialist clinicians and multidisciplinary assessment informed classification of the primary pain type. In a prospective cohort, scores were obtained at interview (S-LANSS interview; n = 161, 70% female), and following substitution of self-reported signs with examination findings in the primary pain region (Leeds Assessment of Neuropathic Symptoms and Signs, LANSS examination). Secondly, we retrospectively retrieved questionnaires self-completed by adolescents at their initial clinic appointment (S-LANSS self-completed; n = 456, 73% female). Thirdly, we explored relationships between patient-reported outcomes and S-LANSS scores. S-LANSS interview scores varied with pain classification, and S-LANSS self-completed scores were similarly highest with neuropathic pain (median [interquartile range]: 18 [11, 21]) and complex regional pain syndrome (21 [14, 24]), variable with musculoskeletal pain (13 [7, 19]) and lowest with visceral pain (6.5 [2, 11.5]) and headache (8.5 [4, 14]). As in adults, the cutpoint score of 12/24 was optimal. Sensitivity was highest with inclusion of examination findings and lowest with self-completion (LANSS examination vs S-LANSS interview vs S-LANSS self-completed: 86.3% vs 80.8% vs 74.7%), but specificity was relatively low (37.8% vs 36.7% vs 48%). High S-LANSS scores in non-neuropathic groups were associated with female sex and high pain catastrophizing. The S-LANSS is a sensitive screening tool for pain with neuropathic features in adolescents, but needs to be interpreted in the context of clinical evaluation (clinicaltrials.gov NCT03312881). PERSPECTIVE: This article reports high sensitivity of the S-LANSS screening tool for identifying pain with neuropathic features in adolescents with moderate-severe chronic pain. However, as sensitivity is lower than in adult populations, further interdisciplinary evaluation is necessary to inform diagnosis and management.

The Hausa Northwick Park Neck Pain Questionnaire: translation, cross-cultural adaptation and psychometric assessment in patients with non-specific neck pain

PURPOSE

To translate and cross-culturally adapt the Northwick Park Neck Pain Questionnaire (NPQ) into Hausa and assess its psychometric properties.

MATERIALS AND METHODS

The NPQ was translated and cross-culturally adapted into Hausa using recommended guidelines. A consecutive sample of 92 Hausa-speaking patients with non-specific neck pain recruited from three tertiary hospitals in north-western Nigeria, completed the questionnaire to assess factorial validity (using confirmatory factor analysis), convergent validity (by correlating the Hausa-NPQ with the Numerical Pain Rating Scale [NPRS]), and internal consistency (using Cronbach's α). A subsample of 50 patients completed the questionnaire again 3 days after the first administration to assess relative reliability using intraclass correlation coefficients (ICC) and absolute reliability using standard error of measurement (SEM), smallest detectable change (SDC), and 95% limits of agreement (LOA).

RESULTS

The factor analysis confirmed a single-factor structure with excellent internal consistency (α = 0.94). The questionnaire showed a strong positive correlation with the NPRS (rho = 0.68). The ICC was 0.86, with SEM and SDC of 6.32 and 17.5, respectively. The LOA was - 29.3 to + 37.1 with no evidence of proportional bias.

CONCLUSIONS

The Hausa-NPQ is a valid and reliable measure of disability due to neck pain.

Morphological and functional brain changes in chronic cancer-related pain: A systematic review

The purpose of this study was to perform a systematic review of the available literature on morphological and functional brain changes measured by modern neuroimaging techniques in patients suffering from chronic cancer-related pain. A systematic search was conducted in PubMed, Embase, and Web of Science using different keyword combinations. In addition, a hand search was performed on the reference lists and several databases to retrieve supplementary primary studies. Eligible articles were assessed for methodological quality and risk of bias and reviewed by two independent researchers. The search yielded only four studies, three of which used MRI and one PET-CT. None of the studies measured longitudinal morphological (i.e., gray or white matter) changes. All studies investigated functional brain changes and found differences in specific brain regions and networks between patients with chronic cancer-related pain and pain-free cancer patients or healthy volunteers. Some of these alterations were found in brain networks that also show changes in non-cancer populations with chronic pain (e.g., the default mode network and salience network). However, specific findings were inconsistent, and there was substantial variation in imaging methodology, analysis, sample size, and study quality. There is a striking lack of research on morphological brain changes in patients with chronic cancer-related pain. Moreover, only a few studies investigated functional brain changes. In the retrieved studies, there is some evidence that alterations occur in brain networks also involved in other chronic non-cancer pain syndromes. However, the low sample sizes of the studies, finding inconsistencies, and methodological heterogeneity do not allow for robust conclusions.

Widespread Pain With Nociplastic Features is an Independent Predictor of Low Physical Activity in People with Multiple Sclerosis

Exploring the relationship between underlying pain mechanisms and physical activity could inform interventions to optimize physical activity in persons with multiple sclerosis (PwMS). This cross-sectional nationwide survey examined whether pain phenotype is a significant predictor of self-reported physical activity in PwMS. The study included 938 persons with a self-reported diagnosis of MS (93% reported neurologist-diagnosed MS) who completed surveys of demographic, clinical information, pain intensity, indicators of underlying pain mechanisms (Fibromyalgia Survey Criteria and painDETECT), and physical activity (Godin Leisure-Time Exercise Questionnaire). Responses were used to categorize pain phenotypes as widespread pain with nociplastic features (WPNF), neuropathic, nociceptive, or mixed (neuropathic/WPNF). Following current physical activity guidelines, self-reported physical activity was categorized as active or insufficiently active/sedentary. Applying multivariable logistic regression, participants with no chronic pain had 2.30 higher odds of being physically active when compared to participants with chronic mixed pain. Similarly, participants with neuropathic and nociceptive pain had, respectively, 1.90 and 1.66 higher odds of being physically active compared to individuals with mixed pain. Higher scores on the fibromyalgia survey criteria (operationalized in this study as an indicator of WPNF) were a significant independent predictor of insufficient physical activity (OR = .93, P < .01). Findings indicate that experience and phenotype of chronic pain, in particular WPNF, are associated with physical inactivity in PwMS. This suggests that assessing pain phenotype may be important to identify individuals at risk of inadequate physical activity and may guide the tailoring of behavioral therapeutic approaches to help PwMS achieve the recommended level of physical activity. PERSPECTIVE: This study examines the association between pain mechanism and physical activity in multiple sclerosis. These findings highlight the possibility that a basic screening for pain mechanism could offer clinically useful information without requiring extensive neurobiological phenotyping and may inform the development of behavioral interventions to enhance physical activity in multiple sclerosis.

Determinants of health-related quality of life in older people with chronic musculoskeletal pain: a cross-sectional study

BACKGROUND

This study aimed to identify the significant physical, psychological, and social determinants associated with EuroQuol-5D (EQ-5D) among Chinese older people with chronic musculoskeletal pain, and to evaluate how these determinants affected the five dimensions of EQ-5D.

METHOD

This is a cross-sectional study. Data were collected through a cohort involving 946 community-dwelling older people aged ≥ 60 with chronic musculoskeletal pain in Hong Kong. Selected independent variables were categorized into physical, psychological, and social domains. Physical variables included age, sex, body mass index (BMI), pain severity score, number of pain regions, the most painful site, and the number of comorbidities. Psychological variables included depression level measured using the 9-question Patient Health Questionnaire (PHQ-9), and anxiety level measured using the Generalized Anxiety Disorder Assessment (GAD-7). Social variables included living, marital, and social welfare recipient's status. The dependent variables comprised the index scores and the five dimensions of the EQ-5D descriptive system. Ordinal least squares (OLS) model and logistic regression model were used for data analysis.

RESULTS

The mean age of the participants was 67.1 (SD = 5.1), with 77.6% being female. Higher pain severity scores (beta (β) coefficient =-0.044, P < 0.001), depression scores (β=-0.007, P < 0.001) and higher anxiety scores (β=-0.01, P < 0.001) were associated with lower EQ-5D index scores. Specifically, knee pain (β=-0.061, P < 0.001) was significantly associated with lower EQ-5D index scores. Participants with higher pain severity and depression scores were more likely to report problems in most EQ-5D dimensions. Participants with anxiety primarily faced challenges related to mood, and those with knee pain were more likely to have problems with mobility and daily activities.

CONCLUSION

Among the selected determinants in our study, pain intensity, depression, anxiety, and knee pain were identified as key determinants associated with reduced HRQoL in older Chinese people with chronic musculoskeletal pain. Each of these determinants showed distinct associations with different dimensions of the EQ-5D, potentially informed resource allocation and the development of targeted interventions to improve the overall HRQoL of this specific population.

Phenotypic characteristics of patients with chronic widespread pain and fibromyalgia: a cross-sectional cluster analysis

OBJECTIVE

This study aimed to explore whether phenotypic characteristics of patients with chronic widespread pain (CWP) and fibromyalgia (FM) can be aggregated into definable clusters that may help to tailor treatments.

METHOD

Baseline variables (sex, age, education, marital/employment status, pain duration, prior CWP/FM diagnosis, concomitant rheumatic disease, analgesics, tender point count, and disease variables derived from standardized questionnaires) collected from 1099 patients (93.4% females, mean age 44.6 years) with a confirmed CWP or FM diagnosis were evaluated by hierarchical cluster analysis. The number of clusters was based on coefficients in the agglomeration schedule, supported by dendrograms and silhouette plots. Simple and multiple regression analyses using all variables as independent predictors were used to assess the likelihood of cluster assignment, reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Only one cluster emerged (Cluster 1: 455 patients). Participants in this cluster were characterized as working (OR 66.67, 95% CI 7.14 to 500.00), with a medium-term/higher education (OR 16.80, 95% CI 1.94 to 145.41), married/cohabiting (OR 14.29, 95% CI 1.26 to 166.67), and using mild analgesics (OR 25.64, 95% CI 0.58 to > 999.99). The odds of being an individual in Cluster 1 were lower when having a worse score on the PDQ (score ≥ 18) (OR < 0.001, 95% CI < 0.001 to 0.02).

CONCLUSION

We identified one cluster, where participants were characterized by a potentially favourable clinical profile. More studies are needed to evaluate whether these characteristics could be used to guide the management of patients with CWP and FM.

An Italian Survey and Focus Groups on Fibromyalgia Impairment: Impact on Work and Possible Reasonable Accommodations

Fibromyalgia symptoms affect the sufferers' working life; however, through reasonable accommodations in workplaces, they can continue to work satisfactorily. There are no Italian studies on factors that facilitate or hinder fibromyalgia-affected people's working life. Our objective was to explore, in a pre-pandemic setting, the quality of working life of fibromyalgia sufferers and reasonable accommodations to improve it. Quantitative and qualitative methods were applied; a survey-questionnaire, participatory-developed, was online-administered to a sample of self-reported FM sufferers (N = 1176). Then, two Focus Groups (FGs), involving 15 fibromyalgia-affected women, were held. Data were analyzed by a thematic analysis approach. Among survey-respondents, 20% were unemployed and only 14% went to work gladly. Variability of pain (84%) and fatigue (90%) were the most perceived reasons for difficulties at work. Negative relationships at work were reported by most participants. The FGs' discussions addressed different strategies for overcoming the main obstacle of "not being believed by colleagues and employers" and reasonable accommodations. However, a negative hopeless attitude towards the solution of problems at work was also apparent. Different critical issues in the workplace emerged from the survey and the FGs. Coordinated actions, according to a transdisciplinary approach, are needed to manage fibromyalgia-induced difficulties in the workplace.

Acceptability, values, and preferences of older people for chronic low back pain management; a qualitative evidence synthesis

BACKGROUND

Chronic primary low back pain (CPLBP) and other musculoskeletal conditions represent a sizable attribution to the global burden of disability, with rates greatest in older age. There are multiple and varied interventions for CPLBP, delivered by a wide range of health and care workers. However, it is not known if these are acceptable to or align with the values and preferences of care recipients. The objective of this synthesis was to understand the key factors influencing the acceptability of, and values and preferences for, interventions/care for CPLBP from the perspective of people over 60 and their caregivers.

METHODS

We searched MEDLINE, CINAHL and OpenAlex, for eligible studies from inception until April 2022. We included studies that used qualitative methods for data collection and analysis; explored the perceptions and experiences of older people and their caregivers about interventions to treat CPLBP; from any setting globally. We conducted a best fit framework synthesis using a framework developed specifically for this review. We assessed our certainty in the findings using GRADE-CERQual.

RESULTS

All 22 included studies represented older people's experiences and had representation across a range of geographies and economic contexts. No studies were identified on caregivers. Older people living with CPLBP express values and preferences for their care that relate to therapeutic encounters and the importance of therapeutic alliance, irrespective of the type of treatment, choice of intervention, and intervention delivery modalities. Older people with CPLBP value therapeutic encounters that validate, legitimise, and respect their pain experience, consider their context holistically, prioritise their needs and preferences, adopt a person-centred and tailored approach to care, and are supported by interprofessional communication. Older people valued care that provided benefit to them, included interventions beyond analgesic medicines alone and was financially and geographically accessible.

CONCLUSIONS

These findings provide critical context to the implementation of clinical guidelines into practice, particularly related to how care providers interact with older people and how components of care are delivered, their location and their cost. Further research is needed focusing on low- and middle-income settings, vulnerable populations, and caregivers.

Experiences of occupational therapists within an ACT-based interdisciplinary pain management program

BACKGROUND

Acceptance and Commitment Therapy (ACT)-based interdisciplinary pain rehabilitation programs have shown effective results. While occupational therapy within these programs has made a unique contribution to pain management because of its focus on occupation and use of group activities, little is known about occupational therapists' own experiences of it.

AIM

The aim of this study was to describe the occupational therapists' experiences of working in a manual-based interdisciplinary pain management program grounded in ACT.

MATERIAL AND METHODS

Six occupational therapists at a pain rehabilitation clinic were interviewed. Data were analysed using Braun and Clark's thematic analysis.

RESULTS

The occupational therapists experienced that ACT and occupational therapy complement each other and that ACT facilitated comprehension of occupational therapy interventions. With ACT, the team gained a common language, which made teamwork and patient comprehension more efficient. A behavioural analysis (SORC) served as a link between occupational therapy and ACT.

CONCLUSIONS

Manual-based occupational therapy activity group interventions with elements of ACT were felt to enhance the patient's understanding of their rehabilitation and supported teamwork.

SIGNIFICANCE

This study provides further support for use of ACT in occupational therapy within interdisciplinary pain management programs. Occupational therapists' use of SORC is an area of development.

The Effect of Family Nursing Conversations as an Add-on to Multidisciplinary Treatment in Patients with Chronic Non-Cancer Pain: A Quasi-Experimental Trial

Introduction

Chronic non-cancer pain (CNCP) is a lifelong condition with radical consequences, calling for management involving patients' families. Interventions based on the family systems nursing framework by Wright and Leahey have proved beneficial in other populations but require investigation in a CNCP population. This trial assumed that family nursing conversations (FNCs) based on the family systems nursing framework would increase patients' and family members' self-efficacy concerning CNCP management.

Objective

To investigate whether an intervention with FNCs as an add-on to the usual multidisciplinary treatment of CNCP would have an effect on patients' and family members' self-efficacy. Additionally, to investigate any impact on family function, health-related quality of life, anxiety, and depression.

Methods

The trial applied a prospective non-blinded quasi-experimental design with two comparable groups of patients and family members: a historical control group (HCG) and an intervention group (IG). The intervention was executed by nurses employed at a multidisciplinary pain center in the Capital Region of Denmark. HCG data were collected before the nurses' intervention training. The primary outcome was self-efficacy. Secondary outcomes were family function, health-related quality of life, anxiety, and depression.

Results

In total, 58 patients and 85 family members were included. The primary outcome, self-efficacy, detected no statistically significant between-group differences in mean change for patients, p = .990, or family members, p = .765. A statistically significant effect in favor of the IG was found in between-group differences in mean change in patients' behavioral family function, p = .034, and anxiety, p = .031. No statistically significant between-group differences were detected in family members' secondary outcomes.

Conclusion

The intervention had no effect on patients' or family members' self-efficacy but a positive effect on patients' behavioral family function and anxiety. The intervention was deeply affected by the COVID-19 pandemic. Hence, any results should be interpreted with caution.

Paradox pain sensitivity using cuff pressure or algometer testing in patients with hemophilia

INTRODUCTION

Pain is a common comorbidity in patients with hemophilia (PwH) due to hemophilic arthropathy. This study aims to explore pain sensitivity in PwH methodologically investigating in cuff pressure testing compared to algometer testing.

METHODS

37 PwH and 35 healthy control subjects (Con) enrolled in this study. Joint health status was assessed. Subjective pain was evaluated using numeric rating scales. Pain sensitivity was measured with pressure algometry and cuff pressure algometry. Pressure pain thresholds of the algometer (PPTa) were measured at knee, ankle joints, and forehead. Subsequently, thresholds of cuff pressure were measured at the left and right lower legs (PPTcuff). In both, lower values represent higher pain sensitivity.

RESULTS

PwH exerted a worse joint health status than Con. Pain sensitivity was higher in PwH compared to Con as PPTa of the knee and ankle joints were lower in PwH. No difference was observed in PPTa at the forehead. Contrastingly, lower pain sensitivity was detected in PwH by higher PPTcuff values compared to Con in both legs.

CONCLUSION

While PPTa of the knee and ankle joints are lower in PwH, PPTcuff are higher in PwH compared to Con. This reveals a paradox situation, highlighting that PwH experience local, joint- and hemophilic arthropathy-related pain, whereas pain sensitivity of non-affected soft tissue structures is lower. The reasons explaining the PPTcuff results remain elusive but might be explained by coping strategies counteracting chronic joint pain, resulting in lower sensitivity at non-affected structures.

Healthcare experiences of fibromyalgia patients and their associations with satisfaction and pain relief. A patient survey

OBJECTIVES

The etiology of fibromyalgia (FM) is disputed, and there is no established cure. Quantitative data on how this may affect patients' healthcare experiences are scarce. The present study aims to investigate FM patients' pain-related healthcare experiences and explore factors associated with high satisfaction and pain relief.

METHODS

An anonymous, online, and patient-administered survey was developed and distributed to members of the Norwegian Fibromyalgia Association. It addressed their pain-related healthcare experiences from both primary and specialist care. Odds ratios for healthcare satisfaction and pain relief were estimated by binary logistic regression. Directed acyclic graphs guided the multivariable analyses.

RESULTS

The patients (n = 1,626, mean age: 51 years) were primarily women (95%) with a 21.8-year mean pain duration and 12.7 years in pain before diagnosis. One-third did not understand why they had pain, and 56.6% did not know how to get better. More than half had not received satisfactory information on their pain cause from a physician, and guidance on how to improve was reported below medium. Patients regretted a lack of medical specialized competence on muscle pain and reported many unmet needs, including regular follow-up and pain assessment. Physician-mediated pain relief was low, and guideline adherence was deficient. Only 14.8% were satisfied with non-physician health providers evaluating and treating their pain, and 21.5% were satisfied (46.9% dissatisfied) with their global pain-related healthcare. Patients' knowledge of their condition, physicians' pain competence and provision of information and guidance, agreement in explanations and advice, and the absence of unmet needs significantly increased the odds of both healthcare satisfaction and pain relief.

CONCLUSIONS

Our survey describes deficiencies in FM patients' pain-related healthcare and suggests areas for improvement to increase healthcare satisfaction and pain relief. (REC# 2019/845, 09.05.19).

Sustainability of cognitive behavioural interventions for chronic back pain: A long-term follow-up

BACKGROUND

There is a significant research gap with respect to the long-term sustainability of psychological treatment effects in chronic pain patients. This study aimed to investigate long-term treatment effects of two psychological treatments: cognitive behavioural therapy (CBT) as a broad-spectrum approach and exposure as a specific intervention for fear-avoidant pain patients.

METHODS

Patients with chronic low back pain were randomized to CBT or exposure in vivo. Long-term follow-up (LTFU) data were available for 64 patients up to 8 years after treatment, with a response rate of 73%. The primary outcomes were pain-related disability and pain intensity and secondary outcomes were emotional distress, psychological flexibility, catastrophizing and pain-related fear. The data analysis was performed with longitudinal multilevel modelling.

RESULTS

Multilevel analyses showed improvements in all primary outcomes as well as all secondary outcomes from pre-treatment to LTFU for both treatments. The mean proportion of cases meeting reliable and clinical improved criteria in all primary outcome was 36% (range: 22%-46%) in the exposure group and 50% (range: 33%-60%) in the CBT group. Dropout analyses revealed significantly higher deterioration rates over time. Pre-treatment to LTFU effect sizes of the primary outcomes ranged from 0.54 to 1.59.

CONCLUSIONS

Our results indicate that the effects of psychological treatments might be stable over several years. Treatment gains for exposure as a stand-alone treatment seem to be of shorter duration than a general CBT intervention. Thus, psychological treatments might offer a promising and sustainable long-term perspective for patients with chronic back pain.

SIGNIFICANCE

The long-term stability of treatment effects is a highly neglected issue despite its inherent importance in the context of chronic pain. This study is the first to investigate treatment effects of cognitive behavioural therapy and in vivo exposure in chronic back pain sufferers up to 8 years after treatment. The findings contribute to an understanding of the sustainability of psychological cognitive behavioural therapy-based intervention effects.

Is fibromyalgia an autoimmune disorder?

Fibromyalgia (FM) is a multifactorial syndrome which includes not only widespread pain and stiffness, now recognized as major symptoms, but also numerous other somatic, emotional, and neuropsychic manifestation. The lack of specific validated biological and instrumental biomarkers has made FM a condition of unexplained medical significance, and its pathophysiology remains controversial and subject to debate. The current hypothesis regarding the pathogenesis of FM proposes that its development is influenced by various mechanism, including genetic predisposition, stressful life events, inflammatory processes, and cognitive-emotional factors. However, despite the extensive research conducted to date, the available data do not provide a clear understanding of the pathogenesis of FM. In this article, we report the opposing viewpoints of two leading experts who debate the question of whether FM is an autoimmune disease, based on scientific data regarding this condition. Both perspectives are discussed and the latest evidence on the pathophysiology of FM is reported to provide a comprehensive understanding of this complex syndrome.

Topical Chinese patent medicines for chronic musculoskeletal pain: systematic review and trial sequential analysis

PURPOSE

Chronic musculoskeletal pain (CMP) is defined as persistent or recurrent pain that occurs in the joints, musculo-soft tissue, spine or bones for more than three months and is not completely curable. Although topical Chinese patent medicine (CPM) is the most extensively utilized medication in Asia and is widely used for pain management, its efficacy remains controversial. This article presents a systematic review of clinical studies on the therapeutic properties of topical CPM for CMP patients to better inform clinical decision-making and provide additional and safer treatment options for patients with CMP.

METHOD

We performed a comprehensive search on PubMed, Cochrane Library, web of science and Chinese databases (CNKI and WanFang data) from 2010 to 2022. In all the studies, knee osteoarthritis, cervical spondylosis, low back pain, and periarthritis of shoulder met the International Pain Association definition of chronic musculoskeletal pain. We included only randomized controlled trials (RCTs) using topical CPM primarily for chronic musculoskeletal pain in adults. To determine the effect of topical CPM on clinical symptoms, we extracted the Visual Analog Scale (VAS, range 0-10) and the Western Ontario and McMaster Universities Arthritis Index pain scores (WOMAC pain, range 0-20), in which the lower the score, the better the results. We also accepted the comprehensive outcome criteria developed by the Chinese National Institute of Rheumatology as an endpoint (total effectiveness rate, range 0-100%, higher score = better outcome), which assesses the overall pain, physical function and wellness. Finally, trial sequential analysis of VAS pain score and total effectiveness rate was performed using TSA software.

RESULTS

Twenty-six randomized controlled trials (n = 3180 participants) compared topical CPM with oral Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (n = 15), topical NSAIDs (n = 9), physiotherapy (n = 5), exercise therapy (n = 4), and intra-articular Sodium hyaluronate injection (n = 2). Sixteen studies found that topical CPM was statistically significant in improving CMP pain (measured by VAS pain and Womac pain scores)(p < 0.05), and 12 studies found topical CPMs to be more clinically effective (assessed by ≥ 30% reduction in symptom severity) in treating patients with CMP (p < 0.05). Trial sequential analysis indicates that the current available evidence is robust, and further studies cannot reverse this result. In most of the studies, randomisation, allocation concealment and blinding were not sufficiently described, and no placebo-controlled trials were identified.

CONCLUSION

Most studies showed superior analgesic effects of topical CPM over various control treatments, suggesting that topical CPM may be effective for CMP and is an additional, safe and reasonable treatment option. These reported benefits should be validated in higher-quality RCTs.