A global study of pain prevalence across 52 countries: examining the role of country-level contextual factors

Opioid Therapy in Chronic Pain: Assessment of Clinical Outcomes and Relationships With Endocrine Biomarkers

BACKGROUND

Long-term opioid treatment (L-TOT) may have consequences that are mediated by factors affecting functionality and health-related quality of life. This study aimed at investigating associations between L-TOT and clinical outcomes including sustained attention, short-term and working memory, worst pain intensity, sleep quality, mood, and health-related quality of life in patients with chronic non-cancer pain (CNCP). Additionally, the study aimed at exploring whether endocrine biomarkers mediate the relationship between L-TOT and these outcomes.

METHODS

Cross-sectional study with 82 adult CNCP patients divided into two groups (opioid treated (n = 38) and controls not treated with opioids (n = 44)). Linear regression analyses assessed associations between L-TOT, outcome variables, and the mediating effects of endocrine biomarkers. A Bootstrap approach with 95% confidence intervals was applied to analyse the natural indirect effect.

RESULTS

The opioid group had worse sleep quality (p = 0.018), physical functioning (p = 0.0186), social functioning (p = 0.002), and higher pain intensity (p < 0.001) compared with controls. Men in the L-TOT group experienced worse measures for the same variables, and additionally for anxiety (p = 0.028), depression (p = 0.040), role physical (p = 0.038), role emotional (p < 0.001), fatigue (p = 0.019), and emotional well-being (p = 0.001). Only the association between L-TOT and anxiety in men was significantly mediated by total testosterone (β = 1.6, Bias-Corrected Bootstrap 95% CI: 0.1; 4.1, p = 0.045).

CONCLUSIONS

CNCP patients in L-TOT showed significantly poorer outcomes than controls. Only testosterone mediated anxiety in men, indicating a natural indirect effect. Causality and mediating effects of endocrine biomarkers need to be further explored, but the associations are an alert to the potential effects of opioids.

SIGNIFICANCE STATEMENT

This study reveals the broader health impacts of opioid use, particularly the role of hormone-related factors in men, which may be linked to specific adverse effects and consequences. Investigating these hormonal dynamics could lead to improved treatment strategies and outcomes.

Stress-Related Brain Alterations in Chronic Pain

BACKGROUND

Stress symptoms are commonly experienced by people with chronic pain. Although stress and chronic pain are associated with similar effects on brain morphology, the present study aims to clarify the relationship between stress severity, chronic pain, and brain morphology.

METHODS

Fifty-two people with chronic pain and 38 pain-free healthy controls (HC) underwent T1-weighted magnetic resonance imaging. Severity of stress symptoms was measured using the civilian version of the posttraumatic stress disorder checklist (PCL-C). A series of multiple linear regressions determined the main effects of group, stress symptom severity (PCL-C total score and symptom-specific scores) and their interaction on grey matter volume of selected regions of interest.

RESULTS

The interaction term was significantly associated with variations in grey matter volume in the left and right putamen, the left middle cingulate cortex (MCC) and the right posterior insula. Results showed significantly smaller left and right putamen when reporting higher stress levels, and significantly larger left MCC and right posterior insula at lower stress levels in people with chronic pain compared to HCs. In addition, increasing stress severity was significantly associated with larger left and right putamen in HCs, and significantly associated with smaller left MCC and right posterior insula in people with chronic pain.

CONCLUSIONS

Severity of stress moderated chronic pain-related grey matter alterations. More severe stress, especially avoidance, was associated with smaller left MCC, a core region of the "pain matrix". The MCC is strongly linked with the somatosensory network and critical for empathy, especially toward pain-related stimuli.

SIGNIFICANCE

To our knowledge, this is the first study to show that stress severity differentially impacts grey matter integrity in people with chronic pain compared to pain-free healthy controls. Briefly, our results indicate that higher levels of stress were associated with larger putamen and right posterior insula in pain-free participants, potentially reflecting mechanisms of resilience to trauma in this group. Higher levels of stress, especially avoidance symptoms, were associated with smaller left middle cingulate cortex, a region with strong links to the somatosensory network and critical for empathy, especially toward pain-related stimuli.

The current state of digital manikins to support pain self-reporting: a systematic literature review

This systematic literature review aimed to explore the current state of digital manikins to support pain self-reporting and to explore the extent to which manikins had progressed along the translational pathway. We systematically searched six electronic databases using a combination of key words and MeSH terms for "pain" and "manikin" to identify original studies in English that used a digital pain manikin for collecting information from adults with any condition. We extracted and descriptively synthesised data on the characteristics of studies and digital pain manikins and mapped them to a stage of the translational pathway (ie, design, testing, metric validation, and diffusion). We screened 6,189 articles, of which we included 104. Articles reported on 31 unique digital pain manikins. Most studies were conducted in Europe (n = 60; 58%), recruited people with pain/painful conditions (n = 69; 66%) from clinical settings (n = 67; 64%). Of the 31 manikins, the majority were two-dimensional (n = 21; 68%) with a front and back body view (n = 18; 58%) and allowed users to draw their pain on any area of the manikin (n = 23; 74%). Most manikins were still in the development and testing stages (n = 23; 74%). Only eight (26%) had progressed fully through the translational pathway, taking between 7 and 20 years to go from early development to diffusion. We found a substantial number of mostly two-dimensional digital pain manikins reported on in the last decade. However, most were still at early stages of the translational pathway, with only few having progressed through to diffusion into research and health care settings.

The relationship between leisure time activities and chronic musculoskeletal pain in schoolteachers

BACKGROUND

Leisure activities (LAs) have a positive effect on well-being, healthy aging, cognitive functions, physical function, and mental health.

PURPOSE

To determine the prevalence of chronic musculoskeletal pain (CMSP) in schoolteachers and evaluate the relationship between different types of LAs and CMSP.

METHODS

A total of 433 in-service schoolteachers (303 female, 130 male) participated in this cross-sectional study between January 2023 and March 2023 using an online survey. Common LAs in Turkey, including reading books/magazines/newspapers or writing stories/letters, leisure physical activities (PAs), computer-based LAs, television viewing, LAs on smartphones, music listening, going to the cinema/theatre/opera/ballet/concert, gardening, cooking meal/pastry, meeting with friends, and painting/marbling/ceramic/knitting, and their durations were recorded.

RESULTS

The median age of the participants was 38.0 (IQR, 35.0-45.0) years. The prevalence of CMSP was 44.8%. Multiple logistic regression analysis including age, sex, body mass index, comorbidities, weekly standing duration at work, and LAs showed that there was an inverse relationship between CMSP and PAs (OR = 0.564, 95% CI: 0.357-0.890) and listening to music (OR = 0.555, 95% CI: 0.317-0.973). Moreover, LAs on smartphones (OR = 4.318, 95% CI: 2.004-9.308), gardening (OR = 1.827, 95% CI: 1.097-3.043), and having a thyroid disorder (OR = 2.212, 95% CI: 1.045-4.684) were predictive variables for CMSP.

CONCLUSIONS

Considering that PAs and music listening are inversely associated with CMSP, it may be beneficial to make them a part of the lifestyle of both healthy individuals and individuals with CMSP. Physicians should also be aware that LAs on smartphones carry a greater risk for CMSP.

Sex, gender, and pain: Evidence and knowledge gaps

Sex and gender contribute to the variation in pain experience. A range of biological, psychological, and social factors are relevant, which point to potential pain mechanisms and the reasons for this sex/gender-based variation. This review provides a brief critical overview of the evidence for these patterns. It draws on both experimental and clinical studies and identifies some of the biological and psychosocial factors that are thought to impact on men and women's pain. There are limitations and gaps in understanding, and numerous challenges exist, ranging from difficulties with concepts through to methodology. There is a focus on gender as a dimensional set of psychosocial constructs, as this offers one approach to help enhance our understanding of men and women's pain.

Phytochemical profile and biological activities of the hydroethanolic extract of Pouteria guianensis: A pharmacological investigation

ETHNOPHARMACOLOGICAL RELEVANCE

The investigation of Brazil's vast plant biodiversity is crucial. The genus Pouteria, though minimally explored chemically and pharmacologically, has numerous ethnopharmacological reports.

AIM OF THE STUDY

This study aims to evaluate the antioxidant, anti-inflammatory, antinociceptive, angiogenic, and cytotoxic properties of hydroethanolic extract from the leaves of P. guianensis, as well as to characterize its chemical composition.

MATERIAL AND METHODS

Several extracts from P. guianensis leaves were evaluated for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) reduction model. Chromatographic analyses and chemometric correlations were also applied. The 80 % hydroethanolic extract was selected and dereplicated using spectrometric techniques, and its anti-inflammatory and antinociceptive activities were assessed through carrageenan-induced paw edema, pain models, and the hot plate test. Antiangiogenic properties were evaluated using the chorioallantoic membrane (CAM) technique and cytokines levels were also measured.

RESULTS

Chemometric analyses identified myricitrin as a potential active marker for antioxidant activity, with mass spectrometry revealing a high phenolic content, particularly flavonoids quantified at 2.47 % and tannins at 17.19 %. Previous oral administration (p.o.) of the 80 % hydroethanolic extract of P. guianensis demonstrated significant anti-inflammatory and antinociceptive effects without impairing the animals' motor function. The hydroethanolic extract reduced TNF-α and IL-1β levels and also exhibited antiangiogenic properties, suggesting potential mechanisms for its anti-inflammatory action. Furthermore, no toxicity was observed in the CAM model.

CONCLUSION

This study highlights the significant pharmacological activities of P. guianensis hydroethanolic extract, warranting further investigation into its mechanisms of action. Additionally, it provides the first chemical characterization of the species, revealing a high phenolic content.

Exploring the presence of long COVID-like symptoms in patients with chronic pain: a large-scale internet-based cross-sectional study in Japan

ABSTRACT

Individuals with chronic pain not only endure the direct burden of pain but also experience various symptoms, including sleep disturbances and fatigue, which deteriorate their quality of life. Notably, these symptoms closely resemble those observed in "long COVID," a prolonged health complication that can arise after coronavirus disease 2019 (COVID-19) infection. Because the similarities between chronic pain and long COVID remain unexplored, this study aimed to investigate their relationship using Japanese epidemiological data. Using the Japan COVID-19 and Society Internet Survey in 2022, which included 32,000 participants, we analyzed data on the presence of chronic pain, history of COVID-19 infection, and presence of 17 long COVID-like symptoms, including gastrointestinal upset, back pain, limb/joint pain, headache, chest pain, shortness of breath, dizziness, sleep disorder, hearing disorder, taste disorder, smell disorder, memory impairment, poor concentration, hair loss, decreased libido, fatigue, and cough. Individuals with history of COVID-19 experienced a significantly greater number of long COVID-like symptoms (median: 5) compared with those with neither COVID-19 nor chronic pain (median: 4, P < 0.001). Individuals with chronic pain alone and those with both COVID-19 and chronic pain exhibited an even greater number of symptoms (median: 8 and 9, respectively). In addition, individuals with chronic pain exhibited greater prevalence odds for 15 of the 17 symptoms than those with neither COVID-19 nor chronic pain (P < 0.001). Our findings indicate that long COVID-like symptoms are not specifically associated with COVID-19. Instead, the data suggest that chronic pain contributes as an independent risk factor for these symptoms.

Demographic variation in pain across 22 countries

BACKGROUND

Recent work has explored the sociocultural aspects of pain. However, global evidence is scarce, and little is known about how levels of pain differ across cultures and across demographic groups within those different cultures.

METHODS

Using a nationally representative dataset of 202,898 individuals from 22 countries and a random effects meta-analysis, we examine the proportion of people in pain across key demographic groups (age, gender, marital status, employment status, education, immigration status, religious service attendance, race/ethnicity) and across countries.

RESULTS

We find substantial variation in pain across countries and demographic groups. Unadjusted proportions tests show that Egypt (0.60), Brazil (0.59), Australia (0.56), and Turkey (0.53) have the greatest proportion of people in pain whereas Israel (0.25), South Africa (0.29), Poland (0.32), and Japan (0.33) have the lowest proportion. The random effects meta-analysis shows that, across countries, the proportion of people in pain is highest in older age groups, among women and other gender groups, the widowed, those who were retired, those who had low level of education, and those who attended a religious service more than once a week. The analysis shows no difference in the proportion of people in pain regarding immigration status.

CONCLUSIONS

Pain varies substantially across countries and key demographic groups. This work provides valuable foundational insights for future research on the sociocultural factors of pain.

Consumer perspectives of the group itself in group-delivered programs for people with chronic pain: A systematic review and meta-synthesis

Group-delivered programs for chronic pain are evidence-based and frequently used. The contribution of group factors to outcomes is unclear and there are no integrated findings on consumer perceptions of the group itself in programs for people with chronic pain. The aim of this systematic review was to search and synthesise qualitative data specifically related to the group itself in studies investigating group-delivered programs for people with chronic pain (PROSPERO, CRD42023382447). MEDLINE, EMBASE, EmCare, PsycINFO, Scopus, and CINAHL databases were searched, and qualitative studies that explored the experiences of consumers who had attended any style of group-delivered program for people with chronic pain were included. Methodological quality was assessed using the Critical Appraisal Skills Programme checklist and meta-synthesis was guided by a thematic synthesis approach. Ninety-three studies were included, with 1806 participants. Programs were predominantly multi-component, with diverse interventions and facilitators. Three analytical themes were generated: (1) Peer interaction: a program component in and of itself; (2) Comparison: frequently used and mostly helpful; and (3) Beyond the program: when the group itself contributes to change. Findings highlighted that most consumers valued the group itself, finding interaction, and comparing themselves with peers useful. Future research related to group factors in programs for people with chronic pain should include consumer participation and co-design. PERSPECTIVE: This review demonstrates that many consumers valued peer interaction and used comparison-based cognitive processing within group-delivered programs for chronic pain. Dialogue-based interactions with similar others promoted cognitive, affect, and behaviour changes. Group factors may have been underestimated and outcomes could be influenced if peer interactions within programs were optimised.

Conversational Agents to Support Pain Management: A Scoping Review

BACKGROUND

Pain-related conditions are the leading cause of years lived with disability globally. Managing pain presents significant challenges, including the need to address multiple biopsychosocial factors and the difficulty in delivering evidence-based treatments. Digital health technologies, such as conversational agents, offer the potential for personalised and accessible pain management. However, the characteristics and effectiveness of these interventions are not yet fully understood. This scoping review aims to comprehensively evaluate the applications and effectiveness of conversational agents in supporting pain management in adults (i.e., healthy individuals at risk of developing pain, individuals currently experiencing pain and healthcare providers or students involved in managing pain conditions).

METHODS

Searches were systematically conducted across six databases-MEDLINE PubMed, ACM Digital Library, CINAHL, Embase, PsycINFO, Cochrane CENTRAL-and five trial registries from inception.

RESULTS

Twenty-eight studies were included, focusing on capturing health information (n = 8), providing emotional support (n = 7), facilitating adherence to self-management exercises (n = 6), delivering psychological treatment (n = 5), offering organisational support (n = 1) and educating healthcare providers (n = 1). These studies addressed conditions with pain as a central or common symptom, including dementia (n = 7), cancer (n = 5) and musculoskeletal disorders (n = 4), among others. None of the conversational agents on the market covered all four stages recommended for translational research (development, feasibility, effectiveness and implementation).

CONCLUSION

The use of conversational agents in pain management is relatively new and involves diverse and promising appllications. However, evidence supporting their effectiveness in improving pain-related outcomes remains limited and heterogeneous. Future reseacrh should prioritise feasibility, reliability, and user experience studies to inform the design of robust randomised controlled trials.

SIGNIFICANCE

This scoping review comprehensively examines the use of conversational agents (CAs) in adult pain management. The study identified six applications of CAs to support pain management and highlights a lack of high-quality randomised controlled trials, particularly those preceded by development and feasibility studies. Clinicians and researchers can use these insights to guide future studies and improve applications of CAs in pain management.

Cryotherapy Is Effective in Nulliparous Women with Primary Dysmenorrhea: A Randomized Controlled Trial

Primary dysmenorrhea is a prevalent condition causing severe menstrual pain in nulliparous women, negatively impacting daily functioning and well-being. This randomized controlled trial investigated the efficacy of cryotherapy in alleviating pain and enhancing secondary outcomes such as sleep quality, quality of life, and physical activity. Fifty-eight nulliparous women were randomly assigned to a cryotherapy group or a control group. Pain intensity was measured using the Numeric Rating Scale, whereas secondary outcomes were evaluated with the Pittsburgh Sleep Quality Index, World Health Organization Quality of Life-Brief Version, and the International Physical Activity Questionnaire. Socioeconomic factors, including household income, education, and occupation, were also assessed. Cryotherapy significantly reduced pain intensity from a baseline of 7.1 ± 1.4 to 1.8 ± 1.7 (p < 0.001) compared with a modest reduction in the control group (5.9 ± 1.9-5.4 ± 2.1). Sleep quality improved more in the cryotherapy group (6.90 ± 3.0 to 5.03 ± 2.5) than in the control group (6.88 ± 3.6 to 5.68 ± 2.8). However, no statistically significant changes were observed in the quality of life or physical activity levels, likely because menstrual pain alone may not sufficiently influence these domains, which are affected by broader psychosocial and behavioral factors. These findings demonstrate that cryotherapy is a simple, cost-effective intervention for managing primary dysmenorrhea, providing substantial pain relief and modest improvements in sleep quality. Further research is recommended to evaluate its long-term benefits and potential for broader applications in menstrual health management.

Pain Prevalence and Intensity Among Older Family Caregivers Versus Non-Caregivers in the United States

ObjectiveWe compared pain prevalence and intensity between caregivers and non-caregivers, as well as between different types of caregivers.MethodUsing two rounds of data from the National Social Life, Health, and Aging Project, we used regression models to analyze differences in pain prevalence and intensity between caregivers and non-caregivers at baseline (2010-2011) and follow-up (2015-2016). The sample consisted of 2332 participants aged 62 and older (352 caregivers and 1980 non-caregivers).ResultsCross-sectionally, caregivers were more likely than non-caregivers to report pain. Longitudinally, caregivers with pain at baseline were more likely to report the presence of pain and greater pain intensity five years later compared to non-caregivers who also reported pain at baseline. More hours of care per week was associated with greater pain intensity at baseline and follow-up among caregivers with pain.DiscussionCaregivers' pain is a public health concern, with efforts to mitigate the effects of caregiving on pain needed.

Common neural correlates of chronic pain - A systematic review and meta-analysis of resting-state fMRI studies

Maladaptive brain plasticity has been reported in chronic pain (CP) conditions, though it remains unclear if there are common alterations across pathologies. Therefore, we systematically synthesized literature comparing resting-state functional magnetic resonance imaging (rs-fMRI) in CP patients and healthy controls (HC), and meta-analyzed data whenever applicable. Separate meta-analyses were performed for each method - (fractional) amplitude of low-frequency fluctuations (fALFF, ALFF), regional homogeneity (ReHo), seed-based connectivity (according to the seed) and independent component analysis (according to the network). In qualitative synthesis, sensory-discriminative pain processing - thalamus, insula, temporal and sensory cortices - and cognitive and emotional processing - cingulate, prefrontal and parietal cortices and precuneus - regions concentrated CP/HC differences. Meta-analyses revealed decreased ALFF and increased ReHo in the precuneus, increased fALFF in the left posterior insula and disrupted within- and cross-network connectivity of default mode network (DMN) nodes, as well as altered connectivity in top-down pain modulation pathways. Specifically, it showed decreased anterior and increased posterior components' representation within DMN, enhanced connectivity between the medial prefrontal cortex (mPFC, part of the DMN) and anterior insula (part of the salience network), and decreased mPFC connectivity with the periaqueductal gray matter (PAG). Collectively, results suggest that CP disrupts the natural functional organization of the brain, particularly impacting DMN nodes (mPFC and precuneus), insula and top-town pain modulation circuits.

Evaluating the efficacy of transcranial direct current stimulation (tDCS) in managing neuropathic pain-induced emotional consequences: Insights from animal models

Neuropathic pain is a global health concern due to its severity and its detrimental impact on patients' quality of life. It is primarily characterized by sensory alterations, most commonly hyperalgesia and allodynia. As the disease progresses, patients with neuropathic pain develop co-occurring emotional disorders, such as anxiety and depression, which further complicate therapeutic management. While pharmacotherapy remains the first-line treatment, limitations in its efficacy and the prevalence of side effects often leave patients with insufficient pain relief. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, has recently emerged as a promising alternative for chronic pain management. This review provides an overview of preclinical studies examining the effects of tDCS in rodent models of neuropathic pain. It specifically highlights the potential of tDCS to modulate the emotional-affective component of pain, with a focus on identifying optimal cortical targets for stimulation to enhance the translational application of tDCS in managing pain-related emotional disorders.

Disparities, Inequities, and Injustices in Populations With Pain: Nursing Recommendations Supporting ASPMN's 2024 Position Statement

The American Society for Pain Management Nursing (ASPMN) upholds the principle that all persons with pain have equal rights to evidence-based, high quality pain assessment, management, and treatment. This practice recommendation's goals are to 1) summarize known pain-related disparities, inequities, and injustices among commonly marginalized and at risk groups, 2) offer recommendations to ascertain that just and equitable pain care is provided to all people, and 3) outline a call to action for all nurses to embrace diversity, equity, inclusion, and a sense of belonging in order to mitigate pain-related disparities, inequities, and injustices within clinical environments and the nursing profession. This paper provides background and rationale for the 2024 ASPMN position statement on disparities, inequities and injustices in people with pain.

Large-Scale Plasma Proteomics to Profile Pathways and Prognosis of Chronic Pain

While increasing peripheral mechanisms related to chronic pain, the plasma proteomics profile associated with it and its prognosis remains elusive. This study utilizes 2923 plasma proteins and chronic pain of 51 644 participants from UK Biobank and finds 474 proteins linked to chronic pain in six sites: head, neck or shoulder, back, stomach or abdominal, hip, and knee, with 11 proteins sharing across pain sites. The identified proteins are largely enriched in immune and metabolic pathways and highly expressed in tissues like lungs and small intestines. Phenome-wide analysis highlights the significance of pain-related proteome on diverse facets of human health, and in-depth Mendelian randomization validates 10 proteins (CD302, RARRES2, TNFRSF1B, BTN2A1, TNFRSF9, COL18A1, TNF, CD74, TNFRSF4, and BTN2A1) as markers of chronic pain. Furthermore, protein sets capable of classifying pain patients and healthy participants, particularly performing best in hip pain (area under curve, AUC = 0.725), are identified. Interestingly, the prediction of pain spreading over ten years achieves an AUC of 0.715, with leptin identified as a crucial predictor. This study delineates proteins associated with various pain conditions and identifies proteins capable of classifying pain and predicting pain spreading, offering benefits for both research and clinical practice.

New generation capsaicin-diclofenac containing, silicon-based transdermal patch provides prolonged analgesic effect in acute and chronic pain models

OBJECTIVE

Pain is one of the major public health burdens worldwide, however, conventional analgesics are often ineffective. Capsaicin-the active compound of Capsicum species, being responsible for their pungency-has been part of traditional medicine long ago. Capsaicin is a natural agonist of the Transient Receptor Potential Vanilloid 1 receptor-localized on capsaicin-sensitive sensory neurons and strongly involved in pain transmission-, and has been in focus of analgesic drug research for many years. In this study, we aimed to develop a sustained release transdermal patch (transdermal therapeutic system, TTS) combining the advantages of low-concentration capsaicin and diclofenac embedded in an innovative structure, as well as to perform complex preclinical investigations of its analgesic effect.

METHODS

Drug delivery properties of the TTS were investigated with Franz cell and flow-through cell tests. Analgesic effect of the TTS was examined in in vivo models of acute postoperative and inflammatory, chronic neuropathic and osteoarthritic pain.

RESULTS

Modified silicone polymer matrix-based TTS containing low-concentration capsaicin and diclofenac has been developed, releasing both compounds according to zero-order kinetics. Moreover, capsaicin and diclofenac facilitated the liberation of each other. Combined TTS significantly reduced acute postoperative and inflammatory pain, as well as chronic neuropathic and osteoarthritic pain. Interestingly, in acute postoperative and chronic osteoarthritic pain, capsaicin prolonged and potentiated the pain-relieving effect of diclofenac.

CONCLUSIONS

New generation combined low-concentration capsaicin-diclofenac containing TTS can be an effective therapeutic tool in acute and chronic pain states involving neuropathic and inflammatory components.

Two in one: a randomized controlled trial on an internet-based intervention (Lenio) for management of both chronic pain and depressive symptoms

The high prevalence of chronic pain and comorbid depression, along with their negative impacts on individuals and society, highlights the need for accessible and effective interventions. This study examined the feasibility, efficacy, and acceptability of Lenio, an Internet-based self-help intervention, combined with the COGITO smartphone application for managing these conditions. The randomized controlled trial involved an intervention group (IG) using Lenio and COGITO, an active control group (ACG) using a transdiagnostic app, and a wait-list control group (WCG) receiving usual treatment. Lenio incorporates cognitive behavioral therapy and third-wave techniques, supported by COGITO's gamified daily exercises to enhance adherence. Across 263 participants assessed at three intervals over 16 weeks, the IG showed significant improvement in somatic-affective depressive symptoms compared to the WCG post-intervention and both control groups at follow-up. However, the ACG outperformed the IG in managing pain at post-intervention though these effects did not persist until follow-up. The interventions were well-received and feasible, with older participants benefiting more from the Lenio/COGITO combination. Lenio and COGITO could bridge gaps to conventional therapy, potentially easing pain by enhancing psychological well-being and coping strategies. Future studies should investigate tailored interventions for chronic pain and their long-term effectiveness.

Protocol

Full trial protocol can be accessed via DOI: 10.1186/s13063-023-07440-8.

Clinical trial registration

https://drks.de/register/de/trial/DRKS00026722/preview, identifier DRKS-IDDRKS00026722.

Inhibitory effects of dopamine agonists on pain-responsive neurons in the central nucleus of the amygdala

The central nucleus of the amygdala (CeA) is a heterogenous region of primarily GABAergic neurons that contributes to numerous behaviors, including fear learning, feeding, reward, and pain. Dopaminergic inputs to the CeA have been shown to regulate many of these behaviors, but how dopamine exerts these effects at the cellular level has not been well characterized. We used the Targeted Recombination in Active Populations (TRAP) mouse line to fluorescently label pain-responsive CeA neurons, and then targeted these cells for patch-clamp recordings in acute slices to test the effects of dopamine agonists. The D1 agonist SKF-38393 and D2 agonist quinpirole both had inhibitory effects, reducing the input resistance and evoked firing and increasing rheobase of labeled CeA neurons. Both agents also inhibited the NMDA component of excitatory postsynaptic currents (EPSCs) evoked by basolateral amygdala (BLA) stimulation, but did not affect the AMPA component. D1 activation, but not D2, also appeared to have a presynaptic effect, increasing the frequency of spontaneous EPSCs. These results provide new insights into how dopamine regulates activity within pain-responsive CeA networks.

NEW & NOTEWORTHY

Dopamine is known to regulate activity within the central amygdala (CeA), an important region for central pain processing. However, its effects at the cellular level have not been well characterized. We targeted pain-responsive CeA neurons for patch-clamp recordings to examine the cellular and synaptic effects of D1 and D2 agonists. Activation of either D1 or D2 receptors induced inhibitory effects, suggesting dopamine signaling in CeA dampens pain-related activity and could be a target for analgesics.

Association between pain, sleep and intrinsic capacity in Chinese older adults: Evidence from CHARLS

OBJECTIVES

To examine the relationship between pain, sleep, and intrinsic capacity (IC).

DESIGN

A cohort study.

SETTING AND PARTICIPANTS

Data were obtained from participants in China Health and Retirement Longitudinal Study (CHARLS) 2011-2015. The study population consisted of older adults who completed assessments on pain, sleep duration, sleep quality and IC at baseline.

MEASUREMENTS

Pain, sleep duration, and sleep quality were assessed through self-reports from participants. The total IC score was derived from five domains: psychological, sensory, cognitive, locomotor, and vitality. The relationships between pain, sleep duration, sleep quality and IC were analyzed using linear mixed models. The relationship between sleep duration and IC was analyzed using quadratic analysis. Stratified analyses by gender and age were also performed.

RESULTS

A total of 3517 participants were included in the analysis. After adjusting for all covariates, single-site pain (β = -0.29, 95% confidence interval [CI] = -0.38 to -0.20) and multisite pain (β = -0.41, 95% CI = -0.48 to -0.34) were significantly associated with a decrease in IC compared with older adults without pain; long sleep duration (β = -0.15, 95% CI = -0.24 to -0.06) was significantly associated with a decrease in IC compared with older adults with moderate sleep duration; and poor sleep quality (β = -0.63, 95% CI = -0.71 to -0.55) and fair sleep quality (β = -0.33, 95% CI = -0.40 to -0.27) were significantly associated with a decrease in IC compared with older adults with good sleep quality.

CONCLUSION

To maintain IC, it is important to ensure approximately 7.5 h of sleep duration, improve sleep quality, and manage pain. Interventions should begin as early as possible.

Moving towards the use of artificial intelligence in pain management

BACKGROUND AND OBJECTIVE

While the development of artificial intelligence (AI) technologies in medicine has been significant, their application to acute and chronic pain management has not been well characterized. This systematic review aims to provide an overview of the current state of AI in acute and chronic pain management.

DATABASES AND DATA TREATMENT

This review was registered with PROSPERO (ID# CRD42022307017), the international registry for systematic reviews. The search strategy was prepared by a librarian and run in four electronic databases (Embase, Medline, Central, and Web of Science). Collected articles were screened by two reviewers. Included studies described the use of AI for acute and chronic pain management.

RESULTS

From the 17,601 records identified in the initial search, 197 were included in this review. Identified applications of AI were described for treatment planning as well as treatment delivery. Described uses include prediction of pain, forecasting of individualized responses to treatment, treatment regimen tailoring, image-guidance for procedural interventions and self-management tools. Multiple domains of AI were used including machine learning, computer vision, fuzzy logic, natural language processing and expert systems.

CONCLUSION

There is growing literature regarding applications of AI for pain management, and their clinical use holds potential for improving patient outcomes. However, multiple barriers to their clinical integration remain including lack validation of such applications in diverse patient populations, missing infrastructure to support these tools and limited provider understanding of AI.

SIGNIFICANCE

This review characterizes current applications of AI for pain management and discusses barriers to their clinical integration. Our findings support continuing efforts directed towards establishing comprehensive systems that integrate AI throughout the patient care continuum.

Fibromyalgia and Rehabilitation. Not as You Thought. Changing the Stigma

BACKGROUND

A cohort of patients in the rehabilitation wards also suffer from Fibromyalgia, which is considered the most prevalent cause of chronic pain. Poor function, subjective cognitive impairment, instability and imbalance are all common features of Fibromyalgia, among other more prominent features such as the use of chronic pain medication. The main purpose of this study was to examine the differences in Length of Stay (LOS) and functional outcome parameters.

METHODS

A retrospective cohort trial was conducted at the Soroka University Medical Centre. The time of data collection was conducted from January 2015 to December 2021. Patients were divided into two groups based on their exposure status: With Fibromyalgia (n = 43) and Control group Without Fibromyalgia (n = 1119). A 1:10 matching process and regression analysis were performed to avoid confounding factors. Matching was based on age, gender, and ethnicity. Various rehabilitation outcomes were collected along with pain assessment and pain medication use during the hospitalisation. Statistical analysis was performed using R software. A p value of < 0.05 will be considered statistically significant.

RESULTS

No statistically significant difference was found in the duration of hospitalisation, the FIM index at admission and discharge, or the change in the FIM index (ΔFIM) during hospitalisation between the two groups. No statistically significant differences were demonstrated in stability and balance indices (DGI, BBS) or cognitive assessment tests (MoCA).

CONCLUSIONS

The stigma is incorrect, as patients with fibromyalgia can improve their functional parameters during an inpatient rehabilitation programme to the same degree as those without fibromyalgia.

Aqueous and Ethanol Extracts of Acacia sieberiana (Fabaceae) Stem Bark Reverse the Pain-Depression Dyad in Mice Through Modulation of Catecholamines, Proinflammatory Cytokines, and Oxidative Stress

Rationale and Objective: The pain-depression dyad is highly prevalent and has reciprocal psychological and behavioral effects, leading to poor quality of life, increased disability, and challenging therapeutic outcomes. In an attempt to find better substances that can target pain-depression comorbidity, we examined the effect of aqueous (AE) and ethanol (EE) extracts from Acacia sieberiana (A. sieberiana) stem bark on reserpinized mice (female and male Swiss albino mice aged 2-3 months). Methods: The dyad was induced with 3 injections (Days 1-3) of reserpine (1 mg/kg/day, s.c.). Then, animals were treated (Days 4-8) with plant extracts (25, 50 and 100 mg/kg/day, p.o.) or L-tryptophane (100 mg/kg/day, i.p.). Pain-like (tactile and cold allodynia) and depression-like (pole, tail suspension, and force swimming tests) behavioral parameters were evaluated on Days 4 and 8. On Day 9, animals were sacrificed for the quantification of acetylcholinesterase activity, oxidative stress parameters, total catecholamines, dopamine, serotonin, IL-1β, and TNF-α levels in the brain or spinal cord. IL-1β and TNF-α were also assayed in the serum. The acute toxicity and phytochemical analysis of EE were conducted. Results: Reserpine-induced tactile and cold allodynia, depression-like behavior, increased serum IL-1β and TNF-α, brain acetylcholinesterase activity, and decreased catecholamine concentration were all reversed by AE and EE. Plant extracts significantly increased dopamine levels and reduced oxidative stress in the brain and/or spinal cord. No significant effect was observed on brain serotonin and TNF-α. EE elicited the best pharmacological activity and was nontoxic. LC-MS/MS molecular networking phytochemical analysis identified 5 compounds with high certainty including piperine, aurantiamide acetate, and asperphenamate. Conclusion: AE and EE are effective against pain and depression. Their pharmacological activities might be related to the modulation of inflammation, oxidative stress and catecholamine, and the presence of bioactive natural products.

Where is the pain? Spatial patterns of pain co-occurrence in a population-based study of 4833 pain drawings incorporating network analysis

ABSTRACT

Spatial pain patterns are widely used as diagnostic tools, yet population-level estimates, such as the prevalence of pain in specific body regions and likelihood of their co-occurrence, are lacking. Despite this, bilateral limb pain is considered relatively uncommon. Baseline data from a population-based Danish cohort were analysed. Twenty-one pain drawing regions, coded as binary "pain"/"no-pain" variables, were entered into an Ising model. Conditional dependencies between pairs of painful regions were quantified, while accounting for the pain state of other regions. Four-week prevalence of pain was also calculated for body regions. Of 4833 analysed pain drawings, 34.7% (1676) reported bilateral (upper or lower) limb pain and 32.3% (1561) reported symmetrical (mirrored) bilateral limb pain. Strongest positive edge weights of the Ising model were between mirrored contralateral regions; the strongest being between left and right hips (mean: 3.86, 95% confidence interval: 3.84-3.87). Next strongest edge weights were between spatially adjacent ipsilateral regions; the strongest being between the right hip and right buttock (mean: 2.72, 95% confidence interval: 2.71-2.74). Negative edge weights, indicating inhibitory relationships, were consistently seen between nonmirrored contralateral regions, the strongest being between regions adjacent to their mirrored contralateral counterparts. In conclusion, bilateral limb pain, particularly in mirrored regions, is more prevalent than previously thought. Pain co-occurrence is facilitated between mirrored contralateral regions and, to a lesser degree, between adjacent ipsilateral regions. An inhibitory effect occurs between nonmirrored contralateral regions, diminishing with increasing distance from the mirrored region. Potential inhibition between mirrored contralateral regions is likely overshadowed by the more dominant facilitation.

Eating to Feel Better: The Role of Comfort Eating in Chronic Pain

Research has identified that individuals with chronic pain comfort eat in response to their pain, however, little is known about the function that comfort eating serves for chronic pain patients. Given the synergistic relationship between higher body weight and chronic pain, it is important to further understand the role and impact of eating behaviours, such as comfort eating, for individuals with chronic pain. This study aimed to investigate the perceived function of pain-induced comfort eating for chronic pain sufferers. Adult participants (N = 141) with chronic pain were recruited through online advertisements. Participants completed self-report questions on an online survey platform. Over two-thirds of the sample identified with engaging in comfort eating in response to chronic pain flare-ups. Results revealed that the most endorsed function of pain-induced comfort eating was 'to have a pleasant experience' (51.8%), followed by 'distraction' (49.6%) and 'to reduce emotions' (39%). This study provides further evidence that comfort eating is common amongst individuals with chronic pain and sheds light on the perceived function of comfort eating for those who are managing chronic pain. Given the potential impact on outcomes for chronic pain patients, future studies should further investigate the relationship between comfort eating and chronic pain.

Advancements and prospects of transcranial focused ultrasound in pain neuromodulation

ABSTRACT

Transcranial focused ultrasound (tFUS) is an emerging noninvasive neuromodulation technology that has shown great potential in pain modulation. This review systematically elucidates the multilevel biological mechanisms of tFUS neuromodulation, from network-wide effects to cellular and molecular processes, as well as broader systemic influences. Preliminary animal pain model studies have revealed tFUS's ability to improve pain behavioral indicators and modulate neural circuit activity under pathological conditions. A small number of clinical studies also suggest that tFUS may have certain benefits in improving symptom experience and emotional state in chronic pain patients. However, current research generally has limitations such as small sample sizes and short follow-up periods. More high-quality studies are needed to verify the long-term effects and safety of tFUS pain treatment. Overcoming these limitations and advancing large-scale clinical translational research will help fully exploit the application potential of tFUS in precision pain medicine and provide new treatment options for pain relief.

Analgesic activity of aqueous and methanol fruit pulp extracts of Hyphaene thebaica (Arecaceae) (Linn) mart in mice

OBJECTIVES

Pain affects about one in every five persons and is considered a major global health burden. Hyphaene thebaica (Arecaceae), is a medicinal plant used in Cameroon, fruit pulp are macerated and orally administered in traditional medicine to treat various ailments, including hypertension, pain, and inflammation. This study aimed to evaluate the pain-killing effect of fruit pulp extracts of H. thebaica in mice.

METHODS

Aqueous (AEHT) and methanol (MEHT) extracts were prepared from fruit pulp of H. thebaica, followed by a qualitative phytochemical analysis. The extracts were given orally at doses of 100, 200, and 400 mg/kg in acute pain models such as acetic acid, formalin, hotplate, and capsaicin. Control groups included distilled water (negative), and diclofenac, morphine, ruthenium red, diazepam (positive). Naloxone pretreatment was used to assess opioid pathway involvement. Locomotor and sedative effects were evaluated using rota-rod and open-field tests. Acute toxicity was assessed at 2,000 mg/kg.

RESULTS

Phytochemical tests revealed saponins, flavonoids, tannins, and phenols. Both extracts greatly decreased the writhing induced by acetic acid. MEHT inhibited both phases of formalin-induced pain (p<0.01). Both extracts significantly inhibited hotplate-induced nociception (p<0.001), partially reversed by naloxone, except for MEHT. In the capsaicin test, extracts produced a remarkable reduction of paw licking time (p<0.01). No motor coordination alteration or acute toxicity effects were observed.

CONCLUSIONS

The findings demonstrated the analgesic activity of AEHT and MEHT, mediated by the stimulation of opioids and blockage of vanilloid receptors pathways.

Monitoring Chronic Non-Cancer Pain in Denmark Over Two Decades: Prevalence, Mental Health and Loneliness

BACKGROUND

Epidemiological surveys have monitored chronic non-cancer pain (CNCP) and investigated associated factors in Denmark for more than 20 years. This study aimed to analyse CNCP prevalence in the Danish population from 2000 to 2023 and its associations with mental health status and loneliness.

METHODS

Population-based surveys were conducted between 2000 and 2023. In all waves, residents aged ≥ 16 years were randomly selected to complete a self-administered questionnaire. Samples included 10,089 respondents in 2000, 5292 in 2005, 14,330 in 2010, 13,429 in 2013, 13,050 in 2017, 10,384 in 2021 and 9303 in 2023. CNCP was defined as pain lasting ≥ 6 months. Mental status was assessed by Mental Component Summary score of Short Form-12 and severe loneliness by the Three-Item Loneliness Scale. Calibration weighting was applied to reduce potential non-response bias.

RESULTS

The prevalence of CNCP increased steadily by 9.4 percentage points from 2000 (19.5%) to 2023 (28.9%), but with a downward tick during the COVID-19 pandemic in 2021 (25.3%). Women aged 45 years or older had the highest prevalence in all waves. Results showed a worsening of mental health over time in both individuals with and without CNCP; however, the lowest scores were reported by individuals with CNCP. Severe loneliness seemed to be a substantial problem in individuals with CNCP (17.3% in 2021).

CONCLUSIONS

In summary, CNCP was highly prevalent over the given period and associated with mental health status and severe loneliness in recent years.

SIGNIFICANCE

This study demonstrated alarming trend on chronic non-cancer pain prevalence over time in Denmark. The high estimates of prevalence and related issues, such as mental health and severe loneliness deserve further investigation and prioritisation in the public health agenda.

Walking to the same winter: Urban-rural disparities in pain among middle-aged and older Chinese

Chronic pain, as a barometer of population health, remains understudied from a socio-structural lens. This study adopts a life course perspective and integrates hukou as a potential institutional arrangement shaping pain, aiming to advance the understanding of health inequalities in China. Specifically, we examine urban-rural disparities in pain prevalence and investigate how these disparities evolve across the life course by using generalized estimating equations and the China Health and Retirement Longitudinal Study 2011-2020 (N = 16479). Our findings indicate that rural hukou holders experience more pain than their urban counterparts. Among rural hukou holders, urban dwelling is associated with a reduced pain risk. Furthermore, we observe that pain prevalence increases with age, yet such pain trajectories vary across urban and rural populations, showing a converging trend in pain over the life course. This study extends the literature on health inequalities by demonstrating how institutional and geographic characteristics jointly shape urban-rural gradients in pain prevalence. Moreover, it provides novel evidence for the age-as-leveler hypothesis in a non-Western context.

Education, gender, and frequent pain among middle-aged and older adults in the United States, England, China, and India

ABSTRACT

Using cross-sectional data from the United States, England, China, and India, we examined the relationship between education and frequent pain, alongside the modification role of gender in this relationship. We further examined patterns of 3 pain dimensions among participants who reported frequent pain, including pain severity, interference with daily activities, and medication use (these pain dimension questions were not administered in all countries). Our analytical sample included 92,204 participants aged 50 years and above. We found a high prevalence of frequent pain across the 4 countries ranging from 28% to 41%. Probit models showed that higher education was associated with lower risk of pain (United States: -0.26, 95% CI: -0.33, -0.19; England: -0.32, 95% CI: -0.39, -0.25; China: -0.33, 95% CI -0.41, -0.26; India: -0.18, 95% CI -0.21, -0.15). Notably, in China and India, the negative association between higher education and frequent pain was less pronounced among women compared with men, which was not observed in the United States or England. Further analysis showed that individuals with higher education experiencing frequent pain reported less severity, fewer daily activity interferences, and less medication use compared with those with lower education. In the United States, these associations were stronger among women. Our findings highlight the prevalent pain among middle-aged and older adults in these 4 countries and emphasize the potentially protective role of higher education on frequent pain, with nuanced gender differences across different settings. This underscores the need for tailored strategies considering educational and gender differences to improve pain management and awareness.

Neuropathic Pain after Major Limb Amputation: A Cross-Sectional Study

BACKGROUND

Residual limb pain (RLP) and phantom pain can arise following amputation and may require additional treatment or surgery. This study aimed to determine the prevalence of neuropathic RLP following limb amputation and identify prognostic factors for the development of neuropathic RLP.

METHODS

A cross-sectional study was performed of patients who underwent upper or lower extremity amputation between 1990 and 2021 with a minimum of 12 months' follow-up. The primary outcome was the prevalence of neuropathic RLP, defined as a 0 to 10 numeric rating analog scale pain score in the residual limb of greater than or equal to 4, in combination with a score greater than or equal to 4 on the short-form Douleur Neuropathic 4 questionnaire, validated for discriminating between nociceptive and neuropathic pain. The secondary outcome was quality of life for amputation patients with and without (neuropathic) RLP. A multivariable linear regression model was used to identify prognostic factors for neuropathic RLP development.

RESULTS

A total of 121 patients were included: 87 with lower extremity amputations, 29 with upper extremity amputations, and 5 with both. Neuropathic RLP was experienced by 21.5%, whereas 10.7% reported nonneuropathic RLP. Smoking status and complex regional pain syndrome as indications for limb amputation were associated with more severe neuropathic pain symptoms. Patients experiencing neuropathic RLP reported a significantly lower quality of life compared with patients without neuropathic RLP.

CONCLUSIONS

This study demonstrates that neuropathic RLP is common after limb amputation and impacts daily functioning. The absence of numerous manageable prognostic factors associated with neuropathic pain development emphasizes the importance of the consideration of prophylactic interventions at the time of amputation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Impact of different treatments for chronic pain on cognitive function: A systematic review

Introduction

Experimental evidence supports the hypothesis of reciprocal influence between neural systems involved in cognition and central pain processing circuits. Furthermore, studies have demonstrated bidirectional communication between central pain processing areas and the immune system, leading to changes in behaviour, sensory perception, mood, and cognition. However, the academic community has not yet reached a consensus on whether effective analgesic interventions can mitigate or reverse cognitive deterioration.

Methods

This systematic review evaluated the effectiveness of various therapeutic interventions in improving cognitive functions (primary outcome) and altering the profile of immunological markers (secondary outcome) in chronic pain patients. The review was limited to randomised controlled trials addressing chronic pain of any aetiology, with searches conducted in PubMed, EMBASE, and Scopus databases.

Results

The qualitative synthesis of twelve studies conducted between 2003 and 2021, involving 1432 participants in experimental (n = 950) and control (n = 482) groups, revealed some interesting patterns. Only half of the studies (6/12) reported cognitive improvement, with attention being the most analysed cognitive domain, followed by memory and executive function. Fibromyalgia was the most studied aetiology of chronic pain. The strategies of intervention/treatment and durations varied widely; however, milnacipran versus placebo emerged as the most frequently employed intervention. Only one study reported immunological markers, limiting the evaluation of this outcome.

Conclusion

Based on this analysis, it is not possible to affirm that interventions targeting chronic pain improve cognition. This review suggests new research directions and calls for more robust methodological approaches.

Heals on Wheels: Development and Implementation of Community Outreach and Group Medical Visits for People Experiencing Chronic Pain

Background

Chronic pain is a global problem affecting approximately 20% of adults. The prevalence of opioid use for chronic pain has contributed to a widespread crisis of addiction and inadequately managed pain. Though national and international guidelines recommend nonpharmacological, integrative, multi-modal therapies for chronic pain, numerous systemic barriers limit access to these services for those with the highest need and fewest resources.

Objective

This paper describes the development and testing of an innovative "Heals on Wheels" (HoW) community engagement and Group Medical Visit (GMV) program for underserved communities experiencing chronic pain in Hennepin County, Minnesota.

Methods

The HoW program's curriculum was collaboratively adapted from pre-existing Hennepin Health care GMV programs for chronic pain. Free community-based "Appetizer" workshops were developed alongside an 8-week "Full Meal" GMV program titled Easing Pain Holistically (EPH). Three pain-affinity variations of EPH were created (the "Body", "Head", and "Heart") and delivered to 6 cohorts (2 cohorts of each variation). Feasibility was measured by attendance, demographics, and insurance provider information. To evaluate program acceptability, thematic analysis of patients post-GMV weekly progress sheets was performed.

Results

The curriculum for the HoW program included experiential training and education in evidence-based integrative pain management strategies. Fourteen community appetizer workshops (n = 142) were offered in partnership with organizations representing underserved populations. Fifty-five patients completed EPH from 2022 to 2024 with the greatest number of patients in the Heart (n = 23), followed by the Body (n = 19), and the Head (n = 13). Feasibility for the GMV program was demonstrated with average attendance across 6 cohorts at 75.1%. Thematic analysis of qualitative data revealed themes highlighting appreciation for group connection ("sharing") and the EPH program content.

Conclusion

The HoW program shows promise as a feasible and acceptable model of community outreach and engagement to improve access to evidence-based integrative pain care.

Prevalence and epidemiological characteristics of chronic pain in the Spanish population. Results from the pain barometer

BACKGROUND

Chronic pain (CP) is a public health problem worldwide.

AIM

To update the prevalence of CP and compare the clinical and social characteristics of people with CP with those with non-chronic continuous pain and a group without pain.

METHODS

An observational cross-sectional study was carried out in a representative sample of 7058 adults from the Spanish population. Sociodemographic data, the presence of CP and non-chronic continuous pain, characteristics of pain, limitations on activities of daily living (ADL), the presence and level of anxiety and depression (HADS), quality of life (SF-12v2) and social support (DUKE) were collected. Descriptive and bivariate analyses were performed.

RESULTS

The prevalence of CP was 25.9% (95% CI;24.8-26.9) and that of non-chronic continuous pain was 7.7% (95% CI;7.1-8.3). Women presented a higher prevalence of both CP (30.5% vs. 21.3%) and non-chronic continuous pain (8.8% vs. 6.6%). CP was more common in the group between 55 and 75 years old (30.6%, 95% CI = 28.6-32.6%), non-chronic continuous pain affected most the population between 18 and 34 years old (11.2%, 95% CI = 9.6-12.7%). The median duration of CP was 4 years. The lumbar was the most frequent pain site (58.1%), and 27.1% did not know the cause. A greater frequency of limitations on ADL, more anxiety and depression, and worse quality of life were shown among the subjects with CP.

CONCLUSION

CP affects one in four Spanish people and impairs the mental, physical and social health. Differences exist by sex and age in its frequency. Identifying subjects with non-chronic continuous pain is fundamental to prevent their pain from becoming chronic.

SIGNIFICANCE STATEMENT

Indicating the main aspects where this work adds significantly to existing knowledge in the field, and if appropriate to clinical practice. Due to its high prevalence and impact on quality of life, chronic pain has become one of the main health problems nowadays. Attention must be paid to it both from a clinical and social perspective, trying to raise awareness among the population of its possible causes and consequences. In routine clinical practice, greater consideration is given to groups of people with a higher prevalence of chronic pain, such as women and people with middle age, and with no chronic pain to prevent the appearance of chronic pain.

Connecting the Dots: Gender, Sexuality, and Societal Influences on Cognitive Aging and Alzheimer's Disease

Alzheimer's disease (AD) has many etiologies and the impact of gender on AD changes throughout time. As a consequence of advancements in precision medical procedures and methodology, Alzheimer's disease is now better understood and treated. Several risk factors may be addressed to lower one's chances of developing Alzheimer's disease or associated dementia (ADRD). The presence of amyloid-α protein senile plaques, intracellular tau protein neurofibrillary tangles (NfTs), neurodegeneration, and neuropsychiatric symptoms (NPS) characterizes Alzheimer's disease. NPS is common in persons with Alzheimer's disease dementia, although its presentation varies widely. Gender differences might explain this clinical variability. The fundamental goal of this review is to 1) emphasize the function of old age, sex, and gender in the development of Alzheimer's disease, dementia, and ADRD, and 2) explain the importance of sexual hormones, education, and APOE (Apolipoprotein E) status. This is a narrative summary of new ideas and concepts on the differences in the chance of developing dementia or Alzheimer's disease between men and women. A more thorough examination of risk and protective variables in both men and women might hasten research into the epidemiology of neurological illnesses such as dementia and Alzheimer's disease. Similarly, future preventive efforts should target men and women separately.

How is age at menopause and reproductive lifespan associated with chronic pain outcomes in postmenopausal women?

ABSTRACT

Female sex is a prominent risk factor for chronic pain, although the underlying mechanisms are not fully understood. This cross-sectional study aimed to investigate the relationship between age at menopause, reproductive lifespan, and chronic pain in a sample of postmenopausal women aged 40 to 93 years. Data were collected from the Tromsø study conducted in Norway between 2015 and 2016 (Tromsø7). Chronic pain was assessed using a single question, which formed a sample size of 5741 participants. Chronic widespread pain was evaluated using the more comprehensive Graphical Index of Pain, resulting in a sample size of 5920 women. Premenopausal women and those who experienced menstrual cessation due to chemotherapy/radiation or hormonal intrauterine devices were excluded from the analysis. Adjusted relative risk ratios with 95% confidence intervals were calculated to determine associations. The results showed that early menopause was associated with a 1% increase in the prevalence of chronic pain for each year of earlier onset at menopause (0.992, CI 95% 0.985-0.998). This association was also observed in women who experienced natural menopause only. However, the association between menopause and chronic widespread pain did not reach statistical significance in the fully adjusted analysis (0.996, CI 95% 0.975-1.017). There were no significant associations found between reproductive lifespan and either outcome. In conclusion, the findings suggest that early menopause in postmenopausal women is linked to a higher prevalence of chronic pain. However, reproductive lifespan does not appear to have a significant impact on chronic pain or chronic widespread pain.

The effect of peer group management intervention on chronic pain intensity, number of areas of pain, and pain self-efficacy

OBJECTIVES

Chronic pain causes loss of workability, and pharmacological treatment is often not sufficient, whereas psychosocial treatments may relieve continual pain. This study aimed to investigate the effect of peer group management intervention among patients with chronic pain.

METHODS

The participants were 18-65-year-old employees of the Municipality of Helsinki (women 83%) who visited an occupational health care physician, nurse, psychologist, or physiotherapist for chronic pain lasting at least 3 months. An additional inclusion criterion was an elevated risk of work disability. Our study was a stepped wedge cluster, randomized controlled trial, and group interventions used mindfulness, relaxation, cognitive behavioral therapy, and acceptance and commitment therapy. We randomized sixty participants to either a pain management group intervention or to a waiting list with the same intervention 5 months later. After dropouts, 48 employees participated in 6 weekly group meetings. We followed up participants from groups A, B, and C for 12 months and groups D, E, and F for 6 months. As outcome measures, we used the pain Self-Efficacy Questionnaire, the number of areas of pain, the visual analog scale of pain, and the pain self-efficacy. We adjusted the results before and after the intervention for panel data, clustering effect, and time interval.

RESULTS

The peer group intervention decreased the number of areas of pain by 40%, from 5.96 (1-10) to 3.58 (p < 0.001), and increased the pain self-efficacy by 15%, from 30.4 to 37.5 (p < 0.001). Pain intensity decreased slightly, but not statistically significantly, from 7.1 to 6.8.

CONCLUSIONS

Peer group intervention for 6 weeks among municipal employees with chronic pain is partially effective. The number of areas of pain and pain self-efficacy were more sensitive indicators of change than the pain intensity. Any primary care unit with sufficient resources may implement the intervention.

Belief in living a meaningful life and adjustment to chronic pain

OBJECTIVE

Chronic pain is a global health concern and often interferes with multiple aspects of individuals' lives (eg, physical activities), diminishing a person's ability to engage in activities that promote meaning in life. However, it is not well understood how believing that one can live a meaningful life despite pain could contribute to improved function among individuals with chronic pain. The aim of the present study was to better understand the role that belief in living a meaningful life despite pain might have on adjustment to chronic pain.

METHODS

Participants (n = 164) were individuals with chronic pain who completed baseline data from 2 closely related randomized clinical trials. Hierarchical regression analyses were used to examine the hypotheses that one's belief in living a meaningful life despite pain will be associated with function (pain interference and symptoms of posttraumatic stress disorder, depression, and anxiety) and that the belief in living a meaningful life despite pain would moderate the associations between pain intensity and function.

RESULTS

Belief in living a meaningful life despite pain was significantly associated with less pain interference and less severe symptoms of posttraumatic stress disorder, anxiety, and depression, supporting the potential role of this variable in adaptive adjustment to chronic pain. However, one's belief in living a meaningful life despite pain did not moderate the associations between pain intensity and function.

CONCLUSIONS

Results provide important theoretical and clinical information about how believing that one can live a meaningful life despite pain might serve as an important process for adjustment to chronic pain.

An online pain management program for people with hypermobile Ehlers-Danlos Syndrome or hypermobility spectrum disorder: a three-staged development process

PURPOSE

Hypermobile Ehlers-Danlos Syndrome (hEDS) and hypermobility spectrum disorder (HSD) are painful, chronic and multi-systemic conditions. No online pain management programs for hEDS/HSD currently exist. We aimed to develop one by exploring what people with hEDS/HSD want in such programs.

MATERIALS AND METHODS

A Delphi was conducted via online surveys of stakeholders: participants with hEDS/HSD and healthcare professionals (HCP). In survey 1, participants were asked if a hEDS/HSD-specific online pain management program was important, listing up to 20 topics important to know about pain. In survey 2, participants rated the importance of those topics. Consensus was set as ≥75% rating of at least "important". Using topics that reached consensus, the online program was developed. Usability testing was performed using the Systems Usability Scale (SUS).

RESULTS

396 hEDS/HSD and 29 HCP completed survey 1; 151 hEDS/HSD and 12 HCP completed survey 2. 81% of hEDS/HSD and 69% of HCP rated a hEDS/HSD-specific program as at least "important". Thirty-five topics reached consensus to guide content for the HOPE program (Hypermobile Online Pain managemEnt). SUS score was 82.5, corresponding to "high acceptability".

CONCLUSIONS

A hEDS/HSD-specific online pain management program is important to stakeholders. Utilising a Delphi approach to incorporate stakeholder input, an evidence-informed and user appropriate program was developed.

Emerging Therapeutic Modalities and Pharmacotherapies in Neuropathic Pain Management: A Systematic Review and Meta-Analysis of Parallel Randomized Controlled Trials

Background: Neuropathic pain (NP) is a chronic condition caused by abnormal neuronal excitability in the nervous system. Current treatments for NP are often ineffective or poorly tolerated. Hence, we reviewed the efficacy and safety of novel drugs or devices that target neuronal excitability in NP patients compared with placebo, sham, or usual care interventions. Methods: Six databases were searched for parallel randomized controlled trials (RCTs) reporting novel devices (rTMS, SCS, and TENS) or drugs (EMA401, capsaicin 8% patch, and Sativex) for NP. Data were extracted and quality was assessed using the ROB2 tool. The random-effects inverse variance method was used for analysis. Results: In our review of 30 RCTs with 4251 participants, device-based interventions were found to be more effective in reducing pain scores than control interventions (SMD = -1.27, 95% CI: -1.92 to -0.62). However, high heterogeneity was seen (p < 0.01, I 2 = 91%), attributable to the etiology of NP (R 2 = 58.84%) and year of publication (R 2 = 49.49%). Funding source and type of control comparator were ruled out as cause of heterogeneity. Although drug interventions did not differ from placebo interventions in absolute pain reduction (SMD = -1.21, 95% CI: -3.55 to 1.13), when comparing relative change in pain intensity from baseline, drug interventions were found to be effective (SMD = 0.29, 95% CI: 0.04-0.55). Asymmetry in the funnel plot was visualized, suggesting publication bias. Certainty of evidence was very low according to GRADE assessment. Conclusions: Our review indicates that device-based interventions are more effective than control interventions in reducing pain intensity in NP. Nevertheless, available evidence is limited due to heterogeneity and publication bias, prompting the need for more high-quality RCTs to confirm the efficacy and safety of these interventions.

Development of a Novel Co-Amorphous Curcumin and L-Arginine (1:2): Structural Characterization, Biological Activity and Pharmacokinetics

Background: Curcumin appears to be well tolerated and effective for managing chronic inflammatory pain, but its poor oral bioavailability has been a hurdle in its use as a therapeutic agent. The current study was performed to characterize a novel co-amorphous compound based on curcumin/L-arginine 1:2 (CAC12). Methods: Stability, solubility and structural characterization of the CAC12 were carried out by spectrometry techniques and in vitro assays, whereas the antinociceptive and anti-inflammatory effects were evaluated by CFA or carrageenan models. The mechanism of action was determined by cytokine quantification, and pharmacokinetic parameters were obtained through UPLC-MS/MS. The co-amorphous compound was prepared by fast solvent evaporation. Powder XRD, 13C-NMR, ATR-FTIR and TGA/DSC thermal analysis showed a 1:2 stoichiometry for the CAC12. Results: CAC12 was 1000 times more soluble than curcumin, and it was stable for 1 month at 40 °C and 75% relative humidity or for 60 min in physiological medium at pH 4.5-6.8. Co-amorphous curcumin/L-arginine, but not curcumin + L-arginine, decreased carrageenan- or CFA-induced inflammation and nociception by decreasing IL-1α, IL-1β, IL-6, TNF-α, MCP-1 and CXCL1 cytokines. The bioavailability of free plasmatic curcumin increased about 22.4 times when it was given as CAC12 relative to a phytosome formulation at the equivalent dose. Conclusions: Results suggest the possible use of CAC12 to treat inflammatory pain disorders in human beings.

Phenome-wide diagnostic comparison among suicide deaths and living individuals with chronic pain diagnoses

BACKGROUND

Chronic pain, regardless of its type, is a significant risk factor for suicide. However, not all individuals with chronic pain also experience suicidal thoughts and behaviors. Better characterization of clinical risk profiles and comorbidities across the medical spectrum among people with chronic pain who die by suicide is urgently needed to aid treatment and prevention strategies.

METHODS

This case-control study leverages population-based data from the Utah Suicide Mortality Risk Study. Specifically, we identify clinical phenotypes from diagnostic data that differentiate between individuals that died by suicide with chronic pain diagnoses (N = 1,410) and living control individuals who also had chronic pain diagnoses (N = 4,664). Medical diagnostic codes were aggregated via phecodes to perform a phenotype-based phenome-wide association study. Using multivariable logistic regression analysis adjusting for covariates and multiple testing, differences in 1,727 common clinical phenotypes (phecodes) were assessed between suicide deaths and controls with chronic pain diagnoses. Models were also stratified by sex.

RESULTS

Chronic pain diagnoses were nearly three times more prevalent in individuals who died by suicide compared with those who did not. Sixty-five phecodes were significantly overrepresented among suicide deaths with chronic pain diagnoses compared with controls with chronic pain diagnoses. Utah suicide deaths with chronic pain had significantly more psychiatric diagnoses (mood disorders, anxiety disorders, attention deficit hyperactivity disorder, posttraumatic stress disorder, personality disorders, schizophrenia/psychosis, substance use related traits and prior overdoses, and diagnoses related to previous suicidal thoughts and behaviors) in addition to insomnia and specific pain related diagnoses compared to Utah controls with chronic pain (odds ratios ranged from 1.40-7.10). Twenty-five phecodes were overrepresented in controls with chronic pain compared to suicides. These were related to preventative care, cancer, obesity and other conditions (odds ratios ranged from 0.16-0.73). Sex-specific analyses largely replicated the combined analyses, yet the strength of the association was stronger for women with phecodes related to prior self-harm.

CONCLUSIONS

Results identified multiple clinical comorbidities with chronic pain that differentiate suicide deaths from living control individuals with a history of diagnosed chronic pain. Our findings may help discern individuals with chronic pain who may be at greater risk for suicide death.

Prevalence and Associated Factors of Postoperative Acute Pain for Mothers Who Gave Birth With Cesarean Section: A Systematic Review and Meta-Analysis

BACKGROUND

Cesarean section frequently is associated with different undesirable postoperative outcomes. Acute postoperative pain is one of the most frequently experienced adverse outcomes that occurs as the result of actual tissue damage. Previous studies have shown inconsistent results regarding the prevalence and predictors of acute postoperative pain. Therefore, this study aimed to assess the pooled prevalence and associated factors of postoperative pain after cesarean section.

METHODS

This is a systematic review and meta-analysis study that was performed on the basis of studies published within the last 10 years on the prevalence and associated factors of postoperative pain after cesarean section. After PubMed, Google Scholar, HINAR, Scopus, Web of Sciences, Cochrane, EMBASE, and gray literature extensive search for primary studies, their quality was assessed and data was extracted. STATAMP, version 17.0, was used for all possible analyses of the study.

RESULTS

Twenty-eight studies were included in this systematic review and meta-analysis. The pooled prevalence of postoperative pain was 58% (95% confidence interval [CI] 48%, 67%) with heterogeneity (I2 99.33%). Incision length >10 centimeters (odds ratio [OR] 2.34 [95% CI 1.71, 2.97]); spinal anesthesia without adjuvant (OR 3.45 [95% CI 1.56, 5.33]); general type of anesthesia (OR 3.54 [95% CI 2.61, 4.48]); presence of preoperative anxiety (OR-1.73, 95% CI 1.12-2.35); and no peripheral nerve block (OR 3.23 [95% CI, 2.27-4.18]) were associated with the prevalence of postoperative pain significantly.

CONCLUSIONS

The pooled prevalence of acute postoperative pain after cesarean section was high (58%), which needs more strategies for pain management. Incision length >10 centimeters, spinal anesthesia without adjuvants, general type of anesthesia, preoperative anxiety, and no peripheral nerve block were significantly associated with this prevalence.

It's not all that bad: associations among pain characteristics and sexual well-being in people living with chronic pain

BACKGROUND

Individuals experiencing chronic pain often report adverse effects on their sexual functioning. However, other important aspects of sexual well-being (SWB), such as sexual distress and sexual self-esteem, have received little attention. This is an important omission because a SWB involves more than just good sexual function. Similarly, past research has not examined how chronic pain characteristics affect the different aspects of SWB.

AIM

The goal of this cross-sectional study was to examine the SWB of individuals living with chronic pain and to examine the extent to which SWB is associated with different chronic pain characteristics.

METHODS

A total of 310 individuals (28.1% men, 70.6% women, 1.3% transgender men) with ages between 21 and 50 (M = 31.96, SD = 6.13) who were in a romantic relationship and with self-reported chronic pain for three months or longer completed an online survey.

OUTCOMES

The following indicators of SWB were included in the study: frequency of genital sexual activity, sexual satisfaction, sexual self-esteem, sexual desire, sexual function, genital pain, and sexual distress.

RESULTS

The results show that most individuals with chronic pain maintain an active and satisfying sexual life and feel positive about themselves as a sexual partner. Slightly more than a fourth reported experiencing at least one sexual functioning difficulty and almost three-fourths of them found those difficulties sexually distressing. A first canonical correlation showed that more negative pain characteristics were associated with poorer SWB. The second canonical correlation showed that greater perceived partner support can offset the negative relationship between pain and some aspects of SWB.

CLINICAL IMPLICATIONS

These findings show that individuals living with chronic pain can experience positive SWB. Furthermore, the buffering effect of partner support suggests it is important to involve romantic partners in interventions aimed at improving the SWB of people living with chronic pain.

STRENGTHS AND LIMITATIONS

The study examined a large number of indicators of SWB using a sample of individuals with different types of chronic pain. Limitations include potential self-selection bias and a sample that was predominantly white and highly educated.

CONCLUSIONS

The results paint a more positive picture of the SWB of individuals living with pain and show that individuals living with chronic pain can experience positive SWB. These findings can help for researchers, educators, and clinicians about how to conceptualize, understand, and improve the SWB of individuals living with chronic pain.

The Effect of Experimentally Induced Pain in the Cervical, Shoulder, or Orofacial Regions on Cervical Neuromuscular and Kinematic Features: A Systematic Review and Meta-analysis

In this systematic review, we synthesize the literature investigating the effect of experimentally induced pain in the cervical, shoulder, or orofacial regions on cervical neuromuscular and kinematic features. Databases were searched up to November 1, 2023. A total of 29 studies using hypertonic saline injection (n = 27) or glutamate injection (n = 2) as experimental pain models were included. Meta-analyses revealed reduced upper trapezius activation during shoulder flexion/abduction when pain was induced in the upper trapezius (standardized mean difference: -.90, 95% confidence interval: [-1.29; -.51]), splenius capitis (-1.03 [-1.44; -.63]), and supraspinatus (-.63 [-1.25; -.01]), but not in the subacromial space (.22 [-.16; .60]). Furthermore, experimentally induced pain caused a caudal redistribution of activation within the upper trapezius (.96 [.58; 1.34]) but did not change the mediolateral distribution (.11 [-.22; .42]). None of these adaptations persisted after pain resolution. Low-quality evidence supported the absence of an effect of experimental pain on upper trapezius muscle activation during manual dexterity and cervical flexion/extension tasks, as well as on cervical flexor and extensor muscle activation during cervical and jaw tasks. Inconsistent and limited evidence, attributed to the large heterogeneity of task and outcomes, precluded drawing meaningful conclusions about the effects of experimentally induced pain in the cervical region on cervical kinematics. Overall, cervical muscle activation tended to decrease in response to experimentally induced pain, and the decrease of muscle activation depended on the location of the painful stimulus. These adaptations are only partially representative of muscle activation patterns observed in clinical populations. PERSPECTIVE: This systematic review and meta-analysis revealed a reduced or unchanged muscle activation during experimental pain in the cervical, shoulder, or orofacial regions, depending on the task and location of nociceptive stimulation. There was inconsistent evidence on cervical kinematics. These findings enhance our understanding of neuromuscular adaptations to acute experimental pain.

Barriers and facilitators for physical activity in people living with chronic pain: a systematic review and combined analysis

ABSTRACT

Chronic pain is a prevalent and complex health issue associated with physical, emotional, and social consequences. Management of pain is multifactorial and challenging; however, physical activity (PA) has consistently been shown to be beneficial. Despite this, PA levels among people with chronic pain are low. This study aimed to identify facilitators and barriers to PA among adults with chronic pain and analyse these using the structure of a validated behaviour change model: the capability, opportunity, and motivation behaviour change model (COM-B). We performed a systematic review of 6 databases and subsequent combined analysis including peer-reviewed primary research published in English up to November 15, 2023. Search terms consisted of 3 components: pain, PA, and facilitators/barriers. Quality appraisal of studies was conducted using appropriate tools. The systematic search yielded 40 eligible studies with a total of 2164 participants. The studies represented various chronic pain conditions, locations, and study designs. The key barriers to engagement in PA were the impact of pain severity, comorbidities, lack of knowledge about PA benefits, and time constraints. Key facilitators were a personalised approach, social support, and awareness of the benefits. The findings were categorised according to the COM-B model, allowing for the identification of modifiable factors. Person-centred approaches, education, and accessible environments were identified as important aspects to consider for successful PA promotion among people with chronic pain. Utilising the factors identified in the COM-B model is crucial for successful future interventions to increasing PA uptake and adherence in this population.

The Effect of Insomnia on the Outcomes of Physical Therapy in Patients with Cervical and Lumbar Pain in Clinical Practice

Background and Objectives: The objective of the study is to determine whether there is a difference in physical therapy outcomes in patients with cervical and/or lumbar pain who have insomnia compared to patients without insomnia during a two-week period of active treatment under the conditions of routine clinical practice. Materials and Methods: The study population consisted of two groups of subjects with chronic back pain, a group with insomnia ("case") with a total of 38 subjects and a control group without insomnia ("control") with a total of 41 subjects, who filled out a set of measurement questionnaires: the McGill Pain Questionnaire and its short form (SF-MPQ), the Insomnia Severity Index (ISI) and the European Quality of Life Questionnaire of Life (Euro Qol; EQ-5D). Determination of the biomarkers of structural damage to the nervous tissue, neurofilament polypeptide (NEF-neurofilament polypeptide), neuron-specific enolase (NSE-neuron-specific enolase) and protein S100B was performed by measuring their concentrations in the blood using the ELISA method (enzyme immunosorbent assay). Statistical analysis of the collected data included a descriptive analysis, hypothesis testing methods and univariable and multivariable regression models. Results: At the end of the treatment visits, the level of pain remained higher in some subjects of the experimental group, but the statistical significance of the baseline difference disappeared because of the higher relative treatment response in the controls. Measured with a visual analogue scale, the treatment improved the patients' quality of life much more in experimental than control subjects, as is proven by the statistically significant difference for the percent change from baseline (~31% vs. ~14%). At baseline, all three neurotropic biomarkers had significantly higher serum values in the subjects of the experimental group than in the control patients, which suggested more damage to the neuronal structures. During the treatment course, their serum concentrations decreased, from 36% to 95%, but for S100B, unlike NES and NEF, there was no statistically significant difference between the study groups at the end of the treatment visits. Conclusions: The results of the study have immediate scientific and practical significance because they contribute to new knowledge about the place and role of insomnia in patients with cervical and/or lumbar pain who are treated with physical medicine methods in the conditions of routine clinical practice. The treatment of insomnia should be an indispensable part of therapeutic treatment for patients with back pain.

Spinal Cord Stimulation vs Medical Management for Chronic Back and Leg Pain: A Systematic Review and Network Meta-Analysis

Importance

Chronic back and lower extremity pain is one of the leading causes of disability worldwide. Spinal cord stimulation (SCS) aims to improve symptoms and quality of life.

Objective

To evaluate the efficacy of SCS therapies compared with conventional medical management (CMM).

Data Sources

MEDLINE, Embase, and Cochrane Library were systematically searched from inception to September 2, 2022.

Study Selection

Selected studies were randomized clinical trials comparing SCS therapies with sham (placebo) and/or CMM or standard treatments for adults with chronic back or leg pain who had not previously used SCS.

Data Extraction and Synthesis

Evidence synthesis estimated odds ratios (ORs) and mean differences (MDs) and their associated credible intervals (CrI) through bayesian network meta-analysis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline for network meta-analyses was followed.

Main Outcomes and Measures

The primary outcomes were pain-related end points, including pain intensity (measured by visual analog scale) and proportion of patients achieving at least 50% pain relief (responder rate) in the back or leg. Quality of life (measured by EQ-5D index score) and functional disability (measured by the Oswestry Disability Index score) were also considered.

Results

A total of 13 studies of 1561 patients were included in the network meta-analysis comparing conventional and novel SCS therapies with CMM across the 6 outcomes of interest at the 6-month follow-up. Both conventional and novel SCS therapies were associated with superior efficacy compared with CMM in responder rates in back (conventional SCS: OR, 3.00; 95% CrI, 1.49 to 6.72; novel SCS: OR, 8.76; 95% CrI, 3.84 to 22.31), pain intensity in back (conventional SCS: MD, -1.17; 95% CrI, -1.64 to -0.70; novel SCS: MD, -2.34; 95% CrI, -2.96 to -1.73), pain intensity in leg (conventional SCS: MD, -2.89; 95% CrI, -4.03 to -1.81; novel SCS: MD, -4.01; 95% CrI, -5.31 to -2.75), and EQ-5D index score (conventional SCS: MD, 0.15; 95% CrI, 0.09 to 0.21; novel SCS: MD, 0.17; 95% CrI, 0.13 to 0.21). For functional disability, conventional SCS was superior to CMM (MD, -7.10; 95% CrI, -10.91 to -3.36). No statistically significant differences were observed for other comparisons.

Conclusions and Relevance

This systematic review and network meta-analysis found that SCS therapies for treatment of chronic pain in back and/or lower extremities were associated with greater improvements in pain compared with CMM. These findings highlight the potential of SCS therapies as an effective and valuable option in chronic pain management.

The role of the neuronal microenvironment in sensory function and pain pathophysiology

The high prevalence of pain and the at times low efficacy of current treatments represent a significant challenge to healthcare systems worldwide. Effective treatment strategies require consideration of the diverse pathophysiologies that underlie various pain conditions. Indeed, our understanding of the mechanisms contributing to aberrant sensory neuron function has advanced considerably. However, sensory neurons operate in a complex dynamic microenvironment that is controlled by multidirectional interactions of neurons with non-neuronal cells, including immune cells, neuronal accessory cells, fibroblasts, adipocytes, and keratinocytes. Each of these cells constitute and control the microenvironment in which neurons operate, inevitably influencing sensory function and the pathology of pain. This review highlights the importance of the neuronal microenvironment for sensory function and pain, focusing on cellular interactions in the skin, nerves, dorsal root ganglia, and spinal cord. We discuss the current understanding of the mechanisms by which neurons and non-neuronal cells communicate to promote or resolve pain, and how this knowledge could be used for the development of mechanism-based treatments.

Temporomandibular disorder pain is associated with increased sick leave and reduced health related quality of life

BACKGROUND

Temporomandibular disorders (TMD) are the most common reason for chronic pain in the orofacial area and significantly impact the lives of those affected. The role of lifestyle factors in TMD, however, remains less explored. This cohort study aims to estimate TMD prevalence by addressing potential selection biases and to evaluate the association between TMD and lifestyle factors with a specific focus on sick leave and health related quality of life.

METHODS

By linking data on TMD in the general population in Västerbotten, northern Sweden (n = 180,000) to health survey data (n = 120,000), information on sociodemographic factors and quality of life was available for 52,961 individuals (50.6% women) with a mean age of 53 years. We applied inverse probability weighting to adjust for selection bias and Poisson regression to explore associations with TMD.

RESULTS

TMD prevalence was 9.2% during the study period, being higher in women (12.9%) than men (5.4%). Weighting for varying visiting frequencies did not affect TMD prevalence (average difference 0.4% points). Individuals with TMD, especially women, reported more sick leave and use of pain medication, with a significant association between TMD and increased sick leave (prevalence ratio 1.89, 95% CI: 1.78-2.01) among both women and men. In addition, TMD was associated with a lower health related quality of life (p < 0.001).

CONCLUSION

The association of TMD with sick leave highlights the condition's profound impact on the lives of affected individuals. These findings underscore the influence of TMD on work life and the burden of TMD on the societal level.

SIGNIFICANCE STATEMENT

The findings provide insight into how TMD affect individuals, by incorporating lifestyle factors, social determinants and the impact of sick leave at a population level. By incorporating these areas into the study of TMD, we can deepen our understanding of how TMD affects individuals' lives. This approach may also create opportunities to develop more comprehensive strategies to address TMD, focusing on broader implications beyond the clinical symptoms.