Volume 25, Issue 1

Objectives The ICEPAIN study is a longitudinal research project focused on building an extensive database on health-related quality of life (HRQoL), lifestyle, and pain among the general population in Iceland. The project started with a cross-sectional data collection and will be followed by similar data collection after 5 and 10 years from participants who have agreed to be contacted again. In this article, descriptive data on the prevalence and nature of chronic pain in the Icelandic general population will be presented in relation to sociodemographic factors, lifestyle, adverse life experiences, and HRQoL. Methods Data were collected through a web-based platform using a national panel representing a randomised population sample of 12,400 individuals aged 18–80 years from the National Population Register of Iceland. The instruments consisted of questionnaires on pain, lifestyle factors, adverse life experiences, and HRQoL. The sample was stratified according to age, gender, and residence. Results The response rate was 45% ( N = 5,557), and most participants (81%) agreed to be contacted again for later data collection. The mean age of the respondents was 54.8 years (SD = 13.7). Half of the participants (50.3%) had experienced some pain the previous week, and 40% had chronic pain (≥3 months). The prevalence of chronic pain was inversely related to educational level and satisfaction with household income and positively associated with body mass index. A significant correlation was found between chronic pain prevalence and several lifestyle variables, such as physical exercises, smoking habits, sleep, and adverse life experiences. Chronic pain had a significant negative impact on both physical and mental components of HRQoL. Conclusion These results indicate a complex relationship between chronic pain, lifestyle, and adverse life experiences. The longitudinal design will provide further information on the long-term development among these variables.

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.

Objectives This study examined the relationship between symbolic function, coping, pain, and long-term outcomes in patients with chronic cervical pain. Methods The study population consisted of 104 subjects who could be candidates for cervical spinal surgery at the Department of Neurosurgery. We followed patients for 2 and 6 years, focusing on pain experience, vocational outcome, and sick leave. Results The SAT9 test revealed that 28% of the patients had poor symbolic function. The group classified as having poor symbolic function reported using more coping strategies and coping resources but had more of an external locus of control. They showed less objective neurophysiological findings but rated more pain on the VAS scale. The group with poor symbolic function had more sick leave days 2 years after consultation, and the vocational outcome was very poor for persons with impaired symbolic function at the 6-year follow-up. At the 6-year follow-up, patients with poor symbolic function still experienced higher pain levels and had more of an external locus of control. Conclusions The SAT9 results indicate that pain could also serve as an expression of distress or discomfort, and the expression of pain can be a way for individuals to communicate their need for rest, recovery, or relief from stressors. In this context, taking sick leave becomes a symbolic action addressing broader well-being concerns. Understanding the symbolic function of stress and pain concerns can be valuable for health professionals and individuals themselves. Open communication, recognizing, and reorganizing the symbolic nature of pain can contribute to a more compassionate understanding of stress-related challenges and pain.

Objectives Patients with chronic pain need healthcare services for pain management. Many also require social security services due to potential negative influence of chronic pain on social and work-related issues. The aim of this study was therefore to investigate the experiences of taking part in cross-sectoral collaborative meetings between social security service and healthcare service for chronic pain patients. Methods A qualitative study using semi-structured individual interviews with 15 informants, including healthcare providers, patients, and social security supervisors who had taken part in 8 different meetings, was conducted. The focus of the interviews was how the informants experienced cross-sectoral collaborative meetings. The data were analyzed following the systematic text condensation method, including the steps of total impression, identifying meaning units, condensation, and synthesizing. Results The findings were categorized into four themes: “Joining the meeting with preconceptions,” which showed how some informants experienced that negative preconceptions toward the social security service were addressed in the cross-sectoral collaborative meetings and solved in some cases. “Get to know each other,” which highlighted that the meetings provided opportunities for participants to increase their knowledge about the involved actors. “Access to detailed health information?” indicated that although concerns about whether sensitive health information should be shared with social security supervisors were raised by healthcare providers, the supervisors found this issue to be less concerning. Finally, “Who has the final word?”, which showed that unclarity over decision-making processes during the meetings was experienced to create disagreement between participants. Conclusions The informants experienced that cross-sectoral collaborative meetings between patients, social security supervisors, and healthcare providers, while challenging, can play a significant role in managing the needs of patients with chronic pain. The study highlights the need for clarification over the roles of the actors and a jointly agreed-upon agenda for the meetings to ensure effective collaboration.

Objectives This study aimed to explore barriers experienced by patients with chronic pain to completing the PainData questionnaire (PDq) at the Interdisciplinary Pain Centre, Herlev and Gentofte Hospital (HGH). The PDq collects patient-reported data relevant for treatment decisions and research. However, at HGH the response rate prior to treatment initiation is only 67% despite a national response rate of over 80%. Methods This qualitative study used individual, semi-structured interviews with patients from HGH. Content analysis was performed, and the study adhered to the COREQ guideline. Results Fifteen participants (4 men, 11 women; median age 57) were interviewed. Four major categories were identified: (1) challenges originating from pain deterioration and stress hindering questionnaire completion, (2) lack of opportunity for nuanced responses, (3) inadequate patient understanding of the questionnaire’s purpose, and (4) appreciation among participants of PainData’s recognition of the long-term consequences of chronic pain. Conclusion This study highlighted key barriers to completing the PDq, including challenges related to its design and patients’ resources. To address these issues, administrators could simplify the questionnaire. Individual clinics could enhance response rates by improving communication about the importance of patient-reported data, refining invitation strategies, and providing additional practical support. Despite these challenges, completion of the PDq encouraged participants to reflect on critical aspects of chronic pain, including its physical and mental health impacts. While the study provided valuable insights, the limited duration of interviews, due to participant fragility, was a notable limitation.

Objectives To compare pain trajectories and acute exercise-induced pain over a 16-week period in patients with hypermobility spectrum disorder (HSD) undergoing high-load (HEAVY) or low-load (LIGHT) shoulder exercise. Methods In this secondary analysis using data from a randomized controlled trial, we included men and women aged 18–65 with HSD and shoulder complaints >3 months. Participants were randomly allocated (1:1 ratio) to 16 weeks of HEAVY or LIGHT shoulder exercise program, performed three times weekly. The HEAVY program consisted of progressive strengthening and full range of motion exercises, while the LIGHT program included low-load exercises performed in neutral to mid-range. Pain was assessed using the numeric rating scale (NRS) before and after each exercise session. Pain trajectories were assessed using pre-exercise pain scores at the final session each week. Exercise-induced pain was evaluated as the change in pain before and after exercise, using the mean of the three sessions each week. Both outcomes were analyzed using linear mixed models. Results Data from 64 out of 100 patients (HEAVY 34, LIGHT 30) were analyzed (80% women, mean age 39.6, mean Beighton score of 5.8). Shoulder pain was reduced by 0.89 NRS in HEAVY (95% CI 0.4 to 1.4) and 0.33 NRS (95% CI −0.25 to 0.91) in LIGHT. The between-group difference in change in pain from baseline to week 16 was 0.56 (95% CI −0.20 to 1.33, p = 0.149). There was no between-group difference in pain trajectories (group × time interaction, p = 0.321). The mean exercise-induced pain over time was similar in both groups (group × time interaction, p = 0.614), with pain below 0.5 NRS throughout the 16 weeks. Conclusions Pain trajectories over 16 weeks were similar in patients with HSD and persistent shoulder complaints performing high-load or low-load shoulder exercises. There was minor to no exercise-induced pain during high-load strengthening exercise, challenging previous beliefs.

Objectives Hypermobile Ehlers–Danlos syndrome (hEDS) is a multisystemic disorder in which pain and psychological symptoms appear to be highly interrelated. We investigate the relationships between pain intensity, pain location, and psychological distress in patients with hEDS. Methods The study sample in this cross-sectional study comprised patients with diagnosed hEDS ( n = 81) aged 18–67 years, with a mean age of 39.5. Sociodemographic information was collected using a questionnaire. Pain intensity was measured using the numeric rating scale, depressive symptoms with the Beck Depression Inventory, and pain-related anxiety with the Pain Anxiety Symptoms Scale. The interrelations between pain intensity and psychological factors were analysed for each of the following anatomical regions: head, neck, upper extremities, chest, back, abdomen, and lower extremities. Results The results show that pain was intense and occurring in multiple anatomical regions. Pain intensity was related to depressive symptoms and pain anxiety, with the strength of the relationship varying across different anatomical regions. Specific findings were that strongest associations of depressive symptoms and pain intensity were in the abdomen and lower extremities. In contrast, pain in the upper extremities did not relate to depressive symptoms or pain anxiety. Conclusion This is the first study on patients with hEDS that elucidates the multisite pain symptoms and their interrelation to psychological symptoms. The total burden of pain can be considered a strong contributing element to the results found in our study. These factors should be considered when treating patients with hEDS.

Objectives Acute Pain Services (APS) have significantly evolved since their establishment in the 1990s, emphasizing multimodal analgesia, which is a pivotal component of enhanced recovery after surgery, to enhance postoperative recovery. Despite improvements, variability in pain trajectories among patients necessitated the development of transitional pain units to address individual needs and ensure safe opioid tapering. The Norwegian National Registry for Advanced Acute Pain Services (AAPS), known as SmerteReg, was established to further enhance understanding of pain treatment in these patients. In this study, we aimed to analyze opioid use patterns and characteristics of opioid users referred to AAPS compared to non-opioid users. Methods Data from SmerteReg (2016–2020) were analyzed, including patient demographics, diagnoses, pain treatment, and patient-reported outcome measures. Patient characteristics at admittance were compared between opioid users and non-opioid users. Multivariate logistic regression was used to explore factors associated with opioid use. Results Of 1,068 patient tracks, 64% were opioid users at admittance. Opioid users were older and more frequently female, reporting higher levels of anxiety, depression, catastrophizing, and sleep problems before admission. Sleep problems before admittance was reported three times more frequent by patients using opioids compared to patients not using an opioid at admittance. Conclusion Pre-admittance opioid use was prevalent among patients referred to AAPS, emphasizing the need for tailored pain management strategies. Women, older patients, and those reporting sleep problems before admittance were more likely to use opioids. The finding that sleep problems before admittance were strongly associated with opioid use, suggests the importance of addressing sleep disturbances in pain management protocols. This study contributes to understanding opioid use patterns and factors influencing pain management in hospitalized patients.

Background The transient receptor potential cation channel subfamily V1 (TRPV1) receptor is an important factor in pain transmission. The present Phase 2a study investigated the effect on evoked pain and safety of a topically administered TRPV1-antagonist (ACD440 Gel) in patients with chronic peripheral neuropathic pain (PNP). Methods This was an exploratory, randomized, placebo-controlled double-blind crossover study in patients with probable or definite PNP demonstrating sensory hypersensitivity, assessed as evoked pain on suprathreshold sensory stimulation, i.e. hyperalgesia. The aetiologies included a mix of postherpetic neuralgia, postoperative neuropathic pains, and chemotherapy-induced pain. Patients administered ACD440 Gel twice daily onto the painful area(s) for 7 days. Primary endpoint was hyperalgesia to brush, cold, heat, and pinprick. Secondary endpoints included spontaneous pain and Neuropathic Pain Symptom Inventory Questionnaire (NPSI). Due to a significant period effect, a post hoc analysis was conducted, including only period 1 data, i.e. a parallel group comparison. Results Fourteen patients were enrolled and completed the study. ACD440 Gel reduced pain intensity evoked by a 40°C thermoroller stimulus in heat hyperalgesic patients, by ACD440 from median 6 (IQR 4.75, 7.75) to 1.5 (IQR 0.75, 2.25), i.e. by −5.0 (95%CI −11.2, 1.2) vs placebo from median 4 (IQR 3.5, 5.0) to median 5.0 (IQR 4.5, 6.5), i.e. by 1.3 (95%CI −1.5, 4.2), p = 0.029. There were no adverse events induced by study treatment. Evoked mechanical hyperalgesia and brush allodynia were not significantly affected, p = 0.07. Conclusion ACD440 Gel demonstrated a significant analgesic effect on thermally evoked pain, especially in suprathreshold heat pain. This is congruent with an attenuation of thermal hyperalgesia in chronic neuropathic pain patients with C-fibre mediated pain, while there was no effect on evoked pain related to Aβ and Aδ stimuli. The results support further clinical development in patients with thermally induced C-fibre mediated pain.

Objectives The purpose of the study was to assess the prevalence of both non-chronic and chronic pain among women of childbearing age and describe the impact that pain has on their health-related quality of life (HRQoL). Methods This is a cross-sectional cohort study, and the data were collected as part of the ICEPAIN nationwide study. Participants were recruited from a randomised sample, stratified by age and residence to secure a proportional sample, by email invitation. Women between 18 and 45 years of age participated, and data were collected through a web-based platform with questionnaires that measured sociodemographic characteristics, lifestyle factors, sleep quality, pain severity, characteristics of pain, pain interference (Brief Pain Inventory), and HRQoL (SF-12-v2). Spearman correlation was used when assessing relationships between demographic and lifestyle factors, and HRQoL and pain. Chi-square, Mann–Whitney U , ANOVA, and multivariate general linear model were used to assess group differences. Results In total, 969 women of childbearing age (18–45 years) participated in the study, and the response rate was 34.8%. The average age was 36.1 ± 6.3 years, and the majority (82.5%) were married, cohabiting, or in a steady relationship. Altogether, 45.9% of the sample reported having pain during the past week ( n = 445); the vast majority, 80.4% ( n = 366), had chronic pain. The majority of the participants, 57.3%, had moderate or severe pain. Chronic pain was significantly correlated with higher age, higher BMI, experiencing pain during the period, and poorer sleep quality. In contrast, no significant correlation was found between chronic pain and parity, residence, education, physical exercise, smoking, or alcohol drinking. Both non-chronic and chronic pain interfered with mood, sleep, general activities, and other aspects of daily life, and the effect of pain was significantly greater among women with chronic pain. Among these, pain severity was strongly correlated with the level of pain interference (0.79). A negative correlation between pain interference and HRQoL (physical component score, −0.64, and mental component score, −0.34) was observed among women with chronic pain. Conclusions Both non-chronic and chronic pain are common among women of childbearing age in Iceland. It interferes with daily life and affects their HRQoL.

Objectives Chronic pain represents a major public health challenge, substantially affecting daily functioning and overall well-being. While self-management strategies can be effective, they are often introduced only after pharmacological or surgical treatments have proven insufficient, highlighting the need for more personalized, accessible, and early interventions in primary care. However, the feasibility and practical implementation of such approaches remain insufficiently explored. Considering these challenges, the aims of this study were to co-create and to evaluate the feasibility of a personalized, multidisciplinary, and coordinated intervention for chronic pain management within municipal healthcare services. Methods The intervention included a generic pain management course (part one) and a personalized second part offering various group-based courses. Participants ( n = 70) were recruited through an orthopedic outpatient clinic and general practitioners. Individual consultations with course leaders were conducted before, during, and after the intervention. Questionnaires assessing health-related quality of life, alcohol consumption, medication use, and sleep were administered at baseline, midway, and post-intervention, along with a self-reported evaluation of the intervention after completion. Results Among the total participants ( n = 70), 81% completed Part 1 of the intervention, while 61% completed the entire intervention. At baseline, participants had a mean EQ-5D-5L score of 0.65 and an EQ-VAS score of 48.8. Regarding alcohol use, 47% were drinking once a month or less, and no participants were drinking alcohol four or more times a week. Insomnia was reported by 84%. Paracetamol was the most used daily medication (41%), followed by non-steroidal anti-inflammatory drugs and weak opioids (26% each). In Part 2 of the intervention, stress management courses were the most frequently selected (26%), followed closely by physical activity and body-mind activity at 23%. Most participants reported benefit, with 63% (Part 1) and 56% (Part 2) indicating good or very good benefit, and 98% would recommend it to others. Conclusion This feasibility study demonstrates the potential for addressing the complex needs of individuals with chronic pain through a personalized and multidisciplinary intervention in primary care. The high completion rates indicate feasibility and acceptability. The findings support further evaluation of resource use, implementation, and effectiveness in future controlled trials.

Objectives Most patients with chronic pain are identified and managed in primary care (PC). Chronic pain management is challenging, which is manifested by increased healthcare utilization (HCU) in this patient group. The interdisciplinary pain rehabilitation program (IPRP) is the gold standard treatment for patients with chronic pain but is scarcely used in PC. The aim of this study was to evaluate the HCU of patients with chronic pain in PC 1 year before and 1 year after an IPRP by examining the distribution of costs and resources. Methods This retrospective cohort study combined data from a national pain registry and HCU data from regional administrative registries, including 146 patients who participated in an IPRP in PC. The outcome measure was the number of outpatient healthcare contacts. Costs and the distribution of resources were compared across the two measurement intervals using paired t -tests. HCU costs were described from a healthcare provider perspective. Results HCU decreased by 16% in the year following IPRP compared to the year before. Costs for outpatient visits dropped by 12% or €434 per participant. Visits to physiotherapists and general practitioners decreased the most, by 31% ( p = 0.048) and 23% ( p < 0.001) respectively. Visits to nurses, occupational therapists, and psychologists/social workers in turn increased marginally (6%, 5% vs 10%). Conclusions IPRP in PC may lead to reduced HCU, freed resources, and streamlined chronic pain management. The study offers valuable insights into expected changes in HCU for chronic pain patients after an IPRP and how these changes may impact daily activities at the PC center.

Objectives This study aimed to evaluate the validity and reliability of the two subscales of a Swedish version of the Brief Pain Coping Inventory-2 (BPCI-2:SWE) in a population of patients seeking primary care physiotherapy for musculoskeletal pain (MSKP). The BPCI-2 is a patient-reported outcome measure (PROM) originally developed to measure traditional pain management strategies (TPMS) and psychological flexibility (PF) in populations with chronic pain. Methods This study followed guidance from the “COnsensus based Standards for the selection of health Measurement INstruments-group” and the stages described by Beaton. The BPCI-2 was translated and cross-culturally adapted from English to Swedish. The BPCI-2:SWE’s content validity was evaluated using the face-validity index and qualitative content analysis of semi-structured interviews in a cohort of 13 patients seeking primary care physiotherapy for MSKP. The BPCI-2:SWE’s construct validity, floor and ceiling effects, reliability, and measurement error were evaluated using a test–retest design in a cohort of 124 patients seeking primary care physiotherapy for MSKP. Results The BPCI-2:SWE had excellent content validity, but patients’ experiences indicated that the scoring method may benefit from amendment. The PF subscale demonstrated good construct validity on hypothesis testing. However, the TPMS subscale did not reach the a priori threshold for good construct validity, correlating positively with pain intensity and demonstrating low correlation with all other PROMs. Neither subscale demonstrated floor or ceiling effects. The PF subscale had moderate, and the TPMS subscale had good, test–retest reliability. Measurement error was relatively high for both subscales at the individual patient level but low at the group level. Conclusions The BPCI-2:SWE is comprehensible and relevant within a Swedish primary care context. The BPCI-2:SWE demonstrated adequate measurement properties for use as an outcome measure in research studies, but future research should further evaluate the BPCI-2:SWE’s reliability, responsiveness, and prognostic utility.

Objectives Canadian Armed Forces (CAF) Veterans report living with chronic pain at nearly double the rate of comparable Canadians. They have unique pain management needs, highlighting the need for further research. Aquatic exercise is one treatment option that may offer meaningful benefits. This study aimed to explore the lived experiences of CAF Veterans incorporating aquatic exercise as part of their pain management routines, offering insight into its potential role in managing chronic pain among military Veterans. Methods Informed by interpretive phenomenological analysis, ten CAF Veterans with chronic pain and experience with aquatic exercise were interviewed. Results Three superordinate themes were constructed: Respite from the pain; reconstructing an identity as a physically capable individual; and reclaiming a sense of self and seeing a new path forward. Exercise has the potential to improve pain, function, and quality of life for individuals living with pain. Among CAF Veterans, aquatic exercise can further support personal growth, development, and recovery after release from the military. Conclusions The findings provide insight for rehabilitation providers of the positive experiences and additional impacts of participating in aquatic exercise for CAF Veterans with chronic pain. Rehabilitation providers may consider incorporating aquatic exercise into physical activity-based rehabilitation programs for CAF Veterans living with musculoskeletal pain. The current investigation was approved by and followed the recommendations of the Health Sciences and Affiliated Teaching Hospitals Research Ethics Board at Queen’s University (REH-797-21).

Objectives Pain is a prevalent non-motor symptom in patients with Parkinson’s Disease (PD) and associated with significant quality-of-life impairments. Yet, qualitative literature examining how patients with PD experience their pain and pain treatment is scarce. The aim of this study is to understand and report firsthand experiences with pain in PD. Methods Individual interviews ( N = 15 patients with PD) following a semi-structured interview guide organized in 7 main topics and 18 subtopics covering both medical and psychological aspects of pain in PD. Data were analyzed by a reflexive thematic analysis. Results Three major themes emerged: (1) Pain is related to PD : A majority of interviewees were confident pain is caused by motor symptoms and related to sleep disturbances. (2) Healthcare professionals neglect pain in PD: frequently, interviewees expressed satisfaction with general PD treatment, yet urged healthcare professionals to show interest in their pain. Many were uncertain as to who was responsible for pain treatment and wished for increased coordination among healthcare professionals. (3) Treatment of pain is insufficient: self-medication was prevalent. Most interviewees told they hide their pain. Interviewees broadly reported low and/or temporary effect of alternative pain treatment, yet perceived training as efficient. Multiple interviewees called for research on physical or psychological rather than pharmacological pain treatment. Conclusion Patients with PD yearn for dialogue on pain with healthcare professionals. Frequently, patients take medication unsupervised, suggesting a need for integrating assessment of self-medication in standard treatment regimes. Patients urge healthcare professionals to discuss pain with them and acknowledge that motor symptoms may cause pain.

Objectives The association between baseline laboratory parameters and experienced well-being in healthy individuals remains uncertain. This study explored the relationship between clinical laboratory profiles and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain, stiffness, and physical functional limitation in healthy individuals in Qatar. Methods Clinical laboratory data were collected from 1,764 Qatar Biobank participants who also completed the WOMAC questionnaire: lipid profiles (high-density lipoprotein, low-density lipoprotein, cholesterol, and triglycerides), endocrine markers (TSH, T3, T4, estradiol, and testosterone), and two inflammatory markers (CRP and fibrinogen). Multiple linear regression was used with 11 clinical indicators as independent variables and the subscale and total WOMAC scores as dependent variables. Multivariate effects of each indicator on the outcomes were assessed, and univariate effects were examined when significant. Results Testosterone had a significant impact on all WOMAC subscales (pain, stiffness, and functional limitation) and the total WOMAC score. Higher testosterone levels were associated with a reduction in pain ( β = −0.03, t = −3.505, p < 0.001, 95% CI = −0.052, −0.015), stiffness ( β = −0.01, t = −2.265, p = 0.024, 95% CI = −0.018, −0.001), physical dysfunction ( β = −0.08, t = −3.265, p = 0.001, 95% CI = −0.135, −0.034), and total WOMAC scores ( β = −0.127, t = −3.444, p < 0.001, 95% CI = −0.199, −0.055). Elevated fibrinogen levels were associated with an increase in stiffness ( β = 0.155, t = 2.241, p = 0.025, 95% CI = 0.019, 0.290), physical dysfunction ( β = 1.17, t = 2.808, p = 0.005, 95% CI = 0.354, 1.997), and total WOMAC scores ( β = 1.610, t = 2.691, p = 0.007, 95% CI = 0.437, 2.784). Conclusion Testosterone may protect against pain, stiffness, and physical dysfunction, while high fibrinogen levels might be a surrogate of systemic inflammation that enhances stiffness and limits physical function. Measuring multiple clinical and laboratory markers in healthy individuals may enhance our understanding of the molecular mechanisms underlying pain.

Background Well-being is closely related to health, recovery, and longevity. Chronic musculoskeletal pain (CMP) is a major health challenge in the general population, which can have a negative effect on subjective well-being. The ability to identify patients’ well-being protective factors, including psychological, social, and lifestyle components, can help guide the therapeutic process in the management of CMP. Recognizing the absence of a dedicated well-being questionnaire, tailored specifically for CMP populations, an 11-item well-being in pain questionnaire (WPQ) was developed. Objectives The objectives were to develop a valid and reliable patient-reported measure of personal pain-specific well-being protective factors and to evaluate its psychometric properties, including (i) internal consistency; (ii) known-group validity between subjects with chronic low back pain (CLBP) and healthy pain-free controls; (iii) convergent validity between the WPQ and measures of health-related quality of life, catastrophizing, sleep quality, symptoms of central sensitization, and anxiety; and (iv) structural validity with exploratory factor analysis. Design This is a cross-sectional validation study. Methods After reviewing previous CMP and well-being literature, the novel WPQ items were constructed by expert consensus and target population feedback. The psychometric properties of the WPQ were evaluated in a sample of 145 participants, including 92 subjects with CLBP and 53 pain-free controls. Results Feedback from a preliminary group of CMP patients about the relevance, content, and usability of the test items was positive. Internal consistency showed acceptable results ( α = 0.89). The assessment of convergent validity showed moderate correlations (≤0.4 or ≥−0.4.) with well-established subject-reported outcome measures. The assessment of structural validity yielded a one-factor solution, supporting the unidimensionality of the WPQ. Conclusions The psychometric results provided evidence of acceptable reliability and validity of the WPQ. Further research is needed to determine the usability of the WPQ as an assessment and outcome tool in the comprehensive management of subjects with CMP.

Objectives To evaluate the psychometric properties of pain catastrophizing scale (PCS) using item response theory (IRT) amongst people with carpal tunnel syndrome (CTS). Methods Retrospective cross-sectional register-based study amongst 1,597 patients with CTS. Two-parameter IRT analysis with rating scale model. Results The average age was 55.3 (16.3) years and 896 (56%) were women. The average PCS total score was 15.1 (11.6) points. For all 13 items, the estimates of difficulty parameter indicated a shift towards higher PCS scores. This was also seen in item characteristic curves and item information function. Respectively, the entire composite score showed the same shift towards higher PCS scores. The discrimination of PCS was excellent 1.98 (95% CI 1.89–2.07). Conclusions Overall, the psychometric properties of the PCS were found to be sufficiently good to recommend this scale for clinical use in CTS. The PCS is well able to distinguish between people with different levels of pain catastrophizing, even if performing better in elevated levels of catastrophizing. Also, the respondents may have a slight tendency to underestimate the severity of their catastrophizing when responding to the PCS. The results may be of interest to both clinicians and researchers in planning and implementing conservative or operative treatment for CTS, setting rehabilitation goals, and evaluating treatment or rehabilitation outcomes.

Objectives The STarT Back screening Tool (SBT) captures patients with low back pain (LBP) at risk of worse prognosis. However, the SBT does not include assessment of multisite and chronic widespread pain (MS-CWP). The aim was to study the differences in prognostic factors in patients with LBP classified according to SBT or SBT in combination with MS-CWP, and the 1-year outcome regarding visits to physiotherapist and sickness absence, in relation to risk scorings. Methods In this 1-year prospective study, adults (18–67 years) seeking care for LBP in primary care were classified into three prognostic risk groups (low, medium, high), using SBT only and using a combined screening tool (SBT and MS-CWP). Differences in prognostic factors at baseline, and outcome in terms of number of physiotherapist visits and sickness absence the year after inclusion were compared for risk groups derived by the two methods. Results Eighty-four patients (61% women) were included in the study. According to SBT alone, 19 were classified as low risk, 48 as medium risk, and 17 as high risk. When using the combined screening tool, additionally seven patients from the medium risk group were classified as high risk. Patients classified as high risk by SBT only or by the combined screening tool showed similar statistically significant worse mental health, health status, kinesiophobia, physical function, and sleep, as compared to the low-risk group. There were no differences in visits to physiotherapist and sickness absence between the risk groups for neither of the tools. Conclusion The combined screening tool resulted in more patients being classified as high risk than with SBT alone. The three risk groups identified either by SBT alone or by the combined screening tool differed significantly on all investigated prognostic factors, suggesting that including MS-CWP to the SBT captures more patients at risk.

Objectives This survey aims to identify and describe the characteristics of registries for neuromodulation implantations used to treat chronic pain in Europe. Neuromodulation therapies such as spinal cord stimulation (SCS) are employed to treat chronic pain through implantable medical devices. These therapies are considered effective and are part of standard care in many countries. Registries can provide valuable real-world data to complement randomized controlled clinical trials. Materials and methods We conducted a web-based survey to gather information on registries monitoring neuromodulation implants for chronic pain treatment, and the survey was sent to 101 European centers. Results We received responses from 47 centers across 17 European countries. Of these, 27 centers reported using a registry for neuromodulation therapies to treat pain, which this study is based upon. National registries exist in Belgium, the Netherlands, the UK, as well as a national registry solution in France. Non-national registries were identified in Denmark, Finland, Norway, Spain, Sweden, Switzerland, and Turkey. We present an overview on data types collected from different registries. Categories of variables collected are quite consistent across registries and are mostly in line with recommendations for chronic pain. The primary objective of the registries is most commonly measuring clinical outcomes and complications, while guideline adherence is less commonly monitored. The most frequently reported challenge is the lack of personnel for planning, designing, and funding for running the registries. Conclusions We identified 27 centers utilizing neuromodulation registries for chronic pain treatment, with 23 providing detailed data. Although the survey’s limitation is its findings are not generalizable to all registries, the findings offer key insights for the establishment and growth of registries in neuromodulation. Registries primarily aim to investigate the clinical and patient-reported outcomes, though variability in other clinical data collection remains a challenge for benchmarking and guideline adherence. Significant financial and organizational hurdles exist, which can be addressed through cooperative initiatives.

Objectives Patients with non-specific neck, back, and/or chronic pain increasingly seek information about their condition on websites of healthcare practitioners. This information can influence their treatment expectation and should align with contemporary biopsychosocial (BPS) understanding of pain. It is unclear whether Dutch websites in the fields of rehabilitation and anaesthesiology align with the BPS model. The aim of this study is to assess the BPS content about non-specific neck, back, and chronic pain in Dutch rehabilitation and anaesthesiology websites. Methods All Dutch rehabilitation and anaesthesiology webpages were potentially eligible for inclusion. All webpages focusing on the topics of neck, back, and chronic pain were included. BPS content analyses were performed according to a standardised rating method with criteria for biomedical, limited-, and reasonably BPS. Analyses were performed separately for specialisms, and for the three topics. Additionally, frequency of nocebo words usage on the websites is explored. Results A total of 71 webpages were included, of which 42 (59.2%) were rehabilitation, 28 (39.4%) were anaesthesiology webpages, and 1 webpage described both. Across all webpages, 7 (9.7%) were rated as biomedical, 54 (75.0%) limited BPS, and 11 (15.3%) reasonably BPS. Differences between specialisms were not significantly different ( p = 0.055). Differences between BPS ratings and the topics were significant ( p = 0.005). Nocebos were present on 22.2% ( n = 16) of the webpages. Conclusion Majority of the anaesthesiology and rehabilitation webpages (84.7%) did not achieve a “reasonable biopsychosocial” rate. Improvements are particularly needed in describing pain as a universal and/or normal phenomenon experienced by most individuals, as well as in explaining how an individual’s environment influences their thoughts, emotions, and behaviours regarding pain perception.

Objectives Chronic pain is a major global public-health issue. In Sweden, 20% adults report moderate to severe chronic pain, with 7% continuously seeking healthcare. Shortcomings in treatment, accessibility, and knowledge in healthcare for chronic pain have previously been reported. A generic treatment structure from primary to specialized care and rehabilitation was missing. This study aims to describe the development process for the creation of a person-centered and coherent care (P3C) pathway for adults with chronic pain in Sweden. Methods A National Action Group with expertise in pain medicine, rehabilitation medicine, psychiatry, anesthesiology, neurosurgery, general medicine, nursing, psychology, physiotherapy, occupational therapy, and patient representation was commissioned to develop the pathway following a stepwise co-designed approach, which included mapping current situation, goals, measures and indicators of the pathway, assessment of consequences and anchoring the process. Results Goals were based on challenges identified in the mapping, including improvements in patient’s well-being, continuity during and between care contacts, timely self-management, communication between levels of care, and knowledge about pain. Points of pathway entrance and exit were described. Measures focused on areas such as early pain analysis, biopsychosocial approach to assessment and treatment, early rehabilitation plan, teamwork, dialogue and joint plans between levels of care, patient participation, and education on pain and its consequences. Process and outcome indicators, and a report on benefits and risks for patients, ethical aspects, costs, and impacts of the pathway on other areas of healthcare were included. Conclusions The P3C pathway addressed the challenges described by patients and practitioners. By being person-centered and coherent, it can promote patient empowerment and equality in care, with emphasis on early and timely interventions, dialogue between patients and practitioners and between levels of care, self-management of pain instead of prolonged medical intervention, value-driven and coordinated care contacts, and increased knowledge about chronic pain, based on existing evidence and experience.

With the aim of improving care for patients with musculoskeletal disorders of different durations, this thesis, defended in December 2024, evaluates team-based rehabilitation in primary care. The objectives of the interventions were to improve physical function and mental well-being, promote health, and prevent ill health. The theoretical underpinnings are anchored in a biopsychosocial understanding of pain, person-centredness, and salutogenesis, i.e. a holistic approach. Both qualitative and quantitative methods were used in this thesis, comprising four studies: an interview study exploring patients’ experiences, a randomised controlled study evaluating effects on sickness absence and health-reported outcomes, a focus group study exploring the healthcare professionals’ experiences, and a process evaluation of the implementation of a team-based rehabilitation model. The results support a person-centred approach, identifying and addressing biopsychosocial factors in musculoskeletal care, being beneficial both for patients’ rehabilitation and the healthcare professionals’ work satisfaction. A person-centred approach with a biopsychosocial understanding of pain is a desired way of working in primary care; however, contextual challenges were identified in the studies, as the organisation also expects high availability and has a volume-based reimbursement system. These factors were perceived as conflicting and stressful by the healthcare professionals.

Background Persistent severe intensity pain after groin hernia repair (PSPG; 200–400/10,000 repairs) is a significant surgical complication impacting the activity of daily living (ADL) and psychosocial functioning. This PhD synopsis presents an outline and a summary of three clinical studies examining outcomes and pathophysiology behind the post-surgical pain state. Objective The studies assessed (I) treatment outcomes, i.e., re-surgery with meshectomy and selective neurectomy vs pharmacotherapy, (II) temporal trajectories of pain intensity following the primary repair, and (III) somatosensory profiles before and after re-surgery. Methods On a national basis, patients experiencing PSPG (>3 months) with an activity-related or maximal pain intensity >7 (NRS; 0–10) referred to our unit were examined. Validated questionnaires classifying NRS, ADL functions, and psychometrics, and standardized quantitative sensory testing assessing somatosensory phenotypes were used. Study I was a prospective, questionnaire-based cohort analysis comparing outcomes from a 5-year perspective. Study II retrospectively examined patient-reported pain intensity trajectories. Study III followed somatosensory outcomes before and after re-surgery. Results In Study I (responder ratio: 172/204 [84%]), patients were allocated to re-surgery ( n = 54) or to pharmacotherapy ( n = 118). Compared to baseline, both cohorts showed significant improvements in pain intensity and ADL functions ( P < 0.0001), with a slight superiority in ADL functions for the re-surgical cohort ( P = 0.02). The number needed to operate for one patient to achieve a positive outcome (≥25% change in NRS/ADL) ranged between 1.5 and 1.9, and for experiencing a negative outcome, between 14 and 28. Study II ( n = 95) identified two main prototypes of post-surgical pain intensity trajectories, where 51% experienced undiminished pain after the primary repair, while 29% experienced normal post-surgical recovery followed by late development of PSPG. Study III ( n = 60) indicated that re-surgery was associated with a loss in the cutaneous somatosensory function and deep mechanical nociceptive function (decrease in evoked pain sensitivity). Summary The thesis corroborates that both re-surgical intervention and pharmacotherapy may ameliorate high-intensity pain and increase ADL functions in PSPG. Since the study design cannot account for non-specific therapeutic effects, a high-quality RCT is still needed. The pathophysiologic results indicate that the implanted mesh acts as a “pain generator”, and future research should be targeted at dampening the immuno-inflammatory response to the implanted mesh.

Objectives Autonomic regulation has been identified as a potential regulator of pain via vagal nerve mediation, assessed through heart rate variability (HRV). Non-invasive vagal nerve stimulation (nVNS) and heart rate variability biofeedback (HRVB) have been proposed to modulate pain. A limited number of studies compare nVNS and HRVB in persons with chronic pain conditions. This systematic review compared interventions of nVNS and HRVB in adults with long-standing pain conditions. Methods PubMed, MEDLINE, CINAHL, SPORTDiscus, Google Scholar, and Cochrane library were used to retrieve the randomized controlled trials for this review between the years 2010 and 2023. Search terms included chronic pain, fibromyalgia, headache, migraine, vagus nerve stimulation, biofeedback, HRV, pain assessment, pain, and transcutaneous. Results Ten full-text articles of 1,474 identified were selected for full qualitative synthesis, with a combined population of 813 subjects. There were n = 763 subjects in studies of nVNS and n = 50 subjects for HRVB. Six of the nine nVNS studies looked at headache disorders and migraines ( n = 603), with two investigating effects on fibromyalgia symptoms ( n = 138) and one the effects on chronic low back pain ( n = 22). Of the nVNS studies, three demonstrated significant results in episode frequency, six in pain intensity (PI) reduction, and three in reduced medication use. The HRVB study showed statistically significant findings for reduced PI, depression scores, and increased HRV coherence. Conclusion Moderate to high-quality evidence suggests that nVNS is beneficial in reducing headache frequency and is well-tolerated, indicating it might be an alternative intervention to medication. HRVB interventions are beneficial in reducing pain, depression scores, use of non-steroidal anti-inflammatory medication, and in increasing HRV coherence ratio. HRVB and nVNS appear to show clinical benefits for chronic pain conditions; however, insufficient literature exists to support either approach.

Objective The objective of this scoping review was to investigate the available literature on physical and quality of life (QoL) outcomes of underwater treadmill exercise trials in clinical chronic pain samples. Methods A scoping search of studies of the effectiveness of underwater treadmill exercise trials from 1947 to 2024 was conducted using the following databases: EMBASE, MEDLINE, SPORTDiscus, CINAHL, and Cochrane Reviews. To be included, studies were required to have included adult participants living with chronic pain (defined as pain lasting for 3 months or longer) who participated in an active underwater treadmill exercise intervention. No restrictions on pain diagnosis were applied. All clinical trials, including but not limited to randomized controlled trials (RCTs), feasibility trials, and pilot studies, were included in the search. Two independent reviewers determined whether studies met inclusion criteria, and a third reviewer resolved any disagreement on study inclusion. Results The initial search identified 2,209 studies: 314 articles were removed for duplications, 1,781 were removed because they did not meet inclusion criteria, and 113 were retained for full-text review. The full-text review yielded nine studies, all of which included samples consisting of participants with osteoarthritis. The following variables were investigated in the included studies to varying degrees: pain, QoL, mobility, balance, strength, and changes in gait kinematics. Multiple studies identified significant differences between control groups or pre-intervention groups and underwater treadmill groups or post-intervention groups in chronic pain, balance, mobility, strength, and QoL. Conclusion Findings suggest that underwater treadmill exercise leads to positive changes in chronic pain, balance, mobility, strength, and QoL. However, more studies, particularly RCTs with larger samples that include individuals with chronic pain conditions other than osteoarthritis, are warranted.

Objectives Diabetic distal symmetric polyneuropathy, affecting up to 50% of adults with diabetes, often leads to painful symptoms; yet current treatments are largely ineffective with standard therapies providing limited relief. The aim of this systematic review is to address the knowledge gap in understanding the neural networks associated with painful diabetic polyneuropathy (P-DPN). By synthesizing evidence from neuroimaging studies, it seeks to identify potential targets for neuromodulation-based treatments, ultimately guiding clinicians and researchers in developing novel, more effective therapeutic interventions for P-DPN. Content A comprehensive search following the preferred reporting items for systematic reviews and meta-analysis was conducted across Embase, PsycINFO, and MEDLINE databases to identify relevant neuroimaging studies from 2010 to May 2024. The search focused on studies involving P-DPN and excluded animal research. After the removal of duplicates and irrelevant studies, 18 studies were included and critically appraised for their contributions to understanding the neural correlates of P-DPN. Summary The review highlights that P-DPN is associated with alterations in brain networks involved in pain perception, particularly in the primary somatosensory cortex highlighting its role in sensory and pain perception. Regions such as the anterior cingulate cortex and thalamus exhibit altered functional connectivity, with the former showing responses to pain treatment. The review also identified increased connectivity between the cingulate cortex, medial prefrontal cortex, medial temporal region, and insula in individuals with P-DPN, pointing to the involvement of these regions in the emotional and cognitive aspects of pain processing. Outlook This review provides a foundational understanding of the neural networks involved in P-DPN, offering potential targets for future neuromodulation therapies. Further research is required to deepen the understanding of these brain alterations and to explore how they can be leveraged for more effective P-DPN treatments.

Objectives Transcutaneous electrical nerve stimulation (TENS) is a noninvasive adjunct to multimodal pain management for acute postoperative care across various surgeries. Despite extensive evidence supporting its efficacy, TENS remains underutilized in clinical practice. This study aimed to assess the knowledge, attitudes, and practices of healthcare professionals regarding TENS in perioperative settings to support its integration into routine clinical practice. Methods A web-based questionnaire was distributed to anesthesiology department heads at all university hospitals ( n = 7) in Sweden and three smaller, randomly selected hospitals across three geographical areas. Department heads forwarded the questionnaire to anesthesiologists, nurse anesthetists, critical care nurses, and registered nurses with basic education working in perioperative settings. The questionnaire included four sections: demographic information, general postoperative phase information, TENS use for postoperative pain relief, and open-ended questions. Results The survey was sent to 870 respondents, yielding a response rate of 28% ( n = 246). Among respondents, 69% reported lacking adequate knowledge to administer TENS, and 79% indicated they did not use TENS in their practice. Furthermore, 45% noted an absence of clinical guidelines supporting the use of TENS in their clinic, while 32% were unsure about the existence of guidelines. However, 60% expressed interest in developing theoretical knowledge and practical skills for TENS application. Conclusions This study highlights that substantial knowledge gaps and the lack of clear clinical guidelines limit the use of TENS for acute postoperative pain management. These deficiencies may lead to inadequate pain control, increased opioid use, and opioid-related adverse effects. We recommend that hospital leadership and professional bodies develop and implement comprehensive educational programs and establish clear, evidence-based clinical guidelines for TENS use in postoperative pain management. Addressing these gaps is essential for improving clinical practice and empowering patients through greater involvement and autonomy in pain management strategies.

Objectives Pressure algometry is a validated method for objectively quantifying pain sensitivity in musculoskeletal disorders, particularly useful for diagnosis and monitoring of treatment responses. However, its application to abdominal pain sensitivity remains insufficiently standardized, especially regarding the influence of physiological factors such as respiration. This study investigated the impact of respiratory phase (inhalation vs exhalation) on abdominal pressure pain thresholds (PT) to support the development of standardized assessment protocols. Methods Thirty-one healthy medical students were recruited for the study. Each participant underwent three assessments of the abdominal PT with varying respiration phases. Furthermore, intraclass correlation coefficients (ICCs) were estimated to quantify the reliability of PT measurements. Results The respiration phase has a significant impact on the PT, which was found to be significantly lower during exhalation than during inhalation (431 ± 177 vs 492 ± 186 kPa, p = 0.0003). The pressure application rate (PAR) for the expiratory measurements was significantly lower compared to the inspiratory PAR (112 ± 56 vs 130 ± 63 kPa/s, p = 0.0007). Both ICCs had similar magnitudes (close to 0.9). No significant difference in PT was found between sexes. Conclusions Our study underscores the impact of respiration on pain perception, revealing increased abdominal PT during inhalation. A standardized approach is needed for abdominal PT assessment to guarantee its success in diagnostic and therapeutic evaluations.

Objectives Pain assessment is challenging given its subjective nature, and existing assessment tools have limitations, especially for patients having problems with verbal communication. A prior study evaluated the Grasp, a handheld device for assessing pain intensity through squeezing, showing a moderate association with the numeric rating scale (NRS). This study examined an improved version of the Grasp with instant visual feedback through color-coded categories and compared it to NRS. Methods Healthy adults underwent two consecutive cold pressor tests (CPTs), reporting pain intensity via NRS or Grasp with colour-coded feedback. Two additional CPTs assessed the association of repeated measurements with both instruments. The Grasp was calibrated to individual strength before CPTs. Results Forty-six subjects completed all tests. Pain intensity association between Grasp and NRS was moderate with a mean Kendall’s τ – b coefficient ( τ – b ) of 0.45, 95% confidence interval (CI) 0.35–0.56. Repeated Grasp measurements showed a moderate association ( τ – b = 0.37, 95% CI 0.27–0.48), while repeated NRS measurements had a stronger association ( τ – b = 0.71, 95% CI 0.64–0.78). After adjusting Grasp to individual squeeze strength (resulting in a 0.0–1.0 scale), a simple equation relating NRS value and mean Grasp value was identified: Grasp = 0.091 × NRS. Grouping reports into mild, moderate, and severe pain resulted in agreement proportions across two CPTs of 69% for Grasp and 79% for NRS. Conclusions The moderately high agreement proportions for pain intensity categories suggest that the Grasp method with colour-coded feedback may be useful for categorical pain intensity assessment, especially in settings where conventional tools (i.e., NRS) are inconvenient or not feasible.

Objectives The cold pressor test, in which subjects immerse part of an extremity in cold water for a specified amount of time, evokes both pain and unpleasantness. As it is low cost and readily available, it is widely used in pain research. However, data on the impact of race, area of exposure, and the effects of instructions are lacking. Methods Cold pressure test data were recorded in a mixed Asian and European healthy population. Trial 1 was a randomised crossover trial varying the extent of hand submersion (two fingers, four fingers, and whole hand) ( n = 54). Trial 2 was a randomised cross-sectional design, investigating instructed and non-instructed pain expectations, n = 40. Results European subjects tolerated the cold pressor test longer than Asian subjects (116 ± 14 versus 93 ± 36 s, p < 0.001), and fewer subjects withdrew their hand in less than two minutes (9% vs 43%, p = 0.007). Stimulation area influenced pain tolerance, with more subjects able to maintain two-finger immersion in cold water for 2 min compared to whole-hand immersion ( p < 0.001). The instruction or no instruction did not affect the numeric rating scale when comparing instruction levels ( p = 0.88). Additionally, pain tolerance was not affected either ( p = 1). Conclusion The cold pressor test is a robust tool across genders, race, and instruction levels. Significant differences were found in pain perception and tolerance across different locations and stimulation intensities. However, instructions in expected pain did not affect the outcomes, reflecting the robustness of the test.

Objectives Disturbed sleep and chronic pain are public health concerns. Sleep disturbances seem to influence inflammation and may contribute to the increased pain sensitivity after sleep restriction (SR), such as after night work. The primary objective of this study was to determine the effects of SR on pain sensitivity and on relevant markers of inflammation. A secondary objective was to determine if SR affected pain sensitivity and inflammatory responses differently in men and women. Methods A paired crossover design with block randomization was applied. Subjects were instructed to follow their habitual sleep (HS) rhythm for two nights (HS condition) and to delay their bedtime to shorten their sleep with 50% for two nights (SR condition). Thirty-nine healthy volunteers between 19 and 44 years old participated (21 women). Experimental pain sensitivity was tested with heat-, electrical-, and pressure pain thresholds (PPTs); electrical temporal summation threshold; pinprick pain; suprathreshold heat pain tolerance; and rating of suprathreshold heat and cold pain. The following markers of inflammation were measured in plasma from a blood sample taken between 10:00 and 12:00: C-reactive protein, fractalkine, tumor necrosis factor, interleukin -8, and monocyte chemoattractant protein-1. Results Most subjects did not comply with the SR instructions. Total sleep time during SR was on average 2.6 h shorter than during HS. Therefore, the SR condition was re-defined to be “at least 40% reduction in the time in bed (TIB) the last night.” The HS condition was re-defined to “at least 85% of normally reported TIB.” SR produced higher suprathreshold heat pain sensitivity and cold pressor pain, compared to HS, but no significant change in electrical pain threshold, electrical temporal summation threshold, PPT, or any of the measured immune parameters. Sex-stratified analyses indicated that the effect on heat pain only occurred in women and that the effect on cold pressor pain was significant only in men. Conclusions The present findings indicate that heat and cold pressor pain were rated higher following SR, whereas pain thresholds remained unchanged. We did not find an effect of SR on biomarkers of inflammation. The findings should be cautiously interpreted given the poor adherence to the SR condition.

Objectives To understand how different individuals respond to placebo effects, it is relevant to disentangle the influence of someone’s personality and genetic variations. The aim of this exploratory study was to investigate the role of different personality characteristics and different single-nucleotide polymorphisms (SNPs) on the responsiveness to placebo analgesia. Methods Secondary data analyses were conducted on an experimental behavioural study in healthy controls primarily aimed at the influence of three learning mechanisms (i.e., verbal suggestions, classical conditioning, or observational learning) or combinations thereof, on placebo analgesia in heat pain. Moderation by five different personality characteristics (optimism, neuroticism, worrying, empathy, and somatosensory amplification) was studied. Also, the predictive role of three different SNPs on the OPRM-1 gene, the COMT gene, and the FAAH gene on placebo analgesia was assessed. The personality characteristics were studied with validated questionnaires. The genetic variants were obtained by sequencing DNA from saliva cells. Results The moderation analysis from 206 participants concerning the personality characteristics did not show significant effects. Of the 108 (52%) genotyped participants, the results showed no significant relationship between any of the SNPs and placebo analgesia. Conclusions Results did not support a role of a person’s personality characteristics or genetic variations in predicting their responsiveness to placebo analgesia through learning mechanisms. The clinical relevance of predicting someone’s responsiveness to placebo effects, therefore, requires careful reconsideration.

Objectives The endocannabinoid system is a neuromodulatory system linked to pain, distress, and physical activity. The endocannabinoids (eCBs) arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol are known to activate the cannabinoid receptors. The eCB system has been reported to be acutely affected by physical activity. Altered connectivity related to pain intensity in patients with fibromyalgia (FM) has been reported. However, how the peripheral eCBs, including eCB-like N -acylethanolamines (NAEs) concentrations, associate with pain-related regions of the brain and physical activity in FM, is not known. This study aimed to investigate eCBs and eCB-like NAEs in plasma and the association with functional connectivity in brain regions relevant for pain and with physical fitness. Methods The plasma concentrations of eCBs and eCB-like NAEs were measured in 31 women with FM and 29 healthy controls (HC). Functional magnetic resonance imaging, measurement of physical fitness and questionnaire regarding pain and depression/anxiety were included. Results Significantly higher concentrations of AEA were found in FM compared to HC. The AEA level correlated positively with pain intensity and was inversely associated with physical fitness, which in turn were inversely correlated with pain intensity and psychological distress in FM. Periaqueductal gray (PAG)-thalamus connectivity was not associated with circulating eCB and eCB-like NAEs. Stronger PAG-thalamus connectivity was related to a higher level of physical activity. Conclusions These results confirm that impaired physical fitness is an important aspect of FM, which can be reflected in the increased eCB levels and in PAG-thalamus connectivity. Further studies are necessary to establish a causal relationship between physical fitness, eCBs, eCB-like NAEs, and brain connectivity.

Objectives A significant subset of patients with mental health disorders (MHDs) fail to respond to standard management and are termed as treatment-resistant. This cohort has limited options for managing their condition. Autonomic dysfunction has been reported in the neurobiology of MHDs including anxiety, depression, obsessive-compulsive disorder (OCD), panic disorder, and bipolar disorder (BD). Stellate ganglion block (SGB) is an emerging treatment that dampens sympathetic activity and has been shown to be of benefit in the management of post-traumatic stress disorder. Methods Patients with treatment-resistant disparate MHDs were reviewed by a multidisciplinary team comprising a psychiatrist, a clinical psychologist, and a pain medicine physician. Patients were offered SGB as a novel strategy in the management of treatment-resistant conditions. Validated outcome measures were completed at baseline, 4 weeks, and 16 weeks post-intervention. Results Four patients with heterogenous treatment-resistant MHDs who received SGB are presented in this report. SGB resulted in an improvement in BD, OCD with alcohol addiction, opioid addiction, and health anxiety. Conclusion SGB could have a role in the management of treatment-resistant MHDs.

Objectives Phantom limb pain (PLP) is common after limb amputation and can lead to chronic pain and psychosocial risks, potentially leading to suicide or euthanasia. This study aimed to explore the consequences of intractable PLP on a person’s life before, during, and after receiving phantom motor imagery (PMI) treatment, focusing on the person’s experiences with PMI and how it influenced his life and decision regarding euthanasia. Methods This case study focused on a single participant from the PMI treatment group of a PLP randomized clinical trial (RCT). The participant, who joined the RCT as a last resort before euthanasia, experienced decreased PLP during the trial, but the pain returned 1 month post-treatment. Subsequently, the participant initiated self-administered PMI training at home. A mixed quantitative–qualitative method approach was used to analyze this case study. Results Understanding and living with PLP was challenging for the participant, making him lose interest in life. Despite starting with low expectations, the participant enjoyed PMI, particularly home training. PLP disappeared during the RCT, returned after therapy cessation, and vanished again during PMI home training. PMI returned his motivation to live, leading him to discontinue his plans for euthanasia. Conclusions This case illustrates the severity of chronic PLP, highlighting also the complex interaction of biopsychosocial factors in pain, which can lead a person to consider euthanasia. Representing the first use of PMI in a home setting, this study, along with previous studies in clinical setting, indicates PMI to be a promising and feasible innovative intervention for decreasing PLP, encouraging further research. This study also emphasizes the need to enhance PLP education among clinicians and people with amputations.

Introduction Trigeminal neuralgia (TN) caused by a dolichoectatic vertebral artery is a rare and atypical form of TN, where an enlarged and tortuous vertebral artery compresses the trigeminal nerve at its root entry zone. The term dolichoectatic is of Greek origin and means elongated, torturous or dilated. The vascular anomaly may lead to the characteristic severe, stabbing facial pain. This type of TN is often identified through advanced imaging techniques such as magnetic resonance imaging or angiography, which reveal the vascular anomaly impinging on the nerve. Treatment options for the type of TN secondary to dolichoectatic vertebrobasilar artery include primarily microvascular decompression or Gamma knife treatment to alleviate nerve compression and reduce symptoms. Case reports The authors present two illustrative cases of elderly patients: an 82-year-old with the right-sided and a 68-year-old patient with the left-sided facial pain, respectively. Both patients presented with lancinating and irritating facial pain. Magnetic resonance imaging in both patients confirmed compression of the trigeminal nerve secondary to a vertebrobasilar dolichoectatic artery. The authors performed microvascular decompression in both patients, which resulted in instant pain relief. Conclusion Early diagnosis and surgical intervention are crucial for effective pain management and improved patient outcomes.

The term “neuroinflammation” (NI) is currently popular, and the meaning is a long way from the original description restricted to findings after stroke, central nervous system (CNS) trauma, or CNS infection. NI has been implied in association with diseases of the CNS, such as Alzheimer’s, Parkinson’s, and Multiple Sclerosis. In addition, it has also been associated with psychiatric/psychological diagnoses, chronic pain diagnoses, stress, many functional disorders, and “central sensitization.” Findings proposed to be evidence for NI have been found not only in the brain but also in the spinal cord, dorsal root ganglia, and peripheral nerves. Worrisome is the mistaken confusion that leads “association” to be “proof of cause,” where there is much dispute over whether findings are really evidence for inflammation. This article is a short review of the literature and a critique of the concept of NI.

Objective The aim of this study is to assess the clinical impression of health professionals at the Pain and Rehabilitation Centre, Linköping University Hospital, Sweden, according to whom patients have gradually become more complex and “difficult” over time. Methods This is a repeated cross-sectional study. Over 8,000 patients assessed between 2009 and 2022 answered questionnaires from the Swedish quality registry for pain rehabilitation. Patient-reported outcome measures were analysed with multivariate data analysis such as principal component analysis. Results During 2009–2022, the first principal component did not change statistically over time ( p = 0.177), and it did not correlate to the year (rho = −0.014; p = 0.21). Patients were divided into three groups (2009–2012, 2013–2016, and 2017–2022), and a partial least squares-discriminant analysis model with group belonging as the Y -variable did not reveal any relevant differences ( R 2 = 0.048; Q 2 = 0.045). For the period 2016–2022, additional data were available, enabling the comparison of pre- vs post-pandemic data by discriminant analysis. No clinically relevant difference was found. Conclusions It was not possible to confirm the clinical impression of health care personnel. While it is important to listen to “clinical hunches” emitted by experienced clinicians, it is also essential not to be too quick to equate such impressions with a true state of affairs.