BACKGROUND:Chronic back pain is a major cause of disability and a socioeconomic burden. Previous studies on back pain have suggested a moderately increased risk for cardiovascular mortality in elderly women, but evidence in elderly men is lacking. We investigated the association between continuous chronic back pain for more than a year and incident cardiovascular events in a cohort of elderly men. METHODS:The Uppsala Longitudinal Study of Adult Men (ULSAM), a community-based cohort of elderly men (mean age, 71 years; n=1,024), was used to investigate the association between continuous back pain lasting more than one year and incident cardiovascular events (defined as a composite of coronary heart disease, cerebrovascular disease or cardiovascular mortality). RESULTS:During up to 20 years follow-up, 504 individuals developed a cardiovascular event. In Cox proportional-hazards models adjusted for a large number of established cardiovascular risk factors, socioeconomic factors, and lifestyle factors (age, systolic blood pressure, antihypertensive treatment, high- and low-density lipoprotein-cholesterol, triglycerides, lipid-lowering treatment, glomerular filtration rate, urinary albumin excretion, body mass index, diabetes, diabetes medication, insulin-sensitivity, C-reactive protein, educational level, smoking, physical activity) continuous chronic back pain was robustly associated with a more than 70 % increased risk for cardiovascular events (multivariable hazard ratio 1.71, 95 % confidence intervals 1.23-2.37, p<0.001). CONCLUSIONS:Continuous chronic back pain for more than a year is a risk factor for cardiovascular events in elderly men. Our findings confirm previous evidence, highlighting chronic pain as a clinically relevant and under-recognized risk factor for cardiovascular disease that warrants consideration in future clinical guidelines.
BACKGROUND:Although acute pain is one of the most common complaints in the emergency department (ED), it is often undertreated. Several interventions, such as the implementation of an acute pain protocol, have been evaluated in order to optimize pain management, with variable results. The aim of this study was to evaluate the long-term efficacy of a nurse-initiated pain-management protocol 10 years after implementation. METHODS:This was a prospective, observational study recruiting all consecutive adult patients with acute pain in the ED of a Level-1 trauma center during a period of 4 weeks. The primary outcome was the percentage of the composite endpoint 'pain awareness'. The secondary outcomes were patient satisfaction; administration of analgesics; NRS scores and waiting time until receiving analgesics. RESULTS:Three hundred and 23 patients were included in this study. The percentage of pain awareness was 69 %. In 41.5 % of patients, analgesics were administered and in 55.1 %, an NRS-score was documented. Regarding patient satisfaction, no significant correlation was observed between waiting time until receiving analgesics and satisfaction. DISCUSSION:The percentage of pain awareness was 69 % with an existing pain protocol in place. Overall, patient satisfaction was positive in the majority of the patients. Further research into the types of analgesics that are more likely to optimize the protocol is necessary.
OBJECTIVES:Current pharmacological treatments of chronic pain are largely ineffective, one reason being that the pathophysiological mechanisms driving chronic pain are not yet elucidated. Emerging evidence, including human biomarker studies, suggests that neuroimmune activation and chronic low-grade inflammation are present. However, some patients with chronic pain regularly use analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs), and it is not clear how such medication might impact the low-grade systemic inflammation pattern of the individual patient. METHODS:This secondary analysis of partially published data was undertaken to explore the relationship between the concentrations of 71 pro- and anti-inflammatory plasma proteins and the use of various analgesic medications (including NSAIDs) in patients participating in interdisciplinary pain multimodal rehabilitation programs for chronic pain. RESULTS:At baseline (n=27), 63 % of patients used paracetamol, 33 % used NSAIDs, 19 % used opioids, 19 % used antidepressants (duloxetine, amitriptyline or mirtazapine), 11 % used chlorzoxazone, 7 % used corticosteroids, and 0 % used gabapentinoids. Using hierarchical cluster analysis, we identified two subgroups of patients - a "high inflammation" and a "low inflammation" subgroup. The main finding was that the distribution of analgesics, including NSAIDs, between the two groups did not differ. However, the low number of subjects must be acknowledged, implying low power and the risk of false negative results. CONCLUSIONS:Larger studies, e.g., focusing on NSAID users before and after treatment discontinuation, are needed to further ascertain the impact of specific medication on the systemic inflammation pattern of chronic pain patients.
OBJECTIVES:Chronic abdominal wall pain may be caused by Anterior Cutaneous Nerve Entrapment Syndrome (ACNES). The diagnostic cornerstone is a characteristic physical examination including a localized area of altered skin sensation covering a point of maximum pain. Recently, the Scratch Collapse Test (SCT) emerged as a sensitive noninvasive test for ACNES. However, this test relies on manual force application, which introduces potential examiner bias and raises concerns regarding its objectivity. Therefore, we modified the Empty Can Test, used to detect rotator cuff injuries, into the Empty Can Scratch Test (ECST). During this test, patients hold weights, thereby eliminating any manual force application. We hypothesized that this more objective ECST would elicit similar results to the SCT through a comparable spinal inhibitory reflex mediated by the common efferent suprascapular nerve. If so, the ECST would have diagnostic potential in suspected ACNES. METHODS:This single-center, prospective, cross-sectional cohort study, conducted between April and August 2022 at the outpatient department of SolviMáx, Centre of Expertise for Complex Abdominal Wall Pathology, included adult participants with suspected unilateral ACNES who underwent both the SCT and ECST. RESULTS:Twenty participants were analyzed (median age 50 years [IQR 38.5-57.5], 75 % women). The SCT was positive in 19 patients (95 %), but the ECST was positive in only 10 patients (50 %). There was no level of agreement between both tests (Cohen's Kappa=0.100, p=0.305). CONCLUSIONS:The ECST does not have a diagnostic role in ACNES. The high diagnostic yield of a SCT in ACNES is confirmed. ETHICAL COMMITTEE NUMBER:METC N22.023.
OBJECTIVES:Chronic pain is a major health problem and is more common among women than men. Interdisciplinary pain rehabilitation programmes (IPR) are effective in reducing pain and restoring function for patients with chronic pain. However, in Sweden, immigrants who do not speak Swedish are commonly not selected for participation in IPR. There is thus a knowledge gap regarding whether IPR has positive effects for immigrants with chronic pain and inadequate Swedish language skills. The aim of this study was to investigate outcomes in patients with chronic pain and inadequate Swedish language skills at one-year follow-up after participation in an IPR with language interpreters, both on the whole group level and separately for women and men, and in comparison with a reference group of patients. METHODS:Design: prospective multi-centre cohort study. Patients: 74 patients (60 women and 14 men). Pain intensity, anxiety and depression, health-related quality of life, fear of movement and the number of doctor visits due to pain were evaluated at baseline, at treatment conclusion (except for doctor visits) and one year after the programme. Patients were compared with a reference group comprising Swedish-speaking patients in a standard interdisciplinary pain rehabilitation programme (135 patients (122 women and 13 men)). RESULTS:At one-year follow-up, the patients showed significant improvements in pain intensity, depression, and fear of movement, and when subgrouping, the female patients showed significant improvements in the same variables: pain intensity (p=0.002), depression (p=0.015), and fear of movement (p=0.007). Anxiety was significantly deteriorated, both for the whole group and for the female patients (p=0.011). The men did not improve, but low numbers preclude statistics or conclusions. On the whole group level, there was also a significantly reduced number of doctor visits due to pain (p<0.001) at one-year follow-up. Compared to those in the reference group, the patients rated themselves significantly poorer before the programme for the variables measured over time (p=/<0.004). All variables improved significantly for the patients in the reference group at one-year follow-up. CONCLUSIONS:Patients with chronic pain and inadequate language skills in the Swedish language seem to benefit from participating in an interdisciplinary pain rehabilitation programme with language interpreters. The result could be of value for the further development of such rehabilitation programmes, but further studies are needed regarding men´s needs in and after a rehabilitation programme. Ethical committee number (IRB#/REC#): Regional ethics review board Stockholm, ref: 2016/858-31; completion 2016/2059-32 and 2020/06982.
INTRODUCTION:Since pain is a multidimensional and subjective experience, pain assessment remains challenging. With advances in artificial intelligence (AI), automatic pain assessment (APA) systems offer a valuable opportunity for objective pain evaluation. However, most approaches focus on a single modality. In this proof-of-concept study, exploring multimodal fusion strategies in a controlled experimental setting, we present a deep learning framework for multimodal fusion that combines facial, acoustic, and textual information to improve APA in cancer patients. METHODS:A multimodal dataset was created from video-recorded interviews with oncologic patients. In Phase I, audio, video, and transcripts were segmented at the sentence level and temporally aligned using the Eudico Linguistic Annotator (ELAN) to ensure frame-level correspondence across modalities. In Phase II, modality-specific features were extracted: Facial Action Units from OpenFace, acoustic descriptors (MFCCs, chroma, spectral contrast, and Mel-spectrogram) from a dedicated speech-processing pipeline, and sentence-level textual embeddings from ITA-BERT. During training, the most effective analytical strategy was chosen through knowledge transfer approaches. The ELAN-assisted annotation pipeline streamlined expert labeling. Two architectures were implemented and compared: bimodal autoencoder fusion models and a transformer-based model with pairwise cross-modal attention. These models were trained and evaluated using subject-independent and stratified 5-fold cross-validation. To address the lack of independence between segments, a strictly subject-independent cross-validation strategy was adopted. RESULTS:Knowledge transfer using pretrained large-scale models outperformed traditional feature-based approaches and was applied to multimodal pain detection. Multimodal models achieved performance comparable to the strongest unimodal modality (text), while showing improved balance across modalities, suggesting potential complementary effects. Both multimodal architectures demonstrated high accuracy in distinguishing between pain and non-pain classes. The bimodal autoencoder achieved stable results across folds, with a mean accuracy of about 80 % and balanced error distribution. The pairwise transformer with cross-modal attention achieved similar performance, with smooth training and validation loss curves. No evident divergence between training and validation loss curves was observed across folds, suggesting stable behavior within the cross-validation setting. However, subject-level overfitting cannot be excluded given the limited sample size. CONCLUSION:Multimodal fusion enhances system robustness by integrating complementary signals. Despite limitations and the need for improvement, multimodal deep learning strategies can support the detection of observable pain-related expressions.
Abstract Introduction Chronic pain affects over 50 million adults in the United States and is associated with autonomic nervous system dysfunction assessed through measurements of heart rate variability (HRV). While exercise has been shown to improve HRV in healthy individuals, the effects of different exercise protocols in chronic pain populations on HRV remain underexplored. Content The purpose of this systematic review investigated how exercise interventions influence HRV and pain in individuals with chronic pain. A literature search was conducted in accordance with PRISMA guidelines across four electronic databases. Six randomized controlled trials met the inclusion criteria and were critically appraised for methodological quality. Studies were included if they involved an exercise intervention and reported HRV. If pain was assessed, it was included as an outcome measure. Summary and Outlook Six randomized controlled trials were identified with 283 participants. All studies measured HRV, while four reported pain outcomes. Five studies reported significant improvements in HRV following exercise interventions (p <0.05), while findings related to pain outcomes were mixed. Methodological reporting of HRV procedures was generally insufficient. Due to heterogeneity across studies, it remains unclear whether exercise improves pain or HRV sufficiently. While pain outcomes are commonly reported, HRV is the only measure specific to \autonomic function, and its reliability as a clinical metric in individuals with chronic pain remains uncertain. Limited research across diverse chronic conditions, sexes, and methodological approaches restricts generalizability. This highlights the need for greater methodological rigor and broader inclusion to strengthen the use of HRV metrics in chronic pain populations.
Abstract Objectives Opioid therapy for chronic pain complicates post-operative pain management. This study evaluated the incidence of failed epidural analgesia, defined as epidural catheter replacement, in opioid-treated chronic pain patients vs. pain-free opioid-naïve controls undergoing elective upper laparotomy. Methods We conducted a retrospective case–control cohort study of adult patients undergoing elective upper laparotomy with epidural anesthesia (EA) for postoperative pain management. The intervention group comprised chronic pain patients, defined as pain lasting >3 months with stable daily opioid use. Controls were pain-free opioid-naïve patients. Patients with known illegal opioid use were excluded. A sample size of 75 chronic opioid-treated pain patients and 75 pain-free patients would allow for detection of a 15 % between group difference in epidural catheter replacement at a 0.05 significance level. Results Seventy-five chronic pain patients and 75 pain-free opioid-naïve controls were included. Chronic pain patients were more often female, had more co-morbidities, and more frequently underwent pancreatic resections; liver resections were more common among controls. The median preoperative daily oral morphine equivalent use among chronic pain patients was 45 mg (IQR, 20–80). Epidural analgesia failure occurred four times more often in chronic pain patients compared with controls (41.3 % vs. 10.7 %; p<0.01). Conclusions Chronic preoperative opioid use for pain significantly increased the rate of postoperative epidural catheter replacement. The findings were not explained by external preoperative, technical or surgical factors, supporting further pathophysiological investigations to tailor mechanism based interventions.
OBJECTIVES:The audit explores adherence to the Danish Health Authorities' recommendations of assessment, diagnosis, and treatment domains in five tertiary multidisciplinary pain centers in three of five regions in Denmark. METHODS:We conducted a systematic clinical audit of medical records from 100 patients with high-impact chronic pain (HICP), sampling 20 records at each center. A structured checklist, based on national guidelines, examined the documentation prevalence across bio-psycho-social issues, pain mechanism identification, and treatment, including non-pharmacological and pharmacological interventions, and discharge planning. Guideline adherence and inter-center variations were examined. Data are presented as median (IQR). RESULTS:The patient age was 51 (42-59) years, and 63 % were females. The median treatment duration was 35 (17-50) weeks, with 14 (6-23) healthcare contacts involving 3.1 (2.7-4.0) healthcare professions per patient. Documentation of the target issues in the medical records was as follows: physical examination 37 % (1-17/center), psychological factors 65 % (5-20/center), socio-economic factors 98 % (19-20/center), pain mechanisms 66 % (3-17/center), non-pharmacological treatments 89 % (14-20/center), group treatment 57 % (3-17/center), analgesic consumption at referral 96 % and at discharge 83 %, add-on pharmacological treatments 69 % (8-18/center), opioid use at referral 38 % (4-11/center), and weaning off during treatment 18 % (2-6/center), non-evidence-based pharmacological treatments 21 % (0-12/center), prospective treatment plans in discharge reports 14 % (2-4/center), and overall assessment of patients' satisfaction with treatment outcomes 40 % (3-11/center). CONCLUSIONS:While socio-economic and psychological assessments, and multidisciplinary, non-pharmacological treatments seemed adequately documented, a wide inter-center variation in the documentation of physical examination, diagnostic, pharmacological, and discharge procedures was observed. Standardizing documentation practices is essential to improve consistency and quality of care in Danish multidisciplinary pain centers.
OBJECTIVES:Focal spinal cord lesions occur across a variety of neurological diseases including non-traumatic cervical myelopathies which can lead to neuropathic pain. Currently, the degree to which signs and symptoms of neuropathic pain correlate with functional impairments and/or anatomical deficits remains unclear. This study aimed to identify structural and functional determinants associated with neuropathic pain in individuals with focal spinal lesions. METHODS:Individuals fulfilling the diagnostic criteria of neuropathic pain were identified among individuals with cervical myelopathy presenting with focal spinal lesions. Lesion volume and the extent of structural damage affecting the spinothalamic tract, dorsal columns, dorsal horn, and ventral horn were evaluated with tract-specific MRI of the cervical spinal cord. Quantitative sensory testing (QST) (i.e., thermal/mechanical thresholds) was performed at the most affected skin area. Additionally, contact heat-evoked potentials (CHEPs) were acquired following stimulation at the most affected skin area to objectively assess the functional integrity of the spinothalamic tract. RESULTS:MRI-derived structural damage was similar for individuals with (n=8) and without (n=8) neuropathic pain in all regions of interest (p>0.05). Mechanical hyperalgesia upon QST was observed in both groups. However, functional preservation of the spinothalamic system, measured by CHEPs, was present in 87 % of individuals with neuropathic pain, compared to 38 % of pain-free individuals (p=0.039). CONCLUSIONS:These observations suggest that segmental hyperexcitability resulting from structural spinal cord damage, in combination with residual sparing of spinothalamic afferents, may represent a key pathophysiological constellation contributing to central neuropathic pain following focal spinal lesions.
OBJECTIVES:This study aims to examine preoperative sociodemographic, clinical, and psychological factors associated with acute worst pain intensity following open carpal tunnel release (CTR). METHODS:This prospective observational study included 83 patients between 18 and 79 years undergoing primary outpatient CTR. All patients filled in consent forms and a questionnaire that assessed demographics, comorbidities, pain and function, sleep quality and pain catastrophizing. The primary outcome was worst pain intensity during the first three postoperative days. Linear regression analyses were done to estimate associations between age, sex, education, comorbidity, pain catastrophizing and sleep quality, and worst postoperative pain intensity. RESULTS:The patients mean age was 60 years and most were women (64 %). Patients rated their worst preoperative pain to 4.5 on a scale from 0 to 10, and worst pain intensity of 5.3 during the first three postoperative days. Postoperatively, 47 % of the patients experienced moderate pain and 32, 5 % reported severe pain in the three first days. In the univariable analyses, poorer sleep quality, more pain catastrophizing, more PRWHE hand pain and disability, and higher preoperative pain were associated with more severe postoperative pain. In the multivariable analysis, only higher level of pain catastrophizing remained associated with more severe postoperative pain. CONCLUSION:Higher preoperative pain catastrophizing was independently associated with higher postoperative pain intensity after CTR. This factor may be useful as part of preoperative screening to identify patients at higher risk for more severe postoperative pain. REC approval # 2018/1562.
OBJECTIVES:Improving treatment outcomes for comorbid chronic pain and posttraumatic stress disorder (PTSD) requires a better understanding of how these conditions interact. METHODS:This study examined the co-occurrence and interrelations of PTSD symptoms and chronic pain in a trauma-exposed sample recruited from the Pain Rehabilitation Unit at Skåne University Hospital, Sweden. Using a network analysis approach, data from 136 adults with chronic pain and traumatic exposure were analyzed. All DSM-5 PTSD symptoms were assessed at both item and cluster levels, alongside a comprehensive evaluation of chronic pain-covering severity, interference, and extent-as well as common comorbidities, including depression and insomnia. RESULTS:The findings revealed significant interconnections between specific PTSD symptoms, particularly those related to arousal and reactivity, and pain severity. Negative trauma-related emotions and detachment emerged as central nodes in the PTSD-pain network, suggesting that these symptoms may represent important targets for integrated treatment approaches. In contrast, pain extent showed weak or non-significant associations with PTSD symptoms and other pain-related variables. CONCLUSIONS:Overall, these findings underscore the need to address both PTSD and chronic pain concurrently in clinical interventions to improve outcomes for individuals with these comorbid conditions. Targeting arousal and reactivity symptoms, identified as potential bridges between the two disorders, could be a promising strategy for enhancing treatment effectiveness. Further research is needed to clarify the mechanisms linking PTSD and chronic pain and to inform the development of integrated, tailored interventions for this patient population with complex symptoms.
OBJECTIVES:Fast-track and outpatient surgery have significantly reduced postoperative hospital stays across many surgical specialties. As a result, patients are increasingly discharged with strong opioid prescriptions, contributing to the global opioid crisis. Careful follow-up and opioid tapering are essential. While multidisciplinary Transitional Pain Services (TPS), involving pain specialists, psychologists, and physiotherapists, have shown promise, their widespread implementation is limited by costs and complexity. To address these barriers, we implemented a nurse-led TPS, supervised by a pain specialist and embedded within a multidisciplinary pain clinic. The aim of this study was to evaluate its effectiveness in clinical practice, including a mechanism-based treatment approach to postsurgical pain aimed at opioid tapering and optimizing the use of adjuvant analgesics. METHODS:This observational cohort study included postoperative patients discharged with >20 mg oral oxycodone equivalents and/or those experiencing or at risk for neuropathic pain. Referred patients received telephone consultations by a nurse practitioner (NP) one to two weeks post-discharge. Each consultation included assessment of pain severity, neuropathic characteristics (using the first two items of the DN4 questionnaire), current analgesic use, and willingness to taper opioids. Patient education and motivational interviewing techniques were employed to support opioid tapering. Descriptive statistics and paired t-tests were used to analyze the data. RESULTS:Between June 2019 and July 2025, 243 patients were enrolled in the TPS. Following nurse-led counseling, 73 % of patients discontinued opioid use entirely, 23 % significantly tapered their dosage (from mean 101-43 mg oral oxycodone equivalent), and 4 % continued at the same dose. Anti-neuropathic medications were initiated in 22 % of patients. CONCLUSIONS:A nurse-led Transitional Pain Service is a feasible and effective approach to support opioid tapering in postoperative patients. In addition, early screening for neuropathic pain allows for targeted treatment. This model offers a scalable alternative to traditional multidisciplinary TPS programs.
OBJECTIVES:Repetitive noxious stimulation can increase perceived pain intensity, a phenomenon known as Temporal Summation of Pain (TSP), thought to reflect central sensitization via neuronal "wind-up" in the spinal cord. As neuronal wind-up occurs only at stimulation frequencies above 0.2 Hz, we have tested whether TSP also appears at two different frequencies using our recently developed TSP protocol in healthy volunteers. METHODS:In a randomized crossover design, 30 healthy male participants (27±4 years) underwent two experimental sessions involving 90 repetitive heat stimuli applied to the forearm at individually determined pain tolerance temperatures. Stimuli were delivered using a thermode at either 0.4 or 0.15 Hz. Pain intensity was rated using a computerized visual analog scale (0-100). TSP was assessed via linear mixed-effects model (LMM), with pain intensity as the dependent variable. RESULTS:All participants finished the study. LMM revealed a significant main effect of stimulation frequency (F 1, 540=14.20, p<0.001), indicating TSP. Pain intensity was higher at 0.4 Hz compared with 0.15 Hz (β=14.77, 95 % confidence intervals (CI) 6.87-22.68, p<0.001). CONCLUSIONS:The presence of TSP at 0.4 Hz but not at 0.15 Hz aligns with previous findings on neuronal wind-up, supporting its reliance to central sensitization. These findings enhance our understanding of the physiological basis of TSP and offer a robust platform for future investigations into pain modulation and therapeutic intervention strategies.
OBJECTIVES:To investigate if sociodemographic factors are associated with selection to an interdisciplinary pain rehabilitation program (IPRP) in Swedish tertiary care, in an intersectional perspective. METHODS:This study involved 39,346 patients referred to tertiary care, who were registered in the Swedish Quality Registry for Pain Rehabilitation during 2009-2016. Self-reported sociodemographic data, and data related to pain and its consequences, were registered prior to IPRP (at baseline). Self-reported data on pain and its consequences were also registered directly after the IPRP and at a 12 months' follow-up. Patients not selected for IPRP reported only baseline data. The statistical analyses used logistic regressions including interaction terms, and the results were analyzed in an intersectional framework to emphasize unequal health care. RESULTS:Sex, age, education, and region of birth were found to influence the likelihood of being selected to IPRP. Non-Nordic-born patients with elementary education had the lowest proportion of selection to IPRP, with a similar proportion for men and women. Other subgroups showed a smaller difference between Nordic and non-Nordic countries in the proportion selected to IPRP. For several groups, longer education had a positive impact on the proportion of selection. Selection increased with age to a peak in middle age and then decreased. Unexpectedly, the youngest patients were less likely than middle-aged patients to be selected. CONCLUSIONS:In Swedish tertiary care, sex, age, education, and region of birth influence selection to IPRP as combinations but not necessarily as single factors. More knowledge is needed to ensure equal, knowledge-based rehabilitation for patients with chronic pain. The regional ethics review board in Uppsala (IRB/REC 2018/036) and the Swedish ethical review authority (IRB/REC 2020-00828) issued ethical approvals.
OBJECTIVES:Persistent pelvic pain (PPP) is often regarded as multifactorial and complex. There is limited knowledge on how patients with PPP resemble and differ from those with persistent non-pelvic pain (PNPP). The specific aims of this study were to compare self-reported background and pain characteristics, affective symptoms, and quality of life at baseline between patients with PPP and those with PNPP at three multidisciplinary pain clinics in Norway, and to explore differences between men and women with PPP. METHODS:This is a cross-sectional study, using registry data from three tertiary, multidisciplinary pain clinics. Patients ≥17 years answered web-based questionnaires on background, baseline pain symptoms, mental health, and quality of life. We used t-tests, chi square, and multivariable logistic regression. RESULTS:Of 934 consenting patients (71 % of those attending), 30 had missing diagnoses, and 127 (13.6 %) were diagnosed with PPP. PPP patients less often reported widespread pain than PNPP patients (adjusted odds ratio (AOR) 0.2, 95 % confidence interval (CI) 0.2-0.4). We found high prevalence of fatigue, insomnia, and anxiety among all the pain patients, but PPP patients were more likely to report depression (AOR 1.6, 95 % CI 1.0-2.6) and pain catastrophizing (AOR 1.8, 95 % CI 1.2-2.8). All the pain patients had a low health-related quality of life. Women with PPP had higher prevalence of severe fatigue than men with PPP. CONCLUSIONS:This study confirms that pain clinic patients generally experience high levels of emotional distress and poor health-related quality of life. PPP patients tend to exhibit higher rates of pain catastrophizing, yet less widespread pain. Understanding the specific symptom profile of PPP patients is crucial for effective treatment in pain clinics. The potential underutilization of pain clinics in the treatment of PPP patients warrants further investigation.
OBJECTIVES:Low back pain (LBP) is the leading cause of disability worldwide. Unhelpful beliefs, low pain resilience, and overreliance on imaging contribute to chronicity and poor outcomes. Despite growing recognition of psychosocial influences, culturally adapted assessment tools for Urdu-speaking populations are lacking. This study aimed to translate and cross-culturally adapt Urdu versions of the back pain attitudes questionnaire (BackPAQ), pain resilience scale (PRS), and medical scans beliefs questionnaire (MSBQ), and to conduct an initial evaluation of their structural validity and internal consistency. METHODS:Following Beaton's six-step protocol and COSMIN guidelines, the BackPAQ, PRS, and MSBQ were translated and culturally adapted into Urdu. A cross-sectional sample of 461 adults with LBP (mean age=38.5 ± 12.3 years; 66.6 % female) completed the translated instruments. Item distributions, internal consistency, and exploratory factor analyses (EFA) were examined. Reliability was evaluated using Cronbach's α and standard error of measurement (SEM). Associations with established Urdu versions of the oswestry disability index and pain catastrophizing scale, were visually examined using scatter plots. RESULTS:EFA supported a four-factor structure for the Urdu BackPAQ (14 items, 46.0 % variance explained, α=0.69). The PRS retained its original two-factor structure (51.5 % variance explained, α=0.88), and the MSBQ demonstrated a unidimensional structure (46.2 % variance explained, α=0.71). Scatter plots indicated small, directionally consistent associations between the Urdu instruments with disability and catastrophizing. CONCLUSIONS:The Urdu versions of the BackPAQ, PRS, and MSBQ demonstrated acceptable structural validity and internal consistency, with the PRS showing excellent content validity. Test-retest reliability, responsiveness, and predictive validity should be evaluated in future clinical and longitudinal studies before broader clinical application.
OBJECTIVE:Spinal pain is highly prevalent and associated with substantial individual burden. Qualitative studies suggest that family members of individuals with spinal pain may also experience burden; however, quantitative data on family-member burden remain limited. This study had two linked objectives. First, we conducted a pragmatic cognitive debriefing study to evaluate the content validity of the Family-Reported Outcome Measure-16 (FROM-16) in a spinal pain context. Second, we conducted an exploratory cross-sectional survey using FROM-16 to estimate family-member burden in a Danish secondary-care hospital department and explore associations with family-member and patient characteristics. METHODS:Content validity of FROM-16 was assessed by semi-structured interviews of family members to patients with spinal pain at The Spine Center of Southern Denmark. The burden of spinal pain was assessed in a cohort of family members to spinal pain patients using FROM-16. Family members were asked about descriptive characteristics, and patient characteristics were extracted from a clinical registry. Summary statistics were reported, and regression modeling was used to explore associations. RESULTS:12 family members were interviewed and raised concerns about some item relevance (e.g., spare time, work and study, sex life). The cohort study included 291 family members, revealing varying burdens, with the highest burden in the emotional domain. However, some items had low response rates. The multivariable model indicated that the burden was highest among younger partners with poor self-rated health and was associated with clinical characteristics, notably disability and pain duration. CONCLUSIONS:The burden of spinal pain on family members varied greatly and was predominantly related to the emotional domain of younger partners with poor self-rated health. However, FROM-16's generic nature may underestimate this burden. Developing a more tailored questionnaire could better capture the impact of spinal pain on family members and inform improved care and support interventions for informal caregivers.
OBJECTIVE:Exercise induced hypoalgesia (EIH) is characterized by an acute reduction in pain perception following exercise. However, lack of knowledge exists regarding the effects of long duration exercise on EIH. This study aims to explore (1) the effect of a 120 min exercise on EIH in trained male cyclists, and (2) whether the potentially observed EIH results differ between local loaded and unloaded central landmarks. METHODS:In a randomized controlled crossover design, 20 trained male cyclists conducted a bicycle ergometer session of 120 min at 70 % of the individual anaerobic threshold (IAT) and a control session in addition to a pre-experimental session (including medical anamnesis, incremental exercise test, IAT determination) with pauses of ≥2 days in between the respective visits. Heart rate (bpm), lactate concentrations (mmol/l), and rate of perceived exertion (RPE; 6-20) were documented. Pre and post, pain sensitivity was measured employing pressure pain thresholds (PPT [N/cm2]) at local muscular (rectus femoris, tibialis anterior), local articular (knee, ankle), and central landmarks (sternum, forehead). RESULTS:Exercise resulted in an average heart rate of 141.2 ± 9.4 bpm, an average lactate concentration of 1.6 ± 0.4 mmol/l, and RPE scores of 14.9 ± 2.9. Regarding PPT, no 'time' × 'session' interaction effects were observed for local muscular (p=0.588), local articular (p=0.588), or central landmarks (p=0.910), with these PPT (N/cm2) values observed: local muscular (exercise: pre=81.0 ± 19.5, post=83.0 ± 18.4, relative change: 4.5 ± 16.6 %; control: pre=85.1 ± 22.9, post=85.3 ± 22.5, relative change: 0.7 ± 10.8 %), local articular (exercise: pre=81.9 ± 21.0, post=80.8 ± 21.5, relative change: -0.7 ± 12.2 %; control: pre=81.7 ± 20.9, post=79.2 ± 23.3, relative change: -3.2 ± 12.8 %), and central (exercise: pre=47.9 ± 13.7, post=45.9 ± 11.7, relative change: -1.1 ± 19.8 %; control: pre=48.8 ± 13.0, post=47.1 ± 13.5, relative change: -3.3 ± 16.1 %). CONCLUSION:Findings suggest that long duration exercise of a standardized moderate intensity may not be effective to induce EIH in trained male cyclists, while also no hyperalgesia is observed. These results are not different between loaded and unloaded body parts. ETHICAL COMMITTEE NUMBER:SK/AE 221026 (University of Wuppertal, Germany).
OBJECTIVES:The neurotrophin receptor TrkA is a clinically and genetically validated target in pain signaling. Anti-nerve growth factor (NGF) monoclonal antibodies have shown clinical efficacy but with side effects such as rapidly progressing osteoarthritis limiting their use, potentially mediated via inhibition of NGF/p75NTR signaling. Therefore, we sought to identify novel and selective small molecule negative allosteric modulators of tropomyosin receptor kinase A (TrkA) and to verify their analgesic effect in vivo. METHODS:We have identified ACD137 as a potent and selective negative allosteric modulator (NAM) of TrkA during a lead optimization program. The potency of ACD137 on TrkA and selectivity over TrkB was determined in cell-based assays. ACD137 was tested for its analgesic and anti-inflammatory effects in a model of chemotherapy induced peripheral neuropathy (CIPN) using paclitaxel and in the mono-iodo acetate (MIA)-induced osteoarthritis model in rats. RESULTS:ACD137 demonstrated an IC50-value on TrkA of 1.2 nM and showed approximately 17,300- and 17,600-fold selectivivity for TrkA over TrkB and TrkC, respectively. After oral administration in rats, ACD137 reduced mechanical allodynia in the CIPN model in a dose-dependent manner with maximal analgesic efficacy similar to the effect of gabapentin. In a comparative arthritis study using the anti-NGF antibody tanezumab as comparator, ACD137 reduced both evoked and non-evoked pain behavior as well as inflammation with similar efficacy as tanezumab. Surprisingly, ACD137 demonstrated a significant protective effect against knee joint deterioration, something that was not observed with tanezumab. CONCLUSIONS:The data demonstrates that ACD137 is a potent, selective and in vivo active negative allosteric modulator of TrkA exhibiting analgesic effects in models of neuropathic and nociceptive pain. The molecule possesses promising properties for further pre-clinical development.
