Scandinavian Journal of Pain最新文献

Objectives: The overlapping neural networks of social and physical pain have been investigated intensively in recent years. It was postulated that triggering social pain might result in greater physical pain. Nonetheless, how this affects somatoform pain disorder has not yet been considered. Since an increased pain processing activity is reported in these patients, the investigation of social exclusion and its effect on this group seems interesting. Hence, the aim of this study was to compare the influence of social exclusion on healthy controls and patients with somatoform pain disorder.

Methods: Nineteen patients with somatoform pain disorder and 19 healthy controls were examined. Cyberball, a virtual ball-tossing paradigm, was used to experimentally induce social exclusion and inclusion. To measure effects on pain perception, pressure pain thresholds and heart rate variability (HRV) were recorded after each round of cyberball. Demographic data, pain medication, and potential psychosocial moderators were collected by questionnaires.

Results: After social exclusion, pressure pain thresholds were significantly reduced in healthy controls (p < 0.01) as well as somatoform pain patients (p < 0.05), while HRV increased only in patients with somatoform pain disorder (p < 0.05) indicating increased parasympathetic activity.

Conclusion: This study is the first to analyse the effects of social exclusion on pain perception in somatoform pain disorder. While the reduction in pressure pain thresholds is in line with the social pain literature, the effects on HRV could be interpreted as a form of pain regulation mechanism. However, further research is needed to investigate the role of parasympathetic activity in socially excluded somatoform pain patients.

Objectives: Pain catastrophizing is a core psychological factor determining pain experience. We addressed the question of whether patients with different pain syndromes group into different pain catastrophizing phenotypes.

Methods: A total of 727 patients with chronic pain associated with four primary syndromes: Breast cancer (BC) survivors (n = 400), fibromyalgia (FM, n = 52), complex regional pain syndrome (CRPS, n = 155), and HIV (n = 120) were first studied for differences in levels of pain catastrophizing (Pain Catastrophizing Scale, PCS) and pain intensity by analysis of variance. Subsequently, individual scores of the PCS subscales "rumination", "magnification," and "helplessness" from the pooled cohorts were submitted to multivariate k-means clustering to explore subgroups.

Results: Three clusters defined by the level of catastrophizing were identified. The "low catastrophizing" cluster (n = 377) included most of the BC patients (71.0%) and the "moderate catastrophizing" cluster (n = 256) most of the FM patients (61.5%). HIV (31.9%) and CRPS (44.7%) patients were over-represented in the "high catastrophizing" cluster (n = 94) with the highest catastrophizing tendencies in all dimensions. These patients reported more helplessness than the patients in the two other clusters.

Conclusions: The primary syndrome causing the pain has an impact on self-reported pain-related catastrophizing. Helplessness is a predominant feature in HIV and CRPS patients and therefore an important target in pain rehabilitation.

Objectives: Inflexibly relying on avoidance of expression may increase and perpetuate pain-related emotional distress in patients with chronic pain. The context-insensitive avoidance (CIA) scale was recently developed to measure the degree to which patients avoid expressing their pain and distress in social situations. This study explored the psychometric properties of the CIA scale in a new sample.

Methods: This study uses baseline data from a treatment trial for n = 115 patients with chronic pain and co-occurring emotional distress. Reliability and construct and criteria validity were studied using the same instruments as in the original psychometric study and further explored in two new measures. A series of multiple regression analyses were conducted to assess the relationship between the CIA scale and criteria variables compared to the other psychological constructs.

Results: The CIA scale showed good reliability. Significant correlations between high scores on the CIA scale and low scores on self-compassion and activity engagement could be replicated. Significant correlations between high scores on the CIA scale and high scores of pain intensity and pain interference could also be replicated. In the exploring part of this study, validity was extended to general problems with emotion regulation and to satisfaction with life in general and contact with friends but not to satisfaction with family, partner, or sexual life. Avoidance of expression was the only significant predictor of pain intensity.

Conclusion: This study could replicate acceptable psychometric properties of a scale measuring CIA of expression. As in the original study, avoidance of expression was associated with increased suffering. Clinically, this instrument may be used to identify patients who may otherwise remain in aggravating silence. Theoretically, it introduces the important concept of context sensitivity to the field of chronic pain. Limitations include uncertainty about causal relationships, and that several important social situations were not examined.

Objectives: The 13-item pain catastrophizing scale (PCS) is the most commonly used measure of pain catastrophizing. A validated Finnish version of the PCS has previously been unavailable. The objectives were to translate the original English version of the PCS into Finnish (PCS-FI), then to evaluate (i) structural validity of the PCS-FI with a confirmatory factor analysis (CFA), (ii) internal reliability with Cronbach's alpha, Omega, and Omega hierarchical, (iii) convergent validity with measures of well-being, quality of life, sleep quality, symptoms of central sensitization, and anxiety, and (iv) known-groups validity between participants with chronic low back pain (CLBP) and pain-free controls.

Methods: The translation process was performed with established guidelines. The PCS-FI was psychometrically validated using 92 participants with CLBP and 53 pain-free controls.

Results: Structural validity with CFA supported a bifactor solution. However, low reliability was found for the three specific factors (ω _h ranging from 0.14 to 0.18) compared to the general factor (ω _h = 0.88) suggesting that only the total score should be used. Convergent validity analysis showed satisfactory correlations and medium effect sizes with the other patient-reported outcome measures. Participants with CLBP had significantly higher total PCS-FI scores than pain-free controls.

Conclusions: The PCS-FI appears to be a valid and reliable instrument for assessing pain-related catastrophizing in Finnish-speaking populations. Ethical approval for this study was obtained from the Research Ethics Committee of the Northern Savo Hospital District, identification number 2131/2022, on the 31st of January 2022.

Objectives: Two-thirds of patients with advanced cancer experience pain. Some of these patients have severe pain refractory to oral and parenteral medication, for whom intrathecal pain treatment could be an option. While intrathecal therapy is presently used with good results in clinical practice, the current evidence is limited. Hence, increased knowledge of intrathecal pain treatment is needed. This retrospective study aimed to assess complications and side effects related to intrathecal pain treatment in patients with terminal cancer.

Methods: A retrospective study on all patients who received intrathecal treatment with morphine and bupivacaine through externalized catheters for cancer-related pain at a single university hospital during a 5-year period.

Results: Treatment-related complications were reported in 24 out of 53 patients. The most common complications were catheter dislocation (13%), catheter occlusion (9%), falls due to bupivacaine-related numbness or weakness (9%), and reversible respiratory depression (8%). There were five serious complications, i.e., meningitis or neurological impairment, of which four were reversible. Side effects related to intrathecal drugs, or the implantation procedure were observed in 35 patients. The most common were bupivacaine-related numbness or weakness (57%) and reversible post-dural puncture headache (19%). Systemic opioid doses decreased during the first 3 weeks of intrathecal treatment, from a median daily dose of 681 to 319 oral morphine milligram equivalents. The median treatment duration time was 62 days.

Conclusions: Complications related to intrathecal treatment are common, but mostly minor and reversible. Side effects are predominantly related to unwanted pharmacological effects from intrathecal drugs. Intrathecal treatment enables the reduction of systemic opioid doses, which indicates a good treatment effect on pain. Hence, intrathecal therapy can be considered a safe pain-relieving treatment in patients with severe refractory cancer-related pain. Future research is warranted on patient acceptability and satisfaction of intrathecal pain treatment.

Objective: The Pain Self-Efficacy Questionnaire (PSEQ) is a widely used patient-reported outcome measure designed to assess the level of pain self-efficacy in patients with low back pain (LBP). Although the PSEQ has been translated into Danish, its measurement properties remain unknown in patients with subacute and chronic LBP in Danish outpatient clinics. The aim of this study was to investigate the construct validity, internal consistency, test-retest reliability, and measurement error of the Danish version of the PSEQ in a group of Danish patients with subacute and chronic LBP in a hospital outpatient setting.

Methods: Patients with LBP referred to two Danish outpatient clinics were recruited for this study. Two days after the consultation, the participants were emailed a link to a survey that included the following outcome measures: the PSEQ, the Oswestry Disability Index, the Numeric Pain Rating Scale, and the Tampa Scale of Kinesiophobia. Five days after completion of the survey, a new survey that included the PSEQ was sent to the participants.

Results: In total, 109 participants were included for the analysis of construct validity and internal consistency, with 94 participants included for the analysis of test-retest reliability and measurement error. Construct validity was found to be high and internal consistency was acceptable, with Cronbach's alpha = 0.93 (95% confidence interval [CI] = 0.91-0.93). Test-retest reliability was found to be good, with an intraclass correlation coefficient (ICC_2.1) of 0.89 (95% CI = 0.82-0.92). The standard error of measurement was calculated to be 4.52 and the smallest detectable change was 12.5 points.

Conclusions: The Danish version of the PSEQ showed acceptable measurement properties in terms of construct validity, internal consistency, and test-retest reliability in a group of patients with subacute and chronic LBP. However, further studies are needed to investigate other aspects of the measurement properties.

Objectives: Pain relief and reduced disability are both common treatment targets for persistent disabling low back pain (LBP). Cross-sectional studies show a moderate relationship between functional disability and pain intensity, but little is known about the relationship between changes in pain intensity and functional disability over multiple time points. The objective of this study was to investigate the associations between changes in functional disability and pain intensity and whether changes occurred simultaneously or differentially during a course of cognitive functional therapy for people with persistent disabling LBP.

Methods: Self-reported measures of pain intensity and patient-specific functional disability were collected prior to each treatment session from 40 participants during a 12-week intervention period. Linear mixed modeling was used to assess simultaneous and lagged associations between pain intensity and functional disability over time. Sensitivity analysis using nonparametric subject-specific methods (simulation modeling analysis) was also performed.

Results: Thirty-five participants had sufficient data for analysis. Using the linear mixed-model approach, there was evidence of a moderate and simultaneous association between pain intensity and functional disability over time (regression coefficient = 0.56, 95% confidence interval: 0.44-0.68, p < 0.001). Simulation modeling analysis supported weak to mostly strong associations and supported for simultaneous change in pain and disability for the majority of participants (22 of 35, 64%).

Conclusion: Changes in pain intensity and functional disability were moderately related across the intervention. Visual inspection of graphs indicated a very close relationship in some individuals and a decoupling of pain intensity and functional disability in others. The changes in pain intensity and functional disability seem to occur simultaneously in most individuals.

Background: Proximal femur fracture surgeries have become increasingly prevalent, presenting unique challenges for postoperative pain management due to patient demographics and comorbidities. Erector spinae plane block (ESPB) has emerged as a relatively safe alternative to paravertebral block (PVB). Our aim was to compare ultrasound-guided continuous ESPB with continuous PVB for postoperative analgesia in patients undergoing proximal femur surgeries under spinal anesthesia.

Methods: A prospective randomized interventional study was conducted on 60 patients between 18 and 60 years of age undergoing proximal femur surgeries under spinal anesthesia with American Society of Anesthesiologists physical status I and II between January 2019 and April 2020. Patients were randomly assigned to receive either ultrasound-guided continuous ESPB (Group E, n = 30) or ultrasound-guided continuous PVB (Group P, n = 30) using a computer-generated randomization table. The mean maximum visual analog scale (VAS) score, VAS score in the first 24 h, the time of rescue analgesia, and total requirement of rescue analgesia were assessed.

Results: The maximum VAS score within the first 24 h was numerically higher in Group P but statistically insignificant (p-value 0.279). VAS scores at 0, 1, 2, 6, and 18 h postoperatively were comparable in both groups. However, at the 24-h mark, the VAS score between Group E and Group P was statistically significant (p-value 0.018) but not clinically relevant. The mean paracetamol and tramadol requirements were comparable between the two groups.

Conclusion: Continuous ESPB is as effective as continuous PVB for postoperative analgesia in proximal femur surgeries. The enhanced safety profile of erector spinae block underscores its significance in postoperative pain management.

Objectives: A high incidence of attention-deficit hyperactivity disorder (ADHD) has been reported in chronic pain (ChP) patients. Furthermore, an association between ChP and muscular dysregulation has been reported in adults with ADHD. The present study investigated whether ADHD was more prevalent among psychiatric outpatients with ChP than those without ChP, and if there was an association between ChP, muscular dysregulation and characteristics of pain in patients with ADHD.

Methods: One-hundred and twenty-one individuals remitted to an outpatient psychiatry unit took part in this naturalistic epidemiological cross-sectional study. They were assessed with a pain self-report form (localization, intensity, and onset) and a test of muscle dysregulation (the Motor Function Neurological Assessment). Prevalence of ADHD among patients with ChP, as well as the qualitative characteristics of ChP within the ADHDgroup are reported. Both ChP and pain intensity correlated with muscular dysregulation through Spearman's rho analysis. Additionally, the relationship between various diagnostic categories (ADHD, affective disorders, anxiety, or personality disorders) and incidence of axial pain was evaluated in logistic regression.

Results: ADHD was significantly more prevalent in patients with ChP, than in patients without ChP. In the ADHD group, ChP and pain intensity was associated with muscular dysregulation, particularly with high muscle tone. ChP was more axial and widespread, than for the patients without ADHD, and started at an early age. ADHD diagnosis predicted axial pain, whereas affective-, anxiety-, or personality disorders did not.

Conclusions: The study suggests that ChP in ADHD is associated with muscular dysregulation and is qualitatively different from ChP in psychiatric patients without ADHD. These findings may lead to further understanding of potential mechanisms involved in ADHD and ChP, and in turn to new treatment strategies for both disorders.

Objectives: The aim of this study was to investigate a panel of inflammatory biomarkers in plasma from forklift truck operators (FLTOs) and healthy controls, and their relation to neck pain characteristics.

Methods: From employees in a warehouse, 26 FLTOs were recruited and 24 healthy age- and sex-matched controls (CONs) were recruited via advertisement. The inclusion criterion for FLTOs was that they should operate reach decker and/or counterbalanced tilting mast forklift trucks. All participants were asked to answer a questionnaire covering demographic data, pain intensity numeric rating scale (NRS), anatomical spread, psychological distress, and health aspects. Pain sensitivity was measured using a pressure algometer. Blood samples were collected and analyzed for inflammatory proteins in plasma using a panel of 71 cytokines and chemokines. Multivariate data analysis including orthogonal partial least square-discriminant analysis (OPLS-DA) was performed to identify significant biomarkers.

Results: Thirty percent of FLTOs reported NRS > 3 in the neck. Shoulder pain was common in 26% of the FLTOs. Pain and discomfort that most often prevented completion of activities were in the neck (20%), lower back (32%), and hips (27%). The FLTOs reported significantly (p = 0.04) higher levels of anxiety than the CON group and they had significantly lower pressure pain thresholds in the trapezius muscle on both right (p < 0.001) and left sides (p = 0.003). A significant OPLS-DA model could discriminate FLTOs from CON based on nine inflammatory proteins where the expression levels of four proteins were upregulated and five proteins were downregulated in FLTOs compared to CONs. Twenty-nine proteins correlated multivariately with pain intensity.

Conclusions: The profile of self-reported health, pain intensity, sensitivity, and plasma biomarkers can discriminate FLTOs with pain from healthy subjects. A combination of both self-reported and objective biomarker measurements can be useful for better understanding the pathophysiological mechanisms underlying work-related neck and shoulder pain.