Assessment of pain-related cognitions in chronic pain patients

Beyond the chronic pain stage: default mode network perturbation depends on years lived with back pain

ABSTRACT

Research has indicated that the default mode network (DMN) is perturbated in patients with chronic pain when compared with healthy controls, and this perturbation is correlated with the duration of pain during the chronic pain stage. It remains unclear whether DMN adaptations manifest during the subacute pain stage and progress over time because of the duration of pain experience, rather than being a specific correlate of the chronic pain stage. Furthermore, information regarding whether these adaptations are related to cognitive processes of adaptation is lacking. To this end, we examined the DMN in 31 patients with chronic back pain (CBP), 77 patients with subacute back pain (SBP), as well as 39 healthy pain-free controls (HC) applying a graph-theoretic network approach on functional resting-state magnetic resonance imaging. Beyond the comparison between groups, we used a linear analysis considering the years lived with pain (YLP) across all patients with back pain and additionally performed a mediation analysis of the role of cognitive pain coping. In line with previous studies, we found significant DMN perturbation in CBP compared with HC. However, this did not apply to the comparison of CBP with SBP. Instead, we observed a positive correlation between DMN perturbation and YLP. This was significantly mediated by coping attitudes towards pain. Default mode network perturbation may thus reflect neural adaptation processes to pain experience rather than a single correlate of the chronic pain stage and be modulated by cognitive adaption. This points to potentially underinvestigated significant adaptation processes that could enable more fine-grained patient stratification.

Predictors of treatment outcome in cognitive behavioural therapy for chronic pain: a systematic review

PURPOSE

The aim of this systematic review was to synthesise the research identifying possible influences on CBT outcomes in chronic pain. Variations in the effectiveness of psychological therapies, such as CBT, in chronic pain have led to research investigating predictors of improved treatment outcomes.

MATERIALS AND METHODS

We identified randomised controlled and cohort studies of CBT for chronic pain, published between 1974 to 2nd August 2023, which identified predictors of CBT outcomes.

RESULTS

Nineteen studies were included in the review. Baseline sociodemographic, physical and emotional factors that influence the outcomes of CBT for chronic pain were identified. The most commonly reported predictors of CBT outcome, with medium to large effect sizes, were anxiety, depression and negative cognitions about pain and coping. Sociodemographic predictors of outcomes demonstrated small effects and lacked replicability.

CONCLUSIONS

There was variability across study designs, CBT delivery and outcomes measures. Further research is needed in chronic pain to identify the predictive factors which influence treatment outcomes, and consistency across study designs and outcome variables is needed to reduce heterogeneity.

The Relationship between Pain Catastrophizing and Cognitive Function in Chronic Musculoskeletal Pain: A Scoping Review

Objective

Chronic musculoskeletal pain (CMP) poses a considerable threat to physical, mental, and financial health worldwide. Beyond physical difficulties, CMP has a pronounced impact on pain behaviors and cognitive function. The purpose of this scoping review was to examine the relationship between pain catastrophizing (PC) and cognitive function in CMP, identify gaps in the literature, and provide future directions for research on the topic.

Methods

Search strings were entered in the following databases: PubMed, CINAHL, Nursing and Allied Health, Ovid Emcare, PsycInfo, and Scopus. Data from the included articles were extracted thematically based on diagnostic classification and included author(s), year of publication, country, aim, sample, methods, intervention (if applicable), and key findings.

Results

30 articles were included after screening. The studied populations included patients with fibromyalgia, chronic low back pain, and CMP. Two studies were designed to assess the relationship between PC and cognition as the primary aim. The included studies demonstrated variable evidence regarding the relationship between PC and cognition. Only four studies included clinically relevant PC populations (i.e., Pain Catastrophizing Scale score >30), and all found significant correlations.

Conclusion

Although evidence exists for the relationship between cognitive function and PC, there is a lack of rigorous research to indicate the strength of this relationship and the specific cognitive functions affected. The literature lacks appropriate populations needed to investigate clinically relevant PC and is limited by heterogeneous neuropsychological test batteries. Future research should include populations demonstrating the behaviors being studied, intentional analysis of outcomes, and appropriate cognitive tests.

MicroRNA-Related Polymorphism and Their Association with Fibromyalgia

MicroRNAs are tissue-specific expressed short RNAs that serve post-transcriptional gene regulation. A specific microRNA can bind to mRNAs of different genes and thereby suppress their protein production. In the context of the complex phenotype of fibromyalgia, we used the Axiom miRNA Target Site Genotyping Array to search genome-wide for DNA variations in microRNA genes, their regulatory regions, and in the 3'UTR of protein-coding genes. To identify disease-relevant DNA polymorphisms, a cohort of 176 female fibromyalgia patients was studied in comparison to a cohort of 162 healthy women. The association between 48,329 markers and fibromyalgia was investigated using logistic regression adjusted for population stratification. Results show that 29 markers had p-values < 1 × 10^-3, and the strongest association was observed for rs758459 (p-value of 0.0001), located in the Neurogenin 1 gene which is targeted by hsa-miR-130a-3p. Furthermore, variant rs2295963 is predicted to affect binding of hsa-miR-1-3p. Both microRNAs were previously reported to be differentially expressed in fibromyalgia patients. Despite its limited statistical power, this study reports two microRNA-related polymorphisms which may play a functional role in the pathogenesis of fibromyalgia. For a better understanding of the disease pattern, further functional analyses on the biological significance of microRNAs and microRNA-related polymorphisms are required.

Stress-induced hyperalgesia instead of analgesia in patients with chronic musculoskeletal pain

Many individuals with chronic musculoskeletal pain (CMP) show impairments in their pain-modulatory capacity. Although stress plays an important role in chronic pain, it is not known if stress-induced analgesia (SIA) is affected in patients with CMP. We investigated SIA in 22 patients with CMP and 18 pain-free participants. Pain thresholds, pain tolerance and suprathreshold pain ratings were examined before and after a cognitive stressor that typically induces pain reduction (SIA). Whereas the controls displayed a significant increase in pain threshold in response to the stressor, the patients with CMP showed no analgesia. In addition, increased pain intensity ratings after the stressor indicated hyperalgesia (SIH) in the patients with CMP compared to controls. An exploratory analysis showed no significant association of SIA or SIH with spatial pain extent. We did not observe significant changes in pain tolerance or pain unpleasantness ratings after the stressor in patients with CMP or controls. Our data suggest that altered stress-induced pain modulation is an important mechanism involved in CMP. Future studies need to clarify the psychobiological mechanisms of these stress-induced alterations in pain processing and determine the role of contributing factors such as early childhood trauma, catastrophizing, comorbidity with mental disorders and genetic predisposition.

A Systematic Review of the Variation in Pain Catastrophizing Scale Reference Scores Based on Language Version and Country in Patients with Chronic Primary (Non-specific) Pain

INTRODUCTION

This systematic review aimed to investigate variations of reference scores for the Pain Catastrophizing Scale (PCS) between language versions and between countries in patients with chronic primary pain (CPP) or chronic primary pain, not otherwise specified (CPP-NOS).

METHODS

Electronic searches of the Ovid/Embase, Ovid/MEDLINE, and Ovid/PsycINFO databases were conducted to retrieve studies assessing PCS scores in adults with CPP or CPP-NOS proposed by the International Classification of Diseases, Eleventh Revision for any country where the translated PCS was available. The protocol for this systematic review was prospectively registered on the International Prospective Register of Systematic Reviews 2018 (registration number: CRD 42018086719).

RESULTS

A total of 3634 articles were screened after removal of duplicates. From these, 241 articles reporting on 32,282 patients with chronic pain were included in the review. The mean (± standard deviation) weighted PCS score across all articles was 25.04 ± 12.87. Of the 12 language versions and 21 countries included in the review, the weighted mean PCS score in Asian languages or Asian countries was significantly higher than that in English, European, and other languages or Western and other countries. The highest mean score of the weighted PCS based on language was in Japanese (mean 33.55), and the lowest was in Russian (mean 20.32). The highest mean score of the weighted PCS based on country was from Japan (mean 33.55), and the lowest was from Australia (mean 19.80).

CONCLUSION

The weighted PCS scores for people with CPP or CPP-NOS were significantly higher in Asian language versions/Asian countries than in English, European and other language versions or Western and other countries.

When shared pain is not half the pain: enhanced central nervous system processing and verbal reports of pain in the presence of a solicitous spouse

ABSTRACT

The experience of pain and pain behaviors is not only determined by physiological but also psychosocial factors. In this context, the learning history of the individual and specifically operant reinforcement related to spouse responses might play an important role. We investigated the effect of a solicitous and habitually pain-reinforcing spouse for the processing of pain in patients with chronic pain. Using multichannel electroencephalography, pain behaviors, and self-reports of pain, we examined 20 patients with chronic back pain (10 with solicitous and 10 with nonsolicitous spouses) and 10 matched healthy controls. The participants received a series of painful and nonpainful electrical stimuli applied to the site of pain (back) and a control area (finger) in the presence vs absence of the spouse. The global field power of the electroencephalogram with a focus in the frontal region was enhanced in patients with chronic back pain who had a solicitous spouse compared to those with a nonsolicitous spouse and the healthy controls. This was specific for the painful stimulation at the back and occurred only in the presence but not the absence of the spouse. Pain ratings of intensity and unpleasantness were also higher in the patients with solicitous spouses when the spouse was present during painful stimulation. These data suggest that significant other responses indicative of operant reinforcement may have a direct effect on the cerebral processing of pain and related pain perception.

Psychiatric Comorbidities Associated with Persistent Postoperative Opioid Use

PURPOSE OF REVIEW

This review outlines the psychiatric comorbidities associated with persistent opioid use in the postoperative period. We finish our analysis with evidence-based, patient-centered interventions that can be rendered in the perioperative setting to decrease postoperative opioid requirements.

RECENT FINDINGS

Opioids are overprescribed in the USA, especially in the postoperative setting. Excess opioids can result in diversion and contribute to the ongoing opioid epidemic. Mental health and substance use disorders can contribute to persistent postoperative opioid use. Adequately managing these disorders preoperatively promises to reduce persistent postoperative opioid use. Due to the lack of homogenous, evidence-based recommendations on the appropriate quantity and duration of postoperative opioid therapy, there is wide variability in provider prescribing habits. Further research is needed to establish surgery-specific postoperative opioid therapy protocols. Opioids continue to be a mainstay in the treatment of postoperative pain. Unmonitored postoperative opioid use can lead to opioid use disorder. Mental health disorders increase susceptibility to persistent postoperative opioid use. By managing these psychiatric illnesses preoperatively, clinicians have the ability to decrease opioid consumption postoperatively. Lastly, given the healthcare burden of opioid misuse and abuse, it is important to establish concrete protocols to guide provider-prescribing habits.

Inflammatory Bowel Disease and Pain Interference: A Conceptual Model for the Role of Insomnia, Fatigue, and Pain Catastrophizing

Background

People with inflammatory bowel disease (IBD) commonly experience pain influenced by complex interactions among factors, including disease activity, sleep, psychopathology, and changes in pain processing pathways. Treatments for pain in IBD are limited, highlighting the need for research that explores modifiable factors linked to pain. The aim of this study was to investigate relationships among multiple patient factors and to construct a conceptual model for pain interference in IBD.

Methods

A cross-sectional survey of adults with IBD. Study domains included demographic, comorbidity, psychological, IBD, insomnia, fatigue, and pain features. Structural equation modeling (SEM) was used to examine relationships and interactions among active IBD, insomnia, fatigue, pain experiences (severity, catastrophizing, and interference), and additional patient factors (demographics and psychological).

Results

One hundred and seventy-four participants, aged 18-85 years, reported the presence of pain. Combining the questionnaire data using SEM resulted in a final model with an excellent fit (χ 2(8) = 9.579, P = .297, χ 2/N = 1.197, CFIN = 0.997, TLI = 0.987, RMSEA = 0.034). The presence of anxiety and depression was the additional patient factors to be retained in the path analysis. SEM results indicated that greater pain interference was directly influenced by greater fatigue, worse pain catastrophizing, and worse pain severity. Pain interference was indirectly impacted by IBD activity, worse insomnia, and the presence of depression and anxiety.

Conclusions

The proposed conceptual model highlights the role of multiple potentially modifiable factors, including insomnia, pain catastrophizing, and fatigue, contributing to worse pain interference in people with IBD.

Do catastrophizing and autonomic-reduced flexibility mediate pain outcomes in chronic headache?

OBJECTIVES

Maladaptive cognitive strategies and reduced autonomic flexibility have been reported in chronic pain conditions. No study to date addressed the effects of maladaptive coping and reduced autonomic flexibility, as indexed by heart rate variability (HRV), in chronic headaches. The present study aimed to assess the mediating role of pain catastrophizing and HRV on pain outcomes in patients with chronic headache.

METHODS

Thirty-two chronic headache patients and 28 healthy controls were recruited. Self-reported pain severity, pain interference on daily activity, and pain catastrophizing were assessed through the Multidimensional Pain Inventory and the Pain-Related Self Statements Scale. HRV was recorded at rest. Correlations and mediation analysis between self-report, HRV, and pain outcomes were run.

RESULTS

Patients with chronic headache reported significantly higher pain severity (p < .001; d =  - 1.98), pain interference on daily activity (p < .001; d =  - 1.81), and pain catastrophizing (p < .001; d =  - 0.96) compared to controls. They also presented significantly lower HRV (p < .05; d = 0.57). Both pain catastrophizing and HRV were associated with pain interference on daily activity. However, from mediation analysis, pain catastrophizing only emerged as the mediator for pain severity (p < .001; b = 0.30) and pain interference (p < .001; b = 0.14).

CONCLUSION

Present results showed that chronic headache patients are characterized by high catastrophizing and lower physiological adaptability. Pain catastrophizing emerged as the only mediator of pain outcomes, suggesting that cognitive factors might have a major influence on the severity of pain and its interference on daily activities. Further studies are needed to evaluate these autonomic-cognitive interactions in chronic pain.

Preoperative Predictors for Acute Pain After Photorefractive Keratectomy

PURPOSE

The aim of this study was to identify preoperative predictors for the occurrence of early severe postoperative pain in patients undergoing photorefractive keratectomy (PRK). The implementation of preoperative screening methods may facilitate more specific or aggressive pain therapies specifically targeted to individuals at a high risk of experiencing severe postoperative pain.

METHODS

This was exploratory research that included patients who underwent PRK. Before PRK, patients were administered a sociodemographic questionnaire, the Pain Catastrophizing Scale, and the State-Trait Anxiety Inventory and underwent corneal sensitivity and conditioned pain modulation (CPM) tests. Post-PRK pain was assessed using a pain intensity visual analog scale (VAS), and the short-form McGill Pain Questionnaire (SF-MPQ) was completed 21 days before PRK and 1, 24, 48, and 72 hours after PRK. Spearman correlations were calculated for pain scores and preoperative predictors.

RESULTS

This research included 34 eyes of 34 patients. Preoperative corneal sensitivity was positively correlated with post-PRK pain scores as assessed by VAS and SF-MPQ (rho = 0.39 and rho = 0.41, respectively, P < 0.05). No correlations were found between Pain Catastrophizing Scale, State-Trait Anxiety Inventory, and CPM scores and post-PRK pain scores (P > 0.05).

CONCLUSIONS

Abnormal presurgical corneal sensitivity was a protective marker for severe pain after PRK, while scores as assessed by VAS and SF-MPQ and CPM were not related to postoperative pain.

Pain sensitivity is associated with general attitudes towards pain: Development and validation of a new instrument for pain research and clinical application

BACKGROUND

With regard to attitudes towards pain, many questionnaires have been developed. Although undoubtedly useful, they were specifically designed for the use in chronic pain and are less suitable for the assessment in the general population. The purpose of the present paper was to develop a measure for the assessment of general attitudes towards pain applicable in the general population, regardless of clinical condition, and to test its psychometric properties.

METHODS

We developed the General Attitudes Towards Pain Inventory and conducted two studies in order to provide psychometric data: In a general population sample (N = 362, study one), participants were asked to complete a questionnaire battery. To assess test-retest reliability, participants were contacted again after four weeks (retest sample: N = 101). For the evaluation of criterion validity (study two), a sample with sadomasochistic sexual preference (N = 68) was additionally recruited.

RESULTS

Statistical analyses revealed, overall, acceptable internal consistencies and test-retest reliabilities. A ten-factor model showed acceptable fit and was superior to alternative models. The inventory demonstrated convergent and divergent validity. In this context, we found pain sensitivity to be associated with pain attitudes. Finally, compared to the general population sample, individuals with sadomasochistic sexual preference showed significantly higher scores on fascination-pleasure and challenge subscales.

CONCLUSIONS

In the present paper, we introduce a new and comprehensive instrument for pain research and provide evidence for its reliability and validity. In addition, we present new insights into how interindividual differences in pain sensitivity relate to pain attitudes.

Optimising treatment expectations in chronic lower back pain through observing others: a study protocol for a randomised clinical trial

INTRODUCTION

Chronic lower back pain (CLBP) is a frequent cause of medical consultations worldwide, and it results in decreased quality of life and disability. Current treatments for CLBP are often not effective, and alternatives are urgently needed. Three promising possibilities have emerged: (1) open-label placebo treatment reduces chronic pain, (2) placebo treatment is as efficacious as opioid treatment with a high correlation between patient expectation and treatment outcome, and (3) observing positive effects in another patient can improve functional capacity. We hypothesise that treatment expectations can be positively influenced through social observation and improve treatment outcome.

METHODS AND ANALYSIS

In our clinical trial, we will randomise patients with CLBP into five groups. Two groups receive either a 3 week course of treatment with an analgesic (ANA) (metamizole/dipyrone) or with open-label placebos (OLP). For one of each group, we will build treatment expectations through observational learning and assess its impact on the treatment. For this purpose, one group each will watch either a positive or a neutral video. The intervention groups will be compared with a control group that will not be given any medication or observational learning. Participants will be recruited via all institutions in the Hamburg metropolitan area that treat patients with CLBP. Patients are eligible for inclusion if they are at least 18 years or older, have CLBP (of at least 3 months duration), and agree to potentially receive an active ANA or an OLP. Patients with pain-related "red flags" will be excluded. The study requires 150 participants (30 participants per group) to assess the differences in the primary outcome, pain intensity. Secondary outcomes include changes in treatment expectations, anxiety, comorbid depression, stress-related neuroendocrine measures, functional and structural connectivity, functional capacity, and ANA consumption. All outcomes and treatment expectations will be measured before and after the intervention and 3 months post-intervention.

ETHICS AND DISSEMINATION

Ethical approval was obtained in January 2020 from the Hamburg Medical Ethics Council (ref number PV7067). Outcomes will be disseminated through publications in peer-reviewed journals and presentations at national and international conference meetings.

TRIAL REGISTRATION NUMBER

The approved trial protocol was registered at the German Clinical Trials Register (DRKS) and can be found at drks.de (Identifier: DRKS00024418).

Study on Pain Catastrophizing From 2010 to 2020: A Bibliometric Analysis via CiteSpace

Purpose: This study aimed to evaluate the global scientific output of research on pain catastrophizing and explore the hotspots and frontiers from 2010 to 2020 using bibliometric methods.

Methods: Publications regarding pain catastrophizing published from 2010 to 2020 were extracted from the Web of Science Core Collection. CiteSpace was used to analyze the number of publications, countries, institutions, journals, authors, cited references, and keywords using standard bibliometric indicators.

Results: A total of 1,576 publications on pain catastrophizing were retrieved from 2010 to December 31, 2020. The number and rate of the annual publications gradually increased totally. Pain (130) was the most productive journal. Meanwhile, Pain ranked first in the frequency (1,432) and centrality (0.31) of the cited journals. The most productive country and institution in this frequency field were the United States (642) and the University of Washington (73), respectively. Jensen MP (34) was the most prolific author, and Sullivan MJL (1,196) ranked first among the cited authors. In the ranking of frequency in the cited references, the first article was a critical review about pain catastrophizing published by Quartana (100). The keyword “Low back pain” had the highest frequency (556). “Total hip” was identified as a frontier research item for 2016–2020.

Conclusion: The findings of this bibliometric study provide the current status and trends in the clinical research of pain catastrophizing and may help researchers to identify hot topics and explore new research directions in this field.

The relationship between psychosocial factors and reported disability: the role of pain self-efficacy

BACKGROUND

Chronic pain and the accompanying level of disability is a healthcare crisis that reaches epidemic proportions and is now considered a world level crisis. Chronic non-specific low back pain (CNLBP) contributes a significant proportion to the chronic pain population. CNLBP occurs with overlapping psychosocial factors. This study was design to investigate specific psychosocial factors and their influence on reported disability in a population with CNLBP.

METHODS

The specific psychosocial factors examined included fear, catastrophizing, depression, and pain self-efficacy. This cross-sectional correlational study investigated the mediating role between pain self-efficacy, the specific psychosocial factors, and reported disability. The study recruited 61 female and 29 male participants from physical therapy clinics. The participants were between 20-to-60 years of age and diagnosed with CNLBP. All participants completed the Fear Avoidance Belief Questionnaire, The Pain Catastrophizing Scale, The Patient Health Questionnaire-9, The Pain Self-Efficacy Questionnaire, and The Lumbar Oswestry Disability Index. The battery of questionnaires measured fear of physical activity, pain catastrophizing, depression, pain self-efficacy, and reported disability. Multivariate regression and mediation analyses was used to analyse the data.

RESULTS

The principal finding was a strong inverse relationship between pain self-efficacy and reported disability with a p-value < 0.001. Further, pain self-efficacy was considered a statistical mediator with consistent p-value < 0.001 for the specific psychosocial factors investigated within this data set. Pain self-efficacy was considered to have a mediating role between reported fear of physical activity and disability, reported pain catastrophizing and disability, and reported depression and disability. Additionally, age and reported pain levels proved to be statistically significant. Adjustments for age and pain level did not alter the role of pain self-efficacy.

CONCLUSION

The results identified a mediating role for pain self-efficacy between the specific psychosocial factors (fear, catastrophizing, and depression) and reported disability. Pain self-efficacy plays a more significant role in the relationships between these specific psychosocial factors and reported disability with CNLBP than previously considered.

Mindfulness-Based Cognitive Therapy as Migraine Intervention: a Randomized Waitlist Controlled Trial

BACKGROUND

Based on promising effects seen in a pilot study evaluating a generic mindfulness-based program for migraine, we developed a migraine-specific adaptation of the Mindfulness-Based Cognitive Therapy (MBCT) program. The aim of this study was to evaluate this program for feasibility and effectiveness in a randomized controlled trial.

METHOD

Fifty-four patients suffering from migraine were randomly allocated to either waitlist or the adapted MBCT. Outcomes were migraine-related parameters as well as variables of psychological functioning and coping. Assessment took place at baseline and post-intervention, for the intervention group also at follow-up (7 months). The effects of the intervention were analyzed by the use of ANCOVAs and linear mixed models.

RESULTS

With respect to migraine parameters we did not find a significant group difference in the primary outcome (headache-related impairment), but the intervention resulted in a significant reduction of headache frequency (p = .04). In the analysis of secondary outcomes, MBCT showed superiority in four out of eight psychological parameters (perceived stress, anxiety, rumination, catastrophizing) with small to medium effect sizes. The intervention proved to be feasible and participants reported high degrees of contentment and achievement of personal goals.

CONCLUSIONS

The migraine-specific MBCT program did not result in improvements with regard to headache-related impairment but showed a reduction in headache frequency as well as improved psychological functioning in secondary outcomes.

TRIAL REGISTRATION

This trial was registered in the German Trial Registry "Deutsches Register Klinischer Studien" (ID: DRKS00007477), which is a WHO-listed primary trial register.

Psychological factors associated with headache frequency, intensity, and headache-related disability in migraine patients

Background

Several psychological cofactors of migraine have been identified, but relationships to different headache parameters (e.g., headache frequency vs. headache-related disability) are only incompletely understood.

Methods

We cross-sectionally assessed 279 migraine patients at their first presentation at our tertiary headache center. We obtained headache and acute medication frequency, pain intensity, the Migraine Disability Assessment Scale (MIDAS), and the Pain Disability Index (PDI) as headache-related outcomes as well as scores of the Hospital Anxiety and Depression Scale (HADS), the Pain Catastrophizing Scale (PCS), Pain-Related Control Scale (PRCS), and Avoidance Endurance Questionnaire (AEQ) as psychological factors.

Results

Linear regression models revealed the highest associations of the psychological factors with the PDI (adjusted R² = 0.296, p < 0.001, independent predictors: PCS, AEQ social avoidance, depression) followed by the MIDAS (adjusted R² = 0.137, p < 0.001, predictors: depression, AEQ social avoidance) and headache frequency (adjusted R² = 0.083, p < 0.001, predictors: depression, AEQ humor/distraction). Principal component analysis corroborated that psychological factors were preferentially associated with the PDI, while the MIDAS loaded together with headache frequency.

Conclusion

Our results suggest that psychological factors are more strongly associated with the subjective degree of headache-related disability measured by the PDI than with the days with disability (MIDAS) or the more objective parameter of headache frequency. This once again highlights the need for comprehensive assessment of migraine patients with different headache parameters and the need for considering psychological treatment, especially in patients with high disability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05453-2.

Group Differences Between Countries and Between Languages in Pain-Related Beliefs, Coping, and Catastrophizing in Chronic Pain: A Systematic Review

Objective

To evaluate the extent to which pain-related beliefs, appraisals, coping, and catastrophizing differ between countries, language groups, and country economy.

Design

Systematic review.

Methods

Two independent reviewers searched 15 databases without restriction for date or language of publication. Studies comparing pain beliefs/appraisals, coping, or catastrophizing across two or more countries or language groups in adults with chronic pain (pain for longer than three months) were included. Two independent reviewers extracted data and performed the quality appraisal. Study quality was rated as low, moderate, or high using a 10-item modified STROBE checklist. Effect sizes were reported as small (0.20–0.49), medium (0.50–0.79), or large (≥0.80).

Results

We retrieved 1,365 articles, read 42 potential full texts, and included 10 (four moderate-quality, six low-quality) studies. A total of 6,797 adults with chronic pain (33% with chronic low back pain) were included from 16 countries. Meta-analysis was not performed because of heterogeneity in the studies. A total of 103 effect sizes were computed for individual studies, some of which indicated between-country differences in pain beliefs, coping, and catastrophizing. Of these, the majority of effect sizes for pain beliefs/appraisal (60%; eight large, eight medium, and eight small), for coping (60%; seven large, 11 medium, and 16 small), and for catastrophizing (50%; two medium, one small) evidenced statistically significant between-country differences, although study quality was low to moderate.

Conclusions

In 50% or more of the studies, mean scores in the measures of pain beliefs and appraisals, coping responses, and catastrophizing were significantly different between people from different countries.

Psycho-sensory relationships in chronic pain

BACKGROUND

Psychological variables contribute to pain- and injury-related outcomes. We examined the hypothesis that anatomical spread and intensity of persistent pain relate to anxiety-related variables: generalised anxiety, fear of pain and pain catastrophising.

METHODS

An online survey was used to gather data from 413 women with persistent pain (low back pain, n = 139; fibromyalgia syndrome, n = 95; neck pain, n = 55; whiplash, n = 41; rheumatoid arthritis, n = 37; migraine, n = 46). The spread and intensity of pain were assessed using the McGill pain chart and a Numerical Rating Scale. A Bayesian Structural Equation Model assessed if the intensity and spread of pain increased with anxiety-related variables. Men were also surveyed (n = 80), but the sample size was only sufficient for analysing if their data were consistent with the model for women.

RESULTS

Across subgroups of women, one standard deviation increase in catastrophising, generalised anxiety and fear corresponded to 27%, 7% and -1% additional pain areas and a 1.1, 0 and -0.1 change in pain intensity (on 0-10 scale), respectively. Overall, our clinical significance criterion - a 30% shift in pain variable in relation to one standard deviation increase in psychological variable - was not met. However, in subgroups it was met for pain spread (low back pain, neck pain and migraine) and pain intensity (migraine and neck pain) in relation to pain catastrophising. The model generally had low goodness-of-fit to men.

CONCLUSION

These data support a meaningful relationship between some anxiety-related variables and pain in women for some conditions. Since the model did not consistently fit the men, we may conclude that the relationships are moderated by sex. Clinician attention to psychological variables as potential contributing factors can be justified; however, research is needed to understand the relationship and whether psychological treatment can reduce pain.

Is the psychological composition of the therapeutic group associated with individual outcomes in group cognitive behavioural therapy for chronic pain?

This study explored whether the psychological composition of a group, with respect to mood, catastrophising, fear of movement and pain self-efficacy characteristics at baseline, is associated with individuals' treatment outcomes following group cognitive behavioural therapy (CBT)-based programmes for chronic pain. Retrospective analyses of outcomes from two independently run CBT-based pain management programmes (Programme A: N = 317 and Programme B: N = 693) were conducted. Mixed modelling analyses did not consistently support the presence of associations between group median scores of depression, catastrophising or fear avoidance with outcomes for individuals in either programme. These results suggest that the psychological profiles of groups are not robust predictors of individual outcomes in CBT groups for chronic pain. By implication, efforts made to consider group composition with respect to psychological attributes may be unnecessary.

Reducing the use of opioids by patients with chronic pain: an effectiveness study with long-term follow-up

This study addresses the problem of long-term opioid use by chronic pain patients. The study involved a secondary analysis of unanalyzed data from a published study of 2 versions of cognitive-behavioural therapy-based interdisciplinary treatment for chronic pain. In this study, we examined whether the use of opioids by 140 chronic pain patients could be ceased sustainably over 12 months after participation in the comprehensive interdisciplinary pain management program aimed at enhancing pain self-management. On admission to the treatment, there were no significant differences between those patients taking or not taking opioids on usual pain, pain interference in daily activities, pain-related disability, depression severity, as well as in pain cognitions. After the treatment, the use of opioids was significantly reduced, both in numbers taking any and in mean doses, and these gains were maintained over the 12-month follow-up. Finally, cessation of opioids during treatment was associated with more substantial and consistent improvements in usual pain, depression severity, pain interference, pain-related disability, and pain cognitions, relative to those who reduced their opioids but did not cease them. These findings support the idea of using training in pain self-management strategies as a viable alternative to long-term opioid use by patients with chronic pain.

Differential sensory and clinical phenotypes of patients with chronic widespread and regional musculoskeletal pain

The differentiation of chronic primary pain syndromes into those with widespread vs regional musculoskeletal pain has been characterized by controversial discussions about common or distinct mechanisms and core clinical and sensory criteria. For example, the recent revision of fibromyalgia criteria has discarded sensory characteristics such as number of "tender points." This study examined empirical evidence related to this diagnostic shift and aimed to identify basic sensory-clinical pain phenotypes in patients with chronic local primary pain (chronic primary back pain [CBP]) and patients with chronic widespread primary pain (fibromyalgia syndrome). Combined sensory-clinical pain phenotypes of 185 patients with previous CBP and fibromyalgia syndrome diagnoses were derived by a stepwise data reduction through descriptive statistical, correlational, principal components and latent class analyses. Clusters were cross-validated by linear discriminant analysis. Four clusters of patients were identified, requiring 4 pressure pain sensitivity markers (number of sensitive tender and control points, pain intensity, and pressure pain threshold at the trapezius) and 2 clinical pain characteristics (pain regions and present pain intensity). Subsequent discriminant analysis revealed that 3 discriminant functions of pressure sensitivity markers sufficed to differentiate the clusters. These sensory-clinical phenotypes differed also in somatic symptoms and impairment but neither in psychopathology nor in psychosocial cofactors. The results highlight the relevance of sensory testing in combination with clinical pain assessment in chronic primary pain syndromes.

Frequency of awake bruxism behaviour in orthodontic patients: Randomised clinical trial: Awake bruxism behaviour in orthodontic patients

INTRODUCTION

The influence of aligners on the activity of the masticatory muscles is still controversial, especially regarding the behaviour associated with awake bruxism (AB).

OBJECTIVE

To compare the frequency of AB behaviours between patients treated with aligners and fixed appliances.

METHODS

The sample comprised 38 Class I patients (mean age 22.08 years), divided by simple randomisation into two groups: OA group; orthodontic aligners (n 19) and FA group; fixed appliance (n 19). The frequency of AB was investigated by the ecological momentary assessment using an online device (mentimeter), during 7 following days at different timepoints, before and after appliance placement and in the 2nd, 3rd, 4th and 6th months of orthodontic treatment. These variables were also evaluated: level of anxiety by the State-Trait Anxiety Inventory, stress by the Perceived Stress Scale, catastrophising related to pain and degree of hypervigilance by the Pain Vigilance and Awareness Questionnaire, and the presence of facial pain evaluated by the DC/TMD.

RESULTS

There was no difference between groups in the frequency of AB behaviours, with mean of 53.5% for group OA and 51.3% for FA. The most frequent behaviour was slightly touching the teeth, and in FA group, there was a significant reduction in this behaviour soon after appliance placement. The groups did not differ concerning the degree of anxiety, stress, catastrophising, hypervigilance and facial pain.

CONCLUSION

The orthodontic treatment performed with aligners or fixed appliances did not influence the frequency of AB during the 6 months of treatment. REGISTRY OF CLINICAL TRIALS: (REBEC): RBR-9zytwf.

Understanding Pain Catastrophizing: Putting Pieces Together

The present narrative review addresses issues concerning the defining criteria and conceptual underpinnings of pain catastrophizing. To date, the concept of pain catastrophizing has been extensively used in many clinical and experimental contexts and it is considered as one of the most important psychological correlate of pain chronicity and disability. Although its extensive use, we are still facing important problems related to its defining criteria and conceptual understanding. At present, there is no general theoretical agreement of what catastrophizing really is. The lack of a consensus on its definition and conceptual issues has important consequences on the choice of the pain management approaches, defining and identifying problems, and promoting novel research. Clinical and research work in absence of a common theoretical ground is often trivial. It is very surprising that clinical and experimental work has grown extensively in the past years, without a common ground in the form of a clear definition of pain catastrophizing and overview of its conceptual basis. Improving the efficacy and efficiency of pan catastrophizing related treatments requires an understanding of the theoretical construct. So far, most interventions have only demonstrated modest effects in reducing pain catastrophizing. Therefore, clarifying the construct may be an important precursor for developing more targeted and effective interventions, thereby easing some of the burden related to this aspect of pain. In our review, we have extracted and de-constructed common elements that emerge from different theoretical models with the aim to understand the concept of catastrophizing, which components can be modulated by psychological interventions, and the general role in pain processing. The analysis of the literature has indicated essential key elements to explain pain catastrophizing: emotional regulation, catastrophic worry (as repetitive negative thinking), rumination, behavioral inhibition and behavioral activation (BIS/BAS) systems, and interoceptive sensitivity. The present paper attempts to integrate these key elements with the aim to re-compose and unify the concept within a modern biopsychosocial interpretation of catastrophizing.

Evaluation of pain intensity in patients treated with aligners and conventional fixed appliances: Randomized clinical trial

OBJECTIVE

This randomized clinical trial aimed to compare the pain intensity in patients treated with orthodontic aligners and conventional fixed appliances.

SETTING AND SAMPLE POPULATION

This study was a randomized clinical trial. The sample comprised 39 patients randomly allocated into 2 groups: OA (orthodontic aligners, n = 20) and FA (Fixed Appliance, n = 19).

MATERIAL AND METHODS

The pain intensity was measured by the visual analogue scale (VAS) in the following periods: T0 (baseline), T1 (seven days after appliance placement) and seven days after each return on the first (T2), third (T3) and sixth (T4) months. The following variables were also investigated in the baseline: conditioned pain modulation, anxiety levels, hypervigilance and catastrophizing. The VAS measurements between groups were compared by the Mann-Whitney test. Comparisons between periods within each group were performed by the Friedman test. Data regarding catastrophizing and hypervigilance were compared by the t test. All tests were applied at a significance level of 5%, with 95% confidence interval.

RESULTS

Both groups presented similar levels of anxiety, hypervigilance, catastrophizing and conditioned pain modulation. Both groups did not differ concerning the pain intensity in all periods. The intragroup evaluation revealed statistical differences between days in the FA group at all moments evaluated, for the OA group, similar findings between days were found for the T1 evaluation; however, at the 6-month period (T4), the pain levels varied over these days without statistical difference. Higher levels of pain were observed in the first seven days after appliance placement.

CONCLUSION

The pain intensity, usually mild, was not influenced by the appliance design, although different patterns of reported pain seem to occur between groups.

Effectiveness of Health-Led Cognitive Behavioral-Based Group Therapy on Pain, Functional Disability and Psychological Outcomes among Knee Osteoarthritis Patients in Malaysia

Background: Psychosocial interventions for patients with osteoarthritis (OA) of the knee to reduce pain and improve physical and psychological functioning are still lacking in Malaysia. Methods: A parallel-group unblinded randomized controlled trial involving 300 patients was conducted in two hospital orthopedics clinics in Malaysia. Patients were randomly assigned to receive cognitive behavioral-based group therapy (n = 150) or no further intervention (n = 150). The primary outcome was the change from baseline in knee pain as determined by the Knee injury and Osteoarthritis Outcome Score (KOOS) at 6 months. The data collected were analyzed by covariate-adjusted mixed design repeated measures analysis of variance. All analyses were performed under the terms of intention-to-treat. Results: At 6 months, mean change from baseline in the KOOS knee pain score was 0.6 points (95% CI −1.73 to 2.94) in the control group and 8.9 points (95% CI 6.62 to 11.23) (denoting less knee pain intensity) in the intervention group (significant treatment effect p < 0.0001). Patients treated with such an approach also experienced significant improvement in functional ability when performing activities of daily living and had improved ability to cope with depression, anxiety and pain catastrophizing. Conclusion: The intervention module delivered by healthcare professionals had a sustained effect on knee OA pain and functionality over 6 months, thereby leading to an overall improvement in psychological well-being, thus benefitting most of the Malaysian knee OA patients.

Assessment of cortical reorganization and preserved function in phantom limb pain: a methodological perspective

Phantom limb pain (PLP) has been associated with reorganization in primary somatosensory cortex (S1) and preserved S1 function. Here we examined if methodological differences in the assessment of cortical representations might explain these findings. We used functional magnetic resonance imaging during a virtual reality movement task, analogous to the classical mirror box task, in twenty amputees with and without PLP and twenty matched healthy controls. We assessed the relationship between task-related activation maxima and PLP intensity in S1 and motor cortex (M1) in individually-defined or group-conjoint regions of interest (ROI) (overlap of task-related activation between the groups). We also measured cortical distances between both locations and correlated them with PLP intensity. Amputees compared to controls showed significantly increased activation in M1, S1 and S1M1 unrelated to PLP. Neural activity in M1 was positively related to PLP intensity in amputees with PLP when a group-conjoint ROI was chosen. The location of activation maxima differed between groups in S1 and M1. Cortical distance measures were unrelated to PLP. These findings suggest that sensory and motor maps differentially relate to PLP and that methodological differences might explain discrepant findings in the literature.

Characterization of pain syndromes in patients with neuromyelitis optica

BACKGROUND

Pain is common and refractory in spinal cord injury (SCI). Currently, most studies evaluated pain in male-predominant traumatic-SCI. Also, concomitant secondary pain syndromes and its temporal evolution were seldom reported.

METHODS

We aimed to prospectively describe the main and secondary pain and its associated factors in inflammatory-SCI evaluating neuromyelitis optica (NMO) patients. In-remission NMO patients underwent neurological, imaging and autoantibody evaluations. Questionnaires detailing main and secondary pains, functional state, mood, catastrophizing, quality of life (QoL) and "non-motor symptoms" were used at two time points.

RESULTS

Pain was present in 53 (73.6%) of the 72 patients included. At-level neuropathic pain was the most common main pain syndrome, affecting 32 subjects (60.4% of those with pain). Over 70% (n = 38) of this cohort reported two pain syndromes. Those without pain were significantly younger (26.1 ± 12.7 y.o. in those without pain and 40.1 ± 12.5, 37.2 ± 11.4 y.o. in those whose main pain was neuropathic and non-neuropathic, respectively, p = .001), and no differences in the inflammatory status were observed between groups. On follow-up, one-fifth (n = 11) had a different main pain syndrome from the first visit. Pain impacted QoL as much as disability and motor strength.

CONCLUSION

Pain is a prevalent and disabling non-motor symptom in NMO-SCI. Most patients experience more than one pain syndrome which can change in time even in the absence of clinical relapse. Age of the inflammatory-SCI was a major determinant of pain. Acknowledging temporal changes and multiplicity of pain syndromes in NMO-SCI may give insights into more precise designs of clinical trials and general management of pain in SCI.

SIGNIFICANCE

In this longitudinal study with NMO-related SCI, pain affected almost three-quarters of patients with NMO. Over 70% have more than one pain syndrome and at-level neuropathic pain is the most common type of pain syndrome. Patients without pain were significantly younger but had the same burden of inflammatory lesions than those with pain. During follow-up, up to one fifth of patients presented with changes in the main pain syndromes, which can occur even in the absence of clinical activity of the inflammatory disease. In this cohort, Pain affected quality of life as much as disability or motor strength.

[Work-Related Medical Rehabilitation in Patients with Musculoskeletal Disorders: a Propensity-Score-Analysis]

PURPOSE

Work-related medical rehabilitation is a multimodal interdisciplinary approach to reduce health-related discrepancies between work capacity and job demands in order to achieve work participation, especially for patients with severely more restricted work ability. The study tested the effects of a work-related medical rehabilitation program, implemented in routine care, compared with common medical rehabilitation in patients with musculoskeletal disorders.

METHODS

Data were assessed in 2014 and 2015 and were analyzed by an as-treated analysis. By means of propensity-score-matching, participants of work-related medical rehabilitation (intervention group, IG) were compared with similar participants of common medical rehabilitation (control group, CG). The primary outcome was a positive work status one year after discharge of rehabilitation. Treatment effects were analyzed by logistic regressions and absolute risk reductions (ARR) were calculated.

RESULTS

312 patients (156 in the IG) were included in the analysis one year after rehabilitation. Propensity-score-matching achieved balanced sample characteristics. Work-related medical rehabilitation increased a positive work status by 11 points (ARR=0.11; 95% CI: 0.02, 0.20; p=0.020) compared to common medical rehabilitation.

CONCLUSION

Work-related medical rehabilitation leads to better work participation outcomes after one year compared with common medical rehabilitation.

Let's talk about pain catastrophizing measures: an item content analysis

BACKGROUND

Concerns have been raised about whether self-report measures of pain catastrophizing reflect the construct as defined in the cognitive-behavioral literature. We investigated the content of these self-report measures; that is, whether items assess the construct 'pain catastrophizing' and not other theoretical constructs (i.e., related constructs or pain outcomes) using the discriminant content validity method.

METHOD

Items (n = 58) of six pain catastrophizing measures were complemented with items (n = 34) from questionnaires measuring pain-related worrying, vigilance, pain severity, distress, and disability. Via an online survey, 94 participants rated to what extent each item was relevant for assessing pain catastrophizing, defined as "to view or present pain or pain-related problems as considerably worse than they actually are" and other relevant constructs (pain-related worrying, vigilance, pain severity, distress, and disability).

RESULTS

Data were analyzed using Bayesian hierarchical models. The results revealed that the items from pain-related worrying, vigilance, pain severity, distress, and disability questionnaires were distinctively related to their respective constructs. This was not observed for the items from the pain catastrophizing questionnaires. The content of the pain catastrophizing measures was equally well, or even better, captured by pain-related worrying or pain-related distress.

CONCLUSION

Based upon current findings, a recommendation may be to develop a novel pain catastrophizing questionnaire. However, we argue that pain catastrophizing cannot be assessed by self-report questionnaires. Pain catastrophizing requires contextual information, and expert judgment, which cannot be provided by self-report questionnaires. We argue for a person-centered approach, and propose to rename 'pain catastrophizing' measures in line with what is better measured: 'pain-related worrying'.

The roles of race, sex and cognitions in response to experimental pain

BACKGROUND

This study reports a multivariate test of sex and race differences in experimental pain, and the degree to which these differences could be uniquely attributable to three levels of cognition: primary appraisals (threat, challenge), secondary appraisals (pain catastrophizing) and/or cognitive processes (mindful observing, non-reactivity). Both the predictive and mediator role of the cognitive variables was of interest.

METHODS

The study employed a cross-sectional experimental design, with the cold pressor task employed as the pain stimulus. The total sample included N = 355 healthy adults (67% female, 33% male; 70% Caucasian, 30% Asian).

RESULTS

Significant sex and race differences on pain tolerance were found, with females and racial minorities reporting less pain tolerance (ps < 0.001). Males reported significantly higher challenge appraisals and non-reactivity, and lower pain catastrophizing than females; Asians reported significantly higher threat appraisals and pain catastrophizing than Caucasians. In multivariate analyses, challenge appraisals and non-reactivity emerged as the strongest predictors of pain tolerance. Furthermore, challenge appraisals mediated the sex-pain tolerance association (p = .017).

CONCLUSIONS

This study showed that race and sex differences, at least in part, may be accounted for by differences in pain-related cognitions.

SIGNIFICANCE

The three levels of cognition investigated in this research represent changeable, important processes for potentially mitigating the impact of pain in vulnerable groups.

The Role of Chronic Stress in Normal Visceroception: Insights From an Experimental Visceral Pain Study in Healthy Volunteers

Visceroception is a complex phenomenon comprising the sensation, interpretation, and integration of sensations along the gut-brain axis, including pain or defecatory urgency. Stress is considered a crucial risk factor for the development and maintenance of disorders of gut-brain signaling, which are characterized by altered visceroception. Although the broad role of stress and stress mediators in disturbed visceroception is widely acknowledged, the putative contribution of chronic stress to variations in normal visceroception remains incompletely understood. We aimed to elucidate the role of chronic stress in shaping different facets of visceroception. From a well-characterized, large sample of healthy men and women (N = 180, 50% female), volunteers presenting with low (n = 57) and elevated (n = 61) perceived chronic stress were identified based on the validated Trier Inventory for Chronic Stress (TICS). Visceral sensitivity together with perceived and recalled intensity and defecatory urgency induced by repeated rectal distensions was experimentally assessed, and compared between low and elevated stress groups. Subgroups were compared regarding state anxiety and salivary cortisol concentrations across experimental phases and with respect to psychological measures. Finally, in the full sample and in chronic stress subgroups, a recall bias in terms of a discrepancy between the perception of experimentally-induced symptoms and their recall was tested. Participants with elevated chronic stress presented with increased state anxiety and higher cortisol concentrations throughout the experimental phases compared to the group with low chronic stress. Group differences in visceral sensitivity were not evident. The elevated stress group perceived significantly higher urgency during the stimulation phase, and recalled substantially higher feelings of urgency induced by rectal distensions, while perceived and recalled intensity were comparable between groups. Volunteers with elevated stress exhibited a recall bias in terms of a higher recall relative to mean perception of urgency, whereas no such bias was observed for the intensity of experimental visceral stimulation. Our findings in healthy men and women provide first evidence that the troublesome symptom of urgency might be particularly modifiable by chronic stress and support the relevance of memory biases in visceroception. These results may help to disentangle the impact of chronic stress on altered visceroception in disturbances of gut-brain communication.

Sex Differences Linking Pain-Related Fear and Interoceptive Hypervigilance: Attentional Biases to Conditioned Threat and Safety Signals in a Visceral Pain Model

Although the broad role of fear and hypervigilance in conditions of the gut-brain axis like irritable bowel syndrome is supported by converging evidence, the underlying mechanisms remain incompletely understood. Even in healthy individuals, it remains unclear how pain-related fear may contribute to pain-related attentional biases for acute visceral pain. Building on our classical fear conditioning work in a clinically relevant model of visceral pain, we herein elucidated pain-related attentional biases shaped by associative learning in healthy women and men, aiming to elucidate possible sex differences and the role of psychological traits. To this end, we compared the impact of differentially conditioned pain-predictive cues on attentional biases in healthy women and men. Sixty-four volunteers accomplished a visual dot-probe task and subsequently underwent pain-related fear conditioning where one visual cue (CS⁺) was contingently paired with a painful rectal distention (US) while another cue remained unpaired (CS^-). During the following test phase, the dot-probe task was repeated to investigate changes in attentional biases in response to differentially valenced cues. While pain-related learning was comparable between groups, men revealed more pronounced attentional engagement with the CS⁺ and CS^- whereas women demonstrated stronger difficulties to disengage from the CS⁺ when presented with a neutral cue. However, when both CS⁺ and CS^- were presented together, women revealed stronger difficulties to disengage from the CS^-. Regression analyses revealed an interaction of sex, with negative affect predicting stronger avoidance of the CS⁺ and stronger difficulties to disengage attention from the CS^- in men. These results provide first evidence that pain-related fear conditioning may induce attentional biases differentially in healthy women and men. Hence, sex differences may play a role in attentional mechanisms underlying hypervigilance, and may be modulated by psychological vulnerability factors relevant to chronic visceral pain.

How much of the effect of exercise and advice for subacute low back pain is mediated by depressive symptoms?

BACKGROUND

Exercise and advice can reduce pain and disability in patients with subacute low back pain. However, the mechanisms by which this combined intervention works are unclear. Our objective was to estimate how much of the effect of a physiotherapist-directed exercise and advice intervention on pain and disability is mediated via changes in depressive symptoms.

METHODS

Causal mediation analysis of a randomized controlled trial. We measured our hypothesized mediator - depressive symptoms (Depression, Anxiety, Stress Scale-21) at 6 weeks, and the outcomes - pain (numerical rating scale) and disability (Roland Morris Disability Questionnaire) at 3 months, estimating the average causal mediation effect (ACME), average direct effect (ADE), and total effect. We pre-specified a causal model to identify potential confounders of the mediator-outcome effect and conducted sensitivity analyses to assess the robustness of the ACME under varying levels of unknown confounding.

RESULTS

Data from 240 patients were analyzed (average age 50.5 (SD 15.6) years, 52% male, median depressive symptoms score 4). The effect of exercise combined with advice was not mediated via depressive symptoms: ACME on pain (0.05, 95%CI -0.24 to 0.15), ACME on disability (-0.10, 95%CI -0.59 to 0.38). However depressive symptoms were associated with pain (regression coefficient 0.06; SE 0.03)) and disability (regression coefficient 0.17; SE 0.05).) CONCLUSIONS: Depressive symptoms did not mediate the effect of exercise and/or advice in this sample. However, depressive symptoms were associated with pain and disability.

Injustice Appraisal, but not Pain Catastrophizing, Mediates the Relationship Between Perceived Ethnic Discrimination and Depression and Disability in Low Back Pain

Despite growing evidence of significant racial disparities in the experience and treatment of chronic pain, the mechanisms by which these disparities manifest have remained relatively understudied. The current study examined the relationship between past experiences of racial discrimination and pain-related outcomes (self-rated disability and depressive symptomatology) and tested the potential mediating roles of pain catastrophizing and perceived injustice related to pain. Analyses consisted of cross-sectional path modeling in a multiracial sample of 137 individuals with chronic low back pain (Hispanics: n = 43; blacks: n = 43; whites: n = 51). Results indicated a positive relationship between prior discriminatory experiences and severity of disability and depressive symptoms. In mediation analyses, pain-related appraisals of injustice, but not pain catastrophizing, were found to mediate these relationships. Notably, the association between discrimination history and perceived injustice was significantly stronger in black and Hispanic participants and was not statistically significant in white participants. The findings suggest that race-based discriminatory experiences may contribute to racial disparities in pain outcomes and highlight the specificity of pain-related, injustice-related appraisals as a mechanism by which these experiences may impair physical and psychosocial function. Future research is needed to investigate temporal and causal mechanisms suggested by the model through longitudinal and clinical intervention studies. PERSPECTIVE: More frequent prior experiences of racial discrimination are associated with greater depressive symptomatology and pain-related disability in individuals with chronic low back pain. These associations are explained by the degree of injustice perception related to pain, but not pain catastrophizing, and were stronger among black and Hispanic participants.

Psychological pain responses in athletes and non-athletes with low back pain: Avoidance and endurance matter

BACKGROUND

Dysfunctional psychological pain responses, namely fear-avoidance (FAR), including catastrophizing and helplessness, as well as endurance-related responses (ER), including thought suppression and overactivity, have been shown to be risk factors for persistent low back pain (LBP). Literature suggests that athletes may differ from non-athletes regarding psychological responses to pain.

OBJECTIVES

This study set out to compare FAR and ER between athletes and non-athletes with LBP. It was hypothesized that athletes would report less frequent FAR and more frequent ER, and that both FAR and ER are associated with LBP intensity and disability.

METHODS

The 173 athletes and 93 non-athletes cross-sectionally reported how frequently they employ FAR and ER on the Avoidance-Endurance Questionnaire (AEQ), as well as LBP intensity and disability on the Chronic Pain Grade Questionnaire (CPGS). MANOVA was applied to compare FAR and ER between athletes and non-athletes. Hierarchical multiple linear regression models were used to determine the unique associations between FAR and ER with LBP intensity and disability.

RESULTS

Athletes reported lower frequencies of behavioural avoidance than non-athletes, but no other FAR variables differed between the groups. Frequencies of ER did not differ between athletes and non-athletes. Regression analysis indicated substantial associations of FAR with LBP intensity, as well as of FAR and ER with disability in athletes and non-athletes.

CONCLUSIONS

The results of the present study suggest that athletes and non-athletes with LBP differ regarding behavioural avoidance, but overall, differences regarding pain responses are marginal. FAR and ER are both reported in athletes and non-athletes and contribute to disability in both groups.

SIGNIFICANCE

Athletes train to endure pain in the course of athletic socialization, at least in the context of exercise. However, there is sparsity of knowledge about psychological pain responses in athletes with low back pain and whether they differ from those in non-athletes. The results of this comparative study suggest that endurance responses are more frequent than avoidance responses among athletes and non-athletes alike. However, both types of responses seem relevant to clinical pain management in athletes as well as non-athletes.

Feasibility, Validity, and Responsiveness of Self-Report and Objective Measures of Physical Activity in Patients With Chronic Pain

BACKGROUND

Accurate tools for measuring physical activity are important for monitoring patients with chronic pain. However, these tools have not been properly validated in this population.

OBJECTIVE

To determine the suitability of two physical activity measures for use in chronic pain populations.

DESIGN

Longitudinal observational study.

SETTING

Pain Management and Research Centre.

PARTICIPANTS

Sixty-four patients presenting to the Pain Management and Research Centre with chronic pain.

METHODS

Participants underwent a 3-week pain management program that included cognitive behavioral strategies, education, and multiple exercises sessions per day. Physical activity was measured by the Active Australia Survey and the Actigraph GT3X at the start and end of the program. Feasibility of the physical activity measures was assessed. Criterion validity and responsiveness between the measures was compared. Correlation of physical activity with self-rated global rating of change (GROC) scales in health were calculated.

MAIN OUTCOME MEASUREMENTS

Minutes per day spent in low, moderate, and vigorous physical activity; global rating of change.

RESULTS

Fifty-two percent (n = 33) and 78% (n = 50) of participants had valid Actigraph and Active Australia data, respectively, for both time points. For criterion validity and responsiveness correlations varied (rho = -.12-.52). All correlations between physical activity measures and GROC were small or negligible (rho ≤ .18).

CONCLUSION

Feasibility of the Actigraph was poor compared to the Active Australia Survey. The criterion validity and responsiveness of the Active Australia Survey to the Actigraph was inconsistent and the relationship of both these measures to clinical outcomes was poor. However, limitations due to missing data mean that further research is required.

LEVEL OF EVIDENCE

III.

PRERECORDED HYPNOTIC PERI-SURGICAL INTERVENTION TO ALLEVIATE RISK OF CHRONIC POSTSURGICAL PAIN IN TOTAL KNEE REPLACEMENT: A RANDOMIZED CONTROLLED PILOT STUDY

This pilot study evaluated the effect sizes associated with prerecorded hypnotic interventions provided during the perisurgical period for reducing risk factors associated with chronic postsurgical pain, including acute postsurgical pain, anxiety, depression, and pain catastrophizing. A total of 25 participants (N = -25) were randomly assigned to receive a hypnotic intervention (n = 8), minimal-effect treatment (n = 8), or treatment as usual (n = 9) during their hospital stay for total knee replacement (TKR). Participants were followed for 6 months after hospital discharge. Results indicate that prerecorded hypnotic intervention exerted medium effects for reducing acute postsurgical pain and large effects for reducing perisurgical anxiety and pain catastrophizing. The findings indicate that a fully powered clinical trial to evaluate the beneficial effects of prerecorded hypnosis to manage pain and psychological distress in patients undergoing TKR is warranted.

Transcranial direct current stimulation to prevent and treat surgery-induced opioid dependence: a systematic review

Opioid misuse leading to dependence is a major health issue. Recent studies explored valid alternatives to treat pain in postsurgical settings. This systematic review aims to discuss the role of transcranial direct current stimulation (tDCS) in preventing and treating postoperative pain and opioid dependence. PubMed and Embase databases were screened, considering studies testing tDCS effects on pain and opioid consumption in surgical settings and opioid addiction. Eight studies met our inclusion criteria. Results showed a reduction of postoperative pain, opioid consumption and cue-induced craving following cortical stimulation. Despite the limited number of studies, this review shows preliminary encouraging evidence regarding the analgesic role of tDCS. However, future studies are needed to further investigate the application of tDCS in postsurgical settings.

Interactive effects of pain catastrophizing and mindfulness on pain intensity in women with fibromyalgia

The objective of this study was to examine the association between facets of trait mindfulness, pain catastrophizing, and pain severity in a sample of patients with fibromyalgia. Patients with fibromyalgia completed validated baseline and diary assessments of clinical pain, mindfulness, and pain catastrophizing. Multilevel modeling analyses indicated that the daily association between catastrophizing and pain intensity was moderated by certain mindfulness facets. Our findings suggest that various aspects of mindfulness may interact differently with pain and catastrophizing, which may have implications for the design and testing of interventions targeting mindfulness and catastrophizing in fibromyalgia patients.

Impact of controllability on pain and suffering

Supplemental Digital Content is Available in the Text.

Introduction:

Chronic pain and pain-related suffering are major health problems. The lack of controllability of experienced pain seems to greatly contribute to the extent of suffering. This study examined how controllability affects the perception of pain and pain-related suffering, and the modulation of this effect by beliefs and emotions such as locus of control of reinforcement, pain catastrophizing, and fear of pain.

Methods:

Twenty-six healthy subjects received painful electric stimulation in both controllable and uncontrollable conditions. Visual analogue scales and the “Pictorial Representation of Illness and Self Measure” were used to assess pain intensity, unpleasantness, pain-related suffering, and the level of perceived control. We also investigated nonverbal indicators of pain and suffering such as heart rate, skin conductance, and corrugator electromyogram.

Results:

Controllability selectively reduced the experience of pain-related suffering, but did not affect pain intensity or pain unpleasantness. This effect was modulated by chance locus of control but was unrelated to fear of pain or catastrophizing. Physiological responses were not affected by controllability. In a second sample of 25 participants, we varied the instruction. The effect of controllability on pain-related suffering was only present when instructions focused on the person being able to stop the pain.

Discussion:

Our data suggest that the additional measure of pain-related suffering may be important in the assessment of pain and may be more susceptible to the effects of perceived control than pain intensity and unpleasantness. We also show that this effect depends on personal involvement.

Electrical impedance of the torso is associated with the pressure pain threshold on myofascial trigger points in patients with chronic neck pain: A cross-sectional study

BACKGROUND

Myofascial trigger points are dysfunctional structures present in skeletal muscles and are related to sensory, motor, and autonomic changes. Despite scientific advances in recent decades in the measurement of musculoskeletal pain, evaluation of this clinical phenomenon is supported with instruments that, although valid and reliable, have a considerable degree of subjectivity.

OBJECTIVE

To correlate electrical impedance of the upper limbs and torso with pain intensity, functional capacity, catastrophizing, pressure pain threshold, and skin temperature on myofascial trigger points in the upper trapezius muscle of patients with neck pain.

METHODS

A single-blind cross-sectional study. Twenty-eight volunteers of both genders were included in the study, were aged 18-45 years, and had chronic neck pain and myofascial trigger points in the upper trapezius. The volunteers were assessed using the Numeric Rating Scale, the Neck Disability Index, the Pain-Related Self-Statement Scale, algometry, infrared thermography, and electrical bioimpedance.

RESULTS

The following significant results were observed: a negative association between the pressure pain threshold on myofascial trigger point in the right upper trapezius and electrical impedance of the torso at 5 kHz (rs=-0.392, p= 0.032), 50 kHz (rs=-0.406, p= 0.026), 250 kHz (rs=-0.388, p= 0.034), and to the frequency 500 kHz (rs=-0.444, p= 0.014).

CONCLUSION

Electrical impedance of the torso is associated with the pressure pain threshold of myofascial trigger points on the upper trapezius of individuals with neck pain. Thus, individuals with a lower pressure pain threshold have higher electrical impedance values of the torso and vice versa.

Psychological, cognitive factors and contextual influences in pain and pain-related suffering as revealed by a combined qualitative and quantitative assessment approach

Previous psychophysiological research suggests that pain measurement needs to go beyond the assessment of Pain Intensity and Unpleasantness by adding the evaluation of Pain-Related Suffering. Based on this three-dimensional approach, we attempted to elucidate who is more likely to suffer by identifying reasons that may lead individuals to report Pain and Pain-Related Suffering more than others. A sample of 24 healthy participants (age range 18-33) underwent four different sessions involving the evaluation of experimentally induced phasic and tonic pain. We applied two decision tree models to identify variables (selected from psychological questionnaires regarding pain and descriptors from post-session interviews) that provided a qualitative characterization of the degrees of Pain Intensity, Unpleasantness and Suffering and assessed the respective impact of contextual influences. The overall classification accuracy of the decision trees was 75% for Intensity, 77% for Unpleasantness and 78% for Pain-Related Suffering. The reporting of suffering was predominantly associated with fear of pain and active cognitive coping strategies, pain intensity with bodily competence conveying strength and resistance and unpleasantness with the degree of fear of pain and catastrophizing. These results indicate that the appraisal of the three pain dimensions was largely determined by stable psychological constructs. They also suggest that individuals manifesting higher active coping strategies may suffer less despite enhanced pain and those who fear pain may suffer even under low pain. The second decision tree model revealed that suffering did not depend on pain alone, but that the complex rating-related decision making can be shifted by situational factors (context, emotional and cognitive). The impact of coping and fear of pain on individual Pain-Related Suffering may highlight the importance of improving cognitive coping strategies in clinical settings.

Psychological Factors Associated with Phantom Limb Pain: A Review of Recent Findings

Phantom limb pain (PLP) is a common phenomenon occurring after the amputation of a limb and can be accompanied by serious suffering. Psychological factors have been shown to play an important role in other types of chronic pain, where they are pivotal in the acquisition and maintenance of pain symptoms. For PLP, however, the interaction between pain and psychological variables is less well documented. In this review, we summarize research on the role of emotional, motivational, cognitive, and perceptual factors in PLP. The reported findings indicate that emotional factors modulate PLP but might be less important compared to other types of chronic pain. Additional factors such as the amount of disability and adjustment to the amputation appear to also play a role. Bidirectional relationships between stress and PLP have been shown quite consistently, and the potential of stress and tension reduction in PLP treatment could be further exploited. Little is known about the role of cognitive variables such as attention or expectation. Catastrophizing seems to aggravate PLP and could be targeted in treatment. Body perception is altered in PLP and poses a potential target for novel mechanistic treatments. More research on psychological factors and their interactions in PLP is needed.

Assessing Psycho-social Barriers to Rehabilitation in Injured Workers with Chronic Musculoskeletal Pain: Development and Item Properties of the Yellow Flag Questionnaire (YFQ)

Purpose To develop a multidimensional scale to asses psychosocial beliefs-the Yellow Flag Questionnaire (YFQ)-aimed at guiding interventions for workers with chronic musculoskeletal (MSK) pain. Methods Phase 1 consisted of item selection based on literature search, item development and expert consensus rounds. In phase 2, items were reduced with calculating a quality-score per item, using structure equation modeling and confirmatory factor analysis on data from 666 workers. In phase 3, Cronbach's α, and Pearson correlations coefficients were computed to compare YFQ with disability, anxiety, depression and self-efficacy and the YFQ score based on data from 253 injured workers. Regressions of YFQ total score on disability, anxiety, depression and self-efficacy were calculated. Results After phase 1, the YFQ included 116 items and 15 domains. Further reductions of items in phase 2 by applying the item quality criteria reduced the total to 48 items. Phase factor analysis with structural equation modeling confirmed 32 items in seven domains: activity, work, emotions, harm & blame, diagnosis beliefs, co-morbidity and control. Cronbach α was 0.91 for the total score, between 0.49 and 0.81 for the 7 distinct scores of each domain, respectively. Correlations between YFQ total score ranged with disability, anxiety, depression and self-efficacy was .58, .66, .73, -.51, respectively. After controlling for age and gender the YFQ total score explained between R2 27% and R2 53% variance of disability, anxiety, depression and self-efficacy. Conclusions The YFQ, a multidimensional screening scale is recommended for use to assess psychosocial beliefs of workers with chronic MSK pain. Further evaluation of the measurement properties such as the test-retest reliability, responsiveness and prognostic validity is warranted.

Association of Neglect-Like Symptoms with Anxiety, Somatization, and Depersonalization in Complex Regional Pain Syndrome

Background

Many patients with complex regional pain syndrome (CRPS) report some foreignness of the affected limb, which is referred to as "neglect-like symptoms" (NLS). Despite similarities of the NLS reports to symptoms of body image disturbances in mental disorders, no study has been conducted to examine such associations.

Methods

We investigated 50 patients with CRPS and 45 pain control patients (N = 27, chronic limb pain; N = 18, migraine headache). NLS, anxiety, depression, depersonalization, and somatization were assessed using validated questionnaires.

Results

Seventy-two percent of the CRPS patients reported at least one NLS vs 29.6% and 33.3% in the two patient control groups. In limb pain controls, NLS correlated with pain intensity. In CRPS patients, NLS correlated with anxiety (rho = 0.658, P  < 0.001), somatization (rho = 0.616, P  < 0.001), depersonalization (rho = 0.634, P  < 0.001), and pain catastrophizing (rho = 0.456, P  < 0.01), but not with intensity of pain, duration of pain, or pain disability.

Conclusions

In CRPS patients, NLS could be a result of somatization, depression, anxiety, and depersonalization, but probably not of pain. Whether these associations are causative must be clarified in longitudinal psychological studies.