Central sensitization and the biopsychosocial approach to understanding pain

Development and Validation of a Treatment Algorithm for Osteoarthritis Pain Management in Patients With End-Stage Kidney Disease Undergoing Hemodialysis

Background

Although osteoarthritis is common in the hemodialysis population and leads to poor health outcomes, pain management is challenged by the absence of clinical guidance. A treatment algorithm was developed and validated to aid hemodialysis clinicians in managing osteoarthritis pain.

Objective

The objective was to develop and validate a treatment algorithm for managing osteoarthritis pain in patients undergoing hemodialysis.

Design

A validation study was conducted based on Lynn's method for content validation.

Setting

To develop and validate a treatment algorithm, interviews were conducted virtually by the primary researcher with clinicians from various institutions across the Greater Toronto and Hamilton Area in Ontario.

Patients

The treatment algorithm was developed and validated for the management of osteoarthritis pain in patients on hemodialysis. Patients were not involved in the development or validation of the tool.

Measurements

The algorithm was measured for content and face validity. Content validity was measured by calculating the content validity index of each component (I-CVI) of the algorithm and the overall scale validity index (S-CVI). Face validity was assessed by calculating the percentage of positive responses to the face validity statements.

Methods

A draft algorithm was developed based on literature searches and expert opinion and validated by interviewing nephrology and pain management clinicians. Through consecutive rounds of 1:1 interviews, content and face validity were assessed by asking participants to rate the relevance of each component of the algorithm and indicate their level of agreeability with a series of statements. Following each round, the I-CVI of the algorithm as well as the S-CVI was calculated and the percentage of positive responses to the statements was determined. The research team revised the algorithm in response to the findings. The final algorithm provides a stepwise approach to the non-pharmacologic and pharmacologic management of pain, including topical, oral, and opioid use.

Results

A total of 18 clinicians from 7 institutions across the Greater Toronto and Hamilton Area were interviewed (10 pharmacists, 5 nurse practitioners, and 3 physicians). The average S-CVI of the algorithm across all 3 rounds was 0.93. At least 78% of participants provided positive responses to the face validity statements.

Limitations

An algorithm was developed based on input from clinicians working in the province of Ontario, limiting the generalizability of the algorithm across provinces. In addition, the algorithm did not include the perspectives of primary care providers or patients/caregivers.

Conclusions

An algorithm for the management of osteoarthritis pain in the hemodialysis population was developed and validated through expert review to standardize practices and encourage clinicians to use evidence-based treatments and address the psychosocial symptoms of pain. As the algorithm possesses a high degree of content and face validity, it may improve osteoarthritis pain management among patients undergoing hemodialysis. Future research will assess the implementation of the algorithm across hemodialysis settings.

Pain relief and associated factors: a cross-sectional observational web-based study in a Quebec cohort of persons living with chronic pain

Objectives

Randomized clinical trials are used to evaluate the efficacy of various pain treatments individually, while a limited number of observational studies have portrayed the overall relief experienced by persons living with chronic pain. This study aimed to describe pain relief in real-world clinical settings and to identify associated factors.

Methods

This exploratory web-based cross-sectional study used data from 1,419 persons recruited in the community. Overall pain relief brought by treatments used by participants was assessed using a 0%-100% scale (10-unit increments).

Results

A total of 18.2% of participants reported minimal pain relief (0%-20%), 60.0% moderate to substantial pain relief (30%-60%), and 21.8% extensive pain relief (70%-100%). Multivariable multinomial regression analysis revealed factors significantly associated with greater pain relief, including reporting a stressful event as circumstances surrounding the onset of pain, living with pain for ≥10 years, milder pain intensity, less catastrophic thinking, use of prescribed pain medications, use of nonpharmacological pain treatments, access to a trusted healthcare professional, higher general health scores, and polypharmacy. Factors associated with lower pain relief included surgery as circumstances surrounding pain onset, use of over-the-counter pain medications, and severe psychological distress.

Discussion

In this community sample of persons living with chronic pain, 8 out of 10 persons reported experiencing at least moderate relief with their treatment. The analysis has enabled us to explore potential modifiable factors as opportunities for improving the well-being of persons living with chronic pain.

Associations Between Psychological Stress and Hand Pain Among Rural and Urban Adults: Findings From the KoGES Community Cohort Study

Despite known health disparities in chronic pain conditions between rural and urban adults, few studies have examined whether longitudinal associations between psychological stress and hand pain differ. Utilizing community-based cohort data, this study examined whether rural and urban adults differed in the extent to which psychological distress was associated with hand osteoarthritis (OA) symptoms and later functional limitations related to hand pain. Community-dwelling adults (mean age = 51.97, 52.3% women) in a rural (n = 2,971) and urban area (n = 2,782) provided demographic data at baseline and, at a 4-year follow-up, responded to questionnaires about psychological distress and clinical symptoms of hand OA. Levels of functional limitations in hands were assessed at an 8-year follow-up. Ordinal logistic and linear regression were conducted to examine the effects of psychological distress on hand OA symptoms and functional limitations, and whether associations between psychological distress and these pain outcomes were moderated by residential area. The results showed that psychological distress was associated with a higher risk for hand OA symptoms and functional limitations, even after adjusting for demographic and health covariates. There was significant moderation by residential area, such that the association between psychological distress and hand OA was significant only among rural adults and the association with functional limitations was stronger in rural adults than urban adults. Findings suggest greater vulnerability to hand arthritis and hand-related functional limitations among rural adults and the potential for tailored intervention programs to help resolve health disparities among rural communities. PERSPECTIVE: This study compares the association between psychological distress and hand pain outcomes between rural and urban adults using community-based cohort data and suggests that rural adults are more vulnerable to experiencing negative effects of psychological distress on concurrent hand OA symptoms and longitudinal functional limitations in hands.

Psychosocial Care for People With Diabetic Neuropathy: Time for Action

Psychological factors and psychosocial care for individuals with diabetic neuropathy (DN), a common and burdensome complication of diabetes, are important but overlooked areas. In this article we focus on common clinical manifestations of DN, unremitting neuropathic pain, postural instability, and foot complications, and their psychosocial impact, including depression, anxiety, poor sleep quality, and specific problems such as fear of falling and fear of amputation. We also summarize the evidence regarding the negative impact of psychological factors such as depression on DN, self-care tasks, and future health outcomes. The clinical problem of underdetection and undertreatment of psychological problems is described, together with the value of using brief assessments of these in clinical care. We conclude by discussing trial evidence regarding the effectiveness of current pharmacological and nonpharmacological approaches and also future directions for developing and testing new psychological treatments for DN and its clinical manifestations.

The relation of psychological status and type D personality with central sensitization in knee osteoarthritis: everything is in your mind!

To evaluate the relation of psychosocial parameters and type D personality with central sensitization in knee osteoarthritis (OA). The study included 126 patients with knee OA according to the American College of Rheumatology criteria. Sociodemographic variables (age, gender, education, marital status, annual income), alcohol consumption/smoking, body mass index, comorbidities, and duration of symptoms were noted. Radiographic evaluation was performed according to the Kellgren-Lawrence grading system. The Western Ontario and McMaster Universities Osteoarthritis Index was used for clinical evaluation. Type D personality, negative affectivity, and social inhibition were evaluated using the type D Scale-14 (DS14). Central sensitization was assessed by the central sensitization inventory (CSI), while psychological status, quality of life, and sleep were assessed by the Hospital Anxiety and Depression Scale (HADS), an abbreviated version of the World Health Organization Quality of Life Instrument (WHOQOL-BREF), and the Jenkins Sleep Evaluation Scale (JSS), respectively. The effect of type D personality on study parameters including central sensitization, as well as the risk factors for the development of central sensitization were assessed by regression analyses. Patients with type D personality had higher CSI, HADS scores and lower WHOQOL-BREF scores for psychological health, social relationship, environment and general quality of life. Linear regression analysis showed that the DS14 total score has a significant positive relation with CSI (β = 0.4, p < 0.05), HADS-depression (β = 0.4, p < 0.05), HADS-anxiety (β = 0.5, p < 0.05), and HADS-total scores (β = 0.5, p < 0.05). It also had a significant negative effect on all domains of WHOQOL-BREF (p < 0.05 for all). Logistic regression analysis revealed that JSS [Odds ratio (OR) 0.83, 95% CI 0.73-0.94; p = 0.003] and negative affectivity (OR 0.78, 95% CI 0.65-0.94; p = 0.008) were independent risk factors for the development of central sensitization in knee OA. Type D personality has an impact on quality of life, central sensitization, and psychological health, with negative affectivity and sleep impairment serving as independent risk factors for central sensitization. While managing patients with knee OA, these intimate relationships should be taken into consideration.

Interplay Between Innovation and Intersubjectivity: Therapists Perceptions of Phantom Motor Execution Therapy and Its Effect on Phantom Limb Pain

Purpose

Interpersonal processes, including therapeutic alliance, may modulate the impact of interventions on pain experience. However, the role of interpersonal context on the effects of technology-enhanced interventions remains underexplored. This study elicited therapists' perspectives on how a novel rehabilitative process, involving Phantom Motor Execution (PME), may impact phantom limb pain. The mediating role of therapeutic alliance, and the way PME influenced its formation, was investigated.

Methods

A qualitative descriptive design, using a framework method, was used to explore therapists' (n=11) experiences of delivering PME treatment. Semi-structured online-based interviews were conducted.

Results

A 3-way interaction between therapist, patient, and the PME device was an overarching construct tying four themes together. It formed the context for change in phantom limb experience. The perceived therapeutic effects (theme 1) extended beyond those initially hypothesised and highlighted the mediating role of the key actors and context (theme 2). The therapeutic relationship was perceived as a transformative journey (theme 3), creating an opportunity for communication, collaboration, and bonding. It was seen as a cause and a consequence of therapeutic effects. Future directions, including the role of expertise-informed adaptations and enabling aspects of customised solutions, were indicated (theme 4).

Conclusion

This study pointed to intrapersonal, interpersonal, and contextual factors that should be considered in clinical implementation of novel rehabilitative tools. The results demonstrated that therapists have unique insights and a crucial role in facilitating PME treatment. The study highlighted the need to consider the biopsychosocial model of pain in designing, evaluating, and implementing technology-supported interventions.

A Systematic Review and Meta-Analysis of Exercise Beneficial for Locomotion in Community-Dwelling Elderly People with Sarcopenia

Sarcopenia, in addition to aging and reduced physical activity, is a progressive skeletal muscle disorder that causes the loss of muscle mass and strength. The most prominent functional change is mobility, which contributes to a decrease in the quality of life. Therefore, we aimed to perform qualitative and quantitative analyses by synthesizing randomized controlled trials (RCTs) that evaluated exercises that affected locomotion in patients with sarcopenia. The RCTs were retrieved in April 2023 from three international electronic databases (Embase, MEDLINE, and PubMed). RCTs published after 2013 were compared with a control group that did not include exercise. Qualitative and quantitative analyses were performed on the identified studies using RevMan 5.4 and risk of bias assessment provided by Cochrane. RCTs involving 594 patients with sarcopenia were included in this study. The analysis model was synthesized as a random effects model, and the standard mean difference (SMD) was used as the effect measure. Exercise interventions were found to not change muscle mass in individuals with sarcopenia (SMD = 0.04; 95% CI: -0.15 to 0.22). However, they had positive effects on lower extremity muscle strength (SMD = 0.34; 95% CI: 0.02 to 0.66) and walking speed (SMD = 0.42; 95% CI: 0.11 to 0.72). For community-dwelling elderly people with sarcopenia, exercise intervention did not lead to an increase in reduced muscle mass, but it brought positive improvements in lower extremity strength and gait speed to improve locomotion.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Teaching the biopsychosocial model of chronic pain: Whom are we talking to?

The biopsychosocial (BPS) model of chronic pain can be illustrated in many ways. Our aim is to adapt three illustrations of the BPS approach selected from the literature to target different groups: patients, health professionals and clinical trainees. In clinician-patient consultations, we use an illustration which shows the interactions among the BPS domains in the creation of suffering and pain behaviours in a "vicious spiral". Moreover, we help our patients understand chronic pain often does not entail remaining tissue damage. In clinical practice, we communicate to other health professionals that the relative contribution of each BPS domain varies from patient to patient. This disproportional contribution may also change dynamically over the time. In teaching clinical trainees, we combine thoroughness (i.e., focus on "details") with an understanding of the "dynamics" of pain chronification/chronic pain, i.e., focus on helping the trainee identify the mutual and joint interactions between different parts of the BPS framework. CONCLUSION: The three illustrations can be used as pedagogical tools for better-informed BPS perspectives in different settings. PRACTICE IMPLICATIONS: Clinicians need to be keen observers and adapt their communication depending on whom they are talking to.

Soft-Tissue Mobilization and Pain Neuroscience Education for Chronic Nonspecific Low Back Pain with Central Sensitization: A Prospective Randomized Single-Blind Controlled Trial

This study was conducted to demonstrate the therapeutic effect of soft-tissue mobilization (STM) combined with pain neuroscience education (PNE) for patients with chronic nonspecific low back pain with central sensitization. A total of 28 participants were recruited and randomly allocated to either the STM group (SMG) (n = 14) or the STM plus PNE group (BG; blended group) (n = 14). STM was applied twice a week for four weeks, with a total of eight sessions, and PNE was applied within four weeks, for a total of two sessions. The primary outcome was pain intensity, and the secondary outcomes were central sensitization, pressure pain, pain cognition, and disability. Measurements were made at baseline, after the test, and at 2-week and 4-week follow-ups. The BG showed significant improvement in pain intensity (p < 0.001), pressure pain (p < 0.001), disability (p < 0.001), and pain cognition (p < 0.001) compared to the SMG. This study demonstrated that STM plus PNE is more effective for all measured outcomes compared to STM alone. This finding suggests that the combination of PNE and manual therapy has a positive effect on pain, disability index, and psychological factors in the short term.

Biopsychosocial factors should be considered when evaluating central sensitization in axial spondyloarthritis

To identify the determinants of central sensitization (CS) in patients with axial spondyloarthritis (axSpA). Central Sensitization Inventory (CSI) was used to determine CS frequency. Disease-related variables including Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS-CRP/-ESR), Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) and Numeric Rating Scale (NRS)_GLOBAL were assessed. Biopsychosocial variables were evaluated by the Multidimensional Scale of Perceived Social Support (MSPSS), Brief Illness Perception Questionnaire (B-IPQ), Hospital Anxiety and Depression Scale (HADS) and subscales for Anxiety (HADS-A) and Depression (HADS-D), and Jenkins Sleep Evaluation Scale (JSS). To determine the predictors of the development and severity of CS, multiple linear and logistic regression analyses were performed. The frequency of CS was 57.4% in the study population (n = 108). CSI score was correlated with the duration of morning stiffness, BASDAI, ASDAS-CRP, ASDAS-ESR, NRS_GLOBAL, BASFI, MASES, ASOoL, JSS, HADS, and B-IPQ total scores (ρ ranged from 0.510 to 0.853). Multiple regression analysis indicated that BASDAI (OR: 10.44, 95% CI: 2.65-41.09), MASES (OR: 2.47, 95% CI: 1.09-5.56) and HADS-A (OR: 1.62, 95% CI: 1.11-2.37) were independent predictors of the development of CS. Additionally, higher NRS_GLOBAL, JSS, HADS-D, and HADS-A scores appeared to determine the severity of CS. This study confirms that worse disease activity, more enthesal involvement, and anxiety independently predict the development of CS. Additionally, higher patient-perceived disease activity, sleep impairment and poor mental health significantly contribute to the severity of CS.

High intensity training improves symptoms of central sensitization at six-month follow-up in persons with chronic nonspecific low back pain: Secondary analysis of a randomized controlled trial

BACKGROUND

High intensity training (HIT) improves disability and physical fitness in persons with chronic nonspecific low back pain (CNSLBP). However, it remains unclear if HIT affects pain processing and psychosocial factors.

OBJECTIVE

To evaluate 1) the effects of HIT on symptoms of central sensitization and perceived stress and 2) the relationship of symptoms of central sensitization and perceived stress with therapy success, at six-month follow-up, in persons with CNSLBP.

METHODS

This is a secondary analysis of a previously published randomized controlled trial. Persons with CNSLBP (n = 51, age=43.6y) completed the Central Sensitization Inventory (CSI) and Perceived Stress Scale (PSS) at baseline (PRE) and six months after 12-week of HIT consisting of concurrent exercise therapy (FU). Two groups were formed based on CSI scores (low-CSI/high-CSI). First, linear mixed models were fitted for each outcome, with time and groups as covariates. Multiple comparisons were executed to evaluate group (baseline), time (within-group), and interaction (between-group) effects. Second, correlation and regression analyses were performed to evaluate if baseline and changes in CSI/PSS scores were related to therapy success, operationalized as improvements on disability (Modified Oswestry Disability Index), and pain intensity (Numeric Pain Rating Scale).

RESULTS

Total sample analyses showed a decrease in both CSI and PSS. Within-group analyses showed a decrease of CSI only in the high-CSI group and a decrease of PSS only in the low-CSI group. Between-group analyses showed a pronounced decrease favouring high-CSI (mean difference: 7.9; 95%CI: 2.1, 12.7) and no differences in PSS (mean difference: 0.1; 95%CI: -3.0, 3.2). CSI, but not PSS, was weakly related to therapy success.

CONCLUSION

HIT improves symptoms of central sensitization in persons with CNSLBP. This effect is the largest in persons with clinically relevant baseline CSI scores. HIT also decreases perceived stress.

The Interaction Between Psychosocial Factors and Exercise-Induced Hypoalgesia in Pain-Free Nurses

Purpose

This cross-sectional study aimed to investigate whether psychosocial factors were predictive for exercise-induced hypoalgesia (EIH) in pain-free adults.

Methods

A sample of 38 pain-free nurses with a mean (SD) age of 26 (6) years were included in this study. Participants completed psychosocial questionnaires prior to physical tests. Pressure pain threshold (PPT) was assessed bilaterally at the calves (local), lower back (semi-local) and forearm (remote) before and immediately after a maximal graded cycling exercise test. Separate linear mixed effects models were used to determine change in PPT before and after cycling exercise (EIH). Multiple linear regression for all psychosocial variables and best subset regression was used to identify predictors of EIH at all locations.

Results

The relative mean increase in PPT at the forearm, lumbar, calf, and globally (all sites pooled) was 6.0% (p<0.001), 10.1% (p<0.001), 13.9% (p<0.001), and 10.2% (p=0.013), respectively. Separate best subset multiple linear regression models at the forearm (predictors; Multidimensional Scale of Perceived Social Support (MSPSS) total), lumbar (predictors; MSPSS total, Pain Catastrophizing Scale (PCS) total, Depression Anxiety Stress Scale (DASS) depression), calf (predictors; MSPSS friends, PCS total), and global (predictors; MSPSS friends, PCS total) accounted for 7.5% (p=0.053), 13% (p=0.052), 24% (p=0.003), and 17% (p=0.015) of the variance, respectively.

Conclusion

These findings confirm that cycling exercise produced EIH in young nurses and provided preliminary evidence to support the interaction between perceived social support, pain catastrophizing and EIH. Further investigation is required to better understand psychological and social factors that mediate EIH on a larger sample of adults at high risk of developing chronic musculoskeletal pain.

What Concept of Manual Therapy Is More Effective to Improve Health Status in Women with Fibromyalgia Syndrome? A Study Protocol with Preliminary Results

BACKGROUND

Fibromyalgia (FM) is defined as a chronic syndrome characterized by diffuse musculoskeletal pain, associated with characteristic signs and symptoms such as fatigue and/or sleep and mood disorders, and whose etiology, pathogenesis and prognosis may or may not be known. There is growing evidence of manual therapy as a treatment for pain in the short and medium term, also in patients affected by FM. However, the heterogeneity of the manual therapy treatments administered are a very common clinical practice, as they are based more on the judgment or tendency of the physiotherapist, rather than on clear scientific evidence. Therefore, the aim of the present study protocol will be to determine which manual therapy approach is more effective in addressing health status by improving symptoms (sensory, cognitive, emotional and social) in patients with FM.

METHODS

a randomized controlled clinical trial with a 3-month follow-up will be carried out with 52 female patients affected by rheumatologist-diagnosed FM will be recruited and evaluated at the Asociación de Fibromialgia y Síndrome de Fatiga Crónica (AFINSYFACRO) in Móstoles, Madrid, Spain. For more details on the protocol, a pilot study was carried out using a non-probability method of judgmental or purposive sampling. Thirteen patients were also evaluated, treated and reevaluated; eight patients were assigned to the myofascial techniques approach (MTA) group and five to the Maitland's mobilization approach (MMA) group.

RESULTS

the preliminary results presented here are intended to show how the planned randomized controlled clinical trial will develop. Patients who received MTA had significantly improved pain and health status outcomes after treatment and at 1-month follow-up, with no significant change in those who received MMA.

CONCLUSIONS

the exact details of the study protocol on which the manual therapy approach is more effective in addressing health status by improving symptoms (sensory, cognitive, emotional, and social) in patients with FM are presented. Preliminary results show that manual therapy is effective in improving pain and health status in patients with fibromyalgia at short and medium term, with significant results in those who received MTA.

Measuring subjective quality of life in autistic adults with the PROMIS global-10: Psychometric study and development of an autism-specific scoring method

LAY ABSTRACT

Quality of Life an outcome that both researchers and autistic advocates agree is extremely important to consider when implementing services, interventions, and supports for autistic people. However, there has been little research on the topic of how quality of life can best be measured in autistic people or whether existing quality of life questionnaires are appropriate for use in the autistic population. This study aimed to validate an established quality of life measure, the Patient-Reported Outcomes Measurement Information System Global-10, in a large sample of autistic adults recruited online. We created a new way to score the Patient-Reported Outcomes Measurement Information System Global-10 scale and generate a "General quality of life" score specific to autistic adults. This new score performed very well in this sample, showing very little measurement error and relating in expected ways to similar constructs, such as physical health and emotional distress. Exploratory analyses found that lower quality of life was associated with female sex and self-identification as a sexual or gender minority (i.e. LGBTQ + identity). These findings suggest that the new Patient-Reported Outcomes Measurement Information System Global-10 quality of life score is a reliable and valid measure of quality of life in autistic adults, although additional studies are necessary to further explore its measurement properties in other subsets of the autistic population, such as individuals with intellectual disabilities. This measure is freely available for use as an outcome in both research and clinical practice, and an online score calculator is available to support the use of this measure in real-world applications.

Central Sensitization and Psychological State Distinguishing Complex Regional Pain Syndrome from Other Chronic Limb Pain Conditions: A Cluster Analysis Model

Complex regional pain syndrome (CRPS) taxonomy has been updated with reported subtypes and is defined as primary pain alongside other chronic limb pain (CLP) conditions. We aimed at identifying CRPS clinical phenotypes that distinguish CRPS from other CLP conditions. Cluster analysis was carried out to classify 61 chronic CRPS and 31 CLP patients based on evoked pain (intensity of hyperalgesia and dynamic allodynia, allodynia area, and after-sensation) and psychological (depression, kinesiophobia, mental distress, and depersonalization) measures. Pro-inflammatory cytokine IL-6 and TNF-α serum levels were measured. Three cluster groups were created: ‘CRPS’ (78.7% CRPS; 6.5% CLP); ‘CLP’ (64.5% CLP; 4.9% CRPS), and ‘Mixed’ (16.4% CRPS; 29% CLP). The groups differed in all measures, predominantly in allodynia and hyperalgesia (p < 0.001, η² > 0.58). ‘CRPS’ demonstrated higher psychological and evoked pain measures vs. ‘CLP’. ‘Mixed’ exhibited similarities to ‘CRPS’ in psychological profile and to ‘CLP’ in evoked pain measures. The serum level of TNF-αwas higher in the ‘CRPS’ vs. ‘CLP’ (p < 0.001) groups. In conclusion, pain hypersensitivity reflecting nociplastic pain mechanisms and psychological state measures created different clinical phenotypes of CRPS and possible CRPS subtypes, which distinguishes them from other CLP conditions, with the pro-inflammatory TNF-α cytokine as an additional potential biomarker.

Psychological Evaluation and Management of Chronic Pancreatitis

Chronic pancreatitis is a chronic digestive disorder that greatly diminishes the quality of life and is associated with significant psychological distress. A best practice recommendation in treating chronic pancreatitis is offering care in a multidisciplinary model that includes access to a behavioral health provider among other medical professionals. Behavioral interventions for patients with chronic pancreatitis have promise to improve the management of pain, comorbid psychiatric symptoms, and quality of life. If surgical interventions such as a total pancreatectomy islet autotransplant are considered, evaluating and mitigating psychosocial risk factors may aid the selection of appropriate candidates.

Relationship between Pain Intensity, Physical Factors, Pronociceptive Pain Modulation Profile and Psychological Vulnerability on Upper Limb Disability in Older Patients with Chronic Shoulder Pain

BACKGROUND

Chronic shoulder pain is a very prevalent condition causing disability and functional impairment. The purpose of the study was to evaluate the relationship between pain intensity, physical variables, psychological vulnerability, pronociceptive pain modulation profile and disability in older people with chronic shoulder pain.

METHODS

A cross-sectional study was carried out. A total of 56 participants with non-specific chronic shoulder pain of the "Complejo Hospitalario Universitario" (Granada) and 56 healthy controls were included. The outcomes evaluated were pain intensity (visual analogue scale), physical factors (dynamometry for grip strength), psychological vulnerability (Fear-Avoidance Beliefs Questionnaire and Tampa Scale of Kinesiophobia), pronociceptive pain modulation profile (pain pressure algometry) and disability (Quick Disability Arm Shoulder Hand questionnaire).

RESULTS

Disability showed a positive correlation with pain and psychological vulnerability (p < 0.05) and a negative correlation with pronociceptive pain variables and dynamometry (p < 0.001). Psychological vulnerability also presented a strong negative correlation with proprioceptive pain variables and dynamometry and a positive correlation with pain (p < 0.05). In regard to the pronociceptive pain modulation profile, a strong negative correlation with pain (p < 0.001) and a positive moderate correlation with dynamometry (p < 0.001) were shown.

CONCLUSIONS

Our results support a strong association between disability, psychological vulnerability and pronociceptive pain modulation profile in older adults with chronic shoulder pain.

Patterns of patient outcomes following specialist pain management in Australasia: a latent class analysis using the ePPOC database

ABSTRACT

The increasing demand for pain management and limited resources available highlight the need to measure treatment effectiveness. We analysed data collected at 75 specialist persistent pain services located in Australia and New Zealand to calculate overall treatment outcome for patients receiving care during 2014-2020. Socio-demographic and clinical information was provided for 23,915 patients, along with patient-reported measures assessing pain, pain interference, depression, anxiety, stress, pain catastrophizing and pain self-efficacy. Latent Class Analysis identified four distinct outcomes based on patients' pattern of responses across the assessment tools at treatment end. Group 1 (n=8,369, 35%) reported low/mild severity across all clinical domains at the end of care, while Group 4 (n= 7,081, 30%) were more likely to report moderate/high severity on all domains. Group 2 (n=1,991, 8%) reported low/mild pain with moderate/high psychological distress at treatment end, and Group 3 (n=6,474, 27%) reported moderate/high pain with low/mild psychological distress. Multi-variable logistic regression identified those factors associated with the different groups. In particular, factors most predictive of a poor (Group 4) vs. good outcome (Group 1) were unemployment (due to pain or other reasons), requiring an interpreter, widespread pain, pain of longer duration and attributing the pain to an injury at work. The results may allow identification of those most likely to benefit from the services currently provided, and inform development of alternative or enhanced services for those at risk of a poor outcome.

Pain Management and Rehabilitation for Central Sensitization in Temporomandibular Disorders: A Comprehensive Review

Temporomandibular disorders (TMD) are a group of musculoskeletal diseases affecting masticatory muscles and temporomandibular joints (TMJ). In this context, the chronic TMD could be considered as a condition with chronic primary orofacial pain, presenting as myofascial TMD pain or TMJ arthralgia. In this context, myogenous TMD may present overlapping features with other disorders, such as fibromyalgia and primary headaches, characterized by chronic primary pain related to dysfunction of the central nervous system (CNS), probably through the central sensitization. This phenomenon could be defined as an amplified response of the CNS to sensory stimuli and peripheral nociceptive, characterized by hyperexcitability in the dorsal horn neurons in the spinal cord, which ascend through the spinothalamic tract. The main objectives of the management of TMD patients are: decreasing pain, increasing TMJ function, and reducing the reflex masticatory muscle spasm/pain. The first-line treatments are physical therapy, pharmacological drugs, occlusal splints, laser therapy, extracorporeal shockwave therapy, transcutaneous electrical nerve stimulation, and oxygen–ozone therapy. Although all these therapeutic approaches were shown to have a positive impact on the central sensitization of TMD pain, there is still no agreement on this topic in the scientific literature. Thus, in this comprehensive review, we aimed at evaluating the evidence on pain management and rehabilitation for the central sensitization in TMD patients.

Musculoskeletal Pain Management and Patient Mental Health and Well-being

Orthopaedic trauma patients have high rates of psychiatric disorders, which put them at risk for worse outcomes after injury and surgery, including worse pain. Mental health conditions, such as depression and anxiety, can affect the perception of pain. Pain can also exacerbate or contribute to the development of mental illness after injury. Interventions to address both mental health and pain among orthopaedic trauma patients are critical. Balancing safety and comfort amid a drug overdose epidemic is challenging, and many clinicians do not feel comfortable addressing mental health or have the resources necessary. We reviewed the literature on the complex relationship between pain and mental health and presented examples of scalable and accessible interventions that can be implemented to promote the health and recovery of our patients. Interventions described include screening for depression in the orthopaedic trauma clinic and the emergency department or inpatient setting during injury and using a comprehensive and evidence-based multimodal pain management regimen that blends pharmacologic alternatives to opioids and physical and cognitive strategies to manage pain.

Modulation Of Experimental Prolonged Pain and Sensitization Using High-Definition Transcranial Direct Current Stimulation: A Double-Blind, Sham-Controlled Study

High definition transcranial direct current stimulation (HD-tDCS) targeting brain areas involved in pain processing has shown analgesic effects in some chronic pain conditions, but less modulatory effect on mechanical and thermal pain thresholds in asymptomatic subjects. This double-blinded study assessed the HD-tDCS effects on experimental pain and hyperalgesia maintained for several days in healthy participants. Hyperalgesia and pain were assessed during three consecutive days following provocation of experimental pain (nerve growth factor injected into the right-hand muscle) and daily HD-tDCS sessions (20-minutes). Forty subjects were randomly assigned to Active-tDCS targeting primary motor cortex and dorsolateral prefrontal cortex simultaneously or Sham-tDCS. Tactile and pressure pain sensitivity were assessed before and after each HD-tDCS session, as well as the experimentally-induced pain intensity scored on a numerical rating scale (NRS). Subjects were effectively blinded to the type of HD-tDCS protocol. The Active-tDCS did not significantly reduce the NGF-induced NRS pain score (3.5±2.4) compared to Sham-tDCS (3.9±2.0, P > .05) on day 3 and both groups showed similarly NGF-decreased pressure pain threshold in the right hand (P < .001). Comparing Active-tDCS with Sham-tDCS, the manifestation of pressure hyperalgesia was delayed on day 1, and an immediate (pre-HD-tDCS to post-HD-tDCS) reduction in pressure hyperalgesia was found across all days (P < .05). PERSPECTIVE: The non-significant differences between Active-tDCS and Sham-tDCS on experimental prolonged pain and hyperalgesia suggest that HD-tDCS has no effect on moderate persistent experimental pain. The intervention may still have a positive effect in more severe pain conditions, with increased intensity, more widespread distribution, or increased duration and/or involving stronger affective components.

Centrally sensitized patients undergoing total knee arthroplasty have higher expectations than do non-centrally sensitized patients

PURPOSE

The goal of this retrospective observational study is to determine whether patients with and without central sensitization (CS) undergoing total knee arthroplasty (TKA) have similar preoperative expectations. It was hypothesized that the degree of preoperative expectations is higher in patients with CS than in those without.

METHODS

The data of 324 patients who underwent primary unilateral TKA for knee osteoarthritis were reviewed and CS was measured using the Central Sensitization Inventory (CSI), which is a validated self-reported questionnaire consisting of a total of 25 questions. CS was defined as a CSI score of 40 or more. Patient expectations were investigated using the Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES) comprising five categories including pain relief, baseline activity, high flexion activity, social activity, and psychological well-being. The expectations of patients, the Western Ontario and McMaster Universities arthritis index (WOMAC) and American Society of Anesthesiologists (ASA) classification scores were compared between the CS and non-CS groups.

RESULTS

The top three patient expectations in both groups were pain relief, psychological well-being, and walking ability. The total score for the expectations was 55.0 ± 8.3 in the CS group and 52.3 ± 10.4 in the non-CS group, indicating that the expectations of the CS group were higher than the non-CS group before TKA (p < 0.05). When the items on the HSS-KRES scale and the five categories were compared, the CS group had significantly higher expectations for pain relief and psychological well-being than did the non-CS group (all p < 0.05).

CONCLUSION

The expectations of patients with CS before TKA were higher than those without CS. Given the limited improvement in patient-reported outcome measures of patients with CS undergoing TKA, they should be counseled to be realistic especially with their preoperative expectations of pain relief and psychological well-being.

LEVEL OF EVIDENCE

III.

Using quantitative sensory testing to predict attrition in an interdisciplinary pain management program: a pilot study

Aim: To determine the extent to which quantitative sensory testing (QST) predicted attrition in an interdisciplinary pain program (IPP). Patients & methods: Participants (n = 53) enrolled in an IPP completed pretreatment assessments of QST and the PROMIS-29 quality of life survey. Results & conclusion: Compared with completers, non-completers (24.5%) reported significantly higher pain intensity (7.1, 95% CI [5.8, 8.4] versus 5.4, 95% CI [4.8, 6.1]) and cold hyperalgesia (14.6°C, 95% CI [8.8, 20.4] versus 7.5°C, 95% CI [4.8, 6.1]), with both variables also predicting attrition. This finding highlights a potentially novel and clinically significant use of QST. Higher overall pain intensity and the presence of remote cold hyperalgesia may identify patients at risk for dropping out of an IPP.

Pain descriptors and determinants of pain sensitivity in knee osteoarthritis: a community-based cross-sectional study

Objectives

To explore pain characteristics in individuals with knee osteoarthritis (KOA), to compare pain sensitivity across individuals with KOA, chronic back pain (CBP) and pain-free individuals (NP), and to examine the relationship between clinical and pain characteristics with pain sensitivity in KOA.

Methods

Cross-sectional, community-based online survey. Two datasets were combined comprising Dutch individuals of ≥ 40 years of age, experiencing chronic knee pain (KOA, N = 445), chronic back pain (CBP, N = 504), or no pain (NP, N = 256). Demographic and clinical characteristics, global health, physical activity/exercise, and pain characteristics including intensity, spreading, duration, quality (SF-MPQ), and sensitivity (PSQ) were assessed. Differences between (sub)groups were examined using analyses of variance or Chi-square tests. Regression analyses were performed to examine determinants of pain sensitivity in the KOA group.

Results

Quality of pain was most commonly described as aching, tender, and tiring-exhausting. Overall, the KOA group had higher levels of pain sensitivity compared to NP group, but lower levels than the CBP group. Univariately, pain intensity, its variability and spreading, global health, exercise, and having comorbidities were weakly related to pain sensitivity (standardized betas: 0.12-0.27). Symptom duration was not related to pain sensitivity. Older age, higher levels of continuous pain, lower levels of global health, and exercise uniquely contributed, albeit modest, to pain sensitivity (P&lt;0.05).

Conclusion

Continuous pain such as aching and tenderness in combination with decreased physical activity may be indicative for a subgroup of individuals at risk for pain sensitivity and, ultimately, poor treatment outcomes.

Colorectal cancer pain upon diagnosis and after treatment: a cross-sectional comparison with healthy matched controls

BACKGROUND

The current study sought to explore whether cancer pain (CP) already exists in patients at colorectal cancer (CRC) diagnosis before treatment compared with patients with colorectal cancer (CRC) after treatment and a healthy matched control group. The study also sought to examine whether factors related to physical health status could enhance pain processes.

METHODS

An observational cross-sectional study was conducted following the STROBE checklist. Twenty-nine newly diagnosed and forty post-treatment patients with CRC and 40 healthy age/sex-matched controls were included for comparison. Pain, local muscle function, and body composition outcomes were assessed by a physiotherapist with > 3 years of experience. ANCOVA and Kruskal-Wallis tests were performed, with Bonferroni and Dunn-Bonferroni post hoc analyses and Cohen's d and Hedge's effect size, as appropriate.

RESULTS

The analysis detected lower values of pressure pain threshold (PPT) points, the PPT index, and abdominal strength and higher values of self-reported abdominal pain in newly diagnosed patients, with even more marked results observed in the post-treatment patients, where lower lean mass and skeletal muscle index values were also found than those in the healthy matched controls (p < 0.05). In the post-treatment and healthy matched control groups, positive associations were observed between the PPT lumbar dominant side points and abdominal isometric strength and lean mass, and negative associations were observed between the lumbar dominant side points and body fat (p < 0.05).

CONCLUSION

Upon diagnosis, patients with CRC already show signs of hyperalgesia and central sensitization and deteriorated physical conditions and body composition, and this state could be aggravated by subsequent treatments.

Multidisciplinary Care for Adults With Chronic Pancreatitis: Incorporating Psychological Therapies to Optimize Outcomes

ABSTRACT

Chronic pancreatitis (CP) is associated with a high disease burden, extensive negative impact on quality of life, increased rates of depression and anxiety, and significant health care utilization and expenditures. Pain is a hallmark feature of CP, present in up to 90% of patients with this condition, and can lead to high rates of disability, hospitalization, and opioid medication use. Current perspectives on the management of CP have evolved to advocate a multidisciplinary approach which offers new pathways for helping patients manage symptoms. Psychologists play an important role in a multidisciplinary team effort by applying scientifically based psychological principles and techniques to improve pain and adaptation to chronic illness. This review will detail the fundamentals of delivering psychological interventions for adults with CP managed in an outpatient setting. Recommendations for integrating psychological care in multidisciplinary management of CP will be offered. Future directions for psychological care in CP multidisciplinary teams are also discussed.

Placebo Responses and Their Clinical Implications in Fibromyalgia: A Meta-Analysis Using SSRI and SNRI Trials

Background: Fibromyalgia (FM) is a chronic primary pain condition, associated with widespread musculoskeletal pain, disturbed sleep, fatigue, cognitive dysfunction, and a range of comorbid conditions such as irritable bowel syndrome, and depression. Despite its high prevalence of 2% in the general population, FM continues to pose scientific and clinical challenges in definition, etiology, and day-to-day management. In terms of treatment, FM can be treated with selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs). Objective: Patients with FM and other chronic primary pain syndromes are known to experience substantial and clinically relevant placebo effects. An update of the placebo responses for various outcomes in the FM population and especially a discussion about clinical implications is therefore needed. Methods: We used data from a large data pool that includes randomized controlled trials (RCTs) examining within-placebo mean change scores of baseline vs. follow-up assessments in FM trials of SSRIs and SNRIs. The primary outcomes were pain, functional disability, and depression and using different scales. We assessed heterogeneity of included trials. Results: A total of 29 RCTs with N = 8,453 patients suffering from FM were included in our analysis. Within-placebo mean change scores of baseline vs. follow-up assessments were large for pain (mean change = 2.31, 95% CI: 0.42-4.21, p = 0.017), functional disability (mean change = 3.31, 95% CI: 2.37-4.26, p < 0.000), and depression (mean change = 1.55, 95% CI: 0.92-2.18, p < 0.000). Heterogeneity was found to be large for all outcomes. Impact: Our results provide preliminary evidence that placebo responses, which also consist of non-specific effects, might play a role in the treatment of FM. Furthermore, we highlight limitations of our analyses and make suggestions for future studies.

Place and Pain: Association Between Neighborhood SES and Quantitative Sensory Testing Responses in Youth With Functional Abdominal Pain

OBJECTIVE

Neighborhood socioeconomic status (SES) is linked to self-reported pain severity and disability but its association with evoked pain responsiveness in individuals with chronic pain remains unclear. The present study examined relations between neighborhood SES, assessed through the area deprivation index (ADI), and static and dynamic pain response indices. It was hypothesized that youth with functional abdominal pain (FAP) living in lower SES neighborhoods would exhibit lower pain threshold, lower pain tolerance, and reduced conditioned pain modulation (CPM) compared to youth living in higher SES neighborhoods.

METHODS

Participants were 183 youth with FAP and their parents. Youth completed a quantitative sensory testing protocol. Family addresses were used to compute ADI scores. Thermal stimuli for pain threshold and tolerance were delivered to participants' forearms using thermodes. CPM, an index of descending pain inhibition, was determined using a thermode as test stimulus and a hot water bath as conditioning stimulus.

RESULTS

As hypothesized, youth with FAP living in lower SES neighborhoods exhibited weaker CPM. Contrary to hypotheses, lower neighborhood SES was associated with neither pain thresholds nor with pain tolerance.

CONCLUSIONS

These findings demonstrated the independent contribution of place of residence-an often neglected component of the biopsychosocial model-to efficiency of descending pain inhibition. Understanding the mechanisms that account for such associations between place and pain could guide the development of public health and policy initiatives designed to mitigate chronic pain risk in underserved and economically marginalized communities.

Adaptive body awareness predicts fewer central sensitization-related symptoms and explains relationship between central sensitization-related symptoms and pain intensity: A cross-sectional study among individuals with chronic pain

BACKGROUND

Central sensitization (CS), defined as the amplification of neural signaling within the CNS that elicits pain hypersensitivity, is thought be a characteristic of several chronic pain conditions. Maladaptive body awareness is thought to contribute and maintain CS. Less is known about the relationship between CS and adaptive body awareness.

PURPOSE

This cross-sectional study investigated relationships among self-reported adaptive body awareness (Multidimensional Interoceptive Awareness Scale-2; MAIA-2), CS-related symptoms (Central Sensitization Inventory; CSI), and pain intensity and further delineate potential direct and indirect links among these constructs.

METHODS

Online surveys were administered to 280 individuals with chronic pain reporting elevated CSI scores. Strategic sampling targeted respondents to reflect the 2010 census. Pearson's correlations characterized overall relationship between variables. Multiple regression analyses investigated potential direct links. A path analysis assessed mediational effects of CS-related symptoms on the relationship between adaptive body awareness and pain intensity.

RESULTS

CSI demonstrated strong, inverse correlations with some MAIA-2 subscales, but positive correlations with others. Higher CSI scores predicted greater pain intensity (b = 0.049, p ≤ 0.001). Two MAIA-2 subscales, Not-Distracting (b = -0.56, p ≤ 0.001) and Not-Worrying (b = -1.17, p ≤ 0.001) were unique predictors of lower CSI. Not-Distracting (b = -0.05, p = 0.003) and Not-Worrying (b = -0.06, p = 0.007) uniquely predicted lower pain intensity. CSI completely mediated the relationship between adaptive body awareness and pain intensity [point estimate = -0.04; 95% bootstrap confident intervals (CI) = -0.05 to -0.02].

CONCLUSIONS

Findings also support future research to explore causal relationships of variables. Findings suggest that frequency of attention to bodily sensations is distinct from cognitive-affective appraisal of bodily sensation, and the two distinct higher order processes may have divergent influences on perceived pain and CS-related symptoms. Results also support future research to explore causal relationships of variables.

The Impact of Psychological Factors and Their Treatment on the Results of Total Knee Arthroplasty

➤

There is a growing body of evidence implicating psychosocial factors, including anxiety, depression, kinesiophobia, central sensitization, and pain catastrophizing, as negative prognostic factors following total knee arthroplasty (TKA).

➤

Symptoms of anxiety and depression likely represent risk factors for negative outcomes in patients undergoing TKA. However, few studies have assessed the impact of preoperative interventions for these conditions on postoperative outcomes.

➤

The Tampa Scale of Kinesiophobia and the Central Sensitization Inventory have demonstrated value in the diagnosis of kinesiophobia and central sensitization. Higher preoperative indices of kinesiophobia and central sensitization predict worse patient-reported outcomes postoperatively.

➤

Although evidence is limited, cognitive-behavioral therapy for kinesiophobia and duloxetine for central sensitization may help to diminish the negative impact of these preoperative comorbidities. It is important to note, however, that outside the realm of TKA, cognitive-behavioral therapy has been recognized as a more effective treatment for central sensitization than medical treatment.

➤

Awareness of these issues will allow surgeons to better prepare patients regarding postoperative expectations in the setting of a comorbid psychosocial risk factor. Further research into the role of preoperative assessment and possible treatment of these conditions in patients undergoing TKA is warranted.

Pressure pain thresholds in individuals with knee pain: a cross-sectional study

Background

Knee osteoarthritis (KOA), chronic widespread pain (CWP) and overweight/obesity are public health problems that often coincide, and there is a multifactorial and unclear relationship between them. The study aimed to (1) investigate pain sensitivity, assessed by pressure pain thresholds (PPTs), among women and men with knee pain and (2) associations with, respectively, radiographic KOA (rKOA), CWP, and overweight/obesity.

Methods

Baseline data from an ongoing longitudinal study involving 280 individuals with knee pain in the 30–60 age group. Pain sensitivity was assessed by PPTs on eight different tender points using a pressure algometer. The participants’ knees were x-rayed. Self-reported CWP and number of pain sites were assessed with a pain figure, and overweight/obesity was measured using body mass index (BMI), visceral fat area (VFA), and body fat percentage, assessed with a bioimpedance. Associations were analysed using regression analyses.

Results

Women reported lower PPTs than men (p < 0.001), but no PPTs differences were found between those with and without rKOA. Low PPTs was associated with female sex, more pain sites, CWP, and a higher VFA and body fat percentage. The tender points second rib and the knees were most affected. The prevalence of CWP was 38 %.

Conclusions

The modifiable factors, increased VFA, and body fat could be associated with increased pain sensitivity among individuals with knee pain. Longitudinal studies are needed to further investigate the associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04408-0.

Nonlinear increase of pain in distance-based and area-based spatial summation

ABSTRACT

When nociceptive stimulation affects a larger body area, pain increases. This effect is called spatial summation of pain (SSp). The aim of this study was to describe SSp as a function of the size or distance of a stimulated area(s) and to test how this function is shaped by the intensity and SSp test paradigm. Thirty-one healthy volunteers participated in a within-subject experiment. Participants were exposed to area-based and distanced-based SSp. For area-based SSp, electrocutaneous noxious stimuli were applied by up to 5 electrodes (5 areas) forming a line-like pattern; for distance-based SSp, the same position and lengths of stimuli were used but only 2 electrodes were stimulated. Each paradigm was repeated using pain of low, moderate, and high intensity. It was found that the pattern of pain intensity followed a logarithmic (power) rather than a linear function. The dynamics of the pain increase were significantly different across pain intensities, with more summation occurring when pain was perceived as low. Results indicated that area-based SSp is more painful than distance-based SSp when low and moderate but not when high pain intensity is induced. Presented findings have important implications for all studies in which the spatial dimension of pain is measured. When the area or separation between nociceptive stimulation increases, pain does not increase linearly and the pattern of the pain increase is a result of the interaction between intensity and the number of nociceptive sites. A power function should be considered when predicting the size of a nociceptive source.

Alexithymia and Somatization in Chronic Pain Patients: A Sequential Mediation Model

Objective

To investigate whether chronic pain (CP) patients with somatization reported higher alexithymic traits than those without somatization and to study the different relationships between psychological characteristics, pain, health-related quality of life (HRQL), and somatization.

Method

A consecutive sample of 134 CP treatment-seeking outpatients were evaluated for alexithymia (TAS-20), somatization (PHQ-15), distress (HADS), HRQL (SF-12), and pain (BPI).

Results

Patients with somatization (37.04%) reported significantly higher TAS-20 total scores (p < 0.001) and difficulty in identifying feelings (DIF) (p < 0.001) than those without somatization. The somatizer group had also a significantly higher disease duration, severity and interference of pain, distress, and lower HRQL than the non-somatizer group. Hierarchical regression analysis showed that although distress, pain interference and the mental HRQL component are closely related to somatization (R² = 0.55), DIF was the strongest predictor of severity of somatization (β = 0.31). A sequential indirect effect from DIF to somatization via distress symptoms and pain interference turned out to be significant [95% CI (0.01, 0.09)]. Support was also found for sequential mediation paths from DIF to somatization via distress and mental HRQL [95% CI (0.01, 0.11)].

Conclusions

Our results pointed-out that alexithymia, particularly DIF, may be major factor for somatization risk in CP patients. Longitudinal observations are needed for evaluating the role of alexithymia in clinical outcomes.

Central mechanisms of pain in orofacial pain patients: Implications for management

BACKGROUND

Central sensitization (CS) is a form of neuroplasticity characterized by changes in the neural sensitivity, responsiveness, and/or output that are not contingent on peripheral input nor activity-dependent. CS is characterized by activation of unmyelinated C-fibers resulting in a cascade of events at molecular and cellular levels which eventuate into generation of synaptic currents at rest. CS, therefore, contributes to heightened generalized pain sensitivity, further complicates the process of reaching a diagnosis, and increases the possibility of treatment failure. BODY: Trigeminal nerve is the main sensory supplier of the anterior part of the head, including the intraoral structures. Primary afferent nociceptors of the trigeminal nerve and low threshold mechanoreceptors synapse with wide dynamic range (WDR) neurons in the pons. This multifaceted network of nerve interactions which is further complicated by the modulatory circuits that can suppress or heighten the activity of WDR neurons is one of the main contributors to CS. The importance of CS in orofacial pain disorders is emphasized in the context of chronic pain development. As for all chronic pain conditions, it is crucial to consider the biopsychosocial aspects of chronic orofacial pain in managing this diverse group of conditions. This review highlights current understanding of the biopsychosocial model and central mechanisms contributing to the pathogenesis of chronic orofacial pain.

Patients' experiences of internet-based Acceptance and commitment therapy for chronic pain: a qualitative study

Background

Chronic pain is a globally widespread condition with complex clusters of symptoms within a heterogeneous patient group. Internet-delivered Acceptance and Commitment Therapy (IACT) has shown promising results in the treatment of chronic pain. How IACT is experienced by patients is less well known. Qualitative studies of patients’ experiences are needed to further understand factors behind both engagement and negative effects. The aim of this study was to explore how IACT was experienced by chronic pain patients who had participated in a controlled trial.

Methods

Through an open and exploratory approach this study aimed to investigate how IACT was experienced when delivered as a guided self-help program to persons with chronic pain. Eleven participants were interviewed over telephone after completing IACT.

Results

Qualitative analysis based on grounded theory resulted in 2 core categories and 8 subcategories. In treatment: Physical and cognitive restraints, Time and deadline, Therapist contact, and Self-confrontation. After treatment: Attitude to pain, Image of pain, Control or Command, and Acting with pain. Individual differences as well as specific conditions of the treatment may explain variations in how the treatment was approached, experienced and what consequences it led to. Therapist guidance and deadlines for homework play complex roles in relation to autonomy and change.

Conclusions

Adjusting treatment content and format based on participants’ characteristics, such as expectations, motivation and restraints, might positively affect engagement, autonomy and change. Further research on attrition and negative effects of treatment might clarify what enables chronic pain patients to benefit from IACT.

Trial registration

clinicaltrials.gov (NCT01603797). Registered 22 May 2012. Retrospectively registered.

Making Sense of "Somatization": A Systematic Review of its Relationship to Pediatric Pain

OBJECTIVES

Pain and other physical symptoms commonly co-occur in childhood. There is debate about the relevance of somatization in understanding pain. The present review critically appraised and synthesized the extant literature on the relationship between pediatric pain and somatization.

METHODS

A systematic review (PROSPERO registration #95956) was conducted in Medline, PsycINFO, EMBASE, and CINAHL using search terms related to pain and somatization in children and adolescents. A total of 156 articles were eligible for inclusion in the review. For studies that measured somatization using a symptom questionnaire, descriptions of "somatization" were extracted. Data regarding the relationship between pain and somatization were extracted for studies measuring somatization using a diagnostic category (e.g., Somatic Symptom and Related Disorders [SSRDs]).

RESULTS

While many studies using somatic symptom questionnaires described somatization as having a psychological component, this was not always captured in measurement tools. Pain was reported as a common symptom in patients with an SSRD diagnosis, though rates varied depending on the specific diagnosis and pain location. Rates of SSRD diagnoses among pain patients were less frequent than rates of pain amongst SSRD patients.

CONCLUSIONS

SSRDs and pain commonly co-occur, though rates differ depending on diagnosis and pain location. Understanding the relationship between pain and somatization is complicated by the discrepancy between how somatization is defined and measured in questionnaire studies. A comprehensive and measurable definition of somatization is needed so researchers can better identify the shared and unique contributions of pain and somatization in pediatric populations.

The Role of Pets in Supporting Cognitive-Behavioral Chronic Pain Self-Management: Perspectives of Older Adults

Cognitive-behavioral self-management strategies are recommended for older adults with chronic pain. The goal of this study was to explore how pet ownership promotes use of these strategies in everyday life. We conducted four focus groups (N = 25) with dog and cat owners aged ≥70 years with persistent pain. Participants described how their pets affect their daily routines and health, including pain and its management. We analyzed transcripts for salient themes, categorizing them according to their alignment with recommended pain self-management strategies: Mood Management (e.g., increases positive affect), Relaxation/Distraction (e.g., soothing presence), Physical Activity (e.g., dog-walking), Behavioral Activation (e.g., motivates activity even when pain present), Social Activation (e.g., facilitates socializing), and Sleep (e.g., encourages routine). Some participants described negative impacts of pet ownership. Having pets can facilitate behaviors and thoughts that may enhance coping with pain. Testing formal ways of leveraging pets' role may expand nonpharmacological options for chronic pain management.

The Landscape of Chronic Pain: Broader Perspectives

Chronic pain is a global health concern. This special issue on matters related to chronic pain aims to draw on research and scholarly discourse from an eclectic mix of areas and perspectives. The purpose of this non-systematic topical review is to précis an assortment of contemporary topics related to chronic pain and its management to nurture debate about research, practice and health care policy. The review discusses the phenomenon of pain, the struggle that patients have trying to legitimize their pain to others, the utility of the acute-chronic dichotomy, and the burden of chronic pain on society. The review describes the introduction of chronic primary pain in the World Health Organization's International Classification of Disease, 11th Revision and discusses the importance of biopsychosocial approaches to manage pain, the consequences of overprescribing and shifts in service delivery in primary care settings. The second half of the review explores pain perception as a multisensory perceptual inference discussing how contexts, predictions and expectations contribute to the malleability of somatosensations including pain, and how this knowledge can inform the development of therapies and strategies to alleviate pain. Finally, the review explores chronic pain through an evolutionary lens by comparing modern urban lifestyles with genetic heritage that encodes physiology adapted to live in the Paleolithic era. I speculate that modern urban lifestyles may be painogenic in nature, worsening chronic pain in individuals and burdening society at the population level.