Search

Objectives: This study aimed to apply the International Association for the Study of Pain (IASP) grading system for identifying nociplastic pain in knee osteoarthritis (KOA) awaiting total knee arthroplasty (TKA) and propose criteria to fine-tune decision-making. In addition, the study aimed to characterize a "probable" versus "no or possible" nociplastic pain mechanism using biopsychosocial variables and compare both groups in their 1-year post-TKA response., Methods: A secondary analysis of baseline data of a longitudinal prospective study involving 197 patients with KOA awaiting total TKA in Belgium and the Netherlands was performed. Two approaches, one considering 4 and the other 3 pain locations (step 2 of the grading system), were presented. Linear mixed model analyses were performed to compare the probable and no or possible nociplastic pain mechanism groups for several preoperative biopsychosocial-related variables and 1-year postoperative pain. Also, a sensitivity analysis, comparing 3 pain mechanism groups, was performed., Results: Thirty (15.22%-approach 4 pain locations) and 46 (23.35%-approach 3 pain locations) participants were categorized under probable nociplastic pain. Irrespective of the pain location approach or sensitivity analysis, the probable nociplastic pain group included more woman, was younger, exhibited worse results on various preoperative pain-related and psychological variables, and had more pain 1-year post-TKA compared with the other group., Discussion: This study proposed additional criteria to fine-tune the grading system for nociplastic pain (except for discrete/regional/multifocal/widespread pain) and characterized a subgroup of patients with KOA with probable nociplastic pain. Future research is warranted for further validation., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: Specific neck exercises are recommended in the rehabilitation of chronic nonspecific neck pain (CNNP). They are unfortunately often accompanied by acute pain flare-ups. Global exercises might be a beneficial addition, as they activate endogenous analgesia without overloading painful structures. However, it is still unclear which type of exercise is most effective. This randomized controlled trial was done to evaluate the effect of an online blended program of global and specific neck exercises, compared to programs including only 1 of both types of exercise., Methods: Forty-eight patients with CNNP were randomized into 3 groups. Online questionnaires were collected at baseline, at midtreatment, immediately after treatment, and at the 3-month follow-up. Quantitative sensory testing and actigraphy were assessed at baseline and after treatment. Linear mixed-model analyses were performed to evaluate treatment effects within and between groups. Neck pain-related disability after treatment was considered the primary outcome., Results: No time × treatment interaction effects were found. All groups improved in neck pain-related disability, pain intensity, self-reported symptoms of central sensitization, local pain sensitivity, physical activity, and pain medication use. No effects were found on quality of life, sleep quality, depression, anxiety, stress, widespread pain sensitivity, health economics, or actigraphy measurements. A higher global perceived effect was reported after performing the blended program, compared to the other groups., Conclusion: A blended exercise program was not superior to the stand-alone programs in reducing disability. Nevertheless, the global perceived effect of this type of exercise was higher. Future research necessitates larger sample sizes to adequately explore the optimal type of exercise for patients with CNNP., Impact: Exercise therapy should be an important part of the rehabilitation of patients with CNNP, regardless of the type of exercise., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Physical Therapy Association. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The objective of this study is to determine whether the change in pain intensity over time differs between somatosensory functioning evolution profiles in knee osteoarthritis (KOA) patients undergoing total knee arthroplasty (TKA). This longitudinal prospective cohort study, conducted between March 2018 and July 2023, included KOA patients undergoing TKA in four hospitals in Belgium and the Netherlands. The evolution of the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale pain over time (baseline, 3 months, and 1 year post-TKA scores) was the outcome variable. The evolution scores of quantitative sensory testing (QST) and Central Sensitization Inventory (CSI) over time (baseline and 1 year post-TKA scores) were used to make subgroups. Participants were divided into separate normal, recovered, and persistent disturbed somatosensory subgroups based on the CSI, local and widespread pressure pain threshold [PPT] and heat allodynia, temporal summation [TS], and conditioned pain modulation [CPM]. Linear mixed model analyses were performed. Two hundred twenty-three participants were included. The persistent disturbed somatosensory functioning group had less pronounced pain improvement (based on CSI and local heat allodynia) and worse pain scores 1 year post-TKA (based on CSI, local PPT and heat allodynia, and TS) compared to the normal somatosensory functioning group. This persistent group also had worse pain scores 1 year post-TKA compared to the recovered group (based on CSI). The study suggests the presence of a "centrally driven central sensitization" subgroup in KOA patients awaiting TKA in four of seven grouping variables, comprising their less pain improvement or worse pain score after TKA. Future research should validate these findings further. The protocol is registered at clinicaltrials.gov (NCT05380648)., (© 2024. The Author(s).)

Purpose: Pain is one of the most prevalent problems reported by breast cancer survivors. As this long-lasting complication can result in disabilities on all different domains of functioning, we aimed to clarify the contribution of different factors (pain-related factors, psychosocial factors, and fatigue) to pain-related disability in female breast cancer survivors., Methods: Seventy women who had completed their primary breast cancer treatment were included in this cross-sectional study. The following outcome measures were evaluated as independent variables for their contribution to pain-related disability (measured by the Pain Disability Index, with a maximum score of 70): pain intensity, self-reported symptoms of central sensitization, fatigue, illness beliefs, pain catastrophizing, and kinesiophobia. At first, bi- and multivariable regression methods were conducted. Secondly, a stepwise regression analysis was performed to determine the explained variance of the PDI., Results: Mean score on the PDI was 16 at 4.5 years post-surgery. Multivariable regression analysis revealed higher levels of kinesiophobia as the main contributor to pain-related disability. Ultimately, stepwise regression showed that up to 40% of variance in pain-related disability could be explained by kinesiophobia, negative perceptions related to illness consequences, and pain catastrophizing., Conclusion: This study shows that breast cancer survivors portray moderate self-reported pain-related disability. Kinesiophobia emerged as the main contributor to pain-related disability at this time point, which could shine a light on the improvement of treatment modalities for pain management in this population.

Background: Pain beliefs might play a role in the development, transition, and perpetuation of shoulder pain., Objective: To systematically review and critically appraise the association and the predictive value of pain beliefs on pain intensity and/or disability in shoulder pain., Methods: An electronic search of PubMed, EBSCOhost, AMED, CINAHL, EMBASE, and PubPsych, and grey literature was searched from inception to July 2017. Study selection was based on observational studies exploring the association and the predictive value of pain beliefs on pain intensity and/or disability in shoulder pain., Results: A total of thirty-three articles were included with a total sample of 10,293 participants with shoulder pain. In the cross-sectional analysis, higher levels of pain catastrophizing and kinesiophobia were significantly associated with more pain intensity and disability, whereas higher levels of expectations of recovery and self-efficacy were significantly associated with lower levels of pain intensity and disability. In the longitudinal analysis, higher levels of pain catastrophizing, fear-avoidance and kinesiophobia at baseline predicted greater pain intensity and disability overtime. Higher levels of self-efficacy and expectations of recovery at baseline predicted a reduction in levels of pain intensity and disability overtime., Conclusions: Evidence suggests that pain beliefs are associated with and predict the course of pain intensity and disability in shoulder pain. However, the overall body of the evidence after applying the GRADE approach was very low across studies. Further research using higher quality longitudinal designs and procedures would be needed to establish firm conclusions., (Copyright © 2018. Published by Elsevier Ltd.)

Objective: Symptoms of central sensitization (CS) have been described in patients with chronic spinal pain (CSP). Although a gold standard to diagnose CS is lacking, psychophysical pain measures are often used. The Central Sensitization Inventory (CSI) is proposed as an alternative method and indirect tool for the evaluation of CS symptomatology. The aim of the current study was to evaluate the convergent validity of the CSI by investigating the association with psychophysical pain measures and self-reported measures of current pain intensity, quality of life, disability, and catastrophizing in CSP patients., Methods: One hundred sixteen patients with nonspecific CSP were included in the present study. Patients completed the CSI, were subjected to pressure pain thresholds (PPTs) and a conditioned pain modulation (CPM) paradigm, and completed questionnaires for current pain intensity, quality of life, pain disability, and pain catastrophizing., Results: Higher CSI scores were weakly correlated with lower PPTs (-0.276 ≤ r ≤ -0.237; all P ≤ 0.01) and not with CPM efficacy (r = 0.017; P = 0.858). Higher CSI scores were moderately correlated with higher current pain intensity (r = 0.320; P < 0.001), strongly correlated with lower physical (r = -0.617; P < 0.001) and emotional (r = -0.635; P < 0.001) quality of life, and moderately correlated with higher pain disability (r = 0.472; P < 0.001) and higher pain catastrophizing (r = 0.464; P < 0.001)., Conclusion: The CSI was weakly associated with PPTs and not with CPM efficacy in CSP patients. Moderate to strong associations were found with current pain intensity, quality of life, disability, and catastrophizing. The current results illustrate that the CSI does not reflect a direct measure of CS, yet is a representation of general distress, possible originating from CS symptoms., (© 2017 World Institute of Pain.)

Background: The impairment in musculoskeletal structures in patients with low back pain (LBP) is often disproportionate to their complaint. Therefore, the need arises for exploration of alternative mechanisms contributing to the origin and maintenance of non-specific LBP. The recent focus has been on central nervous system phenomena in LBP and the pathophysiological mechanisms underlying the various symptoms and characteristics of chronic pain. Knowledge concerning changes in pain processing in LBP remains ambiguous, partly due to the diversity in the LBP population., Objective: The purpose of this study is to compare quantitative sensory assessment in different groups of LBP patients with regard to chronicity. Recurrent low back pain (RLBP), mild chronic low back pain (CLBP), and severe CLBP are compared on the one hand with healthy controls (HC), and on the other hand with fibromyalgia (FM) patients, in which abnormal pain processing has previously been reported., Study Design: Cross-sectional study., Setting: Department of Rehabilitation Sciences, Ghent University, Belgium., Methods: Twenty-three RLBP, 15 mild CLBP, 16 severe CLBP, 26 FM, and 21 HC participated in this study. Quantitative sensory testing was conducted by manual pressure algometry and computer-controlled cuff algometry. A manual algometer was used to evaluate hyperalgesia as well as temporal summation of pain and a cuff algometer was used to evaluate deep tissue hyperalgesia, the efficacy of the conditioned pain modulation and spatial summation of pain., Results: Pressure pain thresholds by manual algometry were significantly lower in FM compared to HC, RLBP, and severe CLBP. Temporal summation of pain was significantly higher in FM compared to HC and RLBP. Pain tolerance thresholds assessed by cuff algometry were significantly lower in FM compared to HC and RLBP and also in severe CLBP compared to RLBP. No significant differences between groups were found for spatial summation or conditioned pain modulation., Limitations: No psychosocial issues were taken into account for this study., Conclusion: The present results suggest normal pain sensitivity in RLBP, but future research is needed. In mild and severe CLBP some findings of altered pain processing are evident, although to a lesser extent compared to FM patients. In conclusion, mild and severe CLBP presents within a spectrum, somewhere between completely healthy persons and FM patients, characterized by pain augmentation.

Background: Commonalities in the core symptoms of fatigue and cognitive dysfunction experienced by chronic fatigue syndrome (CFS, also known as ME) and multiple sclerosis (MS) patients have been described. Many CFS and MS patients also experience chronic pain, which has been attributed to central sensitization in both groups of patients. However, the characteristics of pain in CFS and MS patients have not been compared., Objectives: To compare experimental pain measurements in patients with CFS or MS and healthy controls., Study Design: Observational study., Setting: This study took place in Belgium at Vrije Universiteit Brussel and the University of Antwerp., Methods: Pressure pain thresholds, temporal summation, conditioned pain modulation, and occlusion cuff pressure thresholds rated as painful (1st cuff pressure threshold) and as 3/10 on a verbal numerical scale (2nd cuff pressure threshold) were measured in patients with CFS (n = 48), MS (n = 19) and healthy pain-free controls (n = 30). Adjusted between-group differences were estimated using linear regression models., Results: Finger pain pressure thresholds of patients with CFS, compared with patients with MS, were 25% lower (difference ratio 0.75 [95% CI 0.59, 0.95], P = 0.02) and shoulder pain pressure thresholds were 26% lower (difference ratio 0.74 [0.52, 1.04], P = 0.08). Compared with patients with MS, patients with CFS had 29% lower first cuff pressure threshold (difference ratio 0.71 [0.53, 0.94], P = 0.02) and 41% lower 2nd cuff pressure threshold (0.59 [0.41, 0.86], P = 0.006). Finger temporal summation was higher in patients with CFS than in patients with MS (mean difference 1.15 [0.33, 1.97], P = 0.006), but there were no differences in shoulder temporal summation or conditioned pain modulation at either site. Differences between patients with CFS and MS tended to be greater than between either patient group and healthy controls. Pain pressure thresholds and cuff pressure thresholds tended to be positively correlated, and temporal summation negatively correlated, with higher physical function and lower fatigue in both groups of patients. Subjective pain in patients with CFS but not in patients with MS was strongly negatively correlated with pain pressure thresholds and cuff pressure thresholds, and positively correlated with temporal summation., Limitations: The main limitations of our study are the relatively small sample sizes, its cross-sectional design, and its exploratory nature., Conclusions: We found differences in the characteristics of pain symptoms reported by patients with CFS and patients with MS, which suggest different underlying mechanisms. Specifically, overactive endogenous pain facilitation was characteristic of pain in patients with CFS but not in patients with MS, suggesting a greater role for central sensitization in CFS.

Unlabelled: Compelling evidence has shown chronic widespread and exaggerated pain experience in chronic musculoskeletal pain (MSKP) conditions. In addition, neuroimaging research has revealed morphological and functional brain alterations in these patients. It is hypothesized that brain alterations play a role in the persistent pain complaints of patients with chronic MSKP. Nevertheless, lack of overview exists regarding the relations between brain alterations and clinical measures of pain. The present systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, to investigate the relations between structural or functional brain alterations, using magnetic resonance imaging scans, and clinical pain measures in patients with chronic MSKP. PubMed, Web of Science, Cinahl, and Cochrane databases were searched. First, the obtained articles were screened according to title and abstract. Second, the screening was on the basis of full-text. Risk of bias in included studies was investigated according to the modified Newcastle-Ottawa Scale. Twenty studies met the inclusion criteria. Moderate evidence shows that higher pain intensity and pressure pain sensitivity are related to decreased regional gray matter (GM) volume in brain regions encompassing the cingulate cortex, the insula, and the superior frontal and temporal gyrus. Further, some evidence exists that longer disease duration in fibromyalgia is correlated with decreased total GM volume. Yet, inconclusive evidence exists regarding the association of longer disease duration with decreased or increased regional GM volume in other chronic MSKP conditions. Inconclusive evidence was found regarding the direction of the relation of pain intensity and pressure pain sensitivity with microstructural white matter and functional connectivity alterations. In conclusion, preliminary to moderate evidence demonstrates relations between clinical pain measures, and structural and functional connectivity alterations within brain regions involved in somatosensory, affective, and cognitive processing of pain in chronic MSKP. Nevertheless, inconclusive results exist regarding the direction of these relations. Further research is warranted to unravel whether these brain alterations are positively or negatively correlated to clinical pain measures., Perspective: Structural and functional brain alterations within regions involved in somatosensory, affective, and cognitive pain processing play a crucial role in the persistent pain of chronic MSKP patients. Accordingly, these brain alterations have to be taken into account when assessing and treating patients with chronic MSKP., (Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Objectives: A standardized assessment of central sensitization can be performed with the Central Sensitization Inventory (CSI), an English questionnaire consisting of 25 items relating to current health symptoms. The aim of this study was to translate the CSI into Dutch, to perform a factor analysis to reveal the underlying structure, examine its discriminative power, and test-retest reliability., Methods: The CSI was first translated into Dutch. A factor analysis was conducted on CSI data of a large group of chronic pain patients (n=368). The ability to discriminate between chronic pain patients (n=188) and pain-free controls (n=49) was determined and the test-retest reliability for chronic pain patients (n=36) and controls (n=45) with a time interval of 3 weeks was evaluated., Results: The exploratory factor analysis resulted in a 4-factor model based on 20 items, representing the domains "General disability and physical symptoms" (Cronbach α=0.80), "Higher central sensitivity"(Cronbach α=0.78), "Urological and dermatological symptoms"(Cronbach α=0.60), and "Emotional distress"(Cronbach α=0.80). Furthermore, a parsimonious second-order factor model was found, where the factor "General central sensitization" was underlying the 4 first-order factors. Chronic pain patients scored significantly worse on all 4 factors. The test-retest reliability was excellent values in both chronic pain patients (ICC=0.88) and controls (ICC=0.91)., Discussion: The original CSI was translated into Dutch and did not reveal any problems during data acquisition. The domains represented by the 4 factors may be useful in setting up specific patient profiles and treatment targets. To conclude, the Dutch CSI revealed 4 distinguishable domains, showed good internal consistency for the total score and 3 out of 4 domains, good discriminative power, and excellent test-retest reliability.

Measuring the pectoralis minor muscle length (PML) is of clinical interest, as a short PML has been associated with a decrease of scapular posterior tilting and shoulder pain. However, as no reliability data are available at present, the objective of this study was to examine the inter- and intrarater reliability of the PML measurement in both subjects with and without shoulder impingement symptoms (SIS). Therefore, two assessors performed the PML measurement (3 times/shoulder) in 25 patients with SIS and 25 pain-free controls. Both assessors were blinded for each other's findings. For reliability testing, intra-class coefficients (ICCs; model 2,1) and standard errors of measurements were calculated. Intrarater reliability analysis resulted with ICCs ranging from 0.87 (Standard error of measurement (SEM) 0.21-0.27%) (symptomatic) to 0.93 (SEM 0.19-0.30%) (asymptomatic) in patients with SIS, representing excellent test-retest agreement. Healthy subjects presented with ICCs ranging from 0.76 (SEM 0.29-0.32%) (dominant side) to 0.87 (SEM 0.21-0.32%) (non-dominant side), representing good test-retest agreement. ICCs and SEMs on the symptomatic and asymptomatic side (0.48 and 0.46%; 0.56 and 0.61%) in SIS patients, and on the two sides (non-dominant; 0.47 and 0.45%, dominant; 0.53 and 0.38% respectively) in healthy subjects showed moderate interrater reliability and low dispersion of the measurement errors. We concluded that the PML measurement has good to excellent intrarater reliability and poor to moderate interrater reliability., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In various chronic pain populations, decreased cognitive performance is known to be related to pain severity. Yet, this relationship has not been investigated in patients with chronic fatigue syndrome (CFS). This study investigated the relationship between cognitive performance and (1) pain severity, (2) level of fatigue, and (3) self-reported symptoms and health status in women with CFS. Examining the latter relationships is important for clinical practice, since people with CFS are often suspected to exaggerate their symptoms. A sample of 29 female CFS patients and 17 healthy controls aged 18 to 45 years filled out three questionnaires (Medical Outcomes Study 36-Item Short-Form Health Survey, Checklist Individual Strength (CIS), and CFS Symptom List) and performed three performance-based cognitive tests (psychomotor vigilance task, Stroop task, and operation span task), respectively. In both groups, pain severity was not associated with cognitive performance. In CFS patients, the level of fatigue measured with the CFS Symptom List, but not with the CIS, was significantly correlated with sustained attention. Self-reported mental health was negatively correlated with all investigated cognitive domains in the CFS group. These results provide evidence for the clinical importance of objectively measured cognitive problems in female CFS patients. Furthermore, a state-like measure (CFS Symptom List) appears to be superior over a trait-like measure (CIS) in representing cognitive fatigue in people with CFS. Finally, the lack of a significant relationship between cognitive performance and self-reported pain severity suggests that pain in CFS might be unique.

Background: Besides chronic fatigue, patients with chronic fatigue syndrome (CFS) have debilitating widespread pain. Yet pain from CFS is often ignored by clinicians and researchers., Objectives: To examine whether pain is a unique feature of CFS, or does it share the same underlying mechanisms as other CFS symptoms? Second, it is examined whether effective treatments for pain from CFS are currently available., Study Design: Narrative review covering the scientific literature up through December 2011., Setting: Several universities., Results: From the available literature, it is concluded that musculoskeletal factors are unlikely to account for pain from CFS. Pain seems to be one out of many symptoms related to central sensitization from CFS. This idea is supported by the findings of generalized hyperalgesia (including widespread increased responsiveness to painful stimuli) and dysfunctional endogenous analgesia in response to noxious thermal stimuli. Pain catastrophizing and depression partly account for pain from CFS. Pain increases during exercise is probably due to the lack of endogenous analgesia and activation of several genes in response to exercise in CFS. There is currently no evidence in support for the efficacy of complementary medicine in the treatment of pain from CFS. Intensive education about the biology of pain from CFS (within the framework of central sensitization) has positive short-term effects for patients with CFS, and fatigue-targeting cognitive behavioral therapy appears to be effective for pain from CFS as well., Limitations: The role of the deficient hypothalamus-pituitary-adrenal axis in relation to pain from CFS, as well as the interactions with immune (dys)functioning require further study., Conclusion: Recent research has increased our understanding of pain from CFS, including its treatment. It is advocated to optimize current CFS treatment protocols by targeting the underlying mechanism for those patients having severe pain.

Studies on the concurrent validity of clinically applicable testing protocols for conditioned pain modulation (CPM) and temporal summation of pain (TSP) in breast cancer survivors (BCS) with persistent pain are lacking.

Objective. Specific neck exercises are recommended in the rehabilitation of chronic nonspecific neck pain (CNNP). They are unfortunately often accompanied by acute pain flare-ups. Global exercises might be a beneficial addition, as they activate endogenous analgesia without overloading painful structures. However, it is still unclear which type of exercise is most effective. This randomized controlled trial was done to evaluate the effect of an online blended program of global and specific neck exercises, compared to programs including only 1 of both types of exercise. Methods. Forty-eight patients with CNNP were randomized into 3 groups. Online questionnaires were collected at baseline, at midtreatment, immediately after treatment, and at the 3-month follow-up. Quantitative sensory testing and actigraphy were assessed at baseline and after treatment. Linear mixed-model analyses were performed to evaluate treatment effects within and between groups. Neck pain-related disability after treatment was considered the primary outcome. Results. No time x treatment interaction effects were found. All groups improved in neck pain-related disability, pain intensity, self-reported symptoms of central sensitization, local pain sensitivity, physical activity, and pain medication use. No effects were found on quality of life, sleep quality, depression, anxiety, stress, widespread pain sensitivity, health economics, or actigraphy measurements. A higher global perceived effect was reported after performing the blended program, compared to the other groups. Conclusion. A blended exercise program was not superior to the stand-alone programs in reducing disability. Nevertheless, the global perceived effect of this type of exercise was higher. Future research necessitates larger sample sizes to adequately explore the optimal type of exercise for patients with CNNP. Impact. Exercise therapy should be an important part of the rehabilitation of patients with CNNP, regardless of the type of exercise. [ABSTRACT FROM AUTHOR]

Background: Joint pain is the hallmark of haemophilia; therefore it seems clinically rather a musculoskeletal than a bleeding disorder. Although joint pain in people with haemophilia (PwH) is a complex and multidimensional problem, pain assessment remains primarily focused on the structural evaluation of their joints. Whereas, only few data are available on the potential implication of psychophysical and psychological factors. Objective: This study aimed to perform a psychophysical pain assessment including quantitative sensory testing (QST) and an evaluation of psychological factors in a large sample of PwH, to get insight into the individuals' pain system. Methods: Ninety‐nine adults (36.9 ± 13.5 years) with moderate/severe haemophilia A/B and 46 healthy controls filled in self‐reported pain and psychological questionnaires and underwent a QST evaluation including static and dynamic tests. Static tests focused on the determination of thermal detection and pain thresholds and mechanical pressure pain thresholds. Dynamic tests evaluated pain facilitation and the efficacy of endogenous pain inhibition. Besides comparing PwH and healthy controls, between‐subgroup differences were studied in PwH based on their pain distribution. Results: The study revealed increased thermal and mechanical pain sensitivity and the presence of unhelpful psychological factors such as anxiety/depression in PwH. Among the subgroups, especially PwH with widespread pain showed altered somatosensory functioning. Enhanced pain facilitation and impaired efficacy of endogenous pain inhibition in PwH could not be observed. Conclusion: Altered somatosensory functioning and unhelpful psychological factors, appear to play an important role in the pathophysiology of pain in PwH, especially in PwH with widespread pain. [ABSTRACT FROM AUTHOR]

Prayer is considered to be the most common therapy used in alternative medicine. This study aimed to explore the effect of prayers on endogenous pain modulation, pain intensity, and sensitivity in healthy religious participants. A total of 208 healthy religious participants were enrolled in this study and randomly distributed into two groups, a prayer group (n = 156) and a poem reading or control group (n = 52). Participants from the prayer group were then selectively allocated using the prayer function scale to either an active prayer group (n = 94) receiving an active type of praying or to a passive prayer group (n = 62) receiving a passive type of praying. Pain assessments were performed before and following the interventions and included pressure pain threshold assessment (PPT), conditioned pain modulation (CPM), and a numerical pain rating scale. A significant group-by-time interaction for PPT (p = 0.014) indicated post-intervention increases in PPT in the prayer group but not in the poem reading control group. Participants experienced a decrease in CPM efficacy (p = 0.030) and a reduction in their NPRS (p < 0.001) following the interventions, independent of their group allocation. The results showed that prayer, irrespective of the type, can positively affect pain sensitivity and intensity, but does not influence endogenous pain inhibition during hot water immersion. Future research should focus on understanding the mechanism behind "prayer-induced analgesia." [ABSTRACT FROM AUTHOR]

Objective Although there has been increasing interest in the role of systemic cytokines in chronic spinal pain (CSP), the evidence on their potential contribution is still unclear. Therefore, the current study systematically reviewed the evidence on systemic cytokine level differences between people with CSP compared to healthy controls (HCs) and the potential associations with pain severity. Methods An electronic search was conducted on PubMed, Web of Science and Embase. All included studies were classified as observational studies, exploring the comparison between a CSP group and a HC group, and the association between systemic cytokine levels and pain severity. Results Nine articles were included with a total sample of 400 CSP patients suffering from chronic whiplash associated disorder (CWAD) or chronic low back pain (CLBP). In CLBP, moderate evidence was found for elevated tumor necrosis factor (TNF) α, interleukin (IL) 6, IL-1 receptor antagonist (IL-1RA), and soluble TNF receptor (sTNF-R) type 2, for normal interferon (IFN) γ and IL-2 levels, and for reduced IL-10 levels. No association was found between pain severity and these cytokines in CLBP. In CWAD, moderate evidence was found for elevated CRP and evidence for changes in TNF-α was inconclusive. Evidence for the association between pain severity and CRP was limited, and there is probably no association between pain severity and TNF-α with limited evidence in CWAD. Conclusions Moderate evidence indicates the presence of systemic inflammation in CSP. Evidence regarding the association between pain severity and systemic cytokines is inconclusive and limited. [ABSTRACT FROM AUTHOR]

Background: Conflicting results exist between somatosensory profiles of patients with temporomandibular myalgia (TMDm). The objective of this review was to examine whether adults with TMDm show altered responses to dynamic quantitative sensory tests compared with healthy controls. Methods: We searched five electronic databases for studies, excluding those without suitable controls or where TMDm was associated with confounding non‐musculoskeletal disorders. Risk of bias was assessed with the SIGN case‐control study checklist. Findings were structured around dynamic quantitative sensory tests and their localization. Where possible, we performed meta‐analysis with a random inverse variance model to compare patients with TMDm and healthy controls. Statistical heterogeneity was estimated with Chi² test and inconsistency index, I². Results: We extracted data from 23 studies comprising 1284 adults with chronic TMDm and 2791 healthy controls. Risk of bias was assessed as high for 20 studies. Mechanical temporal summation, the most studied phenomenon (14 studies), is increased in the upper limb of patients with TMDm (SMD = 0.43; 95% CI:.11 to.75; p =.009) but not in the jaw area (p =.09) or in the cervical area (p =.29). Very little evidence for altered thermal temporal summation (five studies), conditioned pain modulation (seven studies), exercise‐induced hypoalgesia (two studies), placebo analgesia (two studies), stress‐induced hypoalgesia (one study) and offset analgesia (one study) was found. Discussion: A major limitation of this review was the risk of bias of included studies. Future studies would benefit from following methodological guidelines and consideration of confounding factors. [ABSTRACT FROM AUTHOR]

Objective Quantitative sensory testing (QST) consists of noninvasive psychophysical assessment techniques to evaluate the functioning of the somatosensory nervous system. Despite the importance of reliability for the correct use of QST results in research and clinical practice, the relative and absolute intra- and inter-rater reliability of a comprehensive QST protocol to evaluate the functioning of both the peripheral and central somatosensory nervous system in a breast cancer population has not yet been investigated. Setting University Hospitals, Leuven, Belgium. Subjects Thirty women at least 6 months after unilateral breast cancer surgery. Methods The protocol included nine static and dynamic QST methods (mechanical pain-detection thresholds, pressure pain thresholds, thermal pain-detection thresholds for heat and cold, temporal summation, and conditioned pain modulation [CPM]) performed in the surgical area and in more distant regions. Absolute and relative intra-rater reliability (60-minute interval) and inter-rater reliabilty (1-week interval) were evaluated with intraclass correlation coefficients, standard error of measurement, and Bland-Altman plots. Results Moderate to excellent relative intra-rater reliability and inter-rater reliability were found for the evaluation of mechanical thresholds, pressure pain thresholds, and temporal summation. The reliability of the CPM paradigm was considered weak. Systematic bias between raters was noticed for the detection of mechanical and cold stimuli at the non-affected trunk and for CPM. Conclusions Except for the evaluation of CPM, the QST protocol was found suitable for identifying differences between subjects (relative reliability) and for individual follow-up after breast cancer surgery (limited systematic bias) during a 1-week time frame. Additional research is required to determine the measurement properties that influence CPM test stability to establish a more reliable CPM test paradigm. [ABSTRACT FROM AUTHOR]

Abstract: Background: Impaired pain inhibitory and enhanced pain facilitatory mechanisms are repeatedly reported in patients with central sensitization pain. However, the exact effects of frequently prescribed opioids on central pain modulation are still unknown. Methods: A randomized, double‐blind, placebo‐controlled cross‐over trial was carried out. Ten chronic fatigue syndrome (CFS)/fibromyalgia (FM) patients, 11 rheumatoid arthritis (RA) patients and 20 controls were randomly allocated to the experimental (10 mg morphine or 0.2 mg/mL Naloxone) and placebo (2 mL Aqua) group. Pressure pain thresholds (PPTs) and temporal summation at the Trapezius and Quadriceps were assessed by algometry. Conditioned pain modulation (CPM) efficacy and deep tissue pain pressure were assessed by adding ischemic occlusion at the opposite upper arm. Results: Deep tissue pain pressure was lower and temporal summation higher in CFS/FM (P = 0.002 respectively P = 0.010) and RA patients (P = 0.011 respectively P = 0.047) compared to controls at baseline. Morphine had only a positive effect on PPTs in both patient groups (P time = 0.034). Accordingly, PPTs increased after placebo (P time = 0.015), and no effects on the other pain parameters were objectified. There were no significant effects of naloxone nor nocebo on PPT, deep tissue pain, temporal summation or CPM in the control group. Conclusions: This study revealed anti‐hyperalgesia effects of morphine in CFS/FM and RA patients. Nevertheless, these effects were comparable to placebo. Besides, neither morphine nor naloxone influenced deep tissue pain, temporal summation or CPM. Therefore, these results suggest that the opioid system is not dominant in (enhanced) bottom‐up sensitization (temporal summation) or (impaired) endogenous pain inhibition (CPM) in patients with CFS/FM or RA. [ABSTRACT FROM AUTHOR]

Background. Expanded distribution of pain is considered a sign of central sensitization (CS). The relationship between recording of symptoms and CS in people with knee osteoarthritis (OA) has been poorly investigated. Objective. The aim of this study was to examine whether the area of pain assessed using pain drawings relates to CS and clinical symptoms in people with knee OA. Design. This was a cross-sectional study. Methods. Fifty-three people with knee OA scheduled to undergo primary total knee arthroplasty were studied. All participants completed pain drawings using a novel digital device, completed self-administration questionnaires, and were assessed by quantitative sensory testing. Pain frequency maps were generated separately for women and men. Spearman correlation coefficients were computed to reveal possible correlations between the area of pain and quantitative sensory testing and clinical symptoms. Results. Pain frequency maps revealed enlarged areas of pain, especially in women. Enlarged areas of pain were associated with higher knee pain severity (rs=.325, P<.05) and stiffness (rs=.341, P<.05), lower pressure pain thresholds at the knee (rs= -.306, P<.05) and epicondyle (rs=-.308, P<05), and higher scores with the Central Sensitization Inventory (rs=.456, P<.01). No significant associations were observed between the area of pain and the remaining clinical symptoms and measures of CS. Limitations. Firm conclusions about the predictive role of pain drawings cannot be drawn. Further evaluation of the reliability and validity of pain area extracted from pain drawings in people with knee OA is needed. Conclusion. Expanded distribution of pain was correlated with some measures of CS in individuals with knee OA. Pain drawings may constitute an easy way for the early identification of CS in people with knee OA, but further research is needed. [ABSTRACT FROM AUTHOR]

Background Conditioned pain modulation ( CPM) is believed to play an important role in the development and exacerbation of chronic pain, because dysfunction of CPM is associated with a shift in balance between pain facilitation and pain inhibition. In many patients with central sensitization, CPM is less efficacious. Besides that, efficacy of CPM is highly variable in healthy people. Consequently, it seems that several individual variables may influence CPM. A systematic review examining personal factors influencing CPM was conducted. Methods This systematic review follows the PRISMA guidelines. 'Pubmed' and 'Web of Science' were searched using different synonyms of CPM. Full-text clinical reports addressing the influence of personal factors on CPM in healthy adults were included. Checklists for RCTs and case-control studies provided by the Dutch Institute for Healthcare Improvement ( CBO) and the Dutch Cochrane Centre were utilized to assess methodological quality. Levels of evidence and strength of conclusion were assigned using the CBO guidelines. Results Forty-six articles were identified that reported the influence of personal factors on CPM. Quality assessment revealed 10 studies with a methodological quality less than 50% wherefore they were excluded (21.8%), resulting in a general total methodological quality score of 72.5%. Overall younger adult age, male gender, ovulatory phase, positive expectations, attention to the conditioning stimulus, and carrier of the 5- HTTLPR long allele result in better CPM. Conclusion It is advised for future studies to take these factors into account. Further research regarding the influence of oral contraceptives, catastrophizing, information about conditioning stimulation, distraction, physical activity, and genetics on CPM magnitude is required. [ABSTRACT FROM AUTHOR]

Objective Temporal summation ( TS) of pain, conditioned pain modulation ( CPM), and exercise-induced analgesia ( EIA) are often investigated in chronic pain populations as an indicator for enhanced pain facilitation and impaired endogenous pain inhibition, respectively, but interactions are not yet clear both in healthy controls and in chronic pain patients. Therefore, the present double-blind randomized placebo-controlled study evaluates pains cores, TS, and CPM in response to exercise in healthy controls, patients with chronic fatigue syndrome and comorbid fibromyalgia ( CFS/ FM), and patients with rheumatoid arthritis ( RA), both under placebo and paracetamol condition. Methods Fifty-three female volunteers - of which 19 patients with CFS/ FM, 16 patients with RA, and 18 healthy controls - underwent a submaximal exercise test on a bicycle ergometer on 2 different occasions (paracetamol vs. placebo), with an interval of 7 days. Before and after exercise, participants rated pain intensity during TS and CPM. Results Patients with rheumatoid arthritis showed decreased TS after exercise, both after paracetamol and placebo ( P < 0.05). In patients with CFS/ FM, results were less univocal. A nonsignificant decrease in TS was only observed after taking paracetamol. CPM responses to exercise are inconclusive, but seem to worsen after exercise. No adverse effects were seen. Conclusion This study evaluates pain scores, TS, and CPM in response to submaximal exercise in 2 different chronic pain populations and healthy controls. In patients with RA, exercise had positive effects on TS, suggesting normal EIA. In patients with CFS/ FM, these positive effects were only observed after paracetamol and results were inconsistent. [ABSTRACT FROM AUTHOR]

Background. Both good physical and cognitive functioning have a positive influence on the execution of activities of daily living. Patients with chronic fatigue syndrome (CFS) as well as patients with fibromyalgia have marked cognitive deficits. Furthermore, a good physical and functional health status may have a positive impact on a variety of cognitive skills--a link that has been observed in young and old individuals who are healthy, although evidence is limited in patients with CFS. Objective. The purpose of this study was to examine whether recovery of upper limb muscle function could be a significant predictor of cognitive performance in patients with CFS and in patients with CFS and comorbid fibromyalgia. Furthermore, this study determined whether cognitive performance is different between these patient groups. Design. A case-control design was used. Methods. Seventy-eight participants were included in the study: 18 patients with CFS only (CFS group), 30 patients with CFS and comorbid fibromyalgia (CFS+FM group), and 30 individuals who were healthy and inactive (control group) were studied. Participants first completed 3 performance-based cognitive tests designed to assess selective and sustained attention, cognitive inhibition, and working memory capacity. Seven days later, they performed a fatiguing upper limb exercise test, with subsequent recovery measures. Results. Recovery of upper limb muscle function was found to be a significant predictor of cognitive performance in patients with CFS. Participants in the CFS+FM group but not those in the CFS group showed significantly decreased cognitive performance compared with the control group. Limitations. The cross-sectional nature of this study does not allow for inferences of causation. Conclusions. The results suggest that better physical health status could predict better mental health in patients with CFS. Furthermore, they underline disease heterogeneity, suggesting that reducing this factor in future research is important to better understand and uncover mechanisms regarding the nature of diverse impairments in these patients. INSET: The Bottom Line. [ABSTRACT FROM AUTHOR]

The clinical presentation and pain experience of patients with (sub)-acute low back pain ((S)ALBP) can strongly vary in clinical practice. However, despite growing evidence that psychological factors are associated with disability in chronic pain conditions including low back pain, studies examining the influence of psychological factors, quantitative sensory testing (QST) (i.e. pressure pain thresholds (PPTs)) and conditioned pain modulation (CPM) on future disability are still lacking in (S)ALBP. This prospective cohort study aims to determine associations between baseline psychological factors, PPTs and CPM in (S)ALBP and disability after 3 months. Fifty-two patients with (S)ALBP underwent a baseline PPT evaluation in rest and during a CPM protocol. Patients were asked to fill in self-report questionnaires: the Visual Analogue Scale (VAS), the Quebec Back Pain Disability Scale (QBPDS), the Pain Catastrophizing Scale (PCS), the Tampa Scale for Kinesiophobia (TSK) and the Illness Perception Questionnaire – Brief version (IPQ-B). At 3-month follow-up, participants were asked to fill in the QBPDS again. Multiple linear regression analysis was conducted to determine associations between baseline factors and disability at follow-up. Thirty-eight patients participated at follow-up. Because of the multicollinearity issue, the TSK score was selected for analyses and the PCS and IPQ-B score were excluded from the model. No significant associations between baseline factors and disability at follow-up were found. Neither baseline psychological factors nor PPTs or CPM in (S)ALBP were significantly associated with disability after 3 months. Our multiple linear regression analysis was likely underpowered to detect significant associations. [ABSTRACT FROM AUTHOR]

Background Context: Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP.Purpose: The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP.Study Design and Setting: This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI).Patient Sample: Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study.Outcome Measures: Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed.Methods: A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest-associated biases in the text of the paper.Results: Fat cross-sectional area and lean muscle fat index were significantly higher in MF and ES in continuous CLBP compared with non-continuous CLBP and RLBP (p<.05). No differencesbetween groups were found for total cross-sectional area and muscle cross-sectional area in MF or ES (p>.05). Also, no significant differences between groups for T2-rest were established. T2-shift, however, was significantly lower in MF and ES in RLBP compared with, respectively, non-continuous CLBP and continuous CLBP (p<.05).Conclusions: These results indicate a higher amount of fat infiltration in the lumbar muscles, in the absence of clear atrophy, in continuous CLBP compared with RLBP. A lower metabolic activity of the lumbar muscles was seen in RLBP replicating a relative lower intensity in contractions performed by the lumbar muscles in RLBP compared with non-continuous and continuous CLBP. In conclusion, RLBP differs from continuous CLBP for both muscle structure and muscle function, whereas non-continuous CLBP seems comparable with RLBP for lumbar muscle structure and with continuous CLBP for lumbar muscle function. These results underline the differences in muscle structure and muscle function between different LBP populations. [ABSTRACT FROM AUTHOR]

Context: Pain is one of the most complex and prevalent symptoms in the cancer population. Despite the protective role of acute cancer-related pain, it is also an important predictor for the likelihood of developing chronic pain after cancer treatment.Objectives: Since the last systematic review on pain prevalence rates during cancer treatment dates already from 2016, the aim of the present systematic review was to provide an overview of pain prevalence rates during cancer treatment since this previous review.Methods: A systematic search of the literature, including studies between 2014 and 2020, was conducted using the databases Pubmed, Embase, Scopus, Web of Science and Cochrane. Studies reporting pain prevalence rates during or within three months after curative cancer treatment was included. Title/abstract and full-text was screened double-blinded, followed by independent evaluation of the risk of bias. All prevalence rates were pooled within meta-analyses and a meta-regression was performed to clarify the amount of heterogeneity.Results: Of the 9052 studies, 12 studies were included in the meta-analysis of which 10 included breast cancer and two lung cancer patients. The pooled pain prevalence rate was 40% (95%CI 0.29-0.51), with a heterogeneity of 96%. Out of the meta-regression, only the covariate "method of pain measurement" significantly clarified the heterogeneity (P < 0.05), resulting in a residual heterogeneity of 94.88%.Conclusion: Five years after the last systematic review published on this topic, pain is still very prevalent during cancer treatment. However, the pain prevalence rates were also very heterogeneous. These two findings emphasize the need for further research on the development of adequate pain assessment and pain management approaches during cancer treatment. [ABSTRACT FROM AUTHOR]

Chronic whiplash is a debilitating condition characterized by increased sensitivity to painful stimuli, maladaptive illness beliefs, inappropriate attitudes, and movement dysfunctions. Previous work in people with chronic low back pain and chronic fatigue syndrome indicates that pain neurophysiology education is able to improve illness beliefs and attitudes as well as movement performance. This single-case study (A-B-C design) with six patients with chronic whiplash associated disorders (WAD) was aimed at examining whether education about the neurophysiology of pain is accompanied by changes in symptoms, daily functioning, pain beliefs, and behavior. Periods A and C represented assessment periods, while period B consisted of the intervention (pain neurophysiology education). Results showed a significant decrease in kinesiophobia (Tampa Scale for Kinesiophobia), the passive coping strategy of resting (Pain Coping Inventory), self-rated disability (Neck Disability Index), and photophobia (WAD Symptom List). At the same time, significantly increased pain pressure thresholds and improved pain-free movement performance (visual analog scale on Neck Extension Test and Brachial Plexus Provocation Test) were established. Although the current results need to be verified in a randomized, controlled trial, they suggest that education about the physiology of pain is able to increase pain thresholds and improve pain behavior and pain-free movement performance in patients with chronic WAD. [ABSTRACT FROM AUTHOR]

Functional abdominal pain disorders (FAPDs) are common among young individuals. To date, relatively little is known regarding the function of the endogenous analgesic mechanisms in this vulnerable group. Therefore, this case-control study aimed to compare conditioned pain modulation (CPM), pressure algometry, and psychosocial variables in 39 young children (aged 6-12 years) with FAPD and 36 age- and sex-matched pain-free controls. Pressure algometry was used to assess pressure pain thresholds (PPTs) at both symptomatic (umbilicus) as remote (trapezius and tibia) test sites. Conditioned pain modulation was recorded as an increase in the PPT at the trapezius test site in response to experimental conditioning pain imposed by the cold pressor task (12 ± 1°C). The assessors were blinded to the diagnoses. Parent-proxy and/or self-reported questionnaires were used to assess child's pain intensity, functional disability, pain-related fear, and parental pain catastrophizing. Compared with pain-free controls, young children with FAPD showed lower PPTs at all test sites (P < 0.05), a lower CPM response (P = 0.02), more functional disability (P < 0.001), and pain-related fear (P < 0.001). Parents of children with FAPD catastrophized more about their child's pain than parents of healthy children (P < 0.001). No sex differences were found for the experimental pain measurements (P > 0.05), nor was there a significant correlation between the child- and parent-reported questionnaires and the CPM effect (P > 0.05). In summary, young children with FAPD demonstrated secondary hyperalgesia and decreased functioning of endogenous analgesia. [ABSTRACT FROM AUTHOR]

One of the essences of rehabilitation is enhancing a persons' functioning and participation in society, including work. According to the International Classification of Functioning, Disability and Health (ICF), participation can be influenced by a wide range of factors, including pain. In many patients with a pain complaint a neuropathic pain component is present. To steer (vocational) rehabilitation, it is important to recognize the presence of neuropathic pain. Expensive and time-consuming instrumental tests (e.g. Quantitative Sensory Testing) to identify presence of neuropathic pain are available in specialized centers but not applicable in daily clinical practice in rehabilitation settings. The aim of this manuscript is to give an overview of alternative screening and assessment methods of neuropathic pain that are applicable in a daily clinical setting and for the different professionals who may be involved in rehabilitation (e.g., physical therapists, occupation! therapists, counselors, etc). The first part elaborates on the definition of neuropathic pain and common terminology. Second, basic anatomy and physiology related to neuropathic pain are presented needed to understand neuropathic pain. Third, the relevant aspects of clinical history and clinical examination are discussed. Finally, screening tools for neuropathic pain and alternative clinical assessments methods for Quantitative Sensory Testing are presented. [ABSTRACT FROM AUTHOR]

• It is hypothesized that dry needling improves pain sensitivity and pain modulation. • There was no difference on pain sensitivity or pain modulation between dry needling and sham needling. • Dry needling shows better antinociceptive pain modulation after treatment. Dry needling is frequently used for the treatment of neck pain but knowledge about its neurophysiological central effects is scarce. To compare the immediate effects of a single session of dry needling (DN) and sham needling (SN) on local and distant pressure pain thresholds and conditioned pain modulation in patients with chronic idiopathic neck pain. Participants with chronic idiopathic neck pain were randomly allocated to a DN or SN group. The primary outcome measure was the pressure pain threshold (PPT) at one peripheral location: quadriceps muscle (Q). Secondary outcome measures were local PPTs at the treated (most painful) (tUT) and non-treated upper trapezius muscle (ntUT), absolute and relative conditioned pain modulation (CPM) effects and pain during hot water immersion. Patients were assessed at baseline and immediately post intervention. Linear mixed models were used to examine interaction effects as well as between- and within-group differences. Fifty-four participants were included for statistical analysis. Linear mixed model analyses showed no significant "group X time" interaction effects for any of the outcome measures. The relative CPM effect at the Q was significantly higher post-intervention, compared to baseline within the DN group (mean difference= 13.52%; 95% CI: 0.46, 26.59). The present study shows no superior effect of DN, compared to SN, in the immediate effect on local and distant PPTs and CPM in patients with chronic idiopathic neck pain. [ABSTRACT FROM AUTHOR]