Treatment of central sensitization in patients with chronic pain: time for change?

Spinal hyperexcitability in patients with chronic musculoskeletal pain or headache as evidenced by alterations in the nociceptive withdrawal reflex: a systematic review and meta-analysis

ABSTRACT

The nociceptive withdrawal reflex (NWR) is a spinal withdrawal reflex induced by painful stimulation. It is a measure of spinal hyperexcitability, which is believed to contribute to chronic musculoskeletal pain (MSKP) and headache. Previous syntheses of the evidence for alterations in the NWR in patients with chronic MSKP and headache needed a comprehensive update. This systematic review and meta-analysis was performed after the Preferred Items for Systematic reviews and Meta-Analyses guidelines. Studies examining NWR-related outcome measures in patients with chronic MSKP and headache compared to pain-free controls were identified through electronic database searches and included after screening against predefined eligibility criteria. Standardized mean differences or mean differences and 95% confidence intervals (CI) were calculated. Thirty-one studies were included in the systematic review and 25 in the meta-analysis. Moderate-quality evidence was found indicating lower NWR threshold (-3.68; 95% CI, -4.56 to -2.80; P < 0.001), larger NWR area (standardized mean difference = 0.69; 95% CI, 0.37-1.01; P < 0.001), and shorter NWR latency (mean difference = -13.68; 95% CI, -22.69, -4.67; P = 0.003) in patients compared to controls. These findings remained robust when performing meta-regressions based on subgroups (ie, headache, fibromyalgia, whiplash-associated disorder, and osteoarthritis). Low-quality evidence demonstrated facilitated temporal summation of NWR threshold (-2.48; 95% CI, -3.13 to -1.83; P < 0.001) in patients compared to controls. Spinal hyperexcitability as evidenced by lowered NWR threshold values and temporal summation of the NWR is present in patients with chronic MSKP and headache. No evidence was found for alterations in NWR duration and NWR magnitude. Future research is needed to address the gap in research on NWR-related outcome measures other than NWR threshold.

The relationship between central sensitization and activity limitation in patients with knee osteoarthritis:The mediating role of pain catastrophizing

BACKGROUND

In patients with knee osteoarthritis, the most distressing symptom is activity limitation which exacerbates the global burden of the disease. Studies have shown that central sensitization has a negative effect on activity capabilities in patients with knee osteoarthritis. However, limited knowledge exists regarding the underlying mechanisms. Therefore, this study aimed to explore the mediating effect of pain catastrophizing on central sensitization and activity limitation among knee osteoarthritis patients.

OBJECTIVES

To explore the association between central sensitization and activity limitation by modelling three dimensions of pain catastrophizing as mediators among patients with knee osteoarthritis.

DESIGN

This is a cross-sectional study.

METHODS

A total of 392 patients were surveyed using the general demographic questionnaire, Animated Activity Questionnaire, Pain Catastrophizing Scale, and Central Sensitization Inventory. Multiple linear regression was used to determine covariates included in the mediating model. The mediating effect was tested using the SPSS PROCESS.

RESULTS

Age, duration of KOA, and K-L grade were included as covariates. The mediating model revealed that central sensitization had a direct effect on activity limitation (c' = -0.166; 95 % CI -0.271, -0.064). The relationship between central sensitization and activity limitation was primarily mediated by two indirect pathways: (1) rumination (a1b1 = -0.095; 95 % CI -0.176, -0.017) and (2) helplessness (a2b2 = -0.074; 95 % CI -0.137, -0.009). The indirect effect of the magnification dimension on activity limitation was not statistically significant (a3b3 = 0.002; 95 % CI -0.051, 0.054).

CONCLUSIONS

The study reveals rumination and helplessness in pain catastrophizing mainly mediate the relationship between central sensitization and activity limitation.

Cluster Headache and Migraine Shared and Unique Insights: Neurophysiological Implications, Neuroimaging, and Biomarkers: A Comprehensive Review

Migraine headache (MH) and cluster headache (CH) are debilitating primary headache disorders that impose a significant global burden. While they share certain clinical features, such as unilateral pain and autonomic dysfunction, their underlying pathophysiological mechanisms remain distinct. Advances in the understanding of neurophysiological features, such as neuroimaging and biomarker research, have provided critical insights into both their overlapping and divergent characteristics. Neurophysiological research has revealed differences in nociceptive processing, cortical excitability, and sensory integration, underscoring the complexity of these conditions. Neuroimaging studies reveal common activation patterns within pain-processing networks, including the trigeminal system and hypothalamus, while highlighting key differences, such as hypothalamic hyperactivity in CH and cortical alterations in MH. Additionally, biomarker research has identified shared elements, including elevated calcitonin gene-related peptide (CGRP), yet distinct variations in its regulation and genetic predispositions. Genome-wide association studies have further elucidated the genetic architecture of these disorders, uncovering susceptibility loci that reinforces their unique yet occasionally intersecting genetic foundations. These multifield advancements not only enhance the understanding of MH and CH pathophysiology but also pave the way for improved diagnostic precision, personalized therapeutic strategies, and future research.

Treatment modalities for patients with Persistent Spinal Pain Syndrome Type II: A systematic review and network meta-analysis

BACKGROUND

Appropriate management of patients with Persistent Spinal Pain Syndrome Type 2 (PSPS-T2) remains challenging. The need for robust evidence for treatment modalities is urgently pressing. The aim of this systematic review and network meta-analysis (NMA) is to compare different treatment modalities for patients with PSPS-T2 on pain intensity.

METHODS

The study protocol was prospectively registered (PROSPERO;CRD42022360160). Four different databases were consulted from database inception to December 18th, 2023. Randomised controlled trials of interventions for PSPS-T2 were included. The revised Cochrane Risk of Bias Tool was used to assess risk of bias. A NMA with standardized mean differences was calculated with pairwise comparisons between all treatment modalities.

RESULTS

Here we include 49 studies in the systematic review and 13 in NMA. A high risk of bias is indicated for 65.3% of the studies. Half of the studies investigate neuromodulation (mainly Spinal Cord Stimulation), 16 explore minimal invasive treatment options (predominantly epidural injections), 6 studies focus on conservative treatments (physiotherapy/cognitive training and medication) and 2 on reoperation. Comparison of neuromodulation versus a combination of conservative and minimal invasive options results in an effect size of 0.45 (95% CI: 0.14-0.76), clearly favouring neuromodulation (z = 2.88; p = 0.004). Additionally, neuromodulation results in a standardised mean difference of 0.36 (95% CI: 0.18-0.53) compared to placebo/sham (z = 4.03; p < 0.0001). No statistically significant difference is found between conservative options and neuromodulation.

CONCLUSIONS

Neuromodulation, followed by conservative treatment options, seems to be the most effective treatment option to obtain pain relief in patients with PSPS-T2. Nevertheless, a personalized approach tailored to individual patient needs is essential for optimizing outcomes, since interventions should be adjusted based on the failure or success of prior therapies.

Central Sensitization and Its Role in Persistent Pain Among Spondyloarthritis Patients on Biological Treatments

Objectives: Spondyloarthritis (SpA) is a chronic inflammatory arthritis that mainly affects the sacroiliac joints and spine. Despite effective biological treatments, persistent pain is common in SpA patients, potentially due to central sensitization (CS), a condition of heightened central nervous system responsiveness. The purpose of this study was to investigate the link between disease activity and CS in SpA patients on biological therapy. Patients and Methods: One hundred and twenty SpA patients with at least six months of treatment with biological agents were included in this cross-sectional study. Patients' demographic, clinical, and functional information were collected. The assessment of CS was conducted using the Central Sensitization Inventory (CSI), whereas disease activity and quality of life were evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP), and Ankylosing Spondylitis Quality of Life (ASQoL). Statistical analyses included correlation assessments and logistic regression to identify predictors of CS. Results: CS (CSI ≥ 40) was present in 40.8% of patients. Disease activity was significantly higher and quality of life was lower in patients with CS. BASDAI and ASQoL scores were strongly correlated with CS (r = 0.774 and r = 0.839, respectively). Logistic regression identified ASQoL and BASDAI scores as independent predictors of CS. ROC curve analysis demonstrated that ASQoL had the highest discriminative ability for predicting CS (AUC = 0.97). Conclusions: CS is significantly associated with higher disease activity and poorer quality of life in SpA patients receiving biological therapy. Incorporating CS assessment into routine clinical practice may enhance our understanding and management of persistent symptoms in SpA, improving patient outcomes.

Is the Central Sensitization in Chronic Nonspecific Low Back Pain Structural Phenomenon or Psychological Reaction? A Narrative Review

Lower back pain (LBP) is a common condition affecting primarily populations in developed countries, placing a significant burden on public health systems around the world. A high rate of pain recurrence increases the risk of developing a chronic syndrome and the occurrence of complex psychosocial and professional problems. Symptoms lasting longer than 12 weeks are associated with the risk of sleep problems, depression, and anxiety. In the 21st century, the development of knowledge about central sensitization (CS) to pain allowed for a better understanding of the pathomechanism of pain and the transformation of LBP into a chronic form. Patients with chronic severe pain often experience accompanying symptoms such as fatigue, depression, anxiety, sleep disorders, appetite disorders, flatulence, dyspepsia, and dizziness-these are part of the picture of CS. The article presents a narrative, chronological review of reports covering the current state of knowledge on the possibility of assessing central sensitization and its impact on low back pain. The authors also attempt to answer the question posed in the title. CS can be seen as an excessive reactivity of nociceptive neurons in the central nervous system to normal or subthreshold afferent chronic stimuli in people with certain mental predispositions.

The problem of pain in systemic lupus erythematosus: A comprehensive analysis of pain distribution using the CHOIR body map and PROMIS measures

BACKGROUND

Our study investigates the associations between pain distribution, biopsychosocial factors, and Patient-Reported Outcomes Measurement Information System (PROMIS) measures in patients with systemic lupus erythematosus (SLE). Employing self-reported pain body maps, we aim to characterize the distribution of pain and its impact on biopsychosocial measures.

METHODS

We retrospectively analyzed the electronic health records (EHR) of 332 adult patients with SLE attending pain clinics at an academic medical center. The study included demographics, pain distribution assessed via self-reported body maps, and PROMIS assessments of biopsychosocial experiences. We used linear regression models adjusted for age and sex to investigate associations between pain distribution and PROMIS outcomes.

RESULTS

Men, on average, indicated pain in 3.2 regions, whereas women reported pain in 5.6 regions. Women predominantly highlighted the hip, buttock, and leg region, whereas men primarily emphasized the shoulder and arm region. We found a positive correlation between pain widespreadness and worse PROMIS measures, including pain interference, behavior, fatigue, depression, anxiety, sleep disturbance, and social isolation. Additionally, widespread pain was associated with lower physical function, emotional support, and satisfaction in roles and activities. Female patients reported higher levels of pain and PROMIS measures compared to males.

CONCLUSION

Our findings highlight the multidimensional impact of pain on SLE patients' lives underscoring the need for holistic pain management approaches. The intricate associations between pain distribution and biopsychosocial factors emphasize the importance of considering spatial dimensions of pain in clinical interventions. Further research is warranted to explore effective interventions addressing psychosocial aspects of pain in SLE, aiming to enhance patient symptom management and quality of life.

A Systematic Review of the Prevalence of Overactive Bladder in Women with Non-Urinary Tract Endometriosis and the Effect of Endometriosis Surgery on Symptoms of Overactive Bladder

INTRODUCTION AND HYPOTHESIS

Overactive bladder (OAB) is characterised by urinary urgency, with or without incontinence, often accompanied by daytime frequency and nocturia, in the absence of urinary tract infection or other identifiable causes. Population studies estimate the prevalence of OAB at 12.8% (EPIC study), increasing with age, reaching up to 43% after age 40. Endometriosis affects about 10% of women of reproductive age. Both OAB and endometriosis are chronic and negatively impact women's quality of life. They appear to share a common pathophysiology related to central sensitisation. We hypothesised that OAB and endometriosis might co-exist, and surgical excision of endometriosis could alleviate OAB symptoms. We aimed to assess the prevalence of OAB in patients with endometriosis and examine the effect of endometriosis surgery on OAB symptoms.

METHODS

A systematic search of MEDLINE, PubMed, Embase, and CINAHL-Plus identified studies reporting on endometriosis and OAB or overlapping conditions such as interstitial cystitis. Studies on bladder or ureteric endometriosis were excluded.

RESULTS

Six studies (772 participants) were included. The prevalence of OAB in endometriosis patients ranged from 9.4% (Brazil) to 32% (France). OAB diagnosis varied, with tools such as International Consultation of Incontinence Modular Questionnaire on Female Lower Urinary Tract Symptoms, Core Lower Urinary Tract Symptom Score, Bristol Female Lower Urinary Tract Symptoms, and urodynamics. Surgical outcomes were inconsistent, with no improvement in three studies, equivocal in one, and worsened in another.

CONCLUSION

Overactive bladder and non-urinary tract endometriosis may co-occur in 20.5% of patients, with surgery showing variable effects on OAB symptoms. Further standardised global research is warranted to fill in evidence gaps such as whether pre-operative desensitisation could improve surgical and quality-of-life outcomes.

Cross-Cultural Adaptation and Validation of the Central Sensitization Inventory Among Chinese Patients with Chronic Non-Specific Low Back Pain

Purpose

This research aims to develop and validate the Chinese version of the Central Sensitization Inventory (CSI-CV) for patients suffering from chronic non-specific low back pain (CNSLBP). The study evaluates both the validity and reliability of the CSI-CV.

Patients and Methods

The cross-cultural adaptation of the scale strictly adhered to the principles of Bombardier and Beaton. Initially, two professors of Chinese-English translation independently translated the original CSI scale into the target language, and then collaborated with an expert in cross-cultural adaptation to merge into a single version. This version was back-translated into English by two professors whose native language is English. Following this, the scale underwent preliminary review by bilingual experts and the research team, and was preliminarily tested, ultimately culminating in the formation of the CSI-CV version. A total of 310 patients with CNSLBP completed the CSI-CV, while 50 of them repeated the survey one week later to test the stability of the scale. The CSI-CV's reliability, validity, and internal consistency were assessed through exploratory factor analysis (EFA), correlation coefficients, and Cronbach's α.

Results

EFA revealed five distinct factors from the 25 CSI-CV items, covering physical symptoms, emotional distress, fatigue and sleep disturbances, headaches and jaw symptoms, and urinary issues, with a total explained variance of 60.24%. The Cronbach's α was 0.910, and the intraclass correlation coefficient (ICC) was 0.924, indicating strong reliability. Moderate correlations were observed between CSI-CV scores and Five-Level EuroQol Five-Dimensional Questionnaire (r = -0.515), the Brief Pain Inventory (r = 0.586) and Oswestry Disability Index (r = 0.416), demonstrating significant associations with these measures.

Conclusion

The CSI-CV exhibits excellent internal consistency, factor structure, and reliability. Its successful cultural adaptation offers valuable insights for improving treatment approaches for patients with CNSLBP.

The Relationship of Pain Intensity, Perceived Injustice, and Pain Catastrophizing to Heart Rate Variability In Naturally Occurring Acute Pain

OBJECTIVES

Behavioral factors of pain catastrophizing and perceived injustice are associated with pain intensity in chronic pain. Diminished heart rate variability (HRV) is also strongly associated with chronic pain. These factors have been less explored earlier in the pain experience and it is unclear whether they play a role in the transition from acute to chronic pain. The aim of this study was to determine the relationship between pain catastrophizing, perceived injustice, pain intensity, and HRV in naturally occurring acute pain.

MATERIALS AND METHODS

Ninety-seven patients were recruited from local outpatient physical therapy clinics. Seated HRV was captured on 94 patients via Polar chest strap while patients were taking a survey via iPad. In addition to sociodemographic data, the survey included the Pain Catastrophizing Scale (PCS), Injustice Experience Questionnaire (IEQ), and Numeric Pain Rating Scale (NPRS). The natural log of high-frequency power (lnHFP) HRV was used in the statistical analysis.

RESULTS

Multiple linear regression modeling revealed that lower pain catastrophizing, higher perceived injustice, and lower pain intensity were associated with lower HRV, and accounted for 11.4% of the variance in HRV.

DISCUSSION

While greater chronic pain intensity is associated with lower HRV, the relationship is reversed in the setting of acute pain. These findings highlight the need to better understand the unique factors that contribute to lower HRV in the acute phase.

Is chronic pain caused by central sensitization? A review and critical point of view

Chronic pain causes disability and loss of health worldwide. Yet, a mechanistic explanation for it is still missing. Frequently, neural phenomena, and among them, Central Sensitization (CS), is presented as causing chronic pain. This narrative review explores the evidence substantiating the relationship between CS and chronic pain: four expert researchers were divided in two independent teams that reviewed the available evidence. Three criteria were established for a study to demonstrate a causal relationship: (1) confirm presence of CS, (2) study chronic pain, and (3) test sufficiency or necessity of CS over chronic pain symptoms. No study met those criteria, failing to demonstrate that CS can cause chronic pain. Also, no evidence reporting the occurrence of CS in humans was found. Worryingly, pain assessments are often confounded with CS measures in the literature, omitting that the latter is a neurophysiological and not a perceptual phenomenon. Future research should avoid this misconception to directly interrogate what is the causal contribution of CS to chronic pain to better comprehend this problematic condition.

Excitation of the bottom-up pathways has no effect on remote muscle fatigue in healthy participants

The aim of this study is to investigate the effect of induced excitation of the bottom-up pathways at the lateral elbow muscles on local muscle fatigue in the neck region in healthy participants. Eligible participants (n:55) were randomly allocated to an intervention group (n:28) or a control group (n:27). The fatigue of bilateral neck flexor(sternocleidomastoid) and extensor (upper trapezius) muscles was evaluated using surface electromyography, at baseline and immediately post-intervention during a neck flexor and extensor endurance test respectively. Excitation of the bottom-up pathways was performed at multiple lateral elbow muscles in the intervention group by using a temporal summation protocol of mechanical pain, and the pressure pain threshold was determined once in each of the multiple lateral elbow muscles in the control group. Linear mixed model analyses were performed for each outcome measure to evaluate changes over time and within- and between-group differences. No significant "group X time" interaction effects were detected for any of the outcome measures. Significant main effects for time was found for "amplitude over time" of the left upper trapezius (p:0.003) and right sternocleidomastoid muscle (p: 0.013), and for "amplitude changes" of the left upper trapezius muscle (p:0.021). Significant within-group changes were identified in some outcomes in the control group: increased "amplitude over time" of the right sternocleidomastoid muscle (p:0.024) and decreased "amplitude changes" of the left upper trapezius muscle (p:0.024), decreased "normalized median frequency slope over time" of the left UT (p: 0.013). There were no significant within-group changes in the intervention group. No significant between-group differences for any of the outcome measures were found. This study shows no effect of the induction of excitation of the bottom-up pathways at the lateral elbow muscles on the neck muscles' fatigue characteristics compared to a control intervention. Clinical Trial Number: NCT05146960. Date of Registration: December 7, 2021.

Sensitization-associated and neuropathic-associated symptoms in patients with unilateral lateral elbow tendinopathy: an exploratory study

OBJECTIVES

We evaluate the presence of sensitization-associated symptoms and neuropathic pain features and identify if there is an association between these symptoms and pressure pain sensitivity, pain, and related-disability in lateral elbow tendinopathy.

METHODS

Thirty-seven (43% women, age: 45.5 ± 9.5 years) patients with lateral elbow tendinopathy completed: demographic (i.e. age, height, and weight); clinical (i.e. pain history, pain intensity, and Disabilities of the Arm, Shoulder and Hand); and psychophysical (i.e. pressure pain thresholds at the elbow, cervical spine, hand, and leg) outcomes, and the Central Sensitization Inventory and Self-administered Leeds Assessment of Neuropathic Symptoms and Signs questionnaires. Step-wise multiple linear regression models were performed to identify predictors of sensitization- or neuropathic-associated symptoms.

RESULTS

Six (16%) patients exhibited sensitization-associated symptoms (mean: 46.5, SD: 6.1), whereas 13 (35%) patients showed neuropathic-associated symptoms (mean: 13.5; SD: 1.4). Sensitization-associated symptoms were positively associated with neuropathic-associated symptoms (r = 0.538, P = .001) and negatively associated with pressure pain thresholds at the leg (r = -0.378, P = .021). Neuropathic-associated symptoms were positively associated with related-disability (r = 0.479, P = .003) and negatively associated with pressure pain threshold at the elbow (r = -0.394, P = .017). Stepwise regression analyses revealed that neuropathic-like symptoms explained 26.8% of the variance of sensitization symptoms (r2: 0.268), whereas pressure pain threshold at the elbow explained an additional 6.6% to neuropathic-like symptoms (r2: 0.334).

CONCLUSION

This explorative study identified sensitization- and neuropathic-associated symptoms in 16% and 35% of the people with lateral elbow tendinopathy. Sensitization- and neuropathic-associated symptoms were associated. Pressure pain sensitivity at the elbow (peripheral sensitization) was associated with neuropathic -associated symptoms.

Do measures of central sensitization relate to movement-evoked pain in people with chronic low back pain? A longitudinal prospective study

BACKGROUND

One of the most frequent complaints among people with musculoskeletal pain is pain during physical activity, commonly referred to as movement-evoked pain. It is suggested to be associated with quantitative sensory testing measures of central pain process in individuals with musculoskeletal pain.

OBJECTIVE

To investigate the predictive association between movement-evoked pain scores and measures of central sensitization in patients with chronic nonspecific low back pain. The secondary aim was to determine whether changes in movement-evoked pain scores are associated with changes in measures of central sensitization.

METHODS

In this longitudinal prospective study, 50 participants with chronic low back pain were included. Pain pressure thresholds, temporal summation of pain, descending pain modulation, and the central sensitization index were assessed as measures of central sensitization. Movement-evoked pain was evaluated using the Back Performance Scale and a 5-minute walk test.

RESULTS

Measures of central sensitization, specifically pressure pain thresholds and temporal summation, demonstrated predictive associations with movement-evoked pain measures. In response to treatment, improvements in movement-evoked pain were associated with improvements in measures of central sensitization (i.e., pressure pain thresholds and temporal summation) and improved pressure pain thresholds in the plantar toe significantly predict movement-evoked pain measures experienced during the 5-minute walk test.

CONCLUSIONS

These results imply that movement-evoked pain is related to processes related to central modulation of pain in patients with nonspecific chronic low back pain.

The Impact of Stressful Life Events on Centralized Pain and Pain Intensity: A Combined Model Examining the Mediating Roles of Anger and Perceived Injustice Among Racially Minoritized Adults With Chronic Pain

Stressful life events are highly associated with chronic pain. Yet, research is needed to identify the psychological mechanisms that link life adversity and pain, especially studies that test comprehensive models, recruit racially diverse samples, and measure varied pain-related symptoms. This study examined the relationship between stressful life events and pain in a racially diverse sample and tested the potential mediating roles of both anger and perceived injustice. Both centralized pain symptoms and pain intensity were the outcomes. Analyses consisted of 2 cross-sectional, mediation models among 673 adults with self-reported chronic pain who were racially diverse (Black: n = 258, Latine: n = 254, Asian American: n = 161). The results indicated a positive relationship between stressful life events and centralized pain symptoms (b = 2.53, P < .001) and pain intensity (b = .20, P < .001). In parallel mediation analyses, anger (b = .91, 95% CI = .67, 1.17) and perceived injustice (b = .86, 95% CI = .64, 1.11) acted as partial mediators on centralized pain symptoms. Also, anger (b = .05, 95% CI = .03, .08) and perceived injustice (b = .11, 95% CI = .08, .14) acted as full mediators on pain intensity. The combined psychosocial variables accounted for 51% of centralized pain symptoms and 26% of pain intensity. The findings suggest that psychosocial factors are significantly associated with pain outcomes. Future research is needed to investigate exposure to adversity in life, anger, and perceived injustice together as psychosocial mechanisms of pain symptoms. PERSPECTIVE: Among racially minoritized adults with chronic pain, this article presents empirical evidence that stressful life events, anger, and perceived injustice are associated with centralized pain symptoms and pain intensity. This could guide psychological intervention to focus on anger and perceived injustice, especially when addressing centralized pain.

Comparisons and associations of psychological factors and the number of painful sites in wheelchair basketball athletes with and without shoulder pain: A cross-sectional case-control study

OBJECTIVE

To compare psychological factors and the number of painful sites between wheelchair basketball athletes (WBA) with and without shoulder pain and examine their associations with shoulder pain.

DESIGN

A cross-sectional, case-control study.

METHODS

Forty-three WBA participated. Shoulder pain was assessed with the Wheelchair User's Shoulder Pain Index (WUSPI), pain catastrophizing with the Pain Catastrophizing Scale (PCS), kinesiophobia by the Tampa Kinesiophobia Scale (TKS), self-efficacy with the General Self-Efficacy Scale (GSES), and the number of painful sites using the Nordic Musculoskeletal Questionnaire. Disability and sport-related data were collected. Spearman's correlation coefficients were calculated. Mann-Whitney U and independent samples t-tests were used for between-group comparisons.

RESULTS

Athletes with shoulder pain (n = 21) had an increased number of painful sites (P < .050) and higher PCS (P = .003). The WUSPI exhibited moderate associations with the number of painful sites during the last year (rho = .581) and past seven days (rho = .602), and PCS (rho = .470), and a weak association with the TKS (rho = .333)(P < .050). The number of painful sites with disability exhibited moderate associations with PCS (rho = .427) and GSES (rho = -.473)(P < .050). WBA classification levels showed moderate associations with the WUSPI (rho = -.400) and the number of painful sites during the last year (rho = -.437), and a weak association with the number of painful sites during past seven days (rho = -.315)(P < .050). The PCS showed weak associations with the number of painful sites during the last year (rho = .365) and the past seven days (rho = .398)(P < .050).

CONCLUSIONS

Results suggest considering WBA classes, pain catastrophizing, self-efficacy and multisite pain in the pain management of WBA.

(Re)Development of pain target competencies in a contemporary, multi-centre undergraduate medical curriculum: The importance of local cultural requirements

Pain is the most common reason to seek healthcare, however pain teaching is often not prominent in medical school curricula. This project reviewed an existing medical curriculum to develop a comprehensive pain curriculum that consolidated pain learning across a medical degree delivered on geographically-distinct campuses, looking to provide contemporary pain learning that was culturally appropriate in a local context. A cross-campus, interdisciplinary pain working group (PWG) was established to work across the two program stages (pre-clinical, clinical) and three clinical campuses. The PWG undertook a three-phase project to i) develop a range of potential target competencies based on expert input and international pain curricula, ii) identify and review existing pain competencies, and iii) undertake iterative review of information, consult with stakeholders, and propose revised competencies. Eight pain competencies were identified within the extant curriculum. Recommendations included two existing competencies remained unchanged, four be modified, two merged, and 26 new competencies adopted including some specific to local Indigenous Māori and Pacific Island communities. The 33 pain target competencies were structured across different teaching domains: science, research, and scholarship (n = 5); population health and epidemiology (n = 3); clinical skills (n = 5); and diagnostics and therapeutics (n = 20). Contemporary pain learning, including around Indigenous health, was not adequately represented. New target competencies were adopted to ensure pain learning is appropriate for medical practice in Aotearoa New Zealand, containing competencies specific to Māori and Pacific Island communities. Curricula review needs to consider local cultural requirements while integrating international best practice to ensure pain learning is appropriate. PERSPECTIVE: A comprehensive pain curriculum was developed across a multi-campus medical school setting. Through a three-phase project, existing pain competencies were reviewed and new target competencies developed, including those specific to local Indigenous communities. Findings highlight the importance of ensuring contemporary curricula include pain learning that is culturally focused and relevant.

Association between Drug Use and Perception of Mental Health in Women Diagnosed with Fibromyalgia: An Observational Study

BACKGROUND/OBJECTIVES

Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and mental health issues. It affects approximately 1.78% of the general population; an estimated 4:1 ratio between women and men is observed. It significantly impacts quality of life and carries both clinical and social stigma. This study aims to evaluate the relationship between drug use and mental health in female patients with fibromyalgia.

METHODS

This study is prospective, observational, and cross-sectional. A questionnaire was administered to 544 subjects, achieving a representative sample size from a population of 800,000 subjects by using an algorithm for proportion estimation with a known sampling frame. The selection was non-random, making the sampling non-probabilistic. Logistic regression models were applied to assess the effect of drug use on perception of mental health; presence of symptoms such as comprehension and memory problems, insomnia, depression, and anxiety; and severity of cognitive symptoms and non-restorative sleep. To quantify the impact, odds ratios and confidence intervals have been observed.

RESULTS

The findings indicate the non-recommended use of medications and reveal the ineffectiveness and adverse effects of drug interactions on mental health. The use of benzodiazepines and sedative-hypnotics is significantly associated with a negative perception of mental health. Benzodiazepines do not improve symptoms or significantly reduce their severity. SSRI antidepressants do not enhance mental health perception; however, when used exclusively, they are effective in reducing the severity, but not the prevalence, of cognitive symptoms.

CONCLUSIONS

The results highlight the complexity of pharmacological management in FM and raise concerns about the inappropriate use of ineffective or counterproductive drug interactions affecting patients' mental health. They underscore the need for multidisciplinary and personalized strategies that include close and careful monitoring, as well as the simultaneous use of non-pharmacological treatments that have demonstrated evidence in improving quality of life without negatively affecting mental health, such as patient education, psychological therapy, physiotherapy, and mindfulness.

'Pain free if I ever will be': lived experience of workers seeking care for pain attributed to musculoskeletal disorders

BACKGROUND

Pain attributed to musculoskeletal disorders are a significant hinderance to work ability and economic growth, especially in developing countries. Quality of life and lived experience of workers with musculoskeletal disorders have not been explored enough to determine whether person-centred care is provided. There is a wealth of evidence for using the biomedical approach in the management of workers with musculoskeletal disorders, which has proved ineffective in reducing absenteeism and symptoms experienced by workers. The purpose of this study was to explore the lived experience of workers seeking care for musculoskeletal disorders and how their pain attitudes and beliefs influenced their experience.

METHODS

A qualitative approach with thematic analysis was used. Purposive sampling was used to recruit six participants for semi-structured interviews. All participants were either experiencing pain attributed to a musculoskeletal disorder or had received care for a musculoskeletal disorder.

RESULTS

Pain attitudes and beliefs of workers with a musculoskeletal disorder and healthcare professionals greatly influenced the care and recovery process of musculoskeletal disorders. There is a primary biomedical lens informing care of workers with musculoskeletal disorders received. Workers expect healthcare professionals to explore their concerns further, but the focus of care for most participants was their presenting complaint. There is also a need for the autonomy of workers to be preserved, and communication between healthcare professionals and workers with musculoskeletal disorders needs to improve.

CONCLUSIONS

Many stakeholders are involved in the recovery process from musculoskeletal disorders. There is a need for a biopsychosocial informed practice to improve return-to-work (RTW) in workers with musculoskeletal disorders. Change is needed at all healthcare system levels to reduce the negative experiences of workers and maladaptive pain beliefs that is associated with persisting symptoms and extended absenteeism.

Neuroplasticity in the transition from acute to chronic pain

Acute pain is a transient sensation that typically serves as part of the body's defense mechanism. However, in certain patients, acute pain can evolve into chronic pain, which persists for months or even longer. Neuroplasticity refers to the capacity for variation and adaptive alterations in the morphology and functionality of neurons and synapses, and it plays a significant role in the transmission and modulation of pain. In this paper, we explore the molecular mechanisms and signaling pathways underlying neuroplasticity during the transition of pain. We also examine the effects of neurotransmitters, inflammatory mediators, and central sensitization on neuroplasticity, as well as the potential of neuroplasticity as a therapeutic strategy for preventing chronic pain. The aims of this article is to clarify the role of neuroplasticity in the transformation from acute pain to chronic pain, with the hope of providing a novel theoretical basis for unraveling the pathogenesis of chronic pain and offering more effective strategies and approaches for its diagnosis and treatment.

Nociplastic pain mechanisms and toll-like receptors as promising targets for its management

ABSTRACT

Nociplastic pain, characterized by abnormal pain processing without an identifiable organic cause, affects a significant portion of the global population. Unfortunately, current pharmacological treatments for this condition often prove ineffective, prompting the need to explore new potential targets for inducing analgesic effects in patients with nociplastic pain. In this context, toll-like receptors (TLRs), known for their role in the immune response to infections, represent promising opportunities for pharmacological intervention because they play a relevant role in both the development and maintenance of pain. Although TLRs have been extensively studied in neuropathic and inflammatory pain, their specific contributions to nociplastic pain remain less clear, demanding further investigation. This review consolidates current evidence on the connection between TLRs and nociplastic pain, with a specific focus on prevalent conditions like fibromyalgia, stress-induced pain, sleep deprivation-related pain, and irritable bowel syndrome. In addition, we explore the association between nociplastic pain and psychiatric comorbidities, proposing that modulating TLRs can potentially alleviate both pain syndromes and related psychiatric disorders. Finally, we discuss the potential sex differences in TLR signaling, considering the higher prevalence of nociplastic pain among women. Altogether, this review aims to shed light on nociplastic pain, its underlying mechanisms, and its intriguing relationship with TLR signaling pathways, ultimately framing the potential therapeutic role of TLRs in addressing this challenging condition.

One-year Results of Minimally Invasive Sutured Fixation of the Slipped Ribs in the Pediatric Population

PURPOSE

Costal cartilage resection with or without rib resection is the gold standard surgery for slipping rib syndrome. Minimally invasive restoration of normal anatomy via nonabsorbable sutures has been described in the adult population with encouraging results. We sought to assess the efficacy of minimally invasive sutured fixation of the hypermobile rib in the pediatric population.

METHODS

A retrospective review was performed at Mayo Clinic involving 31 pediatric patients diagnosed with slipped rib syndrome. Minimally invasive sutured open reduction internal fixation was performed between 2020 and 2022. The standardized Örebro Musculoskeletal Pain Screening Questionnaire was given at dedicated time points pre- and post-operatively to assess efficacy. Significance was determined via the Wilcoxon rank sum test.

RESULTS

SRS was diagnosed clinically in 31 patients (24 females, 7 males, 1220 years-old). Symptoms were present for an average of 18.9 months and patients had seen an average of 4.7 specialists. Traumatic causes were identified in three patients and eight patients had hypermobility. At one month follow up, there were no surgical complications and patients reported significantly less pain (p < 0.001). Preoperative analgesics reduced by 80%. Ultimately, seven patients underwent a second operation; three patients underwent a third operation; one patient underwent five total operations. Recurrent pain was reported in six patients. Only nine patients followed-up at 1-year post-operation.

CONCLUSION

Pediatric patients with SRS demonstrated an early positive response to suture fixation without costal cartilage excision. Reoperation and recurrent pain, however, remain significant in this population.

LEVEL OF EVIDENCE

Level IV.

TYPE OF STUDY

Case series with no comparison group.

Sex Differences in Pain Sensitivity in a Dutch Cohort: Cross-Sectional and Web-Based Multidimensional Study

BACKGROUND

Sex is an important factor influencing the development and treatment of chronic pain, but the extent of its influence is still unclear. Other demographic factors as well as nonpharmacological interventions might influence pain sensitivity differently in men and women.

OBJECTIVE

In this study, we aimed to investigate the influence of sex and other demographic, lifestyle, behavioral, clinical, and environmental factors on pain sensitivity in the Dutch population. Different films were used to investigate how they would impact pain sensitivity and what influence sex and other variables have on the effect of this simple intervention.

METHODS

We performed a study consisting of 2 parts: (1) a cross-sectional research to investigate pain sensitivity differences between men and women and the influence of other demographic variables on the pain sensitivity in a Dutch cohort and (2) an internet intervention study to determine whether a short film could skew pain sensitivity.

RESULTS

All respondents filled in a web-based demographic questionnaire and were randomized into 4 groups. The control group filled in the Pain Sensitivity Questionnaire without watching a preliminary film. A cross-sectional analysis was performed in the control group (n=1746). The other 3 groups watched short films: one group watched a film with scenes of nature (n=2650), another group watched a film on laughing people (n=2735), and the last group watched a film on physically painful events (n=2708). Immediately after the film viewing, participants were directed to the Pain Sensitivity Questionnaire to measure their pain sensitivity. The Pain Sensitivity Questionnaire score was stated as a mean per question on the numeric rating scale from 0-1. The cross-sectional study revealed no significant differences between men and women but showed male-female differences in the Pain Sensitivity Questionnaire when specific background factors were present. Watching a short film had a positive impact on the pain sensitivity of the respondents who had chronic pain, with a higher effect observed in female respondents.

CONCLUSIONS

Scientists performing pain research need to account for factors that can influence the outcome of their study and be aware that these factors can be sex-dependent, and pain sensitivity should be analyzed accordingly. Even relatively small interventions such as watching a film can impact pain sensitivity, especially in respondents with current chronic pain. This effect can vary as well when different background factors are present. Our findings warrant further explorations of the possibilities that simple interventions bring for patients in personalized medicine.

TRIAL REGISTRATION

Landelijk Trial Register NTR-new NL8182; https://onderzoekmetmensen.nl/en/trial/29537.

Association of Aromatase Inhibitor-Induced Musculoskeletal Symptoms with Central Sensitization-Related Symptoms: A Cross-Sectional Study

Introduction

Aromatase inhibitor (AI)-induced musculoskeletal symptoms (AIMSS) can decrease health-related quality of life and lead to discontinuation of AI therapy for postmenopausal women with breast cancer (BC). Although central sensitization (CS) may contribute to AIMSS, the relevance of CS-related symptoms to AIMSS has not been fully clarified. This study aimed to investigate the relationship between AIMSS and CS-related symptoms in women with BC who received AI therapy.

Methods

This cross-sectional study recruited women who underwent BC surgery before at least 1 year and were taking AI for at least 6 months. Participants were assessed for joint pain and CS-related symptoms using the central sensitization inventory (CSI). The severity of CS-related symptoms was classified into three groups, and the prevalence of AIMSS was calculated. Multiple logistic regression analysis was used to assess the relationship between AIMSS and factors of possible relevance to AIMSS, including CSI severity.

Results

Of the 73 women who were included in this study, 31 (42.4%) were categorized into the AIMSS group and 42 (57.6%) into the non-AIMSS group. Participants with a history of chemotherapy and higher CSI score were significantly more likely to have AIMSS. Multiple logistic regression analysis showed that a history of chemotherapy (odds ratio = 4.21) and higher CSI severity (odds ratio = 13.43) had significantly associated with AIMSS.

Conclusion

CS-related symptoms assessed using CSI may be strongly associated with AIMSS. Further longitudinal studies to investigate the causal relationship and effectiveness of CS-targeted interventions are needed to prevent and treat AIMSS effectively.

Exercise as a promising alternative for sciatic nerve injury pain relief: a meta-analysis

Objective

The efficacy of drug therapies in managing neuropathic pain is constrained by their limited effectiveness and potential for adverse effects. In contrast, exercise has emerged as a promising alternative for pain relief. In this study, we conducted a systematic evaluation of the therapeutic impact of exercise on neuropathic pain resulting from sciatic nerve injury in rodent models.

Methods

The PubMed, Embase, and Web of Science databases were retrieved before April 2024. A series of studies regarding the effect of treadmill, swimming, wheel and other exercises on neuropathic pain induced by sciatic nerve injury in rats and mice were collected. Using predefined inclusion criteria, two researchers independently performed literature screening, data extraction, and methodological quality assessment utilizing SYRCLE's risk of bias tool for animal studies. Statistical analysis was conducted using RevMan 5.3 and STATA 12.0 analysis software.

Results

A total of 12 relevant academic sources were included in the analysis of controlled animal studies, with 133 rodents in the exercise group and 135 rodents in the sedentary group. The meta-analysis revealed that exercise was associated with a significant increase in paw withdrawal mechanical threshold [Standard Mean Difference (SMD) = 0.84, 95% confidence interval (CI): 0.28-1.40, p = 0.003] and paw withdrawal thermal latency (SMD = 1.54, 95%CI: 0.93-2.15, p < 0.0001) in rats and mice with sciatic nerve injury. Subgroup analyses were conducted to evaluate the impact of exercise duration on heterogeneity. The results showed that postoperative exercise duration ≤3 weeks could significantly elevate paw withdrawal mechanical threshold (SMD = 1.04, 95% CI: 0.62-1.46, p < 0.00001). Postoperative exercise duration ≤4 weeks could significantly improve paw withdrawal thermal latency (SMD = 1.93, 95% CI:1.19-2.67, p < 0.00001).

Conclusion

Exercise represents an effective method for improving mechanical and thermal hypersensitivity resulting from sciatic nerve injury in rodents. Factors such as pain models, the initiation of exercise, the type of exercise, and the species of rodent do not significantly impact the development of exercise-induced hypoalgesia. However, the duration of postoperative exercise plays a crucial role in the onset of exercise-induced hypoalgesia.

Therapeutic Patient Education as Part of the Physiotherapy Management of Adults with Headache: A Scoping Review

PURPOSE OF REVIEW

Physiotherapy interventions for headache mostly include exercise and manual therapy. Yet, the complex nature of headache, sometimes characterized by symptoms of facilitated central pain mechanisms, demands an individualized approach in which therapeutic patient education could be supportive. This scoping review aimed to summarize the position of therapeutic patient education within the physiotherapy management of adults with headache. PubMed, EMBASE, Web of Science, and Scopus were searched. The search-query comprised terminology relating to "headache", "education", and "physiotherapy". Eligibility criteria were: adults with headache, interventions including education within the domain of physiotherapy, reviews, clinical trials, cohort, case report, case-control studies.

RECENT FINDINGS

Eleven publications were included from the 281 retrieved publications. These publications were clinical trials (n = 4), reviews (n = 4), case-reports (n = 2), and a guideline (n = 1). Type of headaches studied were migraine (n = 3), post-traumatic headache (n = 2), tension-type headache (n = 2), cervicogenic headache (n = 1), primary headaches (n = 1), chronic daily headache (n = 1), and mixed migraine-cervicogenic headache (n = 1). Education seems an umbrella-term for postural education, lifestyle advice, and pain education. Three themes emerged across the publications: handling headache triggers (migraine, post-traumatic headache), promoting active lifestyle (post-traumatic headache, chronic daily headache, migraine), evaluating posture (post-traumatic headache, chronic daily headache, tension-type headache, cervicogenic headache). All publications recommended education in the management of headache. Only one (of the 11 included) publication described the educational program and determined its efficacy. Based on this scoping review, therapeutic patient education seems supported within physiotherapy management of headache. However, it is unclear how such education is tailored to the specific needs of the individual, the headache subtype, or when it should be added to physiotherapy management of headache.

Neuropathic and Nociplastic Pain Profiles are Common in Adult Chronic Nonbacterial Osteitis (CNO)

Chronic nonbacterial osteitis (CNO) is a rare musculoskeletal disease causing chronic bone pain. It is known that chronic musculoskeletal pain may involve other mechanisms than nociceptive pain only. We investigate the prevalence of neuropathic and nociplastic pain in adult CNO and their association with clinical characteristics and treatment outcomes. Survey study among the Dutch adult CNO cohort (n = 84/195 participated), including PAIN-detect for neuropathic pain, and the Central Sensitization Inventory (CSI), Fibromyalgia Rapid Screening Tool (FiRST), and ACTTION-APS Pain Taxonomy (AAPT) for nociplastic pain. Clinical characteristics and CNO-related bone pain scores were compared between patients with exclusive nociceptive pain and those with nociceptive pain plus neuropathic and/or nociplastic pain (mixed pain). 31% (95% CI 21-41) of patients classified as likely having neuropathic pain according to PAIN-detect. 53% (41-64) of patients displayed central sensitization on CSI, 61% (50-72) screened positive for fibromyalgia on FiRST and 14% (7-23) of patients fulfilled the AAPT criteria, all indicative of nociplastic pain. Mixed pain was associated with longer diagnostic delay (mean difference 2.8 years, 95% CI 0.4-5.2, p = 0.023), lower educational level (72% versus 20%, p < 0.001), and opioid use (37% versus 13%, p = 0.036). Despite comparable disease severity and extent, patients with mixed pain reported significantly higher CNO-related bone pain scores. This study demonstrates the high prevalence of mixed pain in adult CNO, in which neuropathic and nociplastic pain exist alongside nociceptive inflammatory bone pain. Disease burden in CNO may extend beyond inflammatory activity, highlighting the need for a multifaceted management approach.

Chronic pain as an emergent property of a complex system and the potential roles of psychedelic therapies

Despite research advances and urgent calls by national and global health organizations, clinical outcomes for millions of people suffering with chronic pain remain poor. We suggest bringing the lens of complexity science to this problem, conceptualizing chronic pain as an emergent property of a complex biopsychosocial system. We frame pain-related physiology, neuroscience, developmental psychology, learning, and epigenetics as components and mini-systems that interact together and with changing socioenvironmental conditions, as an overarching complex system that gives rise to the emergent phenomenon of chronic pain. We postulate that the behavior of complex systems may help to explain persistence of chronic pain despite current treatments. From this perspective, chronic pain may benefit from therapies that can be both disruptive and adaptive at higher orders within the complex system. We explore psychedelic-assisted therapies and how these may overlap with and complement mindfulness-based approaches to this end. Both mindfulness and psychedelic therapies have been shown to have transdiagnostic value, due in part to disruptive effects on rigid cognitive, emotional, and behavioral patterns as well their ability to promote neuroplasticity. Psychedelic therapies may hold unique promise for the management of chronic pain.

The effect of joint position sense therapy on chronic shoulder pain with central sensitization

BACKGROUND

Chronic shoulder pain is a common musculoskeletal problem associated with unreleased pain and functional dysfunction that can evolve into central sensitization. Some forms of manual therapy may exacerbate pain and central sensitization. This study investigated the impact of joint position sense therapy (JPST), a moderate joint proprioception training technique, on central sensitization, shoulder functional dysfunction, and pain in patients with chronic shoulder pain compared with more intense exercises or aggressive manual therapies.

METHODS

We assessed the pressure pain threshold (PPT) in 30 patients with and 30 patients without chronic shoulder pain. The assessment focused on 4 muscle sites: deltoid, upper trapezius, brachioradialis, and tibialis anterior. Thirty patients with chronic shoulder pain were randomly divided into the JPST and control groups. The JPST group underwent additional shoulder joint position-sense training. The efficiency outcomes were the disabilities of the arm, shoulder, and hand questionnaire, visual analog scale (VAS), and PPT, evaluated at baseline and after the intervention.

RESULTS

Significant differences were observed in the PPT values at the brachioradialis (P < .05), deltoid (P < .01), and trapezius (P < .001) among the non-chronic and chronic groups, but not in the tibialis anterior muscle (P > .05). Although both control and JPST interventions effectively improved the disabilities of the arm, shoulder, and hand questionnaire score, pain intensity, and PPT values in the upper limb, the outcomes in the JPST group were significantly different from those in the control group.

CONCLUSIONS

Generalized hyperalgesia changes limited to the upper limbs were observed in patients with chronic shoulder pain. JPST has beneficial effects on pain control and functional dysfunction in patients with chronic shoulder pain.

Sensitization-Associated Symptoms and Neuropathic-like Features in Patients with Cervical Dystonia and Pain

Background: This exploratory study evaluated the presence of sensitization-associated and neuropathic-like symptoms and identified their association with pressure sensitivity, pain, and disability in patients with cervical dystonia (CD). Methods: Thirty-one patients with CD (74.2% women, age: 61.2 years, SD 10.1) participated. Data collected included clinical variables, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), the Central Sensitization Inventory (CSI), the Self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), the Hospital Anxiety and Depression Scale (HADS) and the Pittsburgh Sleep Quality Index (PSQI), as well as widespread pressure pain thresholds (PPTs). Results: Patients with CD with pain (n = 20, 64.5%) showed higher scores on the TWSTRS disability subscale and the CSI (p < 0.001), and lower PPTs (p < 0.05). Fifteen patients (15/31, 48%) showed sensitization-associated symptoms (CSI ≥ 40), whereas five of the patients with pain (5/20, 25%) exhibited neuropathic-like symptoms (S-LANSS ≥ 12). The CSI and S-LANSS were positively associated with the TWSTRS, HADS-A and HADS-D, and negatively associated with PPTs. HADS-D and S-LANSS explained 72.5% of the variance of the CSI (r2: 0.725), whereas CSI explained 42.3% of the variance of the S-LANSS (r2: 0.423). Conclusions: Pain is an important source of disability in CD, and may be a consequence of different mechanisms, including sensitization.

Questionnaires for the Assessment of Central Sensitization in Endometriosis: What Is the Available Evidence? A Systematic Review with a Narrative Synthesis

It has been suggested that central sensitization (CS) may be involved in the failure of standard medical and surgical treatment to relieve endometriosis-related pain. However, there is no gold standard for the diagnosis of CS, and self-reported questionnaires are used as diagnostic surrogates. The main objective of this review was to identify all CS questionnaires used in clinical endometriosis studies. The secondary objective was to qualitatively analyze strengths and weaknesses of each questionnaire. A PubMed and EMBASE systematic literature search conducted in April 2023 using the terms "endometriosis; central pain; central sensitization; questionnaire; patient-reported outcome measure; screening tool" identified 122 publications: six articles were included in the review. The Central Sensitization Inventory (CSI) is the most frequently used questionnaire for the detection of CS in patients with endometriosis. It has been validated in patients with endometriosis, in whom it appears to have good psychometric proprieties. The Fibromyalgia Survey Questionnaire (FSQ) has also been used, although it has not been specifically validated in endometriosis patients. The debate regarding these questionnaires' construct validity is still open and will be so until a gold standard diagnostic tool for CS is found. In fact, some authors argue these questionnaires are measuring psychological vulnerability and a hypervigilant state that is associated with pain, rather than CS itself. However, their use should not be discouraged as they are able to identify chronic pain patients which warrant further attention and who may benefit from broader treatment strategies.

Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Understanding How Patients With Lumbar Radiculopathy Make Sense of and Cope With Their Symptoms

Lumbar radiculopathy, characterized by pain radiating along a nerve root, significantly diminishes the quality of life due to its neuropathic nature. Patients' understanding of their illness and the coping strategies they employ directly influence how they manage their condition. Understanding these illness representations from the patient's perspective is crucial for healthcare providers seeking to optimize treatment outcomes. This study adopted a qualitative interpretive/constructive paradigm to explore this dynamic. A qualitative evidence synthesis approach, utilizing best-fit framework synthesis for data extraction, was applied to analyze primary qualitative studies focused on patient experiences with lumbar radiculopathy. Using SPiDER (Sample, Phenomenon of interest, Design, Evaluation, Research type) to guide the search strategy, extracted data was mapped against the Common-Sense Model of Self-Regulation (CSM) framework. Sixteen studies, with moderate to minor methodological quality concerns, were included in the analysis. Data mapping across CSM domains generated 14 key review findings. Results suggest that patients with high-threat illness representations often exhibit maladaptive coping behaviors (e.g., activity avoidance) driven by emotional responses. In contrast, problem-solving techniques appear to contribute to positive outcomes (e.g., exercise adherence and effective self-management) in patients who perceive their condition as less threatening. These findings highlight the potential benefits of interventions designed to reduce perceived threat levels and enhance self-efficacy in patients with lumbar radiculopathy, leading to improved self-management and ultimately better health outcomes.

Transcranial Direct Current Stimulation for Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The effects of transcranial direct current stimulation (tDCS) in the treatment of knee osteoarthritis (KOA) is still unclear. The objective is to evaluate the efficacy and safety of tDCS in improving symptoms in patients with KOA.

METHODS

The following electronic databases were searched for eligible randomized controlled trials (RCTs): PubMed, Embase, Web of Science, and the Cochrane Library. The search was performed from the inception dates to April 30, 2023. Data extraction and quality assessment were performed by two independent reviewers. Standard mean differences (SMDs) with 95% confidence intervals (95% CIs) for pooled data were calculated. A random-effects model was used for the data analyses. The primary outcomes were pain and physical function. Secondary outcomes included stiffness, mobility performance, quality of life, pressure pain tolerance, and plasma levels of brain-derived neurotrophic factor (BDNF).

RESULTS

This meta-analysis included 13 RCTs. tDCS was significantly associated with pain decrease compared with sham tDCS (SMD = -0.62, 95% CI -0.87 to -0.37, P < 0.00001). When comparing tDCS plus other non-tDCS with sham tDCS plus other non-tDCS, there was no longer a significant association with pain decrease (SMD = -0.45, 95% CI -1.08 to 0.17, P = 0.16). The changes in physical function were not significantly different between the tDCS and sham tDCS groups (SMD = -0.09, 95% CI -0.56 to 0.38, P = 0.71). When comparing tDCS plus other non-tDCS with sham tDCS plus other non-tDCS, there was still no significant association with improvement in physical function (SMD = -0.66, 95% CI -1.63 to 0.30, P = 0.18). There was no significant difference with improvement in stiffness (SMD = -0.21, 95% CI -0.77 to 0.34, P = 0.45), mobility performance (SMD = 4.58, 95% CI -9.21 to 18.37, P = 0.51), quality of life (SMD = -7.01, 95% CI -22.61 to 8.59, P = 0.38), and pressure pain tolerance (SMD = 0.30, 95% CI -0.09 to 0.69, P = 0.13). There was a statistically significant reduction in plasma levels of BDNF (SMD = -13.57, 95% CI -24.23 to -2.92, P = 0.01).

CONCLUSION

In conclusion, tDCS could significantly alleviate pain, but it might have no efficacy in physical function, stiffness, mobility performance, quality of life, and pressure pain tolerance among patients with KOA.

Whole Body Cryostimulation: A New Adjuvant Treatment in Central Sensitization Syndromes? An Expert Opinion

Central sensitisation is defined as a multifactorial etiopathogenetic condition involving an increase in the reactivity of nociceptive neurons and alterations in pain transmission and perception in the central nervous system. Patients may present with widespread chronic pain, fatigue, sleep disturbance, dizziness, psychological (e.g., depression, anxiety, and anger) and social impairment. Pain can be spontaneous in onset and persistence, characterised by an exaggerated response and spread beyond the site of origin, and sometimes triggered by a non-painful stimulus. Whole-body cryostimulation (WBC) could be an adjuvant therapy in the management of this type of pain because of its global anti-inflammatory effect, changes in cytokines and hormone secretion, reduction in nerve conduction velocity, autonomic modulation, and release of neurotransmitters involved in the pain pathway. In several conditions (e.g., fibromyalgia, rheumatoid arthritis, and chronic musculoskeletal pain), WBC affects physical performance, pain perception, and psychological aspects. Given its multiple targets and effects at different organs and levels, WBC appears to be a versatile adjuvant treatment for a wide range of conditions of rehabilitation interest. Further research is needed to fully understand the mechanisms of analgesic effect and potential actions on pain pathways, as well as to study long-term effects and potential uses in other chronic pain conditions.

Improvement in functional outcome 1 year after nonsurgical multidisciplinary treatment for chronic pain after total knee arthroplasty: A prospective cohort study

PURPOSE

The purpose of this study was to evaluate a multidisciplinary intervention developed for patients with debilitating chronic pain after total knee arthroplasty (TKA) unresponsive to existing treatment options.

METHODS

A treatment-based prospective cohort study was caried out in 30 TKA patients with debilitating chronic pain at least 1 year after TKA. The treatment was a multidisciplinary intervention. Main inclusion criteria: no indication for surgery. Primary outcome was function measured by KOOS-PS, OKS, OKS-APQ and WORQ. Secondary outcome measures were pain, fear of movement, self-efficacy, quality of life (QoL), health care and pain medication use, work rehabilitation and patient satisfaction. The assessments took place pre- and directly posttreatment, at 1, 3 and 12 months follow-up. The clinical relevance was assessed by predefined minimal important clinical change (MCIC).

RESULTS

At baseline patients were on average 64.7 (±7.9) years old, 67% were female, and they had knee pain for 42 (10-360) months. The results at 12-month follow-up: first, a significant improvement was shown in function, pain, fear of movement, self-efficacy and QoL. Second, in 38.5%-69.2% of patients clinical relevant improvement was shown for functional outcome, 31% for pain, and 50% for self-efficacy. Third, 42% of patients reported 'no healthcare use in the past three months'.

CONCLUSION

One year after a multidisciplinary treatment a clinically relevant improvement was shown in terms of function, pain, self-efficacy and QoL. It seems to be a promising treatment option in this difficult-to-treat patient group with debilitating chronic pain after TKA. Future research should examine the effect of the treatment in a larger study population, considering a control group, and focusing on the working population and evaluating cost-efficacy.

LEVEL OF EVIDENCE

Level II.

Gut dysbiosis in patients with chronic pain: a systematic review and meta-analysis

Introduction

Recent evidence supports the contribution of gut microbiota dysbiosis to the pathophysiology of rheumatic diseases, neuropathic pain, and neurodegenerative disorders. The bidirectional gut-brain communication network and the occurrence of chronic pain both involve contributions of the autonomic nervous system and the hypothalamic pituitary adrenal axis. Nevertheless, the current understanding of the association between gut microbiota and chronic pain is still not clear. Therefore, the aim of this study is to systematically evaluate the existing knowledge about gut microbiota alterations in chronic pain conditions.

Methods

Four databases were consulted for this systematic literature review: PubMed, Web of Science, Scopus, and Embase. The Newcastle-Ottawa Scale was used to assess the risk of bias. The study protocol was prospectively registered at the International prospective register of systematic reviews (PROSPERO, CRD42023430115). Alpha-diversity, β-diversity, and relative abundance at different taxonomic levels were summarized qualitatively, and quantitatively if possible.

Results

The initial database search identified a total of 3544 unique studies, of which 21 studies were eventually included in the systematic review and 11 in the meta-analysis. Decreases in alpha-diversity were revealed in chronic pain patients compared to controls for several metrics: observed species (SMD= -0.201, 95% CI from -0.04 to -0.36, p=0.01), Shannon index (SMD= -0.27, 95% CI from -0.11 to -0.43, p<0.001), and faith phylogenetic diversity (SMD -0.35, 95% CI from -0.08 to -0.61, p=0.01). Inconsistent results were revealed for beta-diversity. A decrease in the relative abundance of the Lachnospiraceae family, genus Faecalibacterium and Roseburia, and species of Faecalibacterium prausnitzii and Odoribacter splanchnicus, as well as an increase in Eggerthella spp., was revealed in chronic pain patients compared to controls.

Discussion

Indications for gut microbiota dysbiosis were revealed in chronic pain patients, with non-specific disease alterations of microbes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023430115.

Central Sensitization and Neuropathic Pain Cumulatively Affect Patients Reporting Inferior Outcomes Following Total Knee Arthroplasty

UPDATE

This article was updated on November 17, 2023, because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 102, the text that had read "In a post hoc analysis of the preoperative results, Group 1 showed significantly inferior WOMAC pain, function, and total scores compared with Group 4 (p < 0.05 for all). Groups 2 and 3 showed worse preoperative WOMAC pain, function, and total subscores compared with Group 4 (p < 0.05 for all). These results remained the same at 2 years after surgery." now reads "In a post hoc analysis of the preoperative results, Groups 1, 2, and 3 showed significantly inferior WOMAC pain, function, and total scores compared with Group 4 (p < 0.05 for all). At 2 years postoperatively, Group 1 showed inferior WOMAC pain, function, and total scores compared with the other groups (p < 0.05 for all). Also, Groups 2 and 3 had worse WOMAC pain, function and total scores compared with Group 4 (p < 0.05 for all)." Also, on page 106, the title of Table IV, which had previously read "Inter-Group Comparison of Preoperative Scores (Post Hoc Analysis)" now reads "Inter-Group Comparison of Postoperative Scores (Post Hoc Analysis)."

Water-Based Exercise in Patients With Nonspecific Chronic Low-Back Pain: A Systematic Review With Meta-Analysis

ABSTRACT

Babiloni-Lopez, C, Fritz, N, Ramirez-Campillo, R, and Colado, JC. Water-based exercise in patients with nonspecific chronic low-back pain: a systematic review with meta-analysis. J Strength Cond Res 38(1): 206-219, 2024-This study aimed to systematically review and synthesize evidence (i.e., active [land-based training] and nonactive controls [e.g., receiving usual care]) regarding the effects of water-based training on patients with nonspecific chronic low-back pain (NSCLBP). Web of Science (WOS), PubMed (MEDLINE), EMBASE, EBSCO (SPORTDiscus; CINAHL), and PEDro were searched, with no date restrictions, until October 2021. The included studies satisfied the following criteria: (a) NSCLBP (≥12 weeks) patients, (b) water-based intervention, (c) control group (land-based trained; nonactive group), and (d) outcomes related to pain, disability, quality of life, or flexibility. The main outcome analyzed in the meta-analysis was pain intensity. Secondary outcomes included disability, body mass index, and flexibility. The random-effects model was used, and effect size (ES) values are presented with 95% confidence intervals (CIs). The impact of heterogeneity was assessed (I2 statistic), with values of <25%, 25-75%, and >75% representing low, moderate, and high levels, respectively. Alpha was set at p < 0.05. In conclusion, 15 studies (n = 524) were meta-analyzed. After intervention, pain intensity was reduced compared with nonactive controls (ES = -3.61; p < 0.001) and a similar reduction was noted when compared with land-based trained group (ES = -0.14; p = 0.359). Greater decrease in disability (ES = 2.15; p < 0.001) and greater increase in sit-and-reach (i.e., flexibility; ES = -2.44; p < 0.001) were noted after intervention compared with the nonactive group. In conclusion, water-based exercise therapy reduces pain intensity, disability, and increases flexibility in NSCLBP compared with nonactive subjects and was equally effective compared with land-based exercise to reduce pain. Favorable effects may be expected at ≤8 weeks. However, due to several methodological issues (e.g., high heterogeneity), for the improvement of most outcomes, we are unable to provide other than a weak recommendation in favor of intervention compared with control treatment.

Cross-cultural adaptation and validation for central sensitization inventory: based on Chinese patients undergoing total knee arthroplasty for knee osteoarthritis

BACKGROUND

This study was conducted to develop a simplified Chinese version of the central sensitization inventory (CSI-CV) and to evaluate its reliability and validity.

METHODS

The CSI-CV was developed through a process involving the translation and back translation of the original CSI. Subsequently, experts reviewed and revised the content of the items to ensure their appropriateness. A total of 325 patients with knee osteoarthritis (KOA), who were scheduled to undergo total knee arthroplasty (TKA), completed the CSI-CV at a prominent orthopedic center in Xi'an, China. Afterward, a random selection of 100 participants was chosen for retesting after one week. The reliability and validity of the inventory were evaluated through exploratory factor analysis, correlation coefficient calculation and other methods.

RESULTS

The CSI-CV consists of 25 items in five dimensions (emotional distress, headache and jaw symptoms, physical symptoms, urological symptoms, and fatigue and sleep problems). The cumulative variance contribution rate was 75.3%, the Cronbach's α coefficient was 0.83, the Guttman split-half reliability coefficient was 0.88 and the intraclass correlation coefficient was 0.965. The CSI-CV scores correlated moderately with the total scores of the brief pain inventory (r = 0.506), Western Ontario and McMaster Universities Osteoarthritis Index (r = 0.466) and EuroQoL Group's five-dimension questionnaire (r = 0.576).

CONCLUSIONS

The findings demonstrate that the CSI was successfully trans-culturally adapted into a simplified Chinese version (CSI-CV) that was reliable and valid for Chinese-speaking patients who awaiting TKA for KOA.

Central effects of trigeminal electrical stimulation

This is a review of the literature on the main neuromodulation techniques, focusing on the possibility of introducing sensory threshold ULFTENS into them. Electro neuromodulation techniques have been in use for many years as promising methods of therapy for cognitive and emotional disorders. One of the most widely used forms of stimulation for orofacial pain is transcutaneous trigeminal stimulation on three levels: supraorbital area, dorsal surface of the tongue, and anterior skin area of the tragus. The purpose of this review is to trigger interest on using dental ULFTENS as an additional trigeminal neurostimulation and neuromodulation technique in the context of TMD. In particular, we point out the possibility of using ULFTENS at a lower activation level than that required to trigger a muscle contraction that is capable of triggering effects at the level of the autonomic nervous system, with extreme ease of execution and few side effects.

Impact of central sensitization on pain, disability and psychological distress in patients with knee osteoarthritis and chronic low back pain

BACKGROUND

Central sensitization (CS) is becoming increasingly recognized as a significant factor in many chronic pain conditions, including knee osteoarthritis (KOA) and chronic low back pain (CLBP). Yet it presently remains unclear how strong is the involvement of CS in KOA and CLBP and which factors are involved in CS in these two chronic disabling diseases.

METHODS

This is a cross-sectional study in which included a total of 178 patients with KOA and 118 patients with CLBP. Inclusion criteria for eligible participants for the KOA group were a confirmed diagnosis of KOA according to the American College of Rheumatology criteria, and for the CLBP group a chronic low back pain for more than 3 months. Subjects were excluded if they presented with a diagnosed psychiatric disorder or if they lacked the capacity to provide informed consent, understand study questionnaires or perform physical performance tests. In each group, were assessed; CS-related symptoms using the Central Sentization Inventory (CSI); demographic and clinical characteristics such as disease duration, pain intensity on a visual analog scale, self-reported function using the Lequesne index for KOA patients and the Oswestry Disability index for CLBP patients, and physical performance with the 6 minutes' walk test; as well as psychosocial risk factors using the Patient Health Questionnaire for depression (PHQ-9), the Generalized Anxiety Disorder (GAD-7) and the Pain Catastrophizing Scale (PCS).

RESULTS

CSI scores significantly correlated with pain intensity and disability in KOA and CLBP patients, and were highly correlated with self-reported symptoms of depression, anxiety and pain catastrophizing. Depression significantly predicted the CSI score in both groups.

CONCLUSION

These findings provide further evidence for the impact of CS on pain, function and physical performance in KOA and CLBP patients. Psychosocial symptoms such as pain catastrophizing, anxiety and depression should also be considered as they are also associated with CS.

Telerehabilitation for persistent Pelvic Girdle Pain within a biopsychosocial framework - A case report

BACKGROUND

Persistent pregnancy-related pelvic girdle pain (PGP) and the resulting consequences may considerably influence a woman's quality of life. The complexity of this condition requires a whole-person centered approach. In response to COVID-19 outbreak, telerehabilitation has emerged as a promising alternative to traditional in-person visits.

PURPOSE

The aim of this report was to present the potential of telerehabilitation for persistent postpartum PGP within the biopsychosocial framework.

CASE DESCRIPTION

A 26-year-old female presented with persistent pregnancy-related PGP of 8 months duration after her first vaginal delivery. The video-consults were performed using telerehabilitation platform. The patient received six telerehabilitation consults of 45 min duration over five weeks. Assessment of physical and psychosocial factors, cognitively focused strategies including pain neurophysiology education, sensory-motor remapping exercises, and graded increase of activity were administered. Rehabilitation was divided into the following phases: assessment, desensitization, graded exposure, and supported independence.

OUTCOMES

The Pelvic Girdle Questionnaire (PGQ) score was significantly reduced from 72.2 during the assessment to 15.3 at discharge. This change was significantly more substantial than the minimal clinically important change estimated for the PGQ.

CONCLUSION

Physiotherapists can utilize telerehabilitation to assist them with enacting appropriate care measures for persistent PGP within a biopsychosocial framework.

Precision management of post-COVID pain: An evidence and clinical-based approach

Background Pain after a SARS-CoV-2 acute infection (post-COVID pain) is becoming a new healthcare emergency but remains underestimated and most likely undertreated due to a lack of recognition of the phenomenon and knowledge of the underlying pain mechanisms. Evidence supporting any particular treatment approach for the management of post-COVID pain is lacking. Large variability in the patient response to any standard pain treatments is clinically observed, which has led to calls for a personalized, tailored approach to treating patients with chronic post-COVID pain (i.e. 'precision pain medicine'). Applying the global concerted action towards precision medicine to post-COVID pain could help guide clinical decision-making and aid in more effective treatments. Methods The current position paper discusses factors to be considered by clinicians for managing post-COVID pain ranging from identification of the pain phenotype to genetic consideration. Results The ability of clinicians to phenotype post-COVID pain into nociceptive, neuropathic, nociplastic or mixed type is suggested as the first step to better planification of a treatment programme. Further, the consideration of other factors, such as gender, comorbidities, treatments received at the acute phase of infection for onset-associated COVID-19 symptoms, factors during hospitalization or the presence of emotional disturbances should be implemented into a treatment programme. Conclusions Accordingly, considering these factors, management of post-COVID pain should include multimodal pharmacological and non-pharmacological modalities targeting emotional/cognitive aspects (i.e. psychological and/or coping strategies), central sensitization-associated mechanisms (i.e. pain neuroscience education), exercise programmes as well as lifestyle interventions (e.g. nutritional support and sleep management). SIGNIFICANCE: This position paper presents an evidence-based clinical reasoning approach for precision management of post-COVID pain.

Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress

BACKGROUND

Chronic pain conditions impose significant burdens worldwide. Pharmacological treatments like opioids have limitations. Non-invasive non-pharmacological therapies (NINPT) encompass diverse interventions including physical, psychological, complementary and alternative approaches, and other innovative techniques that provide analgesic options for chronic pain without medications.

MAIN BODY

This review elucidates the mechanisms of major NINPT modalities and synthesizes evidence for their clinical potential across chronic pain populations. NINPT leverages peripheral, spinal, and supraspinal mechanisms to restore normal pain processing and limit central sensitization. However, heterogeneity in treatment protocols and individual responses warrants optimization through precision medicine approaches.

CONCLUSION

Future adoption of NINPT requires addressing limitations in standardization and accessibility as well as synergistic combination with emerging therapies. Overall, this review highlights the promise of NINPT as a valuable complementary option ready for integration into contemporary pain medicine paradigms to improve patient care and outcomes.

Physiotherapy management of nociplastic pain: A Delphi study of Italian specialists

BACKGROUND AND PURPOSE

Nociplastic pain due to central sensitization (CS) is common in people suffering from chronic pain, but no clinical practice guideline is available in rehabilitative settings for patients' management. The aim of this study is to achieve expert consensus on physiotherapy competencies in the management of people with nociplastic pain and suspected CS mechanisms.

METHODS

A web-based Delphi process was employed. Experts in the rehabilitation field were recruited following pre-defined eligibility criteria. Following completion of three Delphi rounds, the final list of competencies was generated.

RESULTS

In all, 23 participants were recruited. They all completed Round 1 (23/23, 100%), twenty Round 2 and Round 3 (20/23, 87%). Following Round 1, seven areas were identified by the panel as crucial for CS physiotherapy management; 19 competencies out of 40 reached the consensus between experts, and nine additional competencies were added to Round 2 following literary review. Round 2 identified the agreement for all the 29 competencies. During Round 3, all the experts confirmed the final list generated through the consensus process.

DISCUSSION

An agreement between experts was found for the final list of competencies that a physiotherapist should implement every time it approaches people with suspected CS mechanisms. Further research is needed to support the clinical utility of our findings and their applicability in daily practice.

Prognostic factors specific to work-related musculoskeletal disorders: An overview of recent systematic reviews

PURPOSE

Work-related injuries affect a considerable number of people each year and represent a significant burden for society. To reduce this burden, optimizing rehabilitation care by integrating prognostic factors (PF) into the clinical decision-making process is a promising way to improve clinical outcomes. The aim of this study was to identify PF specific to work-related musculoskeletal disorders.

METHODS

We performed an overview of systematic reviews reporting on PF that had the following outcomes of interest: Return to work, pain, disability, functional status, or poor outcomes. Each extracted PF was categorized according to its level of evidence (grade A or B) and whether it was modifiable or not. The risk of bias of each study was assessed with the ROBIS tool.

RESULTS

We retrieved 757 citations from 3 databases. After removing 307 duplicates, 450 records were screened, and 20 studies were retained. We extracted a total of 20 PF with a Grade A recommendation, where 7 were deemed modifiable, 11 non-modifiable and 2 were index test. For example, return to work expectations, previous sick leave, delay in referral and pain intensity were found to be predictors of return-to-work outcomes. We also identified 17 PF with a Grade B recommendation, where 11 were deemed modifiable. For example, poor general health, negative recovery expectations, coping and fear-avoidance beliefs, pain severity, and particularly physical work were found to predict return to work outcomes.

CONCLUSION

We found numerous modifiable PFs that can help clinicians personalize their treatment plan beyond diagnostic-related information for work-related musculoskeletal disorders.

Associations between psychological factors, pressure pain thresholds and conditioned pain modulation and disability in (sub)-acute low back pain: a three-month follow-up study

BACKGROUND

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.

OBJECTIVE

This prospective cohort study aims to determine associations between baseline psychological factors, PPTs and CPM in (S)ALBP and disability after 3 months.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Unravelling Impaired Hypoalgesia at Rest and in Response to Exercise in Patients with Chronic Whiplash-Associated Disorders: Effects of a Single Administration of Selective Serotonin Reuptake Inhibitor versus Selective Norepinephrine Reuptake Inhibitor

(1) Background: Noradrenaline and serotonin have modulatory roles in pain signaling and in exercise-induced hypoalgesia. Patients with chronic whiplash-associated disorders often show impaired exercise-induced hypoalgesia. Therefore, this study aimed to examine the isolated effect of activating serotonergic or noradrenergic descending pathways on hypoalgesia at rest and in response to exercise in patients with chronic WAD by using respectively a single dose of a selective serotonin reuptake inhibitor (SSRI) and a selective norepinephrine reuptake inhibitor (NRI). (2) Methods: Twenty-five people with chronic WAD participated in this double-blind randomized controlled crossover experiment. Serotonin and noradrenaline concentrations were modulated by the oral ingestion of a single dose of citalopram (i.e., SSRI) or atomoxetine (i.e., SNRI). Quantitative sensory testing (including pressure pain thresholds and conditioned pain modulation) was measured before and after exercise in combination with no medication (1), atomoxetine (2), or citalopram (3) at three different test days. (3) Results: Random-intercept linear mixed models analysis was used to analyze pain outcomes (i.e., pain at rest and exercise-induced hypoalgesia) before and after exercise over the three conditions in patients with chronic WAD. No differences in pain at rest were found between the three conditions before exercise. The effect of exercise on pain outcome measures was not influenced by medication intake. The occupational status of the participants had a significant influence on the effect of exercise and medication on pain outcomes (p < 0.05). Patients working full-time had some positive effect of atomoxetine on pain facilitation (p < 0.05). Unemployed patients had some negative effect of citalopram on pain tolerance and experienced exercise-induced hypoalgesia (p < 0.05). (4) Conclusions: A single dose of citalopram or atomoxetine did not result in changes in hypoalgesia at rest and in response to exercise. These results do not support the use of SSRI or selective NRI to overcome impaired hypoalgesia at rest or in response to exercise in people with chronic WAD. Effect of exercise and medication on pain in patients with chronic WAD is influenced by the occupational status.

Validity of the Central Sensitization Inventory to Address Human Assumed Central Sensitization: Newly Proposed Clinically Relevant Values and Associations

Central sensitization cannot be directly demonstrated in humans and thus a gold standard is missing. Therefore, we used human assumed central sensitization (HACS) when associated with humans. The central sensitization inventory (CSI) is a screening questionnaire for addressing symptoms that are associated with HACS. This cross-sectional study compared patients with chronic pain and at least one central sensitivity syndrome with healthy, pain-free controls via ROC analyses. Analyses were performed for all participants together and for each sex separately. Regression analyses were performed on patients with chronic pain with and without central sensitivity syndromes. Based on 1730 patients and 250 healthy controls, cutoff values for the CSI for the total group were established at 30 points: women: 33 points; men: 25 points. Univariate and multivariate regression analyses were used to identify possible predictors for the CSI score in 2890 patients with chronic pain. The CSI score is associated with all independent factors and has a low association with pain severity in women and a low association with pain severity, age, and body mass index in men. The newly established CSI cutoff values are lower than in previous studies and different per sex, which might be of clinical relevance in daily practice and importance in research.