Brain-derived neurotrophic factor contributes to activity-induced muscle pain in male but not female mice.

Activity-induced muscle pain increases release of interleukin-1ß (IL-1ß) in muscle macrophages and the development of pain is prevented by blockade of IL-1ß. Brain derived neurotrophic factor (BDNF) is released from sensory neurons in response to IL-1ß and mediates both inflammatory and neuropathic pain. Thus, we hypothesized that metabolites released during fatiguing muscle contractions activate macrophages to release IL-1ß, which subsequently activate sensory neurons to secrete BDNF. To test this hypothesis, we used an animal model of activity-induced pain induced by repeated intramuscular acidic saline injections combined with fatiguing muscle contractions. Intrathecal or intramuscular injection of inhibitors of BDNF-Tropomyosin receptor kinase B (TrkB) signaling, ANA-12 or TrkB-Fc, reduced the decrease in muscle withdrawal thresholds in male, but not in female, mice when given before or 24hr after, but not 1 week after induction of the model. BDNF messenger ribonucleic acid (mRNA) was significantly increased in L4-L6 dorsal root ganglion (DRG), but not the spinal dorsal horn or gastrocnemius muscle, 24hr after induction of the model in either male or female mice. No changes in TrkB mRNA or p75 neurotrophin receptor mRNA were observed. BDNF protein expression via immunohistochemistry was significantly increased in L4-L6 spinal dorsal horn and retrogradely labelled muscle afferent DRG neurons, at 24hr after induction of the model in both sexes. In cultured DRG, fatigue metabolites combined with IL-1ß significantly increased BDNF expression in both sexes. In summary, fatigue metabolites release, combined with IL-1ß, BDNF from primary DRG neurons and contribute to activity-induced muscle pain only in males, while there were no sex differences in the changes in expression observed in BDNF.

Discordance of global assessment between the patients and physicians predicts 9-year pain-related outcomes in rheumatoid arthritis patients.

Introduction: Perspectives regarding the disease state often differ between patients with rheumatoid arthritis (RA) and physicians. The aim of the present longitudinal cohort study was to investigate the impact of the discordance in global assessments between patients and physicians on 9-year pain-related outcomes in patients with rheumatoid arthritis. Method: Sixty-eight consecutive outpatients with rheumatoid arthritis on their first visit to a tertiary center were included. Baseline measurements included demographic data, drugs used, disease activity, and a modified Health Assessment Questionnaire (mHAQ). Discordance in global assessment between patients and physicians at baseline was defined as 10 mm higher in the patient global assessment (PGA) than in the physician global assessment. A 9-year follow-up assessment included pain intensity, the European Quality of Life 5 Dimensions 3 Level (EQ-5D-3L) scale, Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Pain Disability Assessment Scale (PDAS), and Pain Self-Efficacy Questionnaire (PSEQ). Results: The number of patients with discordance was 26 (38%) in 68 patients. Patients with a 10 mm higher PGA than the physician global assessment at baseline measurements had significantly worse pain intensity, PCS score, PSEQ score, and EQ-5D-3L score measurements at the 9-year follow-up than those with concordance. A higher mHAQ score and 10 mm higher PGA at baseline were significantly independently associated with the EQ-5D-3L scale score and pain intensity at the 9-year follow-up. Conclusion: This longitudinal cohort study suggested that discordance in global assessment between patients and physicians modestly predicted worse 9-year pain-related outcomes in patients with rheumatoid arthritis.

Predictors of high-cost patients with acute whiplash-associated disorder in Japan.

INTRODUCTION: The proportion of neck injuries due to traffic accidents is increasing. Little is known about high-cost patients with acute whiplash-associated disorder (WAD). The present study aimed to investigate whether time to first visit for conventional medicine, multiple doctor visits, or alternative medicine could predict high-cost patients with acute WAD in Japan. METHODS: Data from a compulsory, no-fault, government automobile liability insurance agency in Japan between 2014 and 2019 were used. The primary economic outcome was the total cost of healthcare per person. Treatment-related variables were assessed based on the time to first visit for conventional and alternative medicine, multiple doctor visits, and visits for alternative medicine. Patients were categorized according to total healthcare cost (low, medium, and high cost). The variables were subjected to univariate and multivariate analysis to compare high-cost and low-cost patients. RESULTS: A total of 104,911 participants with a median age of 42 years were analyzed. The median total healthcare cost per person was 67,366 yen. The cost for consecutive medicine, for consecutive and alternative medicine, and total healthcare costs were significantly associated with all clinical outcomes. Female sex, being a homemaker, a history of WAD claim, residential area, patient responsibility in a traffic accident, multiple doctor visits, and visits for alternative medicine were identified as independent predictive factors for a high cost in multivariate analysis. Multiple doctor visits and visits for alternative medicine showed large differences between groups (odds ratios 2673 and 694, respectively). Patients with multiple doctor visits and visits for alternative medicine showed a significantly high total healthcare cost per person (292,346 yen) compared to those without (53,587 yen). CONCLUSIONS: A high total healthcare cost is strongly associated with multiple doctor visits and visits for alternative medicine in patients with acute WAD in Japan.

Preoperative Exercise Has a Modest Effect on Postoperative Pain, Function, Quality of Life, and Complications: A Systematic Review and Meta-Analysis.

OBJECTIVE: Preoperative exercise (prehabilitation) is commonly used as a method to reduce pain and improve function postoperatively. The purpose of this systematic review was to determine therapeutic benefits of preoperative exercise on postoperative pain, function, quality of life (QOL), and risk of complications across various types of surgeries. METHODS: Three electronic databases were used to perform a literature search. Full articles with randomized designs comparing a preoperative exercise program vs no formal program were included. The primary outcome was postoperative pain. QOL, function, and postoperative complications were analyzed as secondary outcomes. The primary meta-analysis was performed in those with joint replacement surgery because there were only 5 with other surgical types. RESULTS: A total of 28 articles were included, of which 23 were from individuals with total joint replacement surgery. Preoperative exercise resulted in lower pain ≤2 months and 3 to 5 months after joint replacement surgery with a moderate standardized mean difference (95% CI at <2 months = -0.34 [-0.59 to -0.09]; at 3 to 5 months = -0.41 [-0.70 to -0.11]) compared with nonexercised controls. However, ≥6 months after joint replacement surgery, preoperative exercise groups showed no significant differences in postoperative pain (standardized mean difference = -0.17 [-0.35 to 0.01]) compared with nonexercised controls. QOL and subjective and objective function were improved ≤2 months after joint replacement surgery but were not different ≥6 months post-surgery. Reduction in risk of postoperative complications was favored with preoperative exercise. CONCLUSION: Preoperative exercise has a modest effect on postoperative pain, function, and quality of life within the first 6 months after surgery and reduces the risk of developing postoperative complications in individuals undergoing joint replacement surgery. The effect of preoperative exercise on other surgery types is inconclusive. IMPACT: This systematic review supports using preoperative exercise to improve pain and function outcomes for those with joint replacement surgery.

Standing on the shoulders of bias: lack of transparency and reporting of critical rigor characteristics in pain research.

ABSTRACT: Rigorous experimental design with transparent reporting in biomedical science reduces risk of bias and allows for scientists to judge the quality of the research. Basic factors of rigor such as blinding, randomization, power analysis, and inclusion of both sexes impact the reproducibility by reducing experimental bias. We designed a systematic study to analyze basic factors of rigor, inclusion of sex, and whether data were analyzed or disaggregated by sex over the past 10 years in the journal PAIN . Studies that included humans reported randomization in 81%, blinding in 48%, and the use of a power analysis calculation in 27% over the past 10 years. Studies that included mice reported randomization in 35%, blinding in 70%, and the use of a power analysis in 9%. Studies that included rats reported randomization in 38%, blinding in 63%, and the use of power analysis in 12%. This study also found that human studies consistently included both sexes over the past decade, but less than 20% of data were disaggregated or analyzed for sex differences. Although mouse and rat studies predominately used males only, there has been a slight increase in inclusion of both sexes over the past few years. Justification for single-sex studies was below 50% in both human and rodent data. In both human and animal studies, transparency in reporting of experimental design and inclusion of both sexes should be considered standard practice and will result in improved quality and reproducibility of published research.

P2X7-NLRP3-Caspase-1 signaling mediates activity-induced muscle pain in male but not female mice.

ABSTRACT: We developed an animal model of activity-induced muscle pain that is dependent on local macrophage activation and release of interleukin-1ß (IL-1ß). Activation of purinergic type 2X (P2X) 7 receptors recruits the NOD-like receptor protein (NLRP) 3 and activates Caspase-1 to release IL-1ß. We hypothesized that pharmacological blockade of P2X7, NLRP3, and Caspase-1 would prevent development of activity-induced muscle pain in vivo and release of IL-1ß from macrophages in vitro. The decrease in muscle withdrawal thresholds in male, but not female, mice was prevented by the administration of P2X7, NLRP3, and Caspase-1 inhibitors before induction of the model, whereas blockade of IL-1ß before induction prevented muscle hyperalgesia in both male and female mice. Blockade of P2X7, NLRP3, Capsase-1, or IL-1ß 24 hours, but not 1 week, after induction of the model alleviated muscle hyperalgesia in male, but not female, mice. mRNA expression of P2X7, NLRP3, Caspase-1, and IL-1ß from muscle was increased 24 hours after induction of the model in both male and female mice. Using multiplex, increases in IL-1ß induced by combining adenosine triphosphate with pH 6.5 in lipopolysaccharide-primed male and female macrophages were significantly lower with the presence of inhibitors of P2X7 (A740003), NLRP3 (MCC950), and Caspase-1 (Z-WEHD-FMK) when compared with the vehicle. The current data suggest the P2X7/NLRP3/Caspase-1 pathway contributed to activity-induced muscle pain initiation and early maintenance phases in male but not female, and not in late maintenance phases in male mice.

The impact of sex and physical activity on the local immune response to muscle pain.

Induction of muscle pain triggers a local immune response to produce pain and this mechanism may be sex and activity level dependent. The purpose of this study was to measure the immune system response in the muscle following induction of pain in sedentary and physically active mice. Muscle pain was produced via an activity-induced pain model using acidic saline combined with fatiguing muscle contractions. Prior to induction of muscle pain, mice (C57/BL6) were sedentary or physically active (24hr access to running wheel) for 8 weeks. The ipsilateral gastrocnemius was harvested 24hr after induction of muscle pain for RNA sequencing or flow cytometry. RNA sequencing revealed activation of several immune pathways in both sexes after induction of muscle pain, and these pathways were attenuated in physically active females. Uniquely in females, the antigen processing and presentation pathway with MHC II signaling was activated after induction of muscle pain; activation of this pathway was blocked by physical activity. Blockade of MHC II attenuated development of muscle hyperalgesia exclusively in females. Induction of muscle pain increased the number of macrophages and T-cells in the muscle in both sexes, measured by flow cytometry. In both sexes, the phenotype of macrophages shifted toward a pro-inflammatory state after induction of muscle pain in sedentary mice (M1 + M1/2) but toward an anti-inflammatory state in physically active mice (M2 + M0). Thus, induction of muscle pain activates the immune system with sex-specific differences in the transcriptome while physical activity attenuates immune response in females and alters macrophage phenotype in both sexes.

A comparison of pain, fatigue, and function between post-COVID-19 condition, fibromyalgia, and chronic fatigue syndrome: a survey study.

ABSTRACT: A growing number of individuals report prolonged symptoms following acute Coronavirus-19 (COVID-19) infection, known as post-COVID-19 condition (post-COVID-19). While studies have emerged investigating the symptom sequelae of post-COVID-19, there has been limited investigation into the characterization of pain, fatigue, and function in these individuals, despite initial reports of a clinical phenotype similar to fibromyalgia syndrome (FMS) and chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME). This study aimed to characterize multiple symptom domains in individuals reporting post-COVID-19 and compare its clinical phenotype with those with FMS and CFS. A total of 707 individuals with a single or comorbid diagnosis of post-COVID-19, FMS, and/or CFS completed multiple surveys assessing self-reported pain, fatigue, physical and cognitive function, catastrophizing, kinesiophobia, anxiety, depression, dyspnea, and sleep quality. In all 3 diagnoses, elevated pain, fatigue, anxiety, depression, catastrophizing, and kinesiophobia were reported. Physical and cognitive function were similarly impacted among individuals with post-COVID-19, FMS, and CFS; however, individuals with post-COVID-19 reported lower pain and fatigue than FMS and CFS. The comorbid diagnosis of post-COVID-19 with FMS and/or CFS further exacerbated pain, fatigue, and psychological domains when compared with post-COVID-19 alone. In summary, individuals with post-COVID-19 report a symptom phenotype similar to FMS and CFS, negatively impacting cognitive and physical function, but with less severe pain and fatigue overall. These findings may help direct future investigations of the benefit of a biopsychosocial approach to the clinical management of post-COVID-19.

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

INTRODUCTION: This systematic review aimed to investigate variations of reference scores for the Pain Catastrophizing Scale (PCS) between language versions and between countries in patients with chronic primary pain (CPP) or chronic primary pain, not otherwise specified (CPP-NOS). METHODS: Electronic searches of the Ovid/Embase, Ovid/MEDLINE, and Ovid/PsycINFO databases were conducted to retrieve studies assessing PCS scores in adults with CPP or CPP-NOS proposed by the International Classification of Diseases, Eleventh Revision for any country where the translated PCS was available. The protocol for this systematic review was prospectively registered on the International Prospective Register of Systematic Reviews 2018 (registration number: CRD 42018086719). RESULTS: A total of 3634 articles were screened after removal of duplicates. From these, 241 articles reporting on 32,282 patients with chronic pain were included in the review. The mean (± standard deviation) weighted PCS score across all articles was 25.04 ± 12.87. Of the 12 language versions and 21 countries included in the review, the weighted mean PCS score in Asian languages or Asian countries was significantly higher than that in English, European, and other languages or Western and other countries. The highest mean score of the weighted PCS based on language was in Japanese (mean 33.55), and the lowest was in Russian (mean 20.32). The highest mean score of the weighted PCS based on country was from Japan (mean 33.55), and the lowest was from Australia (mean 19.80). CONCLUSION: The weighted PCS scores for people with CPP or CPP-NOS were significantly higher in Asian language versions/Asian countries than in English, European and other language versions or Western and other countries.

Our previous research has indicated that the clinical significance of the Pain Catastrophizing Scale (PCS) score would vary across different language versions and different countries (Ikemoto et al. in Eur J Pain 2020; 24(7):1228­1241. https://doi.org/10.1002/ejp.1587 ). This systematic review investigated cross-cultural differences in the PCS score between different languages and countries among patients with chronic primary pain. From 241 articles reporting on 32,282 patients with chronic primary pain, involving 12 language versions and 21 countries, the weighted mean PCS score in Asian languages or Asian countries was significantly higher than that in English, European and other languages or Western and other countries. Given the variations of PCS scores in different contexts, a universal comparison PCS reference or a cutoff score should not be used to compare different cultures even when a sample has the same pain condition.

Retronasal Aroma of Beef Pate Analyzed by a Chewing Simulator.

In retronasal aroma, the targeted aroma compounds are released from food during chewing. The changes in the food structures during chewing strongly influence the release of the compounds, therefore affecting the perception of food. Here, the relationship between retronasal aroma and food deliciousness based on the physicochemical properties of aroma compounds was examined. We considered the consumption of solid foods and the effect of oral parameters in elderly people. Beef pate was used as a model food sample to study the effect of the release of aroma compounds under controlled in vitro mastication and salivation conditions using a chewing simulator. We identified the effects of coexisting ingredients such as beef fat on the time course behavior of the release of aroma compounds. In particular, the release of the middle types of aromas was significantly faster with stronger chewing force, and higher with a high fat content of the sample. In addition, a larger release intensity was observed when soy proteins were partially substituted for beef proteins. Using an appropriate model saliva, a change in the salting-out effect from the saliva composition was found to be a factor, which could explain the lowering of aroma sensation in an elderly person.

Odorant metabolism of the olfactory cleft mucus in idiopathic olfactory impairment patients and healthy volunteers.

BACKGROUND: It remains unclear whether the metabolic activity of nasal mucus in the olfactory and respiratory areas is different. Moreover, age- and olfaction-related changes may affect metabolism. METHODS: Hexanal, octanal, and 2-methylbutanal were selected for in vitro metabolism analysis and compared between the olfactory cleft and respiratory mucus of participants < 50-year-old with normal olfaction using gas chromatography mass spectrometry. The metabolic activity of hexanal in the olfactory cleft mucus was further compared between three groups, (1) normal olfaction, age < 50 years old, (2) normal olfaction, age ≥50 years old, and (3) idiopathic olfactory impairment. To characterize the enzyme(s) responsible for aldehyde reduction, we also tested if epalr22897estat and 3,5-dichlorosalicylic acid, types of reductase inhibitors, affect metabolism. RESULTS: Conversion of aldehydes to their corresponding alcohols was observed in the olfactory cleft and respiratory mucus. The metabolic production of hexanol, octanol, and 2-methybutanol was significantly higher in the olfactory cleft mucus than in the respiratory mucus (p < 0.01). The metabolic conversion of hexanal to hexanol in the mucus of the idiopathic olfactory impairment group was significantly lower than that in the age-matched normal olfaction group. Excluding the nicotinamide adenine dinucleotide phosphate (NADPH) regenerating system from the reaction mixture inhibited metabolism. The addition of either epalr22897estat or 3,5-dichlorosalicylic acid did not inhibit this metabolic conversion. CONCLUSIONS: The enzymatic metabolism of odorants in the olfactory cleft mucus is markedly higher than in the respiratory mucus and decreases in patients with idiopathic olfactory impairment.

Weather sensitivity associated with quality of life in patients with fibromyalgia.

BACKGROUND: Fibromyalgia is characterized by chronic widespread pain, and more than half of patients with fibromyalgia report that weather-related variables aggravate their symptoms. However, the differences in actual symptoms have not been measured between those with and without weather sensitivity. The present study aimed to investigate whether weather sensitivity associated with the minimal clinically important difference values of quality of life in patients with fibromyalgia, between those with and without weather sensitivity. METHODS: Sixty-four consecutive outpatients with fibromyalgia on their first visit to our tertiary center were included. Weather sensitivity was measured using self-perceived symptoms. Pain intensity was measured using the 0-10 Numerical Rating Scale (NRS). Quality of life was measured using the Euro Quality of life-5 Dimensions-3 level (EQ-5D-3L) scale. The variables were subjected to univariable and multivariable analysis using the EQ-5D-3L scale. RESULTS: The mean age of the patients was 50 years. Forty-eight patients (75%) were women. The mean EQ-5D-3L score was 0.55. Thirty-seven patients (58%) reported weather sensitivity. In univariable analysis, the welfare recipient, weather sensitivity, and NRS values were associated with EQ-5D-3L scale scores. In multivariable analysis, NRS value and weather sensitivity were independently associated with EQ-5D-3L scale scores. The NRS and EQ-5D-3L scale scores were significantly worse in those with weather sensitivity than those without weather sensitivity. The difference in NRS values was less than 1.5 points between groups. The differences in EQ-5D-3L scale scores were 0.16 points between groups. CONCLUSIONS: Weather sensitivity was significantly associated with quality of life in patients with fibromyalgia. There was an association with weather sensitivity and the minimal clinically important difference values of quality of life in patients with fibromyalgia. The presence of weather sensitivity could have a key role in the quality of life in patients with fibromyalgia.

Changes in visual attentional behavior in complex regional pain syndrome: A preliminary study.

PURPOSE: The purpose of the present study was to investigate the visual attentional behavior towards a pain-affected area and face/body images using eye tracking in complex regional pain syndrome (CRPS) patients. Moreover, we investigated the relationship between visual attentional behavior and clinical symptoms. PATIENTS AND METHODS: Eight female patients with CRPS type 1 in their upper limbs and 8 healthy adult women participated in this study. First, the participants were asked to watch videoclips in a relaxed manner (Videoclip 1 featured young adults who introduced themselves; Videoclip 2 featured young adults touching the hand of the other person sitting across from them with their hand.) Eye movement data were tracked with eye-tracking glasses. RESULTS: In video clip 1, the fixation duration (FD) and fixation count (FC) on faces tended to be lower in CRPS patients than in healthy controls. This tendency was found in patients with low body cognitive distortions. In video clip 2, CRPS patients displayed significantly lower FD and FC on the unaffected hand while watching a video of the unaffected hand being touched compared with healthy controls. Moreover, patients with low body cognitive distortion displayed significantly longer FD on the affected hand. CONCLUSION: Some CRPS patients differed in visual attentional behavior toward the face and body compared with healthy controls. In addition, our findings suggest that patients with lower body cognitive distortion may have a high visual attention for the affected hand, while patients with higher distortion may be neglecting the affected hand.

How Could COVID-19 Change Scholarly Communication to a New Normal in the Open Science Paradigm?

Author reviews digital transformation of scholarly communication since 1990s and explains how COVID-19 is accelerating open science, with some analogy of chemical reactions. Discussing the current situation of preprint, the potential of peer review, and the essence of open science, developing additional services and balancing incremental and innovation in the transition state is crucial to foster new trust among stakeholders.

Impact of Non-steroidal Anti-inflammatory Drug Administration for 12 Months on Renal Function.

Background: The use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of renal complications. Resolution of renal adverse effects after NSAID administration has been observed after short-term use. Thus, the present study aimed to investigate a series of patients with chronic musculoskeletal pain who underwent long-term NSAID administration followed by switching to tramadol hydrochloride/acetaminophen (TA) combination tablets to study the impact of NSAID-induced renal adverse effects. Methods: This was a longitudinal retrospective study of 99 patients with chronic musculoskeletal pain. The patients were administrated with NSAIDs daily during the first 12 months, followed by daily TA combination tablets for 12 months. Estimated glomerular filtration rate (eGFR) and serum levels of aspartate aminotransferase and alanine transaminase were measured at baseline, after NSAID administration and after TA administration. Results: eGFR was significantly reduced after 12-month NSAID administration (median, from 84.0 to 72.8 ml/min/1.73 m2), and the reduction was not shown after the subsequent 12-month TA administration (median, 71.5 ml/min/1.73 m2). Reduction in eGFR was less in patients who received celecoxib (median, -1.8 ml/min/1.73 m2) during the first 12 months. There was no significant difference in aspartate aminotransferase and alanine transaminase in each period. Conclusions: Thus, patients receiving NSAIDs for 12 months displayed both reversible and irreversible reduction of eGFR upon cessation of NSAIDs and switching to TA. Our data highlight the potential safety benefit of utilizing multimodal analgesic therapies to minimize the chronic administration of NSAIDs.

Arylene-hexaynylene and -octaynylene macrocycles: extending the polyyne chains drives self-association by enhanced dispersion force.

Tetraalkoxyphenanthrylene-hexaynylene and -octaynylene macrocycles, which represent the first examples of isolable arylene-alkynylene macrocycles (AAMs) that contain polyyne chains longer than tetrayne, were synthesized and their self-association behavior was examined. Extending the polyyne chain from diyne to tetrayne, hexayne, and octayne exponentially increased the self-association constant of the macrocycles.

Feasibility of Imported Self-Management Program for Elderly People with Chronic Pain: A Single-Arm Confirmatory Trial.

INTRODUCTION: Multidisciplinary pain management programs incorporating a cognitive-behavioral therapy (CBT) approach have been reported to be helpful for elderly people with chronic pain. However, it is unclear whether the same program for elderly people with chronic pain would translate to different cultures. This study investigated whether a multidisciplinary program based on that of Nicholas et al. (Pain 154(6):824-835, 2013) in Australia would be effective for elderly people with chronic pain in Japan. METHODS: Twenty-seven community-dwelling elderly people with chronic pain were enrolled to confirm changes (effect size d = 0.5) in pain disability, which were previously reported by Nicholas et al. The multidisciplinary program consisted of eight sessions (2 sessions a week for 4 weeks). Pain disability was assessed using the Pain Disability Assessment Scale (PDAS) as the primary outcome at the baseline, the beginning and the end of the program, and the 1- and 3-month (final) follow-up. We also assessed the pain severity, catastrophizing, pain self-efficacy, and physical function with the Timed Up and Go test (TUG) and the two-step test as secondary outcomes. RESULTS: PDAS, pain catastrophizing, and pain self-efficacy were significantly improved immediately after the program compared with baseline, and these effects were maintained at 3-month follow-up. The effect size (d) for the PDAS score was a medium size (0.54) from baseline to 3-month follow-up. Those who showed improvements in TUG immediately after the program tended to report improved psychometric measures at 3-month follow-up. CONCLUSION: These results suggest that the Japanese multidisciplinary program has a similar effect on pain disability as that reported by Nicholas et al. This finding has important implications for the development of pain services in community-dwelling elderly Japanese.

Difference in eye movements during gait analysis between professionals and trainees.

INTRODUCTION: Observational gait analysis is a widely used skill in physical therapy. Meanwhile, the skill has not been investigated using objective assessments. The present study investigated the differences in eye movement between professionals and trainees, while observing gait analysis. METHODS: The participants included in this study were 26 professional physical therapists and 26 physical therapist trainees. The participants, wearing eye tracker systems, were asked to describe gait abnormalities of a patient as much as possible. The eye movement parameters of interest were fixation count, average fixation duration, and total fixation duration. RESULTS: The number of gait abnormalities described was significantly higher in professionals than in trainees, overall and in limbs of the patient. The fixation count was significantly higher in professionals when compared to trainees. Additionally, the average fixation duration and total fixation duration were significantly shorter in professionals. Conversely, in trunks, the number of gait abnormalities and eye movements showed no significant differences between groups. CONCLUSIONS: Professionals require shorter fixation durations on areas of interest than trainees, while describing a higher number of gait abnormalities.

A systematic review of cross-cultural validation of the pain catastrophizing scale.

BACKGROUND: Although it has been suggested that the different cultural and social environments between countries contribute to variations in pain catastrophizing (PC), an international comparison of PC in patients with chronic pain has not yet been reported. Prior to undertaking this comparison, a cross-cultural assessment of the pain catastrophizing scale (PCS) was undertaken to explore the different factor structures among each translated version of the PCS. METHODS: The protocol for this systematic review was prospectively registered on International Prospective Register of Systematic Reviews 2018 (CRD 42018086719). Electronic searches were conducted in the following databases: Ovid/Embase, Ovid/MEDLINE and Ovid/PsycINFO, and then 19 articles (16 language versions) were included in this review. Based on the COSMIN check list, we investigated language translation followed by five domains of cross-cultural validation: structural validity, internal consistency, test-retest reliability and hypotheses testing for construct validity in each study. RESULTS: We found that (a) there were inconsistent structural models among each translated version, leading to variant subdomain structures for rumination, magnification and helplessness; (b) all languages versions showed sufficient internal consistency when assessing whole items and (c) the correlation coefficients between pain intensities and total scores of the PCS among each sample of chronic pain varied across the studies. CONCLUSIONS: These results indicate that the total score of the PCS could be compared across each translated version, however, caution is warranted when each subdomain of the PCS is compared between countries. SIGNIFICANCE: Although the pain catastrophizing scale has been translated into approximately 20 languages, methodological quality during their translation process has not been systematically assessed. We found that all languages versions showed sufficient internal consistency when assessing whole items, however, there were inconsistent structural models among each translated version, leading to variant subdomain structures for rumination, magnification and helplessness.

Associations between the injustice experience questionnaire and treatment term in patients with acute Whiplash-associated disorder in Japan: Comparison with Canadian data.

INTRODUCTION: This study aimed to investigate the differences in the Injustice Experience Questionnaire (IEQ) scores during the early period after the diagnosis of Whiplash-associated disorder (WAD) between Japanese and Canadian samples, and the associations between the IEQ scores and treatment terms in Japanese patients with acute WAD. METHODS: We used secondary data for the IEQ scores of Canadian patients with acute WAD. In Japan, we collected data from 85 consecutively enrolled patients with acute WAD, and their treatment terms were collected; these referred to the number of days between the date of injury and the closure date of the insurance claim and the number of treatment visits. Before treatment, the Numeric Rating Scale, Neck Disability Index, Hospital Anxiety and Depression Scale, IEQ, and Euro Quality of Life five-dimensional questionnaire were administered. The variables were subjected to multivariate analysis with each treatment term. RESULTS: The IEQ scores were higher in Japan than in Canada. Through multiple regression analysis, IEQ scores were independently correlated with treatment terms. The optimal cutoff point of the IEQ scores for a prolonged treatment term was 21 and 22 points, respectively. CONCLUSIONS: The IEQ scores were associated with treatment terms in patients with acute WAD in Japan.