European Journal of Pain最新文献

{"title":"Explorative sensory profile evaluation in central neuropathic pain following spinal cord injury.","authors":"G Landmann, M Ernst, E Opsommer, L Stockinger, J Vollert, R Baron","doi":"10.1002/ejp.4719","DOIUrl":"https://doi.org/10.1002/ejp.4719","url":null,"abstract":"<p><strong>Background: </strong>Sensory profiling in neuropathic pain using quantitative sensory testing (QST) has not been extended to central neuropathic pain due to spinal cord injury (SCI). This study aims to fill this gap by evaluating sensory profiles in patients with neuropathic SCI pain.</p><p><strong>Method: </strong>We retrospectively analysed consecutive QST data from 62 patients with neuropathic spinal cord injury pain (SCIP), following the German Research Network on Neuropathic Pain protocol. The study included at-level and below-level SCIP due to a spinal cord lesion, and at-level SCIP following a cauda equina lesion. QST parameters were compared between diagnostic groups. QST profiles of below-level SCIP (central neuropathic pain) were manually assigned to sensory phenotypes based on literature and expert opinion.</p><p><strong>Results: </strong>No statistical difference in QST parameters between pain diagnoses was found. For central neuropathic pain (below-level SCIP), three phenotypes were descriptively observed: loss of function (59%), thermal and mechanical hyperalgesia combination (16%), and mechanical hyperalgesia (19%). The remaining 5% of patients did not fit a common pattern. There was no statistical difference in clinical and psychological variables between phenotypes. In a subgroup analysis, the loss of function phenotype weakly correlated with older age, longer time since injury, and longer pain duration.</p><p><strong>Conclusions: </strong>Here, we capture sensory phenotypes of central neuropathic pain following SCI. The limited sample size, high rate of missing values, and the retrospective nature of the study mean that results should be seen as strictly exploratory. Further research should replicate these findings and explore the significance of phenotypes.</p><p><strong>Significance statement: </strong>The evaluation of sensory phenotypes by quantitative sensory testing in central neuropathic pain due to SCI adds a new perspective on sensory phenotypes in comparison to peripheral neuropathic pain. The described thermal and mechanical hyperalgesia combination might represent involvement of the spinothalamic tract. In addition, there was a trend towards older age and longer time since injury in patients with loss of function.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142105815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Painful stimulation increases functional connectivity between supplementary motor area and thalamus in patients with small fibre neuropathy.","authors":"Sebastian Scheliga, Maike F Dohrn, Thilo Kellermann, Angelika Lampert, Roman Rolke, Barbara Namer, Greta Z Peschke, Nortje van den Braak, Annette Lischka, Marc Spehr, Han-Gue Jo, Ute Habel","doi":"10.1002/ejp.4720","DOIUrl":"https://doi.org/10.1002/ejp.4720","url":null,"abstract":"<p><strong>Background: </strong>The lead symptom of small fibre neuropathy (SFN) is neuropathic pain. Recent functional magnetic resonance imaging (fMRI) studies have indicated central changes in SFN patients of different etiologies. However, less is known about brain functional connectivity during acute pain processing in idiopathic SFN.</p><p><strong>Methods: </strong>We conducted fMRI with thermal heat pain application (left volar forearm) in 32 idiopathic SFN patients and 31 healthy controls. We performed functional connectivity analyses with right supplementary motor area (SMA), left insula, and left caudate nucleus (CN) as seed regions, respectively. Since pathogenic gain-of-function variants in voltage gated sodium channels (Nav) have been linked to SFN pathophysiology, explorative connectivity analyses were performed in a homogenous subsample of patients carrying rare heterozygous missense variants.</p><p><strong>Results: </strong>For right SMA, we found significantly higher connectivity with the right thalamus in SFN patients compared to controls. This connectivity correlated significantly with intraepidermal nerve fibre density, suggesting a link between peripheral and central pain processing. We found significantly reduced connections between right SMA and right middle frontal gyrus in patients with Nav variants. Likewise, connectivity between left CN and right frontal pole was decreased.</p><p><strong>Conclusions: </strong>Aberrant functional connectivity in SFN is in line with previous research on other chronic pain syndromes. Functional connectivity changes may be linked to SFN, highlighting the need to determine if they result from peripheral changes causing abnormal somatosensory processing. This understanding may be crucial for assessing their impact on painful symptoms and therapy response.</p><p><strong>Significance statement: </strong>We found increased functional connectivity between SMA and thalamus during painful stimulation in patients with idiopathic SFN. Connectivity correlated significantly with intraepidermal nerve fibre density, suggesting a link between peripheral and central pain processing. Our findings emphasize the importance of investigating functional connectivity changes as a potential feature of SFN.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142079741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ART26.12, a novel fatty acid-binding protein 5 inhibitor, shows efficacy in multiple preclinical neuropathy models.","authors":"W G Warren, M Osborn, A David-Pereira, C Tsantoulas, Wenwen Xue, A Yates, S E OSullivan","doi":"10.1002/ejp.4718","DOIUrl":"https://doi.org/10.1002/ejp.4718","url":null,"abstract":"<p><strong>Background: </strong>Painful neuropathy is a pathological condition caused by numerous factors including diabetes, chemotherapy or cancer. ART26.12 is a novel fatty acid-binding protein 5 inhibitor, which our group showed could prevent and treat persistent pain in a preclinical model of oxaliplatin-induced peripheral neuropathy.</p><p><strong>Methods: </strong>In the current study, the efficacy of orally dosed ART26.12 was tested in multiple neuropathy models of different aetiology. Paw withdrawal threshold to von Frey monofilaments and latency to escape a cold plate were used as measurements of mechanical and cold sensitivity.</p><p><strong>Results: </strong>ART26.12 (25 and 50 mg/kg BID), dosed prior to the induction of paclitaxel-induced peripheral neuropathy (PIPN), reversed mechanical allodynia induced by paclitaxel in both male and female rats, and ART26.12 (50 mg/kg BID) prevented the induction of PIPN in female rats. ART26.12 (50 mg/kg BID) also had a protective effect on body weight in the PIPN model. ART26.12 (25 and 100 mg/kg BID) reversed mechanical allodynia when treating established streptozotocin-induced diabetic neuropathy in male rats. In a model of breast cancer-induced bone pain in female rats, ART26.12 (100 mg/kg BID) reversed mechanical allodynia within 1 h of dosing. In the same model, ART26.12 (25 mg/kg BID) reversed mechanical allodynia from day 4 of treatment.</p><p><strong>Conclusion: </strong>Overall, these preclinical data suggest that ART26.12 is a safe and efficacious therapeutic drug for continued development towards the prevention and treatment of peripheral neuropathy.</p><p><strong>Significance statement: </strong>This work now shows that ART26.12, a novel and selective inhibitor of FABP5, can prevent and treat multiple preclinical models of peripheral neuropathy. Given its excellent safety profile, further work is warranted to develop ART26.12 as a potential therapeutic tool for pain management.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142072403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pain catastrophizing and trunk co-contraction during lifting in people with and without chronic low back pain: A cross sectional study.","authors":"Patrick Ippersiel, Richard Preuss, Byungjin Kim, Cristina Giannini, Shawn M Robbins","doi":"10.1002/ejp.4717","DOIUrl":"https://doi.org/10.1002/ejp.4717","url":null,"abstract":"<p><strong>Background: </strong>Trunk co-contraction during lifting may reflect a guarded motor response to a threatening task. This work estimated the impact of pain catastrophizing on trunk co-contraction during lifting, in people with and without low back pain.</p><p><strong>Methods: </strong>Adults with high pain catastrophizing (back pain: n = 29, healthy: n = 7) and low pain catastrophizing (back pain: n = 20, healthy: n = 11), performed 10 repetitions of a lifting task. Electromyography data of rectus abdominis, erector spinae and external oblique muscles were collected, bilaterally. Co-contraction indices were determined for rectus abdominis/erector spinae and external oblique/erector spinae pairings, bilaterally. Pain catastrophizing was measured using the pain catastrophizing scale and task-specific fear using the Photograph series of daily activities scale. Three-way mixed ANOVAs tested the effects of group (back pain vs. healthy), pain catastrophizing (high vs. low), lifting phase (lifting vs. replacing) and their interactions.</p><p><strong>Results: </strong>There were no main effects of pain catastrophizing, lifting phase, nor any interactions (p > 0.05). Group effects revealed greater co-contraction for bilateral erector spinae/rectus abdominis pairings (but not erector spinae-external oblique pairings) in people with back pain, compared to healthy participants, independent of pain catastrophizing and lifting phase (p < 0.05). Spearman correlations associated greater task-specific fear and greater erector spinae-left external oblique co-contraction, only in people with back pain (p < 0.05).</p><p><strong>Conclusions: </strong>Greater co-contraction in the back pain group occurred independent of pain catastrophizing, as measured with a general questionnaire. A task-specific measure of threat may be more sensitive to detecting relationships between threat and co-contraction.</p><p><strong>Significance statement: </strong>This work contributes evidence that people with back pain commonly exhibit trunk co-contraction when lifting. The lack of a relationship between pain catastrophizing and trunk co-contraction, however, challenges evidence linking psychological factors and guarded motor behaviour in this group. Together, this suggests that other factors may be stronger determinants of co-contraction in people with LBP or that a general construct like pain catastrophizing may not accurately represent this relationship.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mindfulness-based stress reduction for chronic pain: Enhancing psychological well-being without altering attentional biases towards pain faces.","authors":"Elena Robles, Iván Blanco, Gustavo Díez, Carmelo Vázquez","doi":"10.1002/ejp.4714","DOIUrl":"https://doi.org/10.1002/ejp.4714","url":null,"abstract":"<p><strong>Introduction: </strong>This study examines the effects of a Mindfulness-Based Stress Reduction (MBSR) program on psychological measures and attentional patterns to pain stimuli, using eye-tracking methods, in individuals with chronic pain.</p><p><strong>Method: </strong>Thirty-two participants with chronic pain and no prior mindfulness experience were randomly assigned to an experimental group or a waiting list group. Both groups completed self-report measures of symptoms, well-being, and an attentional disengagement task using emotional faces as stimuli. Assessments were conducted at two points: before and after the intervention for the experimental group, with the waiting list group serving as a control.</p><p><strong>Results: </strong>Before the MBSR program, chronic pain participants exhibited significant attentional biases towards pain-related stimuli during early attentional stages. Following the program, significant improvements were observed in depression, anxiety, stress, pain acceptance, overall well-being, and life satisfaction. However, it had a limited impact on attentional patterns, with only a significant increase in gaze duration across all stimuli.</p><p><strong>Discussion: </strong>Despite the MBSR program's success in reducing symptoms associated with chronic pain, the lack of broader attentional improvements raises questions about the mechanisms responsible for psychological improvements.</p><p><strong>Significance statement: </strong>This study pioneers the use of eye-tracking to examine how MBSR influences attention in chronic back pain. While the program improved psychological well-being, it did not generally alter attentional patterns, except for an increased ability to maintain attention across stimuli. We discuss whether this attentional change could be associated with the increased acceptance observed in the MBSR program.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does pain influence control of muscle force? A systematic review and meta-analysis.","authors":"Michail Arvanitidis, Deborah Falla, Andy Sanderson, Eduardo Martinez-Valdes","doi":"10.1002/ejp.4716","DOIUrl":"https://doi.org/10.1002/ejp.4716","url":null,"abstract":"<p><strong>Background and objective: </strong>In the presence of pain, whether clinical or experimentally induced, individuals commonly show impairments in the control of muscle force (commonly known as force steadiness). In this systematic review and meta-analysis, we synthesized the available evidence on the influence of clinical and experimental pain on force steadiness.</p><p><strong>Databases and data treatment: </strong>MEDLINE, EMBASE, PubMed, CINAHL Plus and Web of Science databases were searched from their inception to 19 December 2023, using MeSH terms and pre-selected keywords related to pain and force steadiness. Two independent reviewers screened studies for inclusion and assessed their methodological quality using a modified Newcastle-Ottawa risk of bias tool.</p><p><strong>Results: </strong>In total, 32 studies (19 clinical pain and 13 experimental pain) were included. Meta-analyses revealed reduced force steadiness in the presence of clinical pain as measured by the coefficient of variation (CoV) and standard deviation (SD) of force (standardized mean difference; SMD = 0.80, 95% CI = 0.31-1.28 and SMD = 0.61, 95% CI = 0.11-1.11). These findings were supported by moderate and low strength of evidence respectively. In the presence of experimental pain, meta-analyses revealed reductions in force steadiness when measured by the CoV of force but not by the SD of force (SMD = 0.50, 95% CI = 0.01-0.99; and SMD = 0.44, 95% CI = -0.04 to 0.92), each supported by very low strength of evidence.</p><p><strong>Conclusions: </strong>This work demonstrates that pain, particularly clinical pain, impairs force steadiness. Such impairments likely have clinical relevance and could become targets for treatment when managing people experiencing musculoskeletal pain.</p><p><strong>Significance statement: </strong>This systematic review and meta-analyses enhances our understanding of motor impairments observed in people experiencing musculoskeletal pain. It underscores the significance of incorporating force steadiness assessment when managing individuals experiencing musculoskeletal pain. Additionally, it suggests that future research should explore the potential benefits of force steadiness training in alleviating patients' symptoms and enhancing their functional performance. This could potentially lead to the development of innovative therapeutic approaches for individuals suffering from musculoskeletal pain.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142035559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on ‘A sham-controlled, randomized trial of spinal cord stimulation for the treatment of pain in chronic pancreatitis’ by Gulisano et al.","authors":"Jan Willem Kallewaard,&nbsp;Rui V. Duarte,&nbsp;Sam Eldabe,&nbsp;Simon Thomson","doi":"10.1002/ejp.4715","DOIUrl":"10.1002/ejp.4715","url":null,"abstract":"&lt;p&gt;We read with interest the sham-controlled randomized trial of spinal cord stimulation (SCS) to assess pain response in patients with chronic pancreatitis (Gulisano et al., &lt;span&gt;2024&lt;/span&gt;). We are grateful to and applaud the authors' efforts who have conducted a challenging study in a population not routinely considered for SCS and for which there is scarce evidence on the use of this intervention, limited to case reports and small case series (Bieze et al., &lt;span&gt;2024&lt;/span&gt;). Despite the authors' best efforts and unquestionable value of this addition to the SCS literature, we have some concerns with the study that should be highlighted.&lt;/p&gt;&lt;p&gt;We are unaware of any studies that evaluated high-frequency SCS (1000 Hz or other) in patients with chronic pancreatitis and as such its efficacy for this population is unknown. Besides the ability to produce paraesthesia-free stimulation and therefore enable patient blinding, we are unsure as to why this frequency was selected by the authors if no evidence of potential effect was previously available. We would also query whether stimulation at 75% subthreshold of sensation would be as effective as at the level of or above sensation threshold. A main limitation of the current evidence base of SCS and sham-controlled trials is that spinal cord fibre activation has not been evaluated; how is it possible to determine if what the patients received was actually an ‘active intervention’ if it was not confirmed whether spinal cord activation occurred (Mekhail et al., &lt;span&gt;2024&lt;/span&gt;)?&lt;/p&gt;&lt;p&gt;We note there was no eligibility criterion for baseline pain intensity. An entry criterion of ≥4 for chronic pain clinical trials has been recommended (Langford et al., &lt;span&gt;2023&lt;/span&gt;). The baseline pain score in Gulisano et al. was 5.2 ± 1.9 and while we acknowledge that patients with pain intensity levels ≥5 are considered for SCS in routine clinical practice, these baseline scores are considerably lower than previous reports in the same population (Bieze et al., &lt;span&gt;2024&lt;/span&gt;) or SCS studies in a neuropathic pain population evaluated in sham-controlled trials (Duarte et al., &lt;span&gt;2020&lt;/span&gt;). Despite already low pain intensity levels at baseline, patients in the study reported approximately 40% reduction in pain intensity during the open-label extension to 12-month follow-up. This reduction represents a clinically meaningful change and as the authors mention, larger than a 20% response observed during sham-controlled phases of pain therapies. Due to the limited evidence of SCS in this population, it would be of interest to understand if clinically meaningful improvements were also observed in other patient-reported outcomes measures collected (Levy et al., &lt;span&gt;2023&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;We note that after anatomical positioning and on-table testing of paraesthesia pain mapping topography, the stimulation was left ‘activated’ until the next day. Only following confirmation of adequate mapping and x-ray position wa","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejp.4715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vicarious facilitation of facial responses to pain: Does the others' expression need to be painful?","authors":"Peter J Göller, Philipp Reicherts, Stefan Lautenbacher, Miriam Kunz","doi":"10.1002/ejp.4709","DOIUrl":"https://doi.org/10.1002/ejp.4709","url":null,"abstract":"<p><strong>Introduction: </strong>Prior exposure to others' facial expressions of pain can lead to a facilitation of pain responses, including its corresponding response channel, namely facial responses to pain. It has been questioned, however, whether this vicarious pain facilitation occurs only when observing others' pain or whether the observation of other negative expressions can trigger similar facilitation of facial responses to pain. The study aimed to test this, by comparing the impact of viewing others' facial expressions of pain versus another negative expression (sadness) and two control expressions (neutral, happiness) on facial responses to pain.</p><p><strong>Method: </strong>Participants (N = 56; 31 females), watched short video clips of computer-generated facial expressions (pain, sadness, neutral & happiness) before they received painful and non-painful heat stimuli. Facial responses were analysed using the Facial Action Coding System. In addition, subjective and autonomic responses were assessed.</p><p><strong>Results: </strong>The prior exposure to others' expressions of pain and sadness versus neutral did not lead to significantly increased facial responses to pain. Likewise, subjective and autonomic pain responses were not facilitated. However, viewing others' expressions of happiness, consistently reduced facial as well as subjective and autonomic responses to pain compared to others' negative or neutral expressions. This dampening effect was not observed for non-painful heat.</p><p><strong>Discussion: </strong>Facial and other pain responses were most strongly affected by prior exposure to others' facial expressions of happiness, which led to a pain-dampening effect. In contrast, the evidence for vicarious facilitation of pain was rather weak in the present study, with no evidence of pain-specificity.</p><p><strong>Significance statement: </strong>Facial responses to pain - along with subjective and autonomic responses - are reduced when observing others' expressions of happiness, demonstrating pain modulation by positive affective social signals, which may also transfer to clinical contexts.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141987705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Central sensitization inventory is associated with psychological functioning but not with psychophysical assessment of pain amplification.","authors":"Rafaela Stocker Salbego, Paulo César Rodrigues Conti, Flávia Fonseca Carvalho Soares, Dyna Mara Araújo Oliveira Ferreira, Matheus Herreira-Ferreira, Beatriz Amaral de Lima-Netto, Yuri Martins Costa, Leonardo Rigoldi Bonjardim","doi":"10.1002/ejp.4713","DOIUrl":"https://doi.org/10.1002/ejp.4713","url":null,"abstract":"<p><strong>Background: </strong>The central sensitization inventory (CSI) is a questionnaire that has been widely used as a tool for assessing symptoms associated with sensitization. However, its ability to identify individuals with this phenomenon has recently been questioned. The aim of this study was to assess the correlation of CSI with psychosocial and psychophysical factors in patients with painful TMD diagnosed according to diagnostic criteria for temporomandibular disorders (DC/TMD) and asymptomatic controls, as well as to determine the influence of these variables on the CSI scores variations.</p><p><strong>Methods: </strong>This cross-sectional study with 77 patients diagnosed with painful TMD according to DC/TMD and 101 asymptomatic controls realized correlations between CSI, WUR, PPT, CPM and psychosocial questionnaires (HADS, PSQI, PCS and PSS). In cases where significant correlations existed, the potential influence of these variables on CSI variation was explored through linear regression analysis.</p><p><strong>Results: </strong>It has been found that the CSI correlates with psychosocial variables (anxiety, depression, catastrophizing, sleep and stress) (p < 0.0006) regardless of the presence of TMD, and that 68.9% of the variation in CSI scores can be influenced by all these variables (except stress). On the contrary, the CSI does not correlate with psychophysical parameters indicative of pain amplification (wind-up ratio and conditioned pain modulation) (p > 0.320).</p><p><strong>Conclusion: </strong>CSI is more associated with psychosocial factors than with more robust indicators of probable central sensitization (CS), thus limiting its utility in detecting this phenomenon both in TMD patients and healthy individuals.</p><p><strong>Significance statement: </strong>The research highlights a noteworthy relationship between the central sensitization inventory and psychological factors, emphasizing their substantial influence on inventory values. This correlation offers crucial insights into mental health markers within the questionnaire. Additionally, the lack of connection with pain amplification implies a necessary re-evaluation of the inventory's diagnostic suitability, especially in cases of painful temporomandibular disorders. Thus, caution is urged in its application for identifying CS in these individuals.</p>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141906286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topical capsaicin modulates the two-point discrimination threshold—Modulation depends on stimulation modality and intensity","authors":"Ken Steffen Frahm,&nbsp;Ole Kæseler Andersen,&nbsp;Lars Arendt-Nielsen,&nbsp;Sabata Gervasio,&nbsp;Carsten Dahl Mørch","doi":"10.1002/ejp.4701","DOIUrl":"10.1002/ejp.4701","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Spatial acuity concerns the ability to localize and discriminate sensory input and is often tested using the two-point discrimination threshold (2PDT). Sensitization of the pain system can affect the spatial acuity, but it is unclear how 2PDTs of different testing modalities are affected. The aim was to investigate if the 2PDTs for mechanical and heat stimulation at different intensities were modulated by topical capsaicin sensitization.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>30 healthy subjects were divided into either a capsaicin or a placebo group. The 2PDT was tested using two different modalities, mechanical and thermal (laser) delivered at innocuous and noxious intensities. The 2PDT were determined at baseline and re-assessed 48 h later. In the follow-up session, the subjects either had a capsaicin patch (8%) or placebo patch placed in the testing area for 30 min before re-testing the 2PDT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The 2PDT was highly dependent on stimulation modality and intensity. The lowest 2PDT was found for innocuous mechanical stimuli (40.0 mm, 95% CI 38.1–41.9 mm), and the highest 2PDT was found for innocuous thermal stimuli (81.7 mm, 95% CI 73.9–89.5 mm). Topical capsaicin generally increased the 2PDT, but this was only significant for innocuous mechanical stimuli. The perceived intensity of the stimuli was increased following capsaicin and was generally higher for noxious stimuli than for innocuous stimuli (ANOVA, <i>p</i> &lt; 0.001).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study showed that capsaicin provoked pain sensitization increased the 2PDT. The 2PDT tested using innocuous mechanical stimuli showed less variable results indicating that this test is most suitable to detect this aspect of spatial acuity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Significance Statement</h3>\u0000 \u0000 <p>This study investigated how the two-point discrimination threshold (2PDT) can be modulated by topical capsaicin. The 2PDT was assessed for two different modalities (thermal and mechanical) and for two different intensities (innocuous and noxious) before and after capsaicin. The results showed that the 2PDT was generally impaired following capsaicin, but this was only significant for mechanical innocuous stimuli. Furthermore, it was shown that mechanical innocuous stimuli assessed the 2PDT with lower variability than other combinations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":12021,"journal":{"name":"European Journal of Pain","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejp.4701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141906287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}