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Purpose: In patients with urologic chronic pelvic pain syndrome (UCPPS), the presence of widespread pain appears to identify a distinct phenotype, with a different symptom trajectory and potentially different response to treatment than patients with pelvic pain only., Materials and Methods: A 76-site body map was administered four times, at weekly intervals, to 568 male and female UCPPS participants in the MAPP Network protocol. The 76 sites were classified into 13 regions (1 pelvic region and 12 nonpelvic regions). The degree of widespread pain was scored from 0 to 12 based on the number of reported nonpelvic pain regions. This continuous body map score was regressed over other measures of widespread pain, with UCPPS symptom severity, and with psychosocial variables to measure level of association. These models were repeated using an updated body map score (0-12) that incorporated a threshold of pain ≥ 4 at each site., Results: Body map scores showed limited variability over the 4 weekly assessments, indicating that a single baseline assessment was sufficient. The widespread pain score correlated highly with other measures of widespread pain and correlated with worsened UCPPS symptom severity and psychosocial functioning. Incorporating a pain severity threshold ≥4 resulted in only marginal increases in these correlations., Conclusions: These results support the use of this 13-region body map in the baseline clinical assessment of UCPPS patients. It provides reliable data about the presence of widespread pain and does not require measurement of pain severity, making it relatively simple to use for clinical purposes., (© 2024 The Authors. Neurourology and Urodynamics published by Wiley Periodicals LLC.)

Objectives: Cannabis is increasingly being used for chronic pain management, but cannabis' effects remain poorly characterized in chronic nociplastic pain (NPP), which is posited to be caused by disturbances in nervous system pain processing. In this cross-sectional study (n=1213), we used the 2011 Fibromyalgia (FM) Survey Criteria as a surrogate measure for degree of NPP among individuals using medical cannabis for chronic pain., Methods: Using a quartile-split, we investigated associations between the degree of NPP and medication use, cannabis use characteristics, and symptom relief. Continuous variables were assessed using one-way analysis of variance and categorical variables with Pearson χ 2 test and binomial logistic regression for calculation of odds ratios., Results: Participants were predominately female (59%), with a mean ± SD age of 49.4±13.6 years. Higher FM scores were associated with less self-reported improvement in pain and health since initiating medical cannabis use, as well as more cannabis-related side effects. Paradoxically, higher FM scores were also associated with higher usage of concomitant medication use (including opioids and benzodiazepines) but also with substituting cannabis for significantly more medication classes, including opioids and benzodiazepines., Discussion: This article presents evidence that individuals in higher NPP quartiles have higher analgesic intake, higher odds of substituting cannabis for medications, higher side effect burden, and lower therapeutic effect from cannabis. These seemingly contradictory findings may reflect higher symptom burden, polypharmacy at baseline, or that NPP may be challenging to treat with cannabis. Further research is necessary to further explain cannabinoid effects in NPP., Competing Interests: K.F.B. sits on a Data Safety and Monitoring Committee for Vireo Health (unpaid). D.A.W. has consulted for Swing Therapeutics, Inc., and Community Health Focus, Inc. E.L. is Chief Medical Officer at and co-owner of Om of Medicine, a medical cannabis provisioning center in Ann Arbor, MI. S.S. leads the Scottsdale Research Institute, has received funding from the Multidisciplinary Association for Psychedelic Studies, and is a member of the Steering Committee/Entrepreneurship and Social Initiative Impact Advisor Board for the Lambert Center for the Study of Medicinal Cannabis and Hemp. D.J.C. has consulted for Pfizer, Inc., Eli Lilly and Co., Tonix Pharmaceuticals, Aptinyx, Regeneron, IMC, and Intec. The remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Chronic pain has economic costs on par with cardiovascular disease, diabetes, and cancer. Despite this impact on the health care system and increasing awareness of the relationship between pain and mortality, efforts to identify simple symptom-based risk factors for the development of pain, particularly in children, have fallen short. This is critically important as pain that manifests during childhood often persists into adulthood. To date, no longitudinal studies have examined symptoms in pain-free children that presage a new, multisite manifestation of pain in the future. We hypothesized that female sex, sleep problems, and heightened somatic symptoms complaints at baseline would be associated with the risk of developing new multisite pain 1 year later., Methods: Symptom assessments were completed by parents of youth (ages 9 to 10) enrolled in the Adolescent Brain Cognitive Development study. Multivariate logistic regression models focused on children who developed multisite pain 1 year later (n=331) and children who remained pain free (n=3335)., Results: Female sex (odds ratio [OR]=1.35; 95% CI, 1.07, 1.71; P =0.01), elevated nonpainful somatic symptoms (OR=1.17; 95% CI, 1.06, 1.29; P <0.01), total sleep problems (OR=1.20; 95% CI, 1.07, 1.34; P <0.01), and attentional issues (OR=1.22; 95% CI, 1.10, 1.35; P <0.001) at baseline were associated with new multisite pain 1 year later. Baseline negative affect was not associated with new multisite pain., Discussion: Identifying symptom-based risk factors for multisite pain in children is critical for early prevention. Somatic awareness, sleep and attention problems represent actionable targets for early detection, treatment, and possible prevention of multisite pain in youth., Competing Interests: The authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Urologic chronic pelvic pain syndrome (UCPPS) is a complex, debilitating condition in which patients often report nonpelvic pain in addition to localized pelvic pain. Understanding differential predictors of pelvic pain only vs widespread pain may provide novel pathways for intervention. This study leveraged baseline data from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network's Symptom Pattern Study to investigate the impact of childhood sexual and nonsexual violent trauma on pelvic and nonpelvic pain sensitivity among adult patients with UCPPS, as well as potential mediators of this association. Study participants who met inclusion criteria for UCPPS completed questionnaires assessing childhood and recent trauma, affective distress, cognitive dysfunction, and generalized sensory sensitivity. Experimental pain sensitivity was also evaluated using standardized pressure pain applied to the pubic region and the arm. Bivariate analyses showed that childhood violent trauma was associated with more nonviolent childhood trauma, more recent trauma, poorer adult functioning, and greater pain sensitivity at the pubic region, but not pain sensitivity at the arm. Path analysis suggested that childhood violent trauma was indirectly associated with pain sensitivity at both sites and that this indirect association was primarily mediated by generalized sensory sensitivity. More experiences of recent trauma also contributed to these indirect effects. The findings suggest that, among participants with UCPPS, childhood violent trauma may be associated with heightened pain sensitivity to the extent that trauma history is associated with a subsequent increase in generalized sensory sensitivity., (Copyright © 2023 International Association for the Study of Pain.)

Abstract: Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the International Association for the Study of Pain.)

In 2019, the National Health Interview survey found that nearly 59% of adults reported pain some, most, or every day in the past 3 months, with 39% reporting back pain, making back pain the most prevalent source of pain, and a significant issue among adults. Often, identifying a direct, treatable cause for back pain is challenging, especially as it is often attributed to complex, multifaceted issues involving biological, psychological, and social components. Due to the difficulty in treating the true cause of chronic low back pain (cLBP), an over-reliance on opioid pain medications among cLBP patients has developed, which is associated with increased prevalence of opioid use disorder and increased risk of death. To combat the rise of opioid-related deaths, the National Institutes of Health (NIH) initiated the Helping to End Addiction Long-TermSM (HEAL) initiative, whose goal is to address the causes and treatment of opioid use disorder while also seeking to better understand, diagnose, and treat chronic pain. The NIH Back Pain Consortium (BACPAC) Research Program, a network of 14 funded entities, was launched as a part of the HEAL initiative to help address limitations surrounding the diagnosis and treatment of cLBP. This paper provides an overview of the BACPAC research program's goals and overall structure, and describes the harmonization efforts across the consortium, define its research agenda, and develop a collaborative project which utilizes the strengths of the network. The purpose of this paper is to serve as a blueprint for other consortia tasked with the advancement of pain related science., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Academy of Pain Medicine.)

Evidence-based treatments for chronic low back pain (cLBP) typically work well in only a fraction of patients, and at present there is little guidance regarding what treatment should be used in which patients. Our central hypothesis is that an interventional response phenotyping study can identify individuals with different underlying mechanisms for their pain who thus respond differentially to evidence-based treatments for cLBP. Thus, we will conduct a randomized controlled Sequential, Multiple Assessment, Randomized Trial (SMART) design study in cLBP with the following three aims. Aim 1: Perform an interventional response phenotyping study in a cohort of cLBP patients (n = 400), who will receive a sequence of interventions known to be effective in cLBP. For 4 weeks, all cLBP participants will receive a web-based pain self-management program as part of a run-in period, then individuals who report no or minimal improvement will be randomized to: a) mindfulness-based stress reduction, b) physical therapy and exercise, c) acupressure self-management, and d) duloxetine. After 8 weeks, individuals who remain symptomatic will be re-randomized to a different treatment for an additional 8 weeks. Using those data, we will identify the subsets of participants that respond to each treatment. In Aim 2, we will show that currently available, clinically derived measures, can predict differential responsiveness to the treatments. In Aim 3, a subset of participants will receive deeper phenotyping (n = 160), to identify new experimental measures that predict differential responsiveness to the treatments, as well as to infer mechanisms of action. Deep phenotyping will include functional neuroimaging, quantitative sensory testing, measures of inflammation, and measures of autonomic tone., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Academy of Pain Medicine.)

Exploring the relationship between nociplastic pain and the severity and impact of pelvic pain symptoms could lend insight into the heterogeneous symptom presentation and treatment response that complicates management of chronic pelvic pain. In this prospective cross-sectional study, we sought to evaluate relationships between degree of nociplastic pain, measured by the Fibromyalgia (FM) Survey Score, and multiple aspects of the chronic pelvic pain (CPP) experience, including severity, frequency, tenderness during pelvic myofascial exam, interference with daily life, and high-impact pain. The study included 303 women who presented to a tertiary referral clinic for chronic pelvic pain and endometriosis. Multiple measures of pelvic pain, including pain severity, frequency, interference, pelvic myofascial pain, and high-impact pain were examined in General Linear Models with FM Survey Score as the primary predictor of interest in models controlling for endometriosis, surgical history, use of opioids, body mass index, and patient age. Higher level of nociplastic pain was associated with greater pelvic pain severity, frequency, interference, and pelvic myofascial pain (all P < .05). For all models, degree of nociplastic pain was more strongly associated with pain outcomes than the presence of endometriosis, and use of opioids was the only stronger predictor of worse pain outcomes. The likelihood of high impact pain increased 7% for each additional point on the FM Survey Score. Degree of nociplastic pain was robustly associated with severity, frequency, and impact of pelvic pain, and was independent of the presence of endometriosis, history of surgical procedures for pelvic pain, age, and BMI. Trial registration: not applicable PERSPECTIVE: This article evaluates the impact of nociplastic pain on symptoms and functional status in chronic pelvic pain. These findings raise the possibility that a simple screening tool for nociplastic pain might provide clinically actionable information without the need for deep neurobiological phenotyping and may inform development of personalized management strategies., (Copyright © 2023 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Symptom heterogeneity in interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, collectively termed urological chronic pelvic pain syndrome, has resulted in difficulty in defining appropriate clinical trial endpoints. We determine clinically important differences for 2 primary symptom measures, pelvic pain severity and urinary symptom severity, and evaluate subgroup differences., Materials and Methods: The Multidisciplinary Approach to the Study of Chronic Pelvic Pain Symptom Patterns Study enrolled individuals with urological chronic pelvic pain syndrome. We defined clinically important differences by associating changes in pelvic pain severity and urinary symptom severity over 3 to 6 months with marked improvement on a global response assessment using regression and receiver operating characteristic curves. We evaluated clinically important differences for absolute and percent change and examined differences in clinically important differences by sex-diagnosis, presence of Hunner lesions, pain type, pain widespreadness, and baseline symptom severity., Results: An absolute change of -4 was clinically important in pelvic pain severity among all patients, but clinically important difference estimates differed by pain type, presence of Hunner lesions, and baseline severity. Pelvic pain severity clinically important difference estimates for percent change were more consistent across subgroups and ranged from 30% to 57%. The absolute change urinary symptom severity clinically important difference was -3 for female participants and -2 for male participants with chronic prostatitis/chronic pelvic pain syndrome only. Patients with greater baseline severity required larger decreases in symptoms to feel improved. Estimated clinically important differences had lower accuracy among participants with low baseline symptoms., Conclusions: A reduction of 30%-50% in pelvic pain severity is a clinically meaningful endpoint for future therapeutic trials in urological chronic pelvic pain syndrome. Urinary symptom severity clinically important differences are more appropriately defined separately for male and female participants.

Abstract: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a common and debilitating disease with poor treatment outcomes. Studies from the multidisciplinary approach to the study of chronic pelvic pain research network established that IC/BPS patients with chronic overlapping pain conditions (COPCs) experience poorer quality of life and more severe symptoms, yet the neurobiological correlates of this subtype are largely unknown. We previously showed that ex vivo toll-like receptor 4 (TLR4) cytokine/chemokine release is associated with the presence of COPCs, as well as widespread pain and experimental pain sensitivity women with IC/BPS. Here, we attempt to confirm these findings in the multisite multidisciplinary approach to the study of chronic pelvic pain Symptom Patterns Study using TLR4-stimulated whole blood (female IC/BPS patients with COPC n = 99; without n = 36). Samples were collected in tubes preloaded with TLR4 agonist, incubated for 24 hours, and resulting supernatant assayed for 7 cytokines/chemokines. These were subject to a principal components analysis and the resulting components used as dependent variables in general linear models. Controlling for patient age, body mass index, and site of collection, we found that greater ex vivo TLR4-stimulated cytokine/chemokine release was associated with the presence of COPCs ( P < 0.01), extent of widespread pain ( P < 0.05), but not experimental pain sensitivity ( P > 0.05). However, a second component of anti-inflammatory, regulatory, and chemotactic activity was associated with reduced pain sensitivity ( P < 0.01). These results confirm that the IC/BPS + COPCs subtype show higher levels of ex vivo TLR4 cytokine/chemokine release and support a link between immune priming and nociplastic pain in IC/BPS., (Copyright © 2022 International Association for the Study of Pain.)

Background and Purpose: Many patients with chronic pain report hypersensitivity not only to noxious stimuli, but also to other modalities including innocuous touch, sound, and light, possibly due to differences in the processing of these stimuli. The goal of this study was to characterize functional connectivity (FC) differences between subjects with temporomandibular disorders (TMD) and pain-free controls during a visual functional magnetic resonance imaging (fMRI) task that included an unpleasant, strobing visual stimulus. We hypothesized the TMD cohort would exhibit maladaptations in brain networks consistent with multisensory hypersensitivities observed in TMD patients., Methods: This pilot study included 16 subjects, 10 with TMD and 6 pain-free controls. Clinical pain was characterized using self-reported questionnaires. Visual task-based fMRI data were collected on a 3T MR scanner and used to determine differences in FC via group independent component analysis., Results: Compared to controls, subjects with TMD exhibited abnormally increased FC between the default mode network and lateral prefrontal areas involved in attention and executive function, and impaired FC between the frontoparietal network and higher order visual processing areas., Conclusions: The results indicate maladaptation of brain functional networks, likely due to deficits in multisensory integration, default mode network function, and visual attention and engendered by chronic pain mechanisms., (© 2023 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

Three categories of pain mechanisms are recognized as contributing to pain perception: nociceptive, neuropathic, and nociplastic (ie, central nervous system augmented pain processing). We use validated questionnaires to identify pain mechanisms in Urologic Chronic Pelvic Pain Syndrome (UCCPS) patients (n = 568, female = 378, male = 190) taking part in the Symptom Patterns Study of the Multidisciplinary Approach to the study of chronic Pelvic Pain Research Network. A cutoff score of 12 on the painDETECT questionnaire (-1 to 38) was used to classify patients into the neuropathic category while the median score of 7 on the fibromyalgia survey criteria (0-31) was used to classify patients into the nociplastic category. Categories were compared on demographic, clinical, psychosocial, psychophysical and medication variables. At baseline, 43% of UCPPS patients were classified as nociceptive-only, 8% as neuropathic only, 27% as nociceptive+nociplastic, and 22% as neuropathic+nociplastic. Across outcomes nociceptive-only patients had the least severe symptoms and neuropathic+nociplastic patients the most severe. Neuropathic pain was associated with genital pain and/or sensitivity on pelvic exam, while nociplastic pain was associated with comorbid pain conditions, psychosocial difficulties, and increased pressure pain sensitivity outside the pelvis. A self-report method classifying individuals on pain mechanisms reveals clinical differences that could inform clinical trials and novel targets for treatment. PERSPECTIVE: This article presents differences in clinical characteristics based on a simple self-report method of classifying pain mechanisms for Urologic Chronic Pelvic Pain Syndrome patients. This method can be easily applied to other chronic pain conditions and may be useful for exploring pathophysiology in pain subtypes., (Copyright © 2022. Published by Elsevier Inc.)

Abstract: Increased sensory sensitivity across non-nociceptive modalities is a common symptom of chronic pain conditions and is associated with chronic pain development. Providing a better understanding of the brain-behavior relationships that underlie multimodal hypersensitivity (MMH) may clarify the role of MMH in the development of chronic pain. We studied sensory hypersensitivity in a cohort of women (n = 147) who had diary confirmation of menstrual status and were enriched with risk factors for chronic pelvic pain, such as dysmenorrhea and increased bladder sensitivity. We administered 2 experimental tasks to evaluate the cross-modal relationship between visual and visceral sensitivity. Visual sensitivity was probed by presenting participants with a periodic pattern-reversal checkerboard stimulus presented across 5 brightness intensities during electroencephalography recording. Self-reported visual unpleasantness ratings for each brightness intensity were simultaneously assessed. Visceral sensitivity was evaluated with an experimental bladder-filling task associated with early clinical symptoms of chronic pelvic pain. Visually evoked cortical activity increased with brightness intensity across the entire scalp, especially at occipital electrode sites. Visual stimulation-induced unpleasantness was associated with provoked bladder pain and evoked primary visual cortex activity. However, the relationship between unpleasantness and cortical activity was moderated by provoked bladder pain. These results demonstrate that activity in the primary visual cortex is not greater in individuals with greater visceral sensitivity. We hypothesize that downstream interpretation or integration of this signal is amplified in individuals with visceral hypersensitivity. Future studies aimed at reducing MMH in chronic pain conditions should prioritize targeting of cortical mechanisms responsible for aberrant downstream sensory integration., (Copyright © 2021 International Association for the Study of Pain.)

Abstract: Altered brain structure and function is evident in adults with multisite chronic pain. Although many such adults trace their pain back to childhood, it has been difficult to disentangle whether central nervous system alterations precede or are consequences of chronic pain. If the former is true, aberrant brain activity may identify children vulnerable to developing chronic pain later in life. We examined structural and functional brain magnetic resonance imaging metrics in a subset of children from the first 2 assessments of the Adolescent Brain and Cognitive Development Study. Children (aged 9-10) who were pain free at baseline and then developed multisite pain 1 year later (n = 115) were matched to control children who were pain free at both timepoints (n = 230). We analyzed brain structure (cortical thickness and gray matter volume) and function (spontaneous neural activity and functional connectivity). Results were deemed significant at the cluster level P < 0.05 false discovery rate corrected for multiple comparisons. At baseline, children who subsequently developed multisite pain had increased neural activity in superior parietal /primary somatosensory and motor cortices and decreased activity in the medial prefrontal cortex. They also exhibited stronger functional connectivity between the salience network, somatosensory, and default mode network regions. No significant differences in the brain structure were observed. Increased neural activity and functional connectivity between brain regions, consistent to that seen in adults with chronic pain, exist in children before developing multisite pain. These findings may represent a neural vulnerability to developing future chronic pain., (Copyright © 2021 International Association for the Study of Pain.)

Objective: To examine how often urologic chronic pelvic pain syndrome (UCPPS) patients progressed from Pelvic Pain Only at baseline to Widespread Pain, or vice versa, during 1-year longitudinal follow-up., Methods: Men and women with UCPPS enrolled in the MAPP-I Epidemiology and Phenotyping Study completed a self-report body map to indicate their locations of pain every 2 months over 12 months. Patients were categorized at each assessment into one of three pain phenotypes: (1) Pelvic Pain Only, (2) an Intermediate group, (3) Widespread Pain. Only patients who completed 3 or more follow-ups were included in this longitudinal analysis. The primary outcome measure was pain classification at the majority (≥60%) of follow-up assessments. Longitudinal trends of somatic symptom burden were also assessed., Results: Among the 93 UCPPS participants with Pelvic Pain Only at baseline, only 2% (n = 2) showed a Widespread Pain phenotype for the majority of assessments over 12 months. Among the 121 participants who had Widespread Pain at baseline, 6% (n = 7) demonstrated Pelvic Pain Only for the majority of assessments over 12 months. Over half of participants (≥53%) stayed in their baseline phenotypic group. Somatic symptom burden remained stable over 12 months for each of the groups with high intra-class correlation coefficient (0.67 to 0.82)., Conclusion: It was uncommon for UCPPS patients to progress from Pelvic Pain Only to Widespread Pain, or vice versa, over 12 months. These data suggest that Pelvic Pain Only and Widespread Pain are distinct UCPPS phenotypes that are relatively stable over 12 months of follow up., (Copyright © 2021. Published by Elsevier Inc.)

Objective: There is increasing demand for prediction of chronic pain treatment outcomes using machine-learning models, in order to improve suboptimal pain management. In this exploratory study, we used baseline brain functional connectivity patterns from chronic pain patients with fibromyalgia (FM) to predict whether a patient would respond differentially to either milnacipran or pregabalin, 2 drugs approved by the US Food and Drug Administration for the treatment of FM., Methods: FM patients participated in 2 separate double-blind, placebo-controlled crossover studies, one evaluating milnacipran (n = 15) and one evaluating pregabalin (n = 13). Functional magnetic resonance imaging during rest was performed before treatment to measure intrinsic functional brain connectivity in several brain regions involved in pain processing. A support vector machine algorithm was used to classify FM patients as responders, defined as those with a ≥20% improvement in clinical pain, to either milnacipran or pregabalin., Results: Connectivity patterns involving the posterior cingulate cortex (PCC) and dorsolateral prefrontal cortex (DLPFC) individually classified pregabalin responders versus milnacipran responders with 77% accuracy. Performance of this classification improved when both PCC and DLPFC connectivity patterns were combined, resulting in a 92% classification accuracy. These results were not related to confounding factors, including head motion, scanner sequence, or hardware status. Connectivity patterns failed to differentiate drug nonresponders across the 2 studies., Conclusion: Our findings indicate that brain functional connectivity patterns used in a machine-learning framework differentially predict clinical response to pregabalin and milnacipran in patients with chronic pain. These findings highlight the promise of machine learning in pain prognosis and treatment prediction., (© 2021 Pfizer. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Objective: Pelvic floor pain, abdominal wall pain, and central nervous system pain amplification can be contributing factors in chronic pelvic pain (CPP), however; limited research has investigated the association of pelvic floor, abdominal, and uterine tenderness with central nervous system pain amplification. We assessed whether pressure pain thresholds on the non-dominant thumbnail, a marker of central nervous system pain amplification, were associated with pelvic floor, abdominal, and uterine tenderness among women with endometriosis or CPP., Study Design: We conducted a cross-sectional study among 88 females with endometriosis and/or CPP. Abdominal (6 locations), pelvic floor (6 locations) and uterine (1 location) tenderness were assessed via a standardized physical exam. Participants reported their pain levels (0-10 scale) with application of 2 kg of pressure at each area, with a pain rating of ≥4 on the 0-10 scale considered moderate to severe pain. Pain sensitivity was measured on the non-dominant thumbnail by applying discrete pressure stimuli using a previously validated protocol., Results: Overall, 50% (44/88), 42% (37/88), and 58% (51/88) of participants reported high pelvic floor, abdominal, and uterine tenderness, respectively. Pressure intensities needed to elicit 'faint' and 'mild' pain were lower for participants with high vs. low pelvic floor tenderness (median intensity for 'faint' pain = 0.50 kgf/cm 2 (min-max:0.25-3.25) vs. 1.06(0.25-3.00), p-value = 0.006; median intensity for 'mild' pain = 2.00(0.63-4.88) vs. 2.63(0.75-6.00), p-value = 0.03). No association was observed between pressure pain sensitivity and abdominal or uterine tenderness (p > 0.11). Participants with endometriosis without pain were less likely to have high pelvic floor (22.2%), abdominal (11.1%), and uterine (25.9%) tenderness compared to participants with endometriosis with pain (63.0%, 50%, 65.2%, respectively) and participants with chronic pelvic pain (60%, 73.3%, 93.3%, respectively)., Conclusions: These results suggest that high pelvic floor tenderness among women with endometriosis/CPP may be a marker of heightened pain sensitivity suggestive of central nervous system pain amplification and may impact treatment response. Future research should examine whether this clinical phenotype predicts response to medical and behavioral treatments (e.g, anti-convulsants, behavioral therapy, Physical Therapy)., Competing Interests: Declaration of Competing Interest S.A. has served as a consultant for Abbvie, Bayer, Myovant Sciences and Merck, and receives royalties as an author for UpToDate. D.J.C. has served as a consultant for Pfizer, Lilly, Tonix, Aptinyx, Samumed, Zynerba, and has received research funding from Aptinyx. S.E.H. has served as a consultant for Aptinyx, and has received research funding from Arbor Medical Innovations and Aptinyx. S.A.M. has served as an advisory board member for Abbvie and Roche. A.L.S., E.M., and C.B.S. report no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Childhood trauma and adversity have been linked to chronic pain and pain sensitivity, particularly centralized pain. Yet, there remain numerous gaps in our understanding of this link., Purpose: We explored the association between nonviolent and violent childhood trauma and a component of centralized pain (i.e., generalized sensory sensitivity) and pain sensitivity using self-report measures of centralized pain and quantitative sensory testing (QST)., Methods: Patients scheduled for a total knee arthroplasty (n = 129) completed questionnaires and QST prior to surgery., Results: We found that self-report measures of centralized pain (i.e., widespread pain, somatic awareness, and sensory sensitivity) displayed a graded relationship across trauma groups, with patients with a history of violent trauma reporting the highest scores. Univariable multinomial logistic regression analyses showed that higher sensory sensitivity was associated with increased risk of being in the nonviolent trauma group compared to the no trauma group. Furthermore, higher widespread pain, higher somatic awareness, and higher sensory sensitivity distinguished the violent trauma group from the no trauma group. In multivariable analyses, sensory sensitivity is uniquely distinguished between the violent trauma group and the no trauma group. QST did not distinguish between groups., Conclusions: The findings highlight the need for future research and interventions that reduce sensory sensitivity for chronic pain patients with a history of violent childhood trauma., (© Society of Behavioral Medicine 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background/objectives: The physiological mechanisms underlying the pain-modulatory effects of clinical neurostimulation therapies, such as spinal cord stimulation (SCS) and dorsal root ganglion stimulation (DRGS), are only partially understood. In this pilot prospective study, we used patient-reported outcomes (PROs) and quantitative sensory testing (QST) to investigate the physiological effects and possible mechanisms of action of SCS and DRGS therapies., Materials and Methods: We tested 16 chronic pain patients selected for SCS and DRGS therapy, before and after treatment. PROs included pain intensity, pain-related symptoms (e.g., pain interference, pain coping, sleep interference) and disability, and general health status. QST included assessments of vibration detection theshold (VDT), pressure pain threshold (PPT) and tolerance (PPToL), temporal summation (TS), and conditioned pain modulation (CPM), at the most painful site., Results: Following treatment, all participants reported significant improvements in PROs (e.g., reduced pain intensity [p < 0.001], pain-related functional impairment [or pain interference] and disability [p = 0.001 for both]; better pain coping [p = 0.03], sleep [p = 0.002]), and overall health [p = 0.005]). QST showed a significant treatment-induced increase in PPT (p = 0.002) and PPToL (p = 0.011), and a significant reduction in TS (p = 0.033) at the most painful site, but showed no effects on VDT and CPM. We detected possible associations between a few QST measures and a few PROs. Notably, higher TS was associated with increased pain interference scores at pre-treatment (r = 0.772, p = 0.009), and a reduction in TS was associated with the reduction in pain interference (r = 0.669, p = 0.034) and pain disability (r = 0.690, p = 0.027) scores with treatment., Conclusions: Our preliminary findings suggest significant clinical and therapeutic benefits associated with SCS and DRGS therapies, and the possible ability of these therapies to modulate pain processing within the central nervous system. Replication of our pilot findings in future, larger studies is necessary to characterize the physiological mechanisms of SCS and DRGS therapies., (© 2021 International Neuromodulation Society.)

Neuroimaging has enhanced our understanding of the neural correlates of pain. Yet, how neural circuits interact and contribute to persistent pain remain largely unknown. Here, we investigate the mesoscale organization of the brain through intrinsic functional communities generated from resting state functional MRI data from two independent datasets, a discovery cohort of 43 Fibromyalgia (FM) patients and 20 healthy controls (HC) as well as a replication sample of 34 FM patients and 21 HC. Using normalized mutual information, we found that the global network architecture in chronic pain patients is less stable (more variable). Subsequent analyses of node community assignment revealed the composition of the communities differed between FM and HC. Furthermore, differences in network organization were associated with the changes in the composition of communities between patients with varying levels of clinical pain. Together, this work demonstrates that intrinsic network communities differ substantially between patients with FM and controls. These differences may represent a novel aspect of the pathophysiology of chronic nociplastic pain., Competing Interests: Declaration of Competing Interest D.J.C has received consultant fees, speaking fees, and/or honoraria from Aptinyx, Daiichi Sankyo, Intec Pharma, Eli Lilly, Pfizer, Nix Patterson LLP, Samumed, Theravance, Tonix, Williams, & Connolly LLP and Zynerba. D.J.C has also received research support from Aptinyx and Pfizer. S.E.H. has received Grants and personal fees from Pfizer, Aptinyx, Arbor Medical Innovations; grants from Cerephex, Lilly, and Forest. R.E.H has consulted for Pfizer, Aptinyx Inc. He has received grant funding from Pfizer, Aptinyx and Cerephex. T.E.L., C.M.K., A.S., E.I., I.M., S.E.H., G.A.M., D.J.C., and R.E.H., have all received funding from the National Institutes of Health. The remaining authors declare no competing interests., (Copyright © 2020. Published by Elsevier Inc.)

Aims: The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network initiated a second observational cohort study-the Symptom Patterns Study (SPS)-to further investigate the underlying pathophysiology of Urologic Chronic Pelvic Pain Syndrome (UCPPS) and to discover factors associated with longitudinal symptom changes and responses to treatments., Methods: This multisite cohort study of males and females with UCPPS features a run-in period of four weekly web-based symptom assessments before a baseline visit, followed by quarterly assessments up to 36 months. Controls were also recruited and assessed at baseline and 6 months. Extensive clinical data assessing urological symptoms, nonurological pain, chronic overlapping pain syndromes, and psychosocial factors were collected. Diverse biospecimens for biomarker and microbiome studies, quantitative sensory testing (QST) data under multiple stimuli, and structural and functional neuroimaging scans were obtained under a standardized protocol., Results: Recruitment was initiated (July 2015) and completed (February 2019) at six discovery sites. A total of 620 males and females with UCPPS and 73 Controls were enrolled, including 83 UCPPS participants who re-enrolled from the first MAPP Network cohort study (2009-2012). Baseline neuroimaging scans, QST measures, and biospecimens were obtained on 578 UCPPS participants. The longitudinal follow-up of the cohort is ongoing., Conclusions: This comprehensive characterization of a large UCPPS cohort with extended follow-up greatly expands upon earlier MAPP Network studies and provides unprecedented opportunities to increase our understanding of UCPPS pathophysiology, factors associated with symptom change, clinically relevant patient phenotypes, and novel targets for future interventions., (© 2020 Wiley Periodicals LLC.)

Objectives: Quantitative sensory testing may help predict treatment responses in individuals with chronic pain. Our objective was to determine whether evoked pain sensitivity at baseline predicted preferential treatment responses to either emotional awareness and expression therapy (EAET) or cognitive behavioral therapy (CBT) in individuals with fibromyalgia (FM)., Methods: This was a secondary analysis of a previous randomized clinical trial, in which individuals with FM were randomized to EAET, CBT, or Education as a control intervention. Only females who completed baseline and post-treatment assessments were analyzed (n=196). The primary outcome was change in overall clinical pain severity from pretreatment to posttreatment, and the primary predictor of interest was pressure pain tolerance at baseline., Results: Among patients with low pain tolerance at baseline (n=154), both EAET and CBT led to small but significant improvements in clinical pain severity (CBT mean=0.66, 95% confidence interval [0.24-1.07]; EAET mean=0.76 [0.34-1.17]). Conversely, in patients with normal pain tolerance (n=42), there was no significant improvement in clinical pain after CBT (0.13 [-0.88 to 1.14]), a small improvement after FM Education (0.81 [0.14-1.48]), but a much larger and statistically significant improvement after EAET (2.14 [1.23-3.04])., Discussion: Normal levels of pressure pain tolerance at baseline predicted greater improvement in clinical pain severity after EAET than CBT. Quantitative sensory testing may provide insights about individual responses to psychologically based therapies for individuals with chronic pain.

Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndrome (UCPPS) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. A series of computer-controlled pressure stimuli were delivered to the thumbnail bed, an asymptomatic site distant from the area of UCPPS pain that is considered to be indicative of overall body pain threshold. Stimuli were rated according to a standardized magnitude estimation protocol. Pain sensitivity in participants with UCPPS was compared with healthy controls and a mixed pain group composed of individuals with other chronic overlapping pain conditions, including fibromyalgia, chronic fatigue, and irritable bowel syndromes. Data from 6 participating MAPP testing sites were pooled for analysis. Participants with UCPPS (n = 153) exhibited an intermediate pain sensitivity phenotype: they were less sensitive relative to the mixed pain group (n = 35) but significantly more sensitive than healthy controls (n = 100). Increased pain sensitivity in patients with UCPPS was associated with both higher levels of clinical pain severity and more painful body areas outside the pelvic region. Exploratory analyses in participants with UCPPS revealed that pain sensitivity increased during periods of urologic symptom flare and that less pressure pain sensitivity at baseline was associated with a greater likelihood of subsequent genitourinary pain improvement 1 year later. The finding that individuals with UCPPS demonstrate nonpelvic pain hypersensitivity that is related to clinical symptoms suggests that central nervous system mechanisms of pain amplification contribute to UCPPS.

A critical component of brain network architecture is a robust hub structure, wherein hub regions facilitate efficient information integration by occupying highly connected and functionally central roles in the network. Across a wide range of neurological disorders, hub brain regions seem to be disrupted, and the character of this disruption can yield insights into the pathophysiology of these disorders. We applied a brain network-based approach to examine hub topology in fibromyalgia, a chronic pain condition with prominent central nervous system involvement. Resting state functional magnetic resonance imaging data from 40 fibromyalgia patients and 46 healthy volunteers, and a small validation cohort of 11 fibromyalgia patients, were analyzed using graph theoretical techniques to model connections between 264 brain regions. In fibromyalgia, the anterior insulae functioned as hubs and were members of the rich club, a highly interconnected nexus of hubs. In fibromyalgia, rich-club membership varied with the intensity of clinical pain: the posterior insula, primary somatosensory, and motor cortices belonged to the rich club only in patients with the highest pain intensity. Furthermore, the eigenvector centrality (a measure of how connected a region is to other highly connected regions) of the posterior insula positively correlated with clinical pain and mediated the relationship between glutamate + glutamine (assessed by proton magnetic resonance spectroscopy) within this structure and the patient's clinical pain report. Together, these findings reveal altered hub topology in fibromyalgia and demonstrate, for the first time to our knowledge, a neurochemical basis for altered hub strength and its relationship to the perception of pain.

Urologic chronic pelvic pain syndrome (UCPPS), which encompasses interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, is characterized by chronic pain in the pelvic region or genitalia that is often accompanied by urinary frequency and urgency. Despite considerable research, no definite aetiological risk factors or effective treatments have been identified. The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network uses a novel integrated strategy to characterize UCPPS as a systemic disorder that potentially involves multiple aetiologies. The first phase, MAPP I, included >1,000 participants who completed an intensive baseline assessment followed by a 12-month observational follow-up period. MAPP I studies showed that UCPPS pain and urinary symptoms co-vary, with only moderate correlation, and should be evaluated separately and that symptom flares are common and can differ considerably in intensity, duration and influence on quality of life. Longitudinal clinical changes in UCPPS correlated with structural and functional brain changes, and many patients experienced global multisensory hypersensitivity. Additionally, UCPPS symptom profiles were distinguishable by biological correlates, such as immune factors. These findings indicate that patients with UCPPS have objective phenotypic abnormalities and distinct biological characteristics, providing a new foundation for the study and clinical management of UCPPS.

Objective: Moderate alcohol consumption has been associated with improved health outcomes including reduced risk of heart disease; however, less is known regarding alcohol's effects on chronic pain. The aim of this study was to assess associations between pain, fibromyalgia symptoms, and moderate alcohol use in a large chronic pain sample., Methods: A total of 2,583 new chronic pain patients presenting at a university pain clinic reported alcohol use and completed validated measures; 592 (23%) patients reported drinking, with 502 (85%) classified as moderate drinkers (females ≤7 and males ≤14 drinks/wk). General linear models (GLM) assessed the effects of moderate drinking on pain and symptom outcomes. The sample was stratified by gender and fibromyalgia (FM) status in secondary analyses., Results: Moderate alcohol users reported significantly lower FM symptoms (widespread pain and symptom severity), pain severity, interference, anxiety, depression, and catastrophizing, and they reported higher physical function. Similar findings were observed in gender-stratified analysis, minus associations with FM symptom severity in females and anxiety in males. In patients meeting FM criteria, moderate drinking was associated with lower pain severity, interference, and depression, and higher physical function. Results in non-FM patients were similar to the total sample., Conclusions: Moderate alcohol consumption in chronic pain patients was associated with decreased pain severity and interference, fewer painful body areas, lower somatic and mood symptoms, and increased physical function. A similar effect was observed in non-FM patients, but to a lesser extent in FM patients, suggesting chronic pain patients with less centralized forms of pain may benefit most from moderate alcohol consumption.

Chronic overlapping pain conditions (COPCs) are characterized by aberrant central nervous system processing of pain. This "centralized pain" phenotype has been described using a large and diverse set of symptom domains, including the spatial distribution of pain, pain intensity, fatigue, mood imbalances, cognitive dysfunction, altered somatic sensations, and hypersensitivity to external stimuli. Here, we used 3 cohorts, including patients with urologic chronic pelvic pain syndrome, a mixed pain cohort with other COPCs, and healthy individuals (total n = 1039) from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network to explore the factor structure of symptoms of centralized pain. Using exploratory and confirmatory factor analysis, we identified 2 general factors in all 3 cohorts, one characterized by a broad increased sensitivity to internal somatic sensations,environmental stimuli, and diffuse pain, termed Generalized Sensory Sensitivity, and one characterized by constitutional symptoms-Sleep, Pain, Affect, Cognition, Energy (SPACE). Longitudinal analyses in the urologic chronic pelvic pain syndrome cohort found the same 2-factor structure at month 6 and 1 year, suggesting that the 2-factor structure is reproducible over time. In secondary analyses, we found that Generalized Sensory Sensitivity particularly is associated with the presence of comorbid COPCs, whereas SPACE shows modest associations with measures of disability and urinary symptoms. These factors may represent an important and distinct continuum of symptoms that are indicative of the centralized pain phenotype at high levels. Future research of COPCs should accommodate the measurement of each factor.

Objective: To determine whether women with chronic pelvic pain and variable degrees of endometriosis demonstrate altered pain sensitivity relative to pain-free healthy women in a control group and whether such differences are related to the presence or severity of endometriosis or comorbid pain syndromes., Methods: Four patient subgroups (endometriosis with chronic pelvic pain [n=42], endometriosis with dysmenorrhea [n=15], pain-free endometriosis [n=35], and chronic pelvic pain without endometriosis [n=22]) were each compared with 30 healthy women in a control group in this cross-sectional study. All patients completed validated questionnaires regarding pain symptoms and underwent screening for comorbid pain disorders. Pain sensitivity was assessed by applying discrete pressure stimuli to the thumbnail using a previously validated protocol., Results: While adjusting for age and education, pain thresholds were lower in all subgroups of women with pelvic pain relative to healthy women in the control group (all P values <.01). There was no difference in pain thresholds when comparing patients with endometriosis without pelvic pain with healthy women in the control group (mean difference 0.02 kg/m2, 95% confidence interval -0.43 to 0.47). The presence and severity of endometriosis and number of comorbid pain syndromes were not associated with a difference in pain thresholds., Conclusion: Women with chronic pelvic pain demonstrate increased pain sensitivity at a nonpelvic site compared with healthy women in a control group, which is independent of the presence or severity of endometriosis or comorbid pain syndromes. These findings support the notion that central pain amplification may play a role in the development of pelvic pain and may explain why some women with pelvic pain do not respond to therapies aimed at eliminating endometriosis lesions., Level of Evidence: II.

Unlabelled: Although chronic pain in childhood can last into adulthood, few studies have evaluated the characteristics of adults with chronic pain who report childhood chronic pain. Thus, 1,045 new patients (mean age, 49.5 ± 15.4) at an academic tertiary care pain clinic were prospectively evaluated using validated self-report questionnaires. Patients also responded to questions about childhood pain. We found that almost 17% (n = 176) of adult chronic pain patients reported a history of chronic pain in childhood or adolescence, with close to 80% indicating that the pain in childhood continues today. Adults reporting childhood chronic pain were predominantly female (68%), commonly reported widespread pain (85%), and had almost 3 times the odds of meeting survey criteria for fibromyalgia (odds ratio [OR] = 2.94, 95% confidence interval [CI] = 2.04-4.23) than those denying childhood chronic pain. Similarly, those with childhood pain had twice the odds of having biological relatives with chronic pain (OR = 2.03, 95% CI = 1.39-2.96) and almost 3 times the odds of having relatives with psychiatric illness (OR = 2.85, 95% CI = 1.97-4.11). Lastly, compared to patients who did not report childhood chronic pain, those who did were more likely to use neuropathic descriptors for their pain (OR = 1.82, 95% CI = 1.26-2.64), have slightly worse functional status (B = -2.12, t = -3.10, P = .002), and have increased anxiety (OR = 1.77, 95% CI = 1.24-2.52)., Perspective: Our study revealed that 1 in 6 adult pain patients reported pain that dated back to childhood or adolescence. In such patients, evidence suggested that their pain was more likely to be widespread, neuropathic in nature, and accompanied by psychological comorbidities and decreased functional status., (Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Quantitative sensory testing (QST) can provide useful information about the underlying mechanisms involved in chronic pain. However, currently available devices typically employed suffer from operator-dependent effects, or are too cumbersome for routine clinical care. This paper presents the design and initial validation of a novel automated pressure-pain type QST platform, termed the multi-modal automated sensory testing (MAST) system. The MAST configuration presented consists of wireless, hand-held thumbnail pressure stimulators (with circular 10 mm² rubber tips) and graphical touch screen interface devices to manage the QST process and obtain patient feedback. Validation testing of the custom-designed force sensor showed a 1 % error for low forces increasing to 2 % error for larger loads up to 100 N (full-scale). Validation of the controller using three ramp rates (64, 248, and 496 kPa/s) and six pressures (32, 62, 124, 273, 620, and 1116 kPa) showed an overall mean error of 1.7 % for applied stimuli. Clinical evaluation revealed decreased pressure pain thresholds in chronic pain patients (98.07 ± SE 16.34 kPa) compared to pain free, healthy control subjects (259.88 ± SE 33.54 kPa, p = 0.001). The MAST system is portable and produces accurate, repeatable stimulation profiles indicating potential for point-of-care applications.

The Biobehavioral Working Group of BACPAC was charged to evaluate a range of psychosocial, psychophysical, and behavioral domains relevant to chronic low back pain, and recommend specific assessment tools and procedures to harmonize biobehavioral data collection across the consortium. Primary references and sources for measure selection were the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials, the Minimum Data Set from the National Institutes of Health (NIH) Research Task Force on Standards for Chronic Low Back Pain, the Patient-Reported Outcomes Measurement Information System, and NeuroQOL. The questionnaire's recommendations supplemented the NIH HEAL Common Data Elements and BACPAC Minimum Data Set. Five domains were identified for inclusion: Pain Characteristics and Qualities; Pain-Related Psychosocial/Behavioral Factors; General Psychosocial Factors; Lifestyle Choices; and Social Determinants of Health/Social Factors. The Working Group identified best practices for required and optional Quantitative Sensory Testing of psychophysical pain processing for use in BACPAC projects.

Chronic pain has become a global health problem contributing to years lived with disability and reduced quality of life. Advances in the clinical management of chronic pain have been limited due to incomplete understanding of the multiple risk factors and molecular mechanisms that contribute to the development of chronic pain. The Acute to Chronic Pain Signatures (A2CPS) Program aims to characterize the predictive nature of biomarkers (brain imaging, high-throughput molecular screening techniques, or "omics," quantitative sensory testing, patient-reported outcome assessments and functional assessments) to identify individuals who will develop chronic pain following surgical intervention. The A2CPS is a multisite observational study investigating biomarkers and collective biosignatures (a combination of several individual biomarkers) that predict susceptibility or resilience to the development of chronic pain following knee arthroplasty and thoracic surgery. This manuscript provides an overview of data collection methods and procedures designed to standardize data collection across multiple clinical sites and institutions. Pain-related biomarkers are evaluated before surgery and up to 3 months after surgery for use as predictors of patient reported outcomes 6 months after surgery. The dataset from this prospective observational study will be available for researchers internal and external to the A2CPS Consortium to advance understanding of the transition from acute to chronic postsurgical pain.

Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndrome (UCPPS) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. A series of computer-controlled pressure stimuli were delivered to the thumbnail bed, an asymptomatic site distant from the area of UCPPS pain that is considered to be indicative of overall body pain threshold. Stimuli were rated according to a standardized magnitude estimation protocol. Pain sensitivity in participants with UCPPS was compared with healthy controls and a mixed pain group composed of individuals with other chronic overlapping pain conditions, including fibromyalgia, chronic fatigue, and irritable bowel syndromes. Data from 6 participating MAPP testing sites were pooled for analysis. Participants with UCPPS (n = 153) exhibited an intermediate pain sensitivity phenotype: they were less sensitive relative to the mixed pain group (n = 35) but significantly more sensitive than healthy controls (n = 100). Increased pain sensitivity in patients with UCPPS was associated with both higher levels of clinical pain severity and more painful body areas outside the pelvic region. Exploratory analyses in participants with UCPPS revealed that pain sensitivity increased during periods of urologic symptom flare and that less pressure pain sensitivity at baseline was associated with a greater likelihood of subsequent genitourinary pain improvement 1 year later. The finding that individuals with UCPPS demonstrate nonpelvic pain hypersensitivity that is related to clinical symptoms suggests that central nervous system mechanisms of pain amplification contribute to UCPPS.

OBJECTIVES: To explore associations between quantitative sensory testing (QST) and pretreatment pain, physical, and psychological characteristics in women with breast cancer. SAMPLE & SETTING: 41 women with treatmentnaive stage 0--III breast cancer at the University of Michigan Comprehensive Cancer Center in Ann Arbor. METHODS & VARIABLES: Participants completed self-report surveys and QST within the month before breast surgery. Pressure pain thresholds (PPTs) were measured bilaterally at each trapezius with a manual QST algometer. PPT values were split, yielding low, moderate, and high pain sensitivity subgroups. Subgroup self-reported characteristics were compared using Spearman's correlation, chi-square, and one-way analysis of variance. RESULTS: Lower PPT (higher sensitivity) was associated with higher levels of pain interference and maladaptive pain cognitions. The high-sensitivity group reported higher pain severities, interference, and catastrophizing and lower belief in internal locus of pain control than the low-sensitivity group. IMPLICATIONS FOR NURSING: Individualized interventions for maladaptive pain cognitions before surgery may reduce pain sensitivity and the severity of chronic pain developed after surgery. [ABSTRACT FROM AUTHOR]

Background: Caffeine's properties as an analgesic adjuvant with nonsteroidal anti-inflammatory drugs/acetaminophen are well documented. However, little clinical research has explored caffeine's effects on opioid analgesia. This study assessed the effects of caffeine consumption on pain and other symptoms in opioid-using and nonusing chronic pain patients meeting the survey criteria for fibromyalgia. Materials and methods: Patients presenting to a university-based pain clinic completed validated self-report questionnaires assessing symptoms. Patients (N=962) meeting the fibromyalgia survey criteria were stratified by opioid use and further split into groups based on caffeine amount consumed per day (no caffeine, or low, moderate, high caffeine). Analysis of covariance with Dunnett's post hoc testing compared pain and symptom severity between the no caffeine group and the caffeine consuming groups. Results: In opioid users, caffeine consumption had modest but significant effects on pain, catastrophizing, and physical function. Lower levels of pain interference were associated with low and moderate caffeine use compared to no caffeine intake. Lower pain catastrophizing and higher physical function were observed in all caffeine dose groups, relative to the no caffeine group. Lower pain severity and depression were observed only in the moderate caffeine group. In opioid nonusers, low caffeine intake was associated with higher physical function; however, no other significant effects were observed. Conclusion: Caffeine consumption was associated with decreased pain and symptom severity in opioid users, but not in opioid nonusers, indicating caffeine may act as an opioid adjuvant in fibromyalgia-like chronic pain patients. These data suggest that caffeine consumption concomitant with opioid analgesics could provide therapeutic benefits not seen with opioids or caffeine alone. [ABSTRACT FROM AUTHOR]

Pain can be elicited through all mammalian sensory pathways yet cross-modal sensory integration, and its relationship to clinical pain, is largely unexplored. Centralized chronic pain conditions such as fibromyalgia are often associated with symptoms of multisensory hypersensitivity. In this study, female patients with fibromyalgia demonstrated cross-modal hypersensitivity to visual and pressure stimuli compared with age- and sex-matched healthy controls. Functional magnetic resonance imaging revealed that insular activity evoked by an aversive level of visual stimulation was associated with the intensity of fibromyalgia pain. Moreover, attenuation of this insular activity by the analgesic pregabalin was accompanied by concomitant reductions in clinical pain. A multivariate classification method using support vector machines (SVM) applied to visual-evoked brain activity distinguished patients with fibromyalgia from healthy controls with 82% accuracy. A separate SVM classification of treatment effects on visual-evoked activity reliably identified when patients were administered pregabalin as compared with placebo. Both SVM analyses identified significant weights within the insular cortex during aversive visual stimulation. These data suggest that abnormal integration of multisensory and pain pathways within the insula may represent a pathophysiological mechanism in some chronic pain conditions and that insular response to aversive visual stimulation may have utility as a marker for analgesic drug development. [ABSTRACT FROM AUTHOR]

Fibromyalgia has been characterized by augmented cross-network functional communication between the brain’s sensorimotor, default mode, and attentional (salience/ventral and dorsal) networks. However, the underlying mechanisms of these aberrant communication patterns are unknown. In this study, we sought to understand large-scale topographic patterns at instantaneous timepoints, known as coactivation patterns (CAPs). We found that a sustained pressure pain challenge temporally modulated the occurrence of CAPs. Using proton magnetic resonance spectroscopy, we found that greater basal excitatory over inhibitory neurotransmitter levels within the anterior insula orchestrated higher cross-network connectivity between the anterior insula and the default mode network through lower occurrence of a CAP encompassing the attentional networks during sustained pain. Moreover, we found that hyperalgesia in fibromyalgia was mediated through increased occurrence of a CAP encompassing the sensorimotor network during sustained pain. In conclusion, this study elucidates the role of momentary large-scale topographic brain patterns in shaping noxious information in patients with fibromyalgia, while laying the groundwork for using precise spatiotemporal dynamics of the brain for the potential development of therapeutics. [ABSTRACT FROM AUTHOR]

Fibromyalgia and opioid use disorder (OUD) are highly impactful chronic illnesses with substantially overlapping psychosocial, biological, and clinical features. Little previous research has examined interactions between fibromyalgia and OUD. Limiting such research has been the previous requirement of a clinical examination to diagnose fibromyalgia. The 2011 American College of Rheumatology Fibromyalgia Survey (ACR-FMS) is a validated self-report instrument with high sensitivity and specificity for fibromyalgia intended to enable fibromyalgia research in settings where a clinical examination is impractical. The present observational study uses the ACR-FMS to determine whether fibromyalgia affects odds of acknowledging pain-related OUD exacerbations among a sample of participants with pain and OUD. Participants with pain and OUD (n 5 125) were recruited from an academic substance use treatment facility. The ACR-FMS, along with an original scale measuring pain-related OUD exacerbation—the Pain-related OUD Exacerbation Scale—was administered through an electronic survey. The factor structure, internal consistency, and construct validity of Pain-related OUD Exacerbation Scale were tested. In addition, descriptive analyses, multiple hierarchical linear regression, ordinal logistic regression, and multinomial logistic regression analyses were performed. Although all participants had pain, those with fibromyalgia demonstrated significantly greater odds of acknowledging pain-related OUD exacerbations. Pain-related OUD Exacerbation Scale was found to have a single-factor solution, strong internal consistency, and construct validity. This study provides first evidence of fibromyalgia as a risk factor for pain-related exacerbation of OUD and introduces a new scale with promising psychometric properties to measure pain-related OUD exacerbation. [ABSTRACT FROM AUTHOR]

Abstract Background Objective Methods Results Conclusion Central sensitization is an important mechanism underlying many chronic pain conditions. Chronic pain and alcohol use disorder (AUD) are highly comorbid. Despite great scientific interest in brain mechanisms linking chronic pain and AUD, progress has been impeded by difficulty assessing central sensitization in AUD.The present study is the first to employ a validated surrogate measure to describe central sensitization in a clinical sample with AUD.Participants with AUD (n = 99) were recruited from an academic addiction treatment center. A well-established surrogate measure of central sensitization, The American College of Rheumatology Fibromyalgia Survey Criteria (ACRFMS) was administered. Participants also responded to questions about quality of life (RAND-36), and AUD. Descriptive analyses and Spearman’s rho correlations were performed.Chronic pain and evidence of central sensitization were prevalent. Greater central sensitization was associated with worse health-related quality of life. Participants higher in central sensitization expressed greater endorsement of pain as a reason for AUD onset, maintenance, escalation, treatment delay, and relapse.The present study bolsters prior assertions that AUD and chronic pain might compound one another via progressive sensitization of shared brain circuitry. These results may inform future mechanistic research and precision AUD treatment. [ABSTRACT FROM AUTHOR]

Endogenous opioid system dysfunction potentially contributes to chronic pain in fibromyalgia (FM), but it is unknown if this dysfunction is related to established neurobiological markers of hyperalgesia. We previously reported that µ-opioid receptor (MOR) availability was reduced in patients with FM as compared with healthy controls in several pain-processing brain regions. In the present study, we compared pain-evoked functional magnetic resonance imaging with endogenous MOR binding and clinical pain ratings in female opioid-naive patients with FM (n = 18) using whole-brain analyses and regions of interest from our previous research. Within antinociceptive brain regions, including the dorsolateral prefrontal cortex (r = 0.81, P < 0.001) and multiple regions of the anterior cingulate cortex (all r > 0.67; all P < 0.02), reduced MOR availability was associated with decreased pain-evoked neural activity. Additionally, reduced MOR availability was associated with lower brain activation in the nucleus accumbens (r = 0.47, P = 0.050). In many of these regions, pain-evoked activity and MOR binding potential were also associated with lower clinical affective pain ratings. These findings are the first to link endogenous opioid system tone to regional pain-evoked brain activity in a clinical pain population. Our data suggest that dysregulation of the endogenous opioid system in FM could lead to less excitation in antinociceptive brain regions by incoming noxious stimulation, resulting in the hyperalgesia and allodynia commonly observed in this population. We propose a conceptual model of affective pain dysregulation in FM. [ABSTRACT FROM AUTHOR]