Chronic overlapping pain conditions increase the risk of long COVID features, regardless of acute COVID status

ABSTRACT

Chronic overlapping pain conditions (COPCs) refer to conditions that have similar central nervous system pathophysiologic mechanisms driving widespread pain as well as common comorbid symptoms such as fatigue and problems with sleep, memory, and mood. If COPCs predict the onset of long COVID, this could offer a valuable orientation for long COVID-related research and clinical care. This retrospective cohort study aimed to determine whether having a COPC predicts the onset of long COVID features using US electronic health records and 1:1 propensity score matching without replacement. The study cohorts included (1) people with acute COVID (n = 1,038,402), (2) people with acute influenza (n = 262,092), and (3) a noninfected cohort comprising people with a routine healthcare encounter (n = 1,081,593). Having a COPC increased the risk of long COVID features in all 3 study cohorts. Among those with COVID, having a pre-existing COPC increased the risk by 1.47 (95% CI = 1.46, 1.47). In the influenza cohort, COPCs increased the risk by 1.39 (95% CI = 1.38, 1.40). In the noninfected cohort, COPCs increased the risk by 1.57 (95% CI = 1.56, 1.59). These findings reinforce the likelihood that nociplastic mechanisms play a prominent role in long COVID. Recognizing that this ubiquitous nonspecific syndrome occurs frequently in the population can inform precision medicine therapies that avoid the pitfalls of viewing long COVID exclusively in the framework of postinfectious disease.

[ 11 C]-PBR28 positron emission tomography signal as an imaging marker of joint inflammation in knee osteoarthritis

ABSTRACT

Although inflammation is known to play a role in knee osteoarthritis (KOA), inflammation-specific imaging is not routinely performed. In this article, we evaluate the role of joint inflammation, measured using [ 11 C]-PBR28, a radioligand for the inflammatory marker 18-kDa translocator protein (TSPO), in KOA. Twenty-one KOA patients and 11 healthy controls (HC) underwent positron emission tomography/magnetic resonance imaging (PET/MRI) knee imaging with the TSPO ligand [ 11 C]-PBR28. Standardized uptake values were extracted from regions-of-interest (ROIs) semiautomatically segmented from MRI data, and compared across groups (HC, KOA) and subgroups (unilateral/bilateral KOA symptoms), across knees (most vs least painful), and against clinical variables (eg, pain and Kellgren-Lawrence [KL] grades). Overall, KOA patients demonstrated elevated [ 11 C]-PBR28 binding across all knee ROIs, compared with HC (all P 's < 0.005). Specifically, PET signal was significantly elevated in both knees in patients with bilateral KOA symptoms (both P 's < 0.01), and in the symptomatic knee ( P < 0.05), but not the asymptomatic knee ( P = 0.95) of patients with unilateral KOA symptoms. Positron emission tomography signal was higher in the most vs least painful knee ( P < 0.001), and the difference in pain ratings across knees was proportional to the difference in PET signal ( r = 0.74, P < 0.001). Kellgren-Lawrence grades neither correlated with PET signal (left knee r = 0.32, P = 0.19; right knee r = 0.18, P = 0.45) nor pain ( r = 0.39, P = 0.07). The current results support further exploration of [ 11 C]-PBR28 PET signal as an imaging marker candidate for KOA and a link between joint inflammation and osteoarthritis-related pain severity.

Plasma proteins and persistent postsurgical pelvic pain among adolescents and young adults with endometriosis

BACKGROUND

Noninvasive biomarkers that predict surgical treatment response would inform personalized treatments and provide insight into potential biologic pathways underlying endometriosis-associated pain and symptom progression.

OBJECTIVE

To use plasma proteins in relation to the persistence of pelvic pain following laparoscopic surgery in predominantly adolescents and young adults with endometriosis using a multiplex aptamer-based proteomics biomarker discovery platform.

STUDY DESIGN

We conducted a prospective analysis including 142 participants with laparoscopically-confirmed endometriosis from the Women's Health Study: From Adolescence to Adulthood observational longitudinal cohort with study enrollment from 2012-2018. Biologic samples and patient data were collected with modified World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project tools. In blood collected before laparoscopic ablation or excision of endometriosis, we simultaneously measured 1305 plasma protein levels, including markers for immunity, angiogenesis, and inflammation, using SomaScan. Worsening or persistent postsurgical pelvic pain was defined as having newly developed, persistent (ie, stable), or worsening severity, frequency, or persistent life interference of dysmenorrhea or acyclic pelvic pain at 1-year postsurgery compared with presurgery. We calculated odds ratios and 95% confidence intervals using logistic regression adjusted for age, body mass index, fasting status, and hormone use at blood draw. We applied Ingenuity Pathway Analysis and STRING analysis to identify pathophysiologic pathways and protein interactions.

RESULTS

The median age at blood draw was 17 years (interquartile range, 15-19 years), and most participants were White (90%). All had superficial peritoneal lesions only and were treated by excision or ablation. One-year postsurgery, pelvic pain worsened or persisted for 76 (54%) of these participants with endometriosis, whereas pelvic pain improved for 66 (46%). We identified 83 proteins associated with worsening or persistent pelvic pain 1-year postsurgery (nominal P<.05). Compared with those with improved pelvic pain 1-year postsurgery, those with worsening or persistent pelvic pain had higher plasma levels of CD63 antigen (odds ratio, 2.98 [95% confidence interval, 1.44-6.19]) and CD47 (odds ratio, 2.68 [95% confidence interval, 1.28-5.61]), but lower levels of Sonic Hedgehog protein (odds ratio, 0.55 [95% confidence interval, 0.36-0.84]) in presurgical blood. Pathways related to cell migration were up-regulated, and pathways related to angiogenesis were down-regulated in those with worsening or persistent postsurgical pelvic pain compared with those with improved pain. When we examined the change in protein levels from presurgery to postsurgery and its subsequent risk of worsening or persistent postsurgical pain at 1-year follow-up, we observed increasing levels of Sonic Hedgehog protein from presurgery to postsurgery was associated with a 4-fold increase in the risk of postsurgical pain (odds ratio [quartile 4 vs 1], 3.86 [1.04-14.33]).

CONCLUSION

Using an aptamer-based proteomics platform, we identified plasma proteins and pathways associated with worsening or persistent pelvic pain postsurgical treatment of endometriosis among adolescents and young adults that may aid in risk stratification of individuals with endometriosis.

Validation of a simple body map to measure widespread pain in urologic chronic pelvic pain syndrome: A MAPP Research Network study

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.

Naturalistic Bladder Filling Reveals Subtypes in Overactive Bladder Syndrome That Differentially Engages Urinary Urgency-Related Brain Circuits: Results From the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN)

PURPOSE

Overactive bladder (OAB) may be attributed to dysfunction in supraspinal brain circuits. Overactive bladder participants enrolled in the LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) study reported sensations of urinary urgency during a bladder-filling paradigm while undergoing brain functional MRI to map supraspinal dysfunction.

MATERIALS AND METHODS

OAB participants and controls (CONs) completed 2 resting-state functional MRI scans following consumption of 350 mL water. Scans were conducted at fuller and emptier bladder states, interleaved with voiding. Urgency ratings (0-10) were assessed. Patterns of urgency during bladder filling were investigated using latent class trajectory models. Clusters of participants encompassing each pattern (ie, subtype) were derived from aggregated groups of OAB and CON independent of diagnosis.

RESULTS

Two distinct patterns of urgency trajectories were revealed: first subtype with OAB and CON who were unresponsive to bladder filling (OAB-1 and CON-1) and second highly responsive subtype predominantly containing OAB (OAB-2). OAB-2 participants scored significantly higher on urinary symptoms but not pain or psychosocial measures. Neuroimaging analyses showed change in urgency due to both bladder filling and voided volume related to multiple loci of brain network connectivity in OAB-2, and in some cases, different than OAB-1 and/or CON-1. Sensorimotor to dorsomedial/dorsolateral prefrontal connectivity mediated the relationship between stimulus (voided volume) and percept (urgency) in OAB-2.

CONCLUSIONS

Our results reveal different OAB subtypes with latent class trajectory models of urgency ratings during natural bladder filling. Functional MRI revealed differences in pathophysiology between subtypes, namely sensorimotor-prefrontal connectivity is a key locus in OAB patients with higher urinary symptoms.

The Chronic Overlapping Pain Condition Screener

Ten Chronic Overlapping Pain Conditions (COPCs) are currently recognized by the National Institutes of Health Pain Consortium (eg, irritable bowel syndrome, chronic migraine headache, and chronic low back pain). These conditions affect millions of Americans; however, assessing these conditions, their co-occurrence, and their relationship to treatment has proven challenging due to time constraints and a lack of standardized measures. We present a Chronic Overlapping Pain Condition-Screener (COPC-S) that is logic-driven, efficient, and freely available in electronic format to nonprofit entities. Thirty experts were convened to identify and modify self-report criteria for each COPC as well as criteria that trigger the administration of the diagnostic criteria from a body map and a brief series of questions. Their recommendations were then programmed into the Research Electronic Data Capture platform and refined for comprehensibility and ease of use by patient focus groups. The electronic screener and physician-administered criteria were both administered to patients with known COPCs in a counter-balanced fashion to determine the level of agreement between methods. The expert panel identified screening items/body map regions and diagnostic criteria for all 10 COPCs. Patients found the content comprehensible and the platform easy to use. Cohen's Kappa statistics suggested good agreement between the electronic COPC-S and criteria administered by a physician (κ = .813). The COPC-S is an efficient tool for screening multiple COPCs and has applicability to research studies, clinical trials, and clinical practice. PERSPECTIVE: Assessing COPCs remains a challenge for researchers and clinicians. The COPC-S is an efficient and logic-driven electronic tool that allows for the rapid screening assessment of 10 COPCs. The instrument may have utility in research and clinical settings.

Risk Factors for the Development of Multisite Pain in Children

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.

Psychosocial predictors of change in sexual activity and sexual function after hysterectomy in women with pelvic pain

BACKGROUND

Potential impact on sexual function is an often-cited concern for many patients considering hysterectomy. The existing literature indicates that sexual function remains stable to slightly improved for most patients who undergo hysterectomy, but most studies demonstrate a small subset of patients in whom sexual function declines after surgery. Unfortunately, there is a lack of clarity as to surgical, clinical, and psychosocial factors that may influence the likelihood of sexual activity after surgery or the magnitude and direction of change in sexual function. Although psychosocial factors are strongly associated with overall female sexual function, there is minimal data exploring the potential impact of these factors on the change in sexual function after hysterectomy.

OBJECTIVE

This study aimed to evaluate the relationship between baseline psychosocial factors and both sexual activity and sexual function at 6 months after hysterectomy.

STUDY DESIGN

Patients undergoing hysterectomy for benign, non-obstetric indications were prospectively recruited as part of an observational cohort study evaluating presurgical predictors of posthysterectomy outcomes on pain, quality of life, and sexual function. The Female Sexual Function Index was administered before hysterectomy and 6 months after surgery. Presurgical psychosocial assessments included validated self-reported measures of depression, resilience, relationship satisfaction, emotional support, and social participation.

RESULTS

Complete data was available for 193 patients, of whom 149 (77.2%) reported sexual activity at 6 months after hysterectomy. In the binary logistic regression model examining sexual activity at 6 months, older age was associated with a lower likelihood of sexual activity (odds ratio, 0.91; 95% confidence interval, 0.85-0.96; P=.002). Higher relationship satisfaction before surgery was associated with a greater likelihood of sexual activity at 6 months (odds ratio, 1.09; 95% confidence interval, 1.02-1.16; P=.008). As expected, preoperative sexual activity was associated with a greater likelihood of postoperative sexual activity (odds ratio, 9.78; 95% confidence interval, 3.95-24.19, P<.001). Analyses using Female Sexual Function Index scores were limited to patients who were sexually active at both time points (n=132 [68.4%]). The total Female Sexual Function Index score did not change significantly from baseline to 6 months, but there were statistically significant changes in several individual domains of sexual function. Patients reported significant improvement in desire (P=.012), arousal (P=.023), and pain (P<.001) domains. However, significant decreases were reported in orgasm (P<.001) and satisfaction (P<.001) domains. The proportion of patients who met the criteria for sexual dysfunction was quite high (>60%) at both time points, but there was not a statistically significant change in the proportion from baseline to 6 months. In the multivariate linear regression model, there was no relationship between change in sexual function score and any of the variables examined, including age, endometriosis history, pelvic pain severity, or psychosocial measures.

CONCLUSION

In this cohort of patients with pelvic pain undergoing hysterectomy for benign indications, both sexual activity and sexual function remained fairly stable after hysterectomy. Higher relationship satisfaction, younger age, and preoperative sexual activity were associated with a greater probability of sexual activity at 6 months after surgery. Psychosocial factors, such as depression, relationship satisfaction, and emotional support, and history of endometriosis were not related to change in sexual function among patients who were sexually active both before hysterectomy and at 6 months after surgery.

Mediators of the association between childhood trauma and pain sensitivity in adulthood: a Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network analysis

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.

Association Between Nociplastic Pain and Pain Severity and Impact in Women With Chronic Pelvic Pain

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.

Early and recent exposure to adversity, TLR-4 stimulated inflammation, and diurnal cortisol in women with interstitial cystitis/bladder pain syndrome: A MAPP research network study

Both early (ELA) and recent life adversity (RLA) have been linked with chronic pain conditions and persistent alterations of neuroendocrine and inflammatory responses. Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a chronic urologic disorder characterized by bladder and/or pelvic pain, and excessive urinary frequency and/or urgency. IC/BPS has been associated with high levels of ELA as well as a distinct inflammatory signature. However, associations between ELA and RLA with inflammatory mechanisms in IC/BPS that might underlie the link between adversity and symptoms have not been examined. Here we investigated ELA and RLA in women with IC/BPS as potential risk factors for inflammatory processes and hypothalamic-pituitaryadrenal (HPA) abnormalities using data from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. Women with IC/BPS and healthy controls (n = 154 and 32, respectively) completed surveys, collected salivary cortisol at awakening and bedtime for 3 days, and gave a blood sample which was analyzed for 7 LPS-stimulated cytokines and chemokines (IL-6, TNFα, IL-1β, MIP1α, MCP1, IL-8, and IL-10). Two cytokine/chemokine composites were identified using principal components analysis. Patients with greater exposure to RLA or cumulative ELA and RLA of at least moderate severity showed elevated levels of a composite of all cytokines, adjusting for age, body mass index, and study site. Furthermore, there was a trending relationship between ELA and the pro-inflammatory composite score. Nocturnal cortisol and cortisol slope were not associated with ELA, RLA, or inflammation. The present findings support the importance of adverse events in IC/BPS via a biological mechanism and suggest that ELA and RLA should be assessed as risk factors for inflammation as part of a clinical workup for IC/BPS.

Stimulated whole-blood cytokine/chemokine responses are associated with interstitial cystitis/bladder pain syndrome phenotypes and features of nociplastic pain: a multidisciplinary approach to the study of chronic pelvic pain research network study

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.

The Biology of Pain: Through the Rheumatology Lens

Chronic pain is a major socioeconomic burden globally. The most frequent origin of chronic pain is musculoskeletal. In inflammatory musculoskeletal diseases such as rheumatoid arthritis (RA), chronic pain is a primary determinant of deleterious quality of life. The pivotal role of peripheral inflammation in the initiation and perpetuation of nociceptive pain is well-established among patients with musculoskeletal diseases. However, the persistence of pain, even after the apparent resolution of peripheral inflammation, alludes to the coexistence of different pain states. Recent advances in neurobiology have highlighted the importance of nociplastic pain mechanisms. In this review we aimed to explore the biology of pain with a particular focus on nociplastic pain in RA.

Trends in pelvic pain symptoms over 2 years of follow-up among adolescents and young adults with and without endometriosis

ABSTRACT

We described trends in pelvic pain characteristics over 2 years of follow-up among adolescents and adults with and without endometriosis participating in the longitudinal observational cohort of the Women's Health Study: From Adolescence to Adulthood, using data reported at baseline and at years 1 and 2 of follow-up. Participants completed a questionnaire at baseline (between November 2012 and May 2019) and annually thereafter that included validated measures of severity, frequency, and life interference of dysmenorrhea, acyclic pelvic pain, and dyspareunia. Our study population included 620 participants with surgically confirmed endometriosis (rASRM stage I/II = 95%) and 671 community-based and hospital-based controls, with median age = 19 and 24 years, respectively. The proportion reporting hormone use varied across the 3 years ranging from 88% to 92% for cases and 56% to 58% for controls. At baseline, endometriosis cases were more likely to report severe, frequent, and life-interfering dysmenorrhea, acyclic pelvic pain, and dyspareunia compared with controls. Among cases, frequency and severity of dysmenorrhea and dyspareunia were relatively static across 2 years. However, acyclic pelvic pain improved. Severe acyclic pain decreased from 69% at baseline to 46% at year 2. Daily pain decreased from 28% to 14%, and life interference from 68% to 38%. Trends among controls remained fairly stable across 2 years. Among endometriosis cases who completed the questionnaire at all 3 time points, 18% reported persistent, severe acyclic pelvic pain at all 3 time points. Over time, different trends were observed by pelvic pain type among endometriosis cases and controls, supporting the importance of assessing multidimensional features of pelvic pain.

An Interventional Response Phenotyping Study in Chronic Low Back Pain: Protocol for a Mechanistic Randomized Controlled Trial

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.

Generalized sensory sensitivity is associated with comorbid pain symptoms: a replication study in women with dysmenorrhea

ABSTRACT

Dysmenorrhea is characterized by high rates of transition to chronic pain. In a previous study using structural equation modeling, we demonstrated that several symptom domains associated with the emerging concept of nociplastic pain can be described using 2 symptom groups: generalized sensory sensitivity (GSS; composed of widespread pain, interceptive sensitivity, and environmental sensitivity) and SPACE (composed of unrefreshing sleep, pain, affective disturbances, cognitive issues, and reduced energy). Here, we perform a secondary cross-sectional analysis examining the same symptoms groups in a cohort of patients with dysmenorrhea without a diagnosis of chronic pain. Our purpose is to determine if the same symptom patterns are apparent and if they are associated with the presence and severity of comorbid pain. Participants were 201 women with dysmenorrhea. We replicated the hypothesized 2-factor structure in this cohort (comparative fit index = 0.971 and root mean square error of approximation =0.055; 90% CI: 0.000-0.097). Generalized sensory sensitivity was associated with the severity of bladder, bowel, and overall pain in multivariable models including SPACE, patient age, and BMI (all β > 0.32, all P < 0.05). Sleep, pain, affective disturbances, cognitive issues, and reduced energy were associated with menstrual pain during nonsteroidal anti-inflammatory drug use, whereas GSS was associated with the same in the absence of nonsteroidal anti-inflammatory drug use (both P < 0.05). This 2-factor model of symptoms seems to be replicable and valid in a cohort of women at risk for developing chronic pain conditions. These symptom groups are promising potential markers of future pain chronification and may point to patients in need of earlier or more aggressive intervention.

Protocol for Biospecimen Collection and Analysis within the BACPAC Research Program

The Biospecimen Collection and Processing Working Group of the NIH HEAL Initiative BACPAC Research Program was charged with identifying molecular biomarkers of interest to chronic low back pain (cLBP). Having identified biomarkers of interest, the Working Group worked with the New York University Grossman School of Medicine, Center for Biospecimen Research and Development-funded by the Early Phase Pain Investigation Clinical Network Data Coordinating Center-to harmonize consortium-wide and site-specific efforts for biospecimen collection and analysis. Biospecimen collected are saliva, blood (whole, plasma, serum), urine, stool, and spine tissue (paraspinal muscle, ligamentum flavum, vertebral bone, facet cartilage, disc endplate, annulus fibrosus, or nucleus pulposus). The omics data acquisition and analyses derived from the biospecimen include genomics and epigenetics from DNA, proteomics from protein, transcriptomics from RNA, and microbiomics from 16S rRNA. These analyses contribute to the overarching goal of BACPAC to phenotype cLBP and will guide future efforts for precision medicine treatment.

Clinical Phenotyping for Pain Mechanisms in Urologic Chronic Pelvic Pain Syndromes: A MAPP Research Network Study

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.

Study protocol: an observational study of distress, immune function and persistent pain in HIV

INTRODUCTION

Many people with HIV report both distress and pain. The relationship between distress and pain is bidirectional, but the mechanisms by which distress exacerbates pain are unclear. The inflammatory response to challenge (inflammatory reactivity, IR) may be a partial mediator, given that neuroimmune interactions provide a substrate for IR to also influence neurological reactivity and, thus, pain-related neural signalling. This prospective, observational, case-control study will characterise the relationships between distress, IR, pain-related signalling as captured by induced secondary hyperalgesia (SH), and pain, in people with HIV who report persistent pain (PP) (cases) or no pain (controls).

METHODS AND ANALYSIS

One hundred people with suppressed HIV, reporting either PP or no pain, will be assessed two or four times over 6 months. The primary outcomes are distress (Hopkins 25-item symptom checklist), IR (multiplex assay after LPS challenge), and PP (Brief Pain Inventory), assessed at the baseline timepoint, although each will also be assessed at follow-up time points. Induced SH will be assessed in a subsample of 60 participants (baseline timepoint only). To test the hypothesis that IR partly mediates the relationship between distress and pain, mediation analysis will use the baseline data from the PP group to estimate direct and indirect contributions of distress and IR to pain. To test the hypothesis that IR is positively associated with SH, data from the subsample will be analysed with generalised mixed effects models to estimate the association between IR and group membership, with SH as the dependent variable.

ETHICS AND DISSEMINATION

Information obtained from this study will be published in peer-reviewed journals and presented at scientific meetings. The study has been approved by the Human Research Ethics Committee of the University of Cape Town (approval number: 764/2019) and the City of Cape Town (ref: 24699).

TRIAL REGISTRATION NUMBER

NCT04757987.

Early Relationships of a Low-Energy Diet With Symptoms of Fibromyalgia

OBJECTIVE

Previous studies have demonstrated that weight loss has been shown to improve pain in weight-bearing joints, and more recent studies suggest that weight loss may be accompanied by improvements in pain in non-weight-bearing regions. In previous work, we demonstrated that these symptoms improve substantially in patients with obesity undergoing 12 weeks of a very low-energy diet (VLED) restricted to 800 kcal as part of a weight-loss program. Preclinical models also have shown analgesic effects of calorie restriction. The purpose of the current observational study was to determine the time course and trajectory of improvement in pain and other symptoms, especially during the early phase of a VLED intervention, prior to major weight loss.

METHODS

Participants were 195 individuals with obesity who had elevated levels of pain and associated symptoms at baseline (score of ≥4 on Fibromyalgia Survey Criteria) and completed a minimum of 3 weeks of a VLED intervention. The primary outcome was improvement in Fibromyalgia Survey Criteria at week 3. In secondary analyses, we created groups of those showing little/no improvement, moderate improvement, and high improvement (little/no improvement mean, 2.21; SD, 1.02; moderate improvement mean, 2.25; SD, 0.81; high improvement mean, 2.42; SD, 0.95; F2,189  = 1.01, P = 0.37), then compared baseline characteristics.

RESULTS

A large proportion of study participants (72%) experienced symptom reductions of 30% or greater by week 3, but there were no differences in the amount of weight lost at this time point. Those who showed little or no improvement (less than 30%) had a higher body mass index at baseline and were more likely to report a diagnosis of depression (both P < 0.05).

CONCLUSION

This degree of improvement after 3 weeks of a VLED is encouraging. These findings help establish the temporal pattern of symptom improvement associated with caloric restriction and suggest that the palliative effects of this diet are at least partly due to the diet itself, rather than the weight loss that ensues.

Neurobiological antecedents of multisite pain in children

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.

Sexual function after hysterectomy according to surgical indication: a prospective cohort study

BACKGROUND

Our aims were to describe characteristics of sexual function prior to and 6months following benign hysterectomy in patients with three common surgical indications, and to identify preoperative factors that influence the magnitude and direction of change in sexual function after the procedure.

METHODS

This prospective observational cohort study enrolled women (n =80) undergoing hysterectomy for benign indications. Patients were categorised into three groups according to surgical indication: (1) pelvic pain (PP), (2) abnormal uterine bleeding (AUB), and (3) pelvic organ prolapse (POP). Primary outcome was Female Sexual Function Index (FSFI), which patients completed preoperatively and 6months postoperatively.

RESULTS

The study included 80 patients, of whom 25.0% (n =20) had surgical indication of PP, 46.3% (n =37) of AUB, and 28.7% (n =23) of POP. PP patients experienced a significant improvement in overall sexual function, as well as orgasm and pain domains following hysterectomy. Significant improvements were not found in AUB and POP patients. In multivariate analysis, lower baseline sexual function (P <0.001), younger age (P =0.013), and pelvic pain<6months (P =0.020) were each independently associated with improvement in sexual function, but surgical indication was not significant.

CONCLUSION

Individual patient factors including younger age, lower baseline sexual function, and short duration of pelvic pain are associated with a higher likelihood of improvement in sexual function after hysterectomy. Surgical indication does not appear to be predictive of postoperative sexual function once accounting for other factors.

Characterizing Pain and Generalized Sensory Sensitivity According to Trauma History Among Patients With Knee Osteoarthritis

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.

Positive Psychosocial Factors and Oxytocin in the Ovarian Tumor Microenvironment

OBJECTIVE

Clinical ovarian cancer research shows relationships between psychosocial factors and disease-promoting aspects of the stress response (e.g., norepinephrine and cortisol). However, little is known about how psychosocial factors might relate to beneficial hormones in the ovarian tumor microenvironment. Here we examine relationships between psychosocial factors and tumor-associated oxytocin, a hormone linked to survival and antitumor processes in ovarian cancer.

METHODS

Patients with ovarian cancer (n = 96) completed assessments of positive psychosocial factors (social support, positive affect, and purpose in life) and distress (perceived stress and depression) at the time of surgery. Levels of oxytocin and interleukin (IL) 6 in ascites fluid were obtained during surgery and analyzed by enzyme-linked immunosorbent assay. Multiple regression analyses adjusting a priori for patient age and disease stage examined associations between psychosocial factors and ascites oxytocin. IL-6 was used as a covariate in secondary analyses to examine the potentially confounding effects of inflammation in these relationships.

RESULTS

Higher levels of positive affect (β = 0.22, p = .034), purpose in life (β = 0.31, p = .021), and social nurturance (β = 0.24, p = .024) were all related to higher levels of tumor-associated oxytocin at the time of surgery. In contrast, we found no effects for distress or social attachment. Relationships between oxytocin, purpose in life, and social nurturance were independent of IL-6, whereas positive affect was no longer significant with IL-6 in the model.

CONCLUSIONS

Tumor-associated oxytocin may be a previously uninvestigated link in the relationship between psychosocial factors and health in ovarian cancer. Future studies should examine causal mechanisms of relationships observed in this study.

Chronic difficulties are associated with poorer psychosocial functioning in the first year post-diagnosis in epithelial ovarian cancer patients

OBJECTIVE

Ovarian cancer is characterized by poor prognosis, high levels of distress, disturbed sleep, and compromised quality of life (QOL). Although life stressors have been shown to significantly impact physical and psychological health in cancer populations, no studies have used a high-resolution stress assessment to differentiate effects of acute versus chronic stressors among women with ovarian cancer. We addressed this issue in the present prospective longitudinal study by examining how acute and chronic stress exposure in the year pre-diagnosis relate to depressive symptoms, sleep quality, and QOL over the first year post-diagnosis in women with ovarian cancer.

METHODS

One hundred thirty-seven women completed the Life Events and Difficulties Schedule within a month of initial treatment for suspected ovarian cancer. Depressive symptoms, sleep, and QOL were measured pre-treatment, at six months, and one-year post-diagnosis. Mixed models were used to examine associations of acute and chronic stress pre-diagnosis with (a) change in psychosocial outcomes over the first year post-diagnosis and (b) levels of psychosocial outcomes across all time points.

RESULTS

Both the number and severity of chronic difficulties (but not acute life events) were related to significantly greater depression, and poorer sleep quality and QOL, across all time-points. In contrast, these stress indices were unrelated to changes in psychosocial functioning over time.

CONCLUSIONS

Chronic but not acute stress exposure predicted average levels of depression, sleep, and QOL in the first year post-diagnosis among women with ovarian cancer. Assessing stressors and designing interventions for reducing stress may thus be beneficial for ovarian cancer patients.

Impact of Fibromyalgia Phenotype in Temporomandibular Disorders

BACKGROUND

Mounting evidence suggests that central nervous system amplification, similar to that seen in fibromyalgia (FM), contributes to the pain experience in a subset of patients with temporomandibular disorders (TMD).

METHODS

In this prospective observational study, patients with TMD completed the 2011 FM survey questionnaire, a surrogate measure of "centralized" pain. The influence of centralized pain on TMD pain, dysfunction, and disability was assessed dichotomously by determining the incidence of FM-positive cases in the sample and by using FM survey scores as a continuous measure of "fibromyalgia-ness" ("FM-ness").

RESULTS

The patients meeting criteria for FM diagnosis (17 of 89) had significantly more disease burden on numerous measures. FM-ness was positively associated with pain at rest, negative mood, tenderness to palpation, perceived jaw functional limitation, and pain-related disability, and it was negatively associated with comfortable pain-free jaw opening. The impact of FM-ness on perceived jaw functional limitation and disability was mediated by levels of spontaneous, ongoing pain in the orofacial region. Importantly, this pattern of findings was still present even in those not meeting the criteria for FM diagnosis.

CONCLUSION

Together, these results imply that higher FM-ness increases TMD patient burden by amplifying spontaneous pain and further hampering painless jaw function, even in patients who do not meet criteria for FM diagnosis. These results are highly relevant for the clinical management of TMD, as they imply that targeting the central nervous system in the treatment of patients with TMD with evidence of pain centralization may help ameliorate both pain and jaw dysfunction.

Natural bladder filling alters resting brain function at multiple spatial scales: a proof-of-concept MAPP Network Neuroimaging Study

Neural circuitry regulating urine storage in humans has been largely inferred from fMRI during urodynamic studies driven by catheter infusion of fluid into the bladder. However, urodynamic testing may be confounded by artificially filling the bladder repeatedly at a high rate and examining associated time-locked changes in fMRI signals. Here we describe and test a more ecologically-valid paradigm to study the brain response to bladder filling by (1) filling the bladder naturally with oral water ingestion, (2) examining resting state fMRI (rs-fMRI) which is more natural since it is not linked with a specific stimulus, and (3) relating rs-fMRI measures to self-report (urinary urge) and physiologic measures (voided volume). To establish appropriate controls and analyses for future clinical studies, here we analyze data collected from healthy individuals (N = 62) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. Participants orally ingested approximately 350 mL of water, and had a 10 min “fuller bladder” rs-fMRI scan approximately 1 h later. A second 10 min “empty bladder” rs-fMRI scan was conducted immediately following micturition. We examined multiple spatial scales of brain function, including local activity, circuits, and networks. We found changes in brain function distributed across micturition loci (e.g., subregions of the salience, sensorimotor, and default networks) that were significantly related to the stimulus (volume) and response (urinary urge). Based on our results, this paradigm can be applied in the future to study the neurobiological underpinnings of urologic conditions.

Metabolic and Structural Skeletal Muscle Health in Systemic Lupus Erythematosus-Related Fatigue: A Multimodal Magnetic Resonance Imaging Study

OBJECTIVE

To investigate the potential structural and metabolic role of skeletal muscle in systemic lupus erythematosus (SLE)-related fatigue.

METHODS

A case-control, multimodal magnetic resonance imaging (MRI) study was conducted. Cases were patients with inactive SLE who reported chronic fatigue. Controls were age- and sex-matched healthy members of the general population. Patients were clinically characterized and then underwent a 3T whole-body MRI scan. Resting and dynamic ³¹ P MRI spectroscopy of the calf muscles was applied, from which phosphocreatine (PCr) recovery halftime, a marker of mitochondrial dysfunction, was computed. In addition, microstructural sequences (T1-weighted anatomic images, T2 mapping, and diffusion tensor imaging) were acquired. Descriptive statistics evaluated group differences and within-case physical fatigue correlations were explored.

RESULTS

Of the 37 recruits (mean age 43.8 years, 89.2% female), cases (n = 19) reported higher levels of physical fatigue, pain, depression, and sleep disturbance compared to the control group (P < 0.0001). PCr was greater (P = 0.045) among cases (mean ± SD 33.0 ± 9.0 seconds) compared to controls (mean ± SD 27.1 ± 6.6 seconds). No microstructural group differences were observed. Within cases, physical fatigue did not correlate with PCr (r = -0.28, P = 0.25).

CONCLUSION

We report preliminary data demonstrating greater skeletal muscle mitochondrial dysfunction among fatigued patients with SLE compared to healthy controls.

Top down or bottom up? An observational investigation of improvement in fibromyalgia symptoms following hip and knee replacement

OBJECTIVES

Many patients with osteoarthritis have comorbid symptoms of FM, but it is unknown how these symptoms respond to surgical procedures that address nociceptive input in the periphery, such as total joint replacement. Here we explore differences in clinical characteristics between patients whose FM symptoms do and do not improve following total hip or knee replacement.

METHODS

Participants were 150 patients undergoing knee or hip replacement who had a minimum FM survey score of 4 or greater prior to surgery. The top tertile of patients experiencing the most improvement in FM symptoms at month 6 were categorized as 'Improve' (n = 48) while the bottom two tertiles were categorized as 'Worsen/Same' (n = 102). Baseline symptom characteristics were compared between groups, as well as improvement in overall pain severity, surgical pain severity and physical function at 6 months.

RESULTS

The Worsen/Same group had higher levels of fatigue, depression and surgical site pain at baseline (all P < 0.05). Additionally, they improved less on overall pain severity and physical functioning 6 months after surgery (both P < 0.05).

CONCLUSION

Most patients derive significant benefit in improvement of comorbid FM symptoms following total joint replacement, but a substantial proportion do not. Understanding the neurobiological basis for these different trajectories may help inform clinical judgment and improve patient care.

Inflammation and the Central Nervous System in Inflammatory Rheumatic Disease

PURPOSE OF REVIEW

To review how peripheral inflammation in rheumatic disease influences the central nervous system. We consider recent studies of rheumatic disease that employ functional and structural neuroimaging in the context of inflammation, as well as recent studies considering how immunosuppressive therapy is associated with changes in brain function and structure.

RECENT FINDINGS

The most compelling evidence thus far comes from studies of rheumatoid arthritis and indicates that higher levels of inflammation are associated with changes in cognitive, affective, and pain-processing brain regions, some of which may be rectified by anti-inflammatory treatment. Comorbid symptoms such as widespread pain and fatigue may also be associated with these changes. Inflammation may be associated with compensatory activation of brain regions to offset structural changes. This emerging line of evidence suggests that communication between the brain and immune system are an important and underappreciated aspect of inflammatory rheumatic disease.

Association of Inflammation With Pronociceptive Brain Connections in Rheumatoid Arthritis Patients With Concomitant Fibromyalgia

OBJECTIVE

Rheumatoid arthritis (RA) patients with concomitant fibromyalgia (FM) exhibit alterations in brain connectivity synonymous with central sensitization. This study was undertaken to investigate how peripheral inflammation, the principal nociceptive stimulus in RA, interacts with brain connectivity in RA patients with FM.

METHODS

RA patients with concomitant FM and those without FM (FM+ and FM-, respectively; n = 27 per group) underwent functional connectivity magnetic resonance imaging. Seed-to-whole-brain functional connectivity analyses were conducted using seeds from the left mid/posterior insula and left inferior parietal lobule (IPL), which are regions that have been previously linked to FM symptoms and inflammation, respectively. The association between functional connectivity and erythrocyte sedimentation rate (ESR) was assessed in each group separately, followed by post hoc analyses to test for interaction effects. Cluster-level, family-wise error (FWE) rates were considered significant if the P value was less than 0.05.

RESULTS

The group of RA patients with FM and those without FM did not differ by age, sex, or ESR (P > 0.2). In FM+ RA patients, increased functional connectivity of the insula-left IPL, left IPL-dorsal anterior cingulate, and left IPL-medial prefrontal cortex regions correlated with higher levels of ESR (all FWE-corrected P < 0.05). Post hoc interaction analyses largely confirmed the relationship between ESR and connectivity changes as FM scores increased.

CONCLUSION

We report the first neurobiologic evidence that FM in RA may be linked to peripheral inflammation via pronociceptive patterns of brain connectivity. In patients with such "bottom-up" pain centralization, concomitant symptoms may partially respond to antiinflammatory treatments.

Adverse Childhood Experiences and Symptoms of Urologic Chronic Pelvic Pain Syndrome: A Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network Study

Background

Adverse Childhood Experiences (ACEs) such as sexual and physical violence, serious illness, and bereavement have been linked to number of chronic pain conditions in adulthood, and specifically to urologic chronic pelvic pain syndrome (UCPPS).

Purpose

We sought to characterize the prevalence of ACEs in UCPPS using a large well-characterized cohort in comparison with a group of healthy controls. We also sought to determine the association of ACE severity with psychological factors known to impact pain and to determine whether ACEs are associated with patterns of improvement or worsening of symptom over a year of naturalistic observation.

Methods

For longitudinal analyses we used functional clusters identifying broad classes of (a) improved, (b) worsened, and (c) stable groups for genitourinary pain and urinary symptoms. We employed a mediation/path analysis framework to determine whether ACEs influenced 1 year outcomes directly, or indirectly through worse perceptions of physical well-being.

Results

ACE severity was elevated in UCPPS (n = 421) participants compared with healthy controls (n = 414; p < .001), and was most strongly associated with factors associated with complex chronic pain, including more diffuse pain, comorbid functional symptoms/syndromes, and worse perceived physical well-being (all p < .001). Finally, worse physical well-being mediated the relationship between ACE severity and less likelihood of painful symptom improvement (OR = .871, p = .007)) and a greater likelihood of painful symptom worsening (OR = 1.249, p = .003) at 1 year.

Conclusions

These results confirm the association between ACEs and UCPPS symptoms, and suggest potential targets for therapeutic interventions in UCPPS.

Clinical Trial registration

NCT01098279.

Oxytocin in the tumor microenvironment is associated with lower inflammation and longer survival in advanced epithelial ovarian cancer patients

BACKGROUND

Prior research demonstrates a protective role for oxytocin in ovarian cancer based on its anti-proliferative, anti-migratory, and anti-invasive effects in vitro and in vivo. However, the role of endogenous oxytocin has not been examined in ovarian cancer patients. Oxytocin also has anti-inflammatory properties that have not been examined in cancer. The purpose of this investigation was to examine relationships between endogenous oxytocin, tumor-associated inflammation (interleukin-6), and survival in advanced epithelial ovarian cancer patients.

METHODS

Tumor microenvironment (ascites) and plasma oxytocin levels were analyzed via ELISA on extracted samples obtained from 79 patients. In vitro models were used to characterize oxytocin and oxytocin receptor expression in four ovarian cancer cell lines and to investigate direct anti-inflammatory effects of oxytocin on tumor cell secretion of interleukin-6. High and variable levels of oxytocin were observed in ascites, up to 200 times greater than in plasma. Higher levels of ascites oxytocin were associated with lower levels of systemic and tumor-associated interleukin-6, an inflammatory cytokine implicated in ovarian tumor progression. Oxytocin also attenuated interleukin-6 secretion from multiple ovarian tumor cell lines in vitro. Higher levels of ascites oxytocin were associated with a significant survival advantage and statistical mediation analyses suggested this effect was partially mediated by interleukin-6.

CONCLUSIONS

These data identify a previously unacknowledged hormone in the ovarian tumor microenvironment and provide initial evidence that oxytocin has protective effects in ovarian cancer via anti-inflammatory mechanisms. Future studies should examine the therapeutic utility of oxytocin.

Impact of early adverse life events and sex on functional brain networks in patients with urological chronic pelvic pain syndrome (UCPPS): A MAPP Research Network study

Pain is a highly complex and individualized experience with biopsychosocial components. Neuroimaging research has shown evidence of the involvement of the central nervous system in the development and maintenance of chronic pain conditions, including urological chronic pelvic pain syndrome (UCPPS). Furthermore, a history of early adverse life events (EALs) has been shown to adversely impact symptoms throughout childhood and into adulthood. However, to date, the role of EAL’s in the central processes of chronic pain have not been adequately investigated. We studied 85 patients (56 females) with UCPPS along with 86 healthy controls (HCs) who had resting-state magnetic resonance imaging scans (59 females), and data on EALs as a part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network Study. We used graph theory methods in order to investigate the impact of EALs on measures of centrality, which characterize information flow, communication, influence, and integration in a priori selected regions of interest. Patients with UCPPS exhibited lower centrality in the right anterior insula compared to HCs, a key node in the salience network. Males with UCPPS exhibited lower centrality in the right anterior insula compared the HC males. Females with UCPPS exhibited greater centrality in the right caudate nucleus and left angular gyrus compared to HC females. Males with UCPPS exhibited lower centrality in the left posterior cingulate, angular gyrus, middle temporal gyrus, and superior temporal sulcus, but greater centrality in the precuneus and anterior mid-cingulate cortex (aMCC) compared to females with UCPPS. Higher reports of EALs was associated with greater centrality in the left precuneus and left aMCC in females with UCPPS. This study provides evidence for disease and sex-related alterations in the default mode, salience, and basal ganglia networks in patients with UCPPS, which are moderated by EALs, and associated with clinical symptoms and quality of life (QoL).

ICD-10 Codes for the Study of Chronic Overlapping Pain Conditions in Administrative Databases

Chronic overlapping pain conditions (COPCs) are a set of painful chronic conditions characterized by high levels of co-occurrence. It has been hypothesized that COPCs co-occur in many cases because of common neurobiological vulnerabilities. In practice, most research on COPCs has focused upon a single index condition with little effort to assess comorbid painful conditions. This likely means that important phenotypic differences within a sample are obscured. The International Classification of Diseases (ICD) coding system contains many diagnostic classifications that may be applied to individual COPCs, but there is currently no agreed upon set of codes for identifying and studying each of the COPCs. Here we seek to address this issue through three related projects 1) we first compile a set of ICD-10 codes from expert panels for ten common COPCs, 2) we then use natural language searches of medical records to validate the presence of COPCs in association with the proposed expert codes, 3) finally, we apply the resulting codes to a large administrative medical database to derive estimates of overlap between the ten conditions as a demonstration project. The codes presented can facilitate administrative database research on COPCs. PERSPECTIVE: This article presents a set of ICD-10 codes that researchers can use to explore the presence and overlap of COPCs in administrative databases. This may serve as a tool for estimating samples for research, exploring comorbidities, and treatments for individual COPCs, and identifying mechanisms associated with their overlap.

Cystitis-induced bladder pain is Toll-like receptor 4 dependent in a transgenic autoimmune cystitis murine model: a MAPP Research Network animal study

Altered Toll-like receptor (TLR)4 activation has been identified in several chronic pain conditions but has not been well studied in interstitial cystitis/bladder pain syndrome (IC/BPS). Our previously published human studies indicated that patients with IC/BPS present altered systemic TLR4-mediated inflammatory responses, which were significantly correlated with reported pain severity. In the present study, we sought to determine whether altered TLR4 activation plays a role in pelvic/bladder pain seen in patients with IC/BPS using our validated IC/BPS-like transgenic autoimmune cystitis model (URO-OVA). URO-OVA mice developed responses consistent with pelvic and bladder pain after cystitis induction, which was associated with increased splenocyte production of TLR4-mediated proinflammatory cytokines IL-1β, IL-6, and TNF-α. Increased spinal expression of mRNAs for proinflammatory cytokines IL-6 and TNF-α, glial activation markers CD11b and glial fibrillary acidic protein, and endogenous TLR4 ligand high mobility group box 1 was also observed after cystitis induction. Compared with URO-OVA mice, TLR4-deficient URO-OVA mice developed significantly reduced nociceptive responses, although similar bladder inflammation and voiding dysfunction, after cystitis induction. Intravenous administration of TAK-242 (a TLR4-selective antagonist) significantly attenuated nociceptive responses in cystitis-induced URO-OVA mice, which was associated with reduced splenocyte production of TLR4-mediated IL-1β, IL-6, and TNF-α as well as reduced spinal expression of mRNAs for IL-6, TNF-α, CD11b, glial fibrillary acidic protein, and high mobility group box 1. Our results indicate that altered TLR4 activation plays a critical role in bladder nociception independent of inflammation and voiding dysfunction in the URO-OVA model, providing a potential mechanistic insight and therapeutic target for IC/BPS pain.

Functional and structural magnetic resonance imaging correlates of fatigue in patients with rheumatoid arthritis

Objectives

Fatigue is a major burden among patients with RA, yet is poorly understood. We sought to conduct the first imaging study to investigate the neurobiological correlates of fatigue in RA and to improve upon the methodological limitations of previous neuroimaging studies that have investigated this symptom in other populations.

Methods

Chronically fatigued RA patients were clinically characterized before undertaking a combined functional and structural mode MRI brain scan. The functional sequences were acquired during a fatigue-evoking task, then network-to-whole-brain analyses were undertaken. The structural analyses employed voxel-based morphometry in order to quantify regional grey matter volume. The scan was repeated 6 months later to test reproducibility.

Results

Fifty-four participants attended both scans [n = 41 female; baseline mean (s.d.) age 54.94 (11.41) years]. A number of significant functional and structural neural imaging correlates of fatigue were identified. Notably, patients who reported higher levels of fatigue demonstrated higher levels of functional connectivity between the Dorsal Attention Network and medial prefrontal gyri, a finding that was reproduced in the repeat scans. Structurally, greater putamen grey matter volumes significantly correlated with greater levels of fatigue.

Conclusion

Fatigue in RA is associated with functional and structural MRI changes in the brain. The newly identified and reproduced neural imaging correlates provide a basis for future targeting and stratification of this key patient priority.

Impact of Self-Acupressure on Co-Occurring Symptoms in Cancer Survivors

Background

Cancer survivors with fatigue often experience depressive symptoms, anxiety, and pain. Previously, we reported that self-acupressure improved fatigue; however, its impact on other co-occurring symptoms and their involvement in treatment action has not been explored.

Methods

Changes in depressive symptoms, anxiety, and pain were examined prior to and following two formulas of self-acupressure and usual care using linear mixed models in 288 women from a previously reported clinical trial. Participants were categorized by random assignment into one of three groups: 1) relaxing acupressure, 2) stimulating acupressure, or 3) usual care. Moderators investigated were body mass index, age, depressive symptoms, anxiety, sleep and pain, and mediators were change in these symptoms.

Results

Following treatment, depressive symptoms improved statistically significantly for the relaxing acupressure group (41.5%) compared with stimulating acupressure (25%) and usual care (7.7%). Both acupressure groups were associated with greater improvements in anxiety than usual care, but only relaxing acupressure was associated with greater reductions in pain severity, and only stimulating acupressure was associated with greater reductions in pain interference. There were no statistically significant moderators of sleep quality, anxiety, or depressive symptoms. Fatigue statistically significantly moderated pain, and age statistically significantly modified fatigue. Changes in depressive symptoms and sleep quality statistically significantly mediated the relationship between relaxing acupressure and usual care on fatigue; however, the effect was small.

Conclusions

Acupressure was associated with greater improvements than usual care in anxiety, pain, and symptoms of depression in breast cancer survivors with troublesome fatigue. These findings warrant further evaluation in suitably controlled randomized trials.

Sensory sensitivity and symptom severity represent unique dimensions of chronic pain: a MAPP Research Network study

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.

A multi-modal MRI study of the central response to inflammation in rheumatoid arthritis

It is unknown how chronic inflammation impacts the brain. Here, we examined whether higher levels of peripheral inflammation were associated with brain connectivity and structure in 54 rheumatoid arthritis patients using functional and structural MRI. We show that higher levels of inflammation are associated with more positive connections between the inferior parietal lobule (IPL), medial prefrontal cortex, and multiple brain networks, as well as reduced IPL grey matter, and that these patterns of connectivity predicted fatigue, pain and cognitive dysfunction. At a second scan 6 months later, some of the same patterns of connectivity were again associated with higher peripheral inflammation. A graph theoretical analysis of whole-brain functional connectivity revealed a pattern of connections spanning 49 regions, including the IPL and medial frontal cortex, that are associated with peripheral inflammation. These regions may play a critical role in transducing peripheral inflammatory signals to the central changes seen in rheumatoid arthritis.

Many diseases, such as rheumatoid arthritis, are characterized by a chronic inflammatory state, but it is not clear whether or how this affects the brain. Here, the authors show that the severity of on-going inflammation predicts altered functional brain connectivity in people with rheumatoid arthritis.

Resting Functional Connectivity of the Periaqueductal Gray Is Associated With Normal Inhibition and Pathological Facilitation in Conditioned Pain Modulation

Conditioned pain modulation (CPM), a psychophysical paradigm that is commonly used to infer the integrity of endogenous pain-altering systems by observation of the effect of one noxious stimulus on another, has previously identified deficient endogenous analgesia in fibromyalgia (FM) and other chronic pain conditions. The mechanisms underlying this deficiency, be they insufficient inhibition and/or active facilitation, are largely unknown. The present cross-sectional study used a combination of behavioral CPM testing, voxel-based morphometry, and resting state functional connectivity to identify neural correlates of CPM in healthy controls (HC; n = 14) and FM patients (n = 15), and to probe for differences that could explain the pain-facilitative CPM that was observed in our patient sample. Voxel-based morphometry identified a cluster encompassing the periaqueductal gray (PAG) that contained significantly less gray matter volume in FM patients. Higher resting connectivity between this cluster and cortical pain processing regions was associated with more efficient inhibitory CPM in both groups, whereas PAG connectivity with the dorsal pons was associated with greater CPM inhibition only in HC. Greater PAG connectivity to the caudal pons/rostral medulla, which was pain-inhibitory in HC, was associated with pain facilitation in FM patients.

PERSPECTIVE

These findings indicate that variation in the strength of the PAG resting functional connectivity can explain some of the normal variability in CPM. In addition, pain-facilitative CPM observed in FM patients likely involves attenuation of pain inhibitory as well as amplification of pain facilitative processes in the central nervous system.