The number of existing functional somatic syndromes (FSSs) is an important risk factor for new, different FSSs

Functional Somatic Syndromes Are Associated With Varied Postoperative Outcomes and Increased Opioid Use After Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic Review.

OBJECTIVE

To perform a systematic review assessing the relationship between functional somatic syndromes (FSSs) and clinical outcomes after spine surgery.

METHODS

A systematic review of online databases (PubMed and Web of Science) through December 2021 was conducted via PRISMA guidelines to identify all studies investigating the impact of at least one FSS (fibromyalgia, irritable bowel syndrome (IBS), chronic headaches/migraines, interstitial cystitis, chronic fatigue syndrome, multiple chemical sensitivity) on outcomes after spine surgery. Outcomes of interest included patient reported outcome measures (PROMs), postoperative opioid use, cost of care, complications, and readmission rates.

RESULTS

A total of 207 records were identified. Seven studies (n = 40,011 patients) met inclusion criteria with a mean MINORS score of 16.6 out of 24. Four studies (n = 21,086) reported postoperative opioid use; fibromyalgia was a strong risk factor for long-term opioid use after surgery whereas the association with chronic migraines remains unclear. Two studies (n = 233) reported postoperative patient reported outcome measures (PROMs) with mixed results suggesting a possible association between fibromyalgia and less favorable PROMs. One study (n = 18,692) reported higher postoperative complications in patients with fibromyalgia.

CONCLUSION

Patients with fibromyalgia and possibly migraines are at higher risk for prolonged postoperative opioid use and less favorable PROMs after spine surgery. There is limited research on the relationship between other Functional somatic syndromes (FSSs) and outcomes following spine surgery. Growing evidence suggests the variation in outcomes after spine procedures may be attributed to non-identifiable organic patient factors such as FSSs.

Predictors of somatic symptom burden in healthcare professionals during the COVID-19 pandemic: an 8-week follow-up study

BACKGROUND

Literature investigating the impact of COVID-19 on healthcare professionals barely addresses predictors of somatic symptom burden during the COVID-19 pandemic.

AIMS

As biopsychosocial models propose that not only the disease but also sociodemographic and psychosocial factors contribute to the development and maintenance of symptoms, this study investigates the predictive value of these factors for bothersome somatic symptoms in SARS-CoV-2 negative healthcare professionals.

METHODS

German healthcare professionals were assessed with self-rating questionnaires and underwent SARS-CoV-2 IgG antibody tests at baseline and 8 weeks later between April and August 2020. Differences in psychosocial variables between the time points were analyzed and regression analyses were performed to predict somatic symptoms at follow-up.

RESULTS

1185 seronegative healthcare professionals completed both assessments. Previous somatic symptom burden, higher levels of anxiety, being a nurse, younger age, higher psychological symptom burden, lower efficiency, and higher fatigability at baseline predicted somatic symptom burden at follow-up. Comparisons between baseline and follow-up showed a significant improvement in psychological impairment and deterioration of physical exhaustion.

CONCLUSIONS

Our study applies a biopsychosocial perspective to bothersome somatic symptoms during the COVID-19 pandemic and contributes to the identification of potential risk factors as a starting point for future interventions that could support the handling of symptoms.

Musculoskeletal Pain, a Possible Indicator of Central Sensitization, Is Positively Associated With Lower Urinary Tract Symptom Progression in Community-Dwelling Older Men

BACKGROUND

Musculoskeletal pain, a possible marker of central sensitization, is associated with higher prevalence of lower urinary tract symptoms (LUTS) among older men. We investigated whether musculoskeletal pain is associated with LUTS progression.

METHODS

Participants were 5 569 men age ≥65 years enrolled in the prospective, multicenter Osteoporotic Fractures in Men (MrOS) Study. Self-reported musculoskeletal pain within 12 months before baseline was categorized as any pain and multilocation pain. Pain interference within 4 weeks of baseline was assessed with the SF-12 questionnaire. LUTS were assessed repeatedly with the American Urological Association Symptom Index (AUA-SI). Men with severe LUTS at baseline were excluded. LUTS progression was defined as the first occurrence of a ≥4-point AUA-SI increase during a 2-year follow-up interval. Incidence rate ratios (IRR) and 95% confidence intervals (CI) were estimated using multivariable pooled logistic regression.

RESULTS

LUTS progression was 37% higher among men with any musculoskeletal pain compared with men without pain (IRR 1.37, 95% CI: 1.21, 1.54). Positive associations were also observed between LUTS progression and pain at 1 (IRR 1.31, 95% CI: 1.13, 1.48) and ≥2 locations (IRR 1.42, 95% CI: 1.24, 1.60). Compared with men without pain interference, men with quite a bit/extreme pain interference were most likely to experience LUTS progression (minimal interference IRR 1.15, 95% CI: 1.03, 1.26; moderate interference IRR 1.28, 95% CI: 1.11, 1.45; quite a bit/extreme interference IRR 1.47, 95% CI: 1.22, 1.71).

CONCLUSIONS

Among men initially without severe LUTS, musculoskeletal pain is associated with an increased risk of LUTS progression. Studies using validated measures of central sensitization and LUTS progression among men are warranted.

Patients With Functional Somatic Syndromes-Fibromyalgia, Irritable Bowel Syndrome, Chronic Headaches, and Chronic Low Back Pain-Have Lower Outcomes and Higher Opioid Usage and Cost After Shoulder and Elbow Surgery

PURPOSE

To perform a systematic review assessing the relationship between functional somatic syndromes (FSSs) and patient-reported outcome measures (PROMs), postoperative opioid consumption, and hospitalization costs after shoulder and elbow surgery.

METHODS

A systematic review of the PubMed and Web of Science databases was conducted according to Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines to identify all studies evaluating the effect of having at least 1 FSS (fibromyalgia, irritable bowel syndrome, chronic headaches, chronic low back pain) on outcomes after shoulder and elbow surgeries. Outcomes of interest included postoperative analgesic use, PROMs, and hospitalization costs.

RESULTS

The review identified a total of 320 studies, of which 8 studies met the inclusion criteria. The total number of participants in our 8 included studies was 57,389. Three studies (n = 620) reported PROMs. These studies demonstrated that the presence of at least 1 FSS is predictive of significantly greater pain scores and lower quality of recovery, Disability Arm Shoulder and Hand, American Shoulder and Elbow Surgeons Shoulder Score, and Single Assessment Numeric Evaluation scores postoperatively. Although scores were inferior in among patients with FSS, 2 of the 3 studies showed improvement in PROMs in this group of patients. Seven studies (n = 56,909) reported postoperative opioid use. Of these, 5 reported that a diagnosis of at least 1 FSS was a strong risk factor for long-term opioid use after surgery. One study (n = 480) found that time-driven activity-based costs were significantly greater in patients with FSSs.

CONCLUSIONS

Patients with functional somatic syndromes have less-favorable PROMs postoperatively, consume more opioids postoperatively, and have greater health care costs after elective shoulder and elbow procedures. Although PROMs among patients with FSSs are inferior compared with those without FSSs, PROMs still improved compared with baseline.

LEVEL OF EVIDENCE

Level III, systematic review of Level II-III studies.

Validation of ICD-9 Codes for Identification of Chronic Overlapping Pain Conditions

Chronic overlapping pain conditions (COPCs) are a collection of chronic pain syndromes that often co-occur and are thought to share underlying nociplastic pathophysiology. Since they can manifest as seemingly unrelated syndromes they have historically been studied in isolation. Use of International Classification of Diseases (ICD) codes in medical records has been proposed as a means to identify and study trends in COPCs at the population level, however validated code sets are needed. Recently, a code set comprising ICD-10 codes as proxies for 11 COPCs was validated. The goal of this project was to validate a code set composed of ICD-9 codes for the identification of COPCs in administrative datasets. Data was extracted using the Electronic Medical Record Search Engine at the University of Michigan Health System from January 1st, 2011 to January 1st, 2015. The source population were patients with one of the candidate ICD-9 codes corresponding to various COPCs. Natural language searches were used as a reference standard. If code sets met a pre-specified threshold of agreement between ICD-9 codes and natural language searches (≥ 70%), they were retained and diagnostic accuracy statistics were calculated for each code set. Validated ICD-9 code sets were generated for 10 of the 11 COPCs evaluated. The majority had high levels of diagnostic accuracy, with all but one code set achieving ≥ 80% specificity, sensitivity, and predictive values. This code set may be used by pain researchers to identify COPCs using ICD-9 codes in administrative datasets.

Multidisciplinary approach to functional somatic syndromes: study protocol for a population-based prospective cohort study

INTRODUCTION

Isfahan functional disorders (ISFUN) cohort study aims to describe the interplay of genetic and environmental factors in shaping the characteristics of functional somatic syndromes (FSS). This study is primarily intended to investigate the epidemiology, risk factors, course and prognosis of FSSs in a sample of adult Iranian population. The other aim is to develop a new delimitation of FSSs based on an integrated multidisciplinary approach comprising of phenotypic and multiomics data.

METHODS AND ANALYSIS

ISFUN is a population-based prospective cohort study designed to follow a population of randomly selected seemingly healthy adults (18-65 years) through annual visits during a 4-year observation period. Structured questionnaires are used for data collection and clinical assessment of the participants. Questionnaire-based diagnosis of FSSs are validated in a medical interview. Human DNA genotyping, microbial amplicon sequencing and urine analysis is under progress for genomics, microbiota and metabolomics profiling, respectively. Enrolment began in September 2017, and study completion is expected in 2022. A total number of 1943 participants were initially recruited.

ETHICS AND DISSEMINATION

Ethical approval for data collection was granted by the National Research Ethics Committee of the Iranian Ministry of Health and Medical Education and the Research Ethics Committee of Isfahan University of Medical Sciences (IR.MUI.REC.1395.1.149). Following the description of the study procedure, we obtained written informed consent from all study participants. Study findings will be disseminated through peer-reviewed publications and presentations at scientific meetings.

Which symptoms best distinguish fibromyalgia patients from those with other chronic pain disorders?

RATIONALE, AIMS AND OBJECTIVES

The primary purpose of this study was to test both classic and novel FM pain and non-pain symptoms to determine their practical efficacy in aiding clinicians to distinguish FM pain from other chronic pain disorders.

METHODS

158 pain patients from two primary care clinics were evaluated with history, physical exam, chart review, and a questionnaire containing 26 exploratory symptoms (10 from the Symptom Impact Questionnaire (SIQR) and 16 from the FM literature)). The symptoms were rated on a 0-10 VAS for severity by those patients reporting pain over the past week. Somers' D and mean severity differences between FM and chronic pain patients without FM were used to rank the discriminatory and diagnostic contributions of symptoms.

RESULTS

Fifty patients (14.2%) carried a chart diagnosis of FM, 108 (30.7%) had pain but not FM, and 192 (54.5%) who had neither pain nor FM. Comparing means between the two pain groups, the 5 best differentiating symptoms (all, P < .0001) were: a persistent deep aching over most of my body, poor balance (7.4 vs 3.1), environmental sensitivity (6.8 vs 3.0), tenderness to touch (6.8 vs 3.6) and pain after exercise (8.1 vs 4.1). Notably, VAS pain though significantly higher for FM was least discriminatory (6.5 vs 5.1, P < .001). The five best symptoms generated a ROC = 0.85 and Somers' D = 0.69, an accuracy of 81%, and an odd's ratio of 14.4.

CONCLUSIONS

Our results herein suggest that clinicians may be well-served to consider symptoms in addition to those contained in current diagnostic criteria when recognizing FM in their chronic pain patients.

Differential Activation of Colonic Afferents and Dorsal Horn Neurons Underlie Stress-Induced and Comorbid Visceral Hypersensitivity in Female Rats

Chronic Overlapping Pain Conditions, including irritable bowel syndrome (IBS) and temporomandibular disorder (TMD), represent a group of idiopathic pain conditions that likely have peripheral and central mechanisms contributing to their pathology, but are poorly understood. These conditions are exacerbated by stress and have a female predominance. The presence of one condition predicts the presence or development of additional conditions, making this a significant pain management problem. The current study was designed to determine if the duration and magnitude of peripheral sensitization and spinal central sensitization differs between restraint stress-induced visceral hypersensitivity (SIH) and chronic comorbid pain hypersensitivity (CPH; stress during pre-existing orofacial pain). SIH in female rats, as determined by the visceromotor response, persisted at least four but resolved by seven weeks. In contrast, CPH persisted at least seven weeks. Surprisingly, colonic afferents in both SIH and CPH rats were sensitized at seven weeks. CPH rats also had referred pain through seven weeks, but locally anesthetizing the colon only attenuated the referred pain through four weeks, suggesting a transition to colonic afferent independent central sensitization. Different phenotypes of dorsal horn neurons were sensitized in the CPH rats seven weeks post stress compared to four weeks or SIH rats. The current study suggests differential processing of colonic afferent input to the lumbosacral spinal cord contributes to visceral hypersensitivity during comorbid chronic pain conditions. PERSPECTIVE: Chronic Overlapping Pain Conditions represent a unique challenge in pain management. The diverse nature of peripheral organs hinders a clear understanding of underlying mechanisms accounting for the comorbidity. This study highlights a mismatch between the condition-dependent behavior and peripheral and spinal mechanisms that contribute to visceral pain hypersensitivity.

"Pacing does help you get your life back": The acceptability of a newly developed activity pacing framework for chronic pain/fatigue

OBJECTIVES

We have developed and feasibility tested an activity pacing framework for clinicians to standardise their recommendations of activity pacing to patients with chronic pain/fatigue. This study aimed to explore the acceptability and fidelity to this framework in preparation for a future trial of activity pacing.

DESIGN

Acceptability and fidelity were explored using semi-structured interviews. Data were analysed using framework analysis.

PARTICIPANTS

Patients who attended a rehabilitation programme for chronic pain/fatigue underpinned by the framework, and clinicians (physiotherapists and psychological wellbeing practitioners) who led the programmes.

RESULTS

Seventeen interviews were conducted, involving 12 patients with chronic pain/fatigue and five clinicians. The framework analysis revealed four deductive themes: (1) Acceptability of the activity pacing framework, (2) Acceptability of the feasibility study methods, (3) Processes of change and (4) Barriers and facilitators to activity pacing; and one inductive theme: (5) Perspectives of patients and clinicians.

CONCLUSIONS

The activity pacing framework appeared acceptable to patients and clinicians, and adherence to the framework was demonstrated. Processes of behaviour change included patients' regulation of activities through activity pacing. Barriers to pacing included work/social commitments and facilitators included identifying the benefits of pacing on symptoms. Different perspectives emerged between clinicians and patients regarding interpretations of symptom-contingent and quota-contingent strategies. The framework recognises fluctuations in symptoms of chronic pain/fatigue and encourages a quota-contingent approach with flexibility. Future work will develop a patient friendly guide ahead of a clinical trial to explore the effects of pacing.

The Role of Prevention in Reducing the Economic Impact of ME/CFS in Europe: A Report from the Socioeconomics Working Group of the European Network on ME/CFS (EUROMENE)

This report addresses the extent to which there may be scope for preventive programmes for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and, if so, what economic benefits may accrue from the implementation of such programmes. We consider the economic case for prevention programmes, whether there is scope for preventive programmes for ME/CFS, and what are the health and economic benefits to be derived from the implementation of such programmes. We conclude that there is little scope for primary prevention programmes, given that ME/CFS is attributable to a combination of host and environmental risk factors, with host factors appearing to be most prominent, and that there are few identified modifiable risk factors that could be the focus of such programmes. The exception is in the use of agricultural chemicals, particularly organophosphates, where there is scope for intervention, and where Europe-wide programmes of health education to encourage safe use would be beneficial. There is a need for more research on risk factors for ME/CFS to establish a basis for the development of primary prevention programmes, particularly in respect of occupational risk factors. Secondary prevention offers the greatest scope for intervention, to minimise diagnostic delays associated with prolonged illness, increased severity, and increased costs.

The association between burning mouth syndrome and urologic chronic pelvic pain syndrome: A case-control study

BACKGROUND

The overlap between some painful conditions is widespread. The aim of this study was to evaluate the overlap between burning mouth syndrome (BMS) and urological chronic pelvic pain syndrome (UCPPS) in an outpatient clinic of a university hospital.

METHODS

A controlled clinical study was performed. BMS patients and healthy controls were enrolled in the study. Patients were screened through laboratory test and a complete urological examination. Two validated questionnaires were submitted to all the patients: National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and International Prostatic Symptom Score (IPSS).

RESULTS

A total of 50 BMS patients and 50 healthy controls were enrolled in the study. Statistically significant differences between the two groups regarding the items of the IPSS questionnaire of Incomplete Emptying (U = 750, P < .001), Intermittency (U = 768.5, P < .001), QoL (U = 848, P < .002), and Total Symptom score (U = 1040, P = .05) were found. Moreover, the responses of NIH-CPSI showed statistically significant differences regarding Pain subscale (U = 714, P < .001), QoL Impact subscale (U = 1016.500, P = .05), and NIH-CPSI total score (U = 953.500, P = .002).

CONCLUSION

To the best our knowledge, the reported data demonstrate for the first time an association between BMS and UCPPS. Further studies with a larger sample are needed to confirm the co-occurrence of urological symptoms in patients with burning mouth syndrome.

Peripheral mechanisms contribute to comorbid visceral hypersensitivity induced by preexisting orofacial pain and stress in female rats

BACKGROUND

Stress exacerbates many chronic pain syndromes including irritable bowel syndrome (IBS). Among these patient populations, many suffer from comorbid or chronic overlapping pain conditions and are predominantly female. Nevertheless, basic studies investigating chronic psychological stress-induced changes in pain sensitivity have been mostly carried out in male rodents. Our laboratory developed a model of comorbid pain hypersensitivity (CPH) (stress in the presence of preexisting orofacial pain inducing chronic visceral pain hypersensitivity that significantly outlasts transient stress-induced pain hypersensitivity (SIH)) facilitating the study of pain associated with IBS. Since CPH and SIH are phenotypically similar until SIH resolves and CPH persists, it is unclear if underlying mechanisms are similar.

METHODS

In the present study, the visceromotor response (VMR) to colorectal distention was recorded in the SIH and CPH models in intact females and ovariectomized rats plus estradiol replacement (OVx + E2). Over several months, rats were determined to be susceptible or resilient to stress and the role of peripheral corticotrophin-releasing factor (CRF) underlying in the pain hypersensitivity was examined.

KEY RESULTS

Stress alone induced transient (3-4 weeks) visceral hypersensitivity, though some rats were resilient. Comorbid conditions increased susceptibility to stress prolonging hypersensitivity beyond 13 weeks. Both models had robust peripheral components; hypersensitivity was attenuated by the CRF receptor antagonist astressin and the mast cell stabilizer disodium cromoglycate (DSCG). However, DSCG was less effective in the CPH model compared to the SIH model.

CONCLUSIONS AND INFERENCES

The data indicate many similarities but some differences in mechanisms contributing to comorbid pain conditions compared to transient stress-induced pain.

The Effects of a Pain Psychology and Neuroscience Self-Evaluation Internet Intervention: A Randomized Controlled Trial

OBJECTIVES

Many patients' chronic musculoskeletal pain is strongly influenced by central nervous system processes such as sensitization or amplification. Education about pain neuroscience can change patients' beliefs but has less consistent effects on pain outcomes. Patients may have greater clinical benefits if the educational intervention is personalized, and they evaluate various psychosocial risk factors with respect to their pain. We developed and tested a brief, internet-based Pain Psychology and Neuroscience (PPN) self-evaluation intervention.

MATERIALS AND METHODS

From a patient registry, 104 adults reporting chronic musculoskeletal pain were randomized to the PPN intervention or a matched, active, education control condition. At baseline and 1-month (primary endpoint) and 10-month follow-ups, participants reported pain severity (primary outcome) and multiple secondary outcomes. Primary analyses compared the 2 experimental conditions using analyses of covariances; post hoc exploratory analyses compared the effects of PPN in subgroups of patients who met criteria for fibromyalgia (FM; n=50) or who did not (n=54; primarily spinal pain).

RESULTS

At 1-month follow-up, compared with the control condition, PPN led to significantly lower pain severity (ηp =0.05) and interference (ηp =0.04), greater brain (ηp =0.07) and psychological (ηp =0.07) attributions for pain, and greater readiness for pain self-management (ηp =0.08). Effects on distress, pain catastrophizing, kinesiophobia, and life satisfaction were not significant. Exploratory analyses showed that the PPN intervention was especially beneficial for patients without FM but was of less benefit for those with FM. Most of the effects (except attributions) were lost at 10 months.

DISCUSSION

A brief PPN self-evaluation intervention, presented on-line, can yield short-term improvements in musculoskeletal pain severity and interference, especially for people with spinal/localized pain rather than FM, perhaps because the psychology/neuroscience perspective is more novel for such patients.

The ALPIM (Anxiety, Laxity, Pain, Immune, and Mood) Syndrome in Adolescents and Young Adults: A Cohort Study

OBJECTIVE

ALPIM (anxiety, laxity, pain, immune, and mood) syndrome has been previously described in adults. The authors aimed to identify its occurrence in adolescents and confirm its existence in adults. Given the association of the disorder with somatic symptoms, separation anxiety disorder (SAD) was explored as an ALPIM comorbidity.

METHODS

Medical records of patients aged 11-34 with a diagnosis of depression or anxiety (panic disorder, SAD, social anxiety or generalized anxiety disorder) seen during a 1-year period were reviewed. Data were collected on the presence of ALPIM comorbidities. Analyses were conducted to detect their co-occurrence and evaluate possible predictors of the ALPIM syndrome.

RESULTS

Inclusion criteria were met by 185 patient charts. A significant association was observed between the ALPIM comorbidities with 20 study subjects (10.8%) meeting criteria for ALPIM syndrome (patients with one or more diagnoses from each ALPIM domain). Patients with SAD had increased odds of being diagnosed with ALPIM (odds ratio=7.14, 95% CI=2.48-20.54, p<0.001). Neither major depression nor generalized anxiety disorder was found to be predictive of ALPIM syndrome. There was no difference in the prevalence of ALPIM-related comorbidities between study subjects <18 years old compared with those ≥18 years old.

CONCLUSIONS

These findings reestablish the association of distinct psychiatric and nonpsychiatric conditions described as the ALPIM syndrome. Furthermore, the syndrome may present during adolescence. SAD may be an independent predictive factor for the occurrence of ALPIM syndrome. Patients with individual ALPIM comorbidities should be assessed for the syndrome, especially if they have a history of SAD.

Functional somatic illnesses in patients with functional bowel disorders. A cross-sectional cohort study in western Saudi Arabia

OBJECTIVES

To study the prevalence of functional gastrointestinal disorders (FGID) in Saudi patients with irritable bowel syndrome (IBS). Methods: A cross-sectional study was conducted in patients with IBS treated at a private tertiary medical center in western Saudi Arabia between 2013 and 2017. We used ROME 3 criteria with data from the Generalized Anxiety Disorder 7-item (GAD-7) scale, the Patient Health Questionnaire-9 (PHQ-9) depression scale, and International Classification of Headache Disorders (ICHD) to assess the prevalence of psychosomatic illness. Statistical analysis of frequency and statistical correlation was performed using Chi-square. Results: The final analysis of 307 patients revealed a combined 425 diagnoses of psychosomatic illness, including diagnoses of headache in 104 patients (34%), migraine in 93 patients (30.5%), fibromyalgia in 169 patients (55%), and depression in 59 patients (19%). There was a statistically significant correlation between patients' ages and diagnoses of joint pain and migraines. Conclusion: Fibromyalgia and headache disorders were common in this cohort of Saudi patients with IBS. This coexistence of illness is partly explained by the functional nature of these illnesses. Collective efforts to provide multidisciplinary care is needed for these patients.

Persistent dentoalveolar pain disorder: A putative intraoral chronic overlapping pain condition

Chronic overlapping pain conditions (COPCs) are conditions that share several clinical characteristics and symptomatology, are usually considered idiopathic in nature, and are frequently comorbid. Currently, there are no established inclusion criteria to determine which conditions should be included under this umbrella term despite different systems proposed. Persistent dentoalveolar pain disorder (PDAP), also referred to as atypical odontalgia and thought to be a component of persistent idiopathic facial pain, is a chronic pain condition that manifests as a persistent tooth pain or pain over a dentoalveolar site formerly occupied by a tooth in the absence of detectable pathology during clinical or radiological examination. PDAP is considered idiopathic in nature, and its pathophysiological mechanisms are not fully understood. Our objective was to investigate whether PDAP fits the conceptual paradigm of COPC given its characteristics and commonalities with other COPC, based on published literature identified through a scoping review. We found that PDAP fits 16 out of 18 common characteristics among COPCs, and based on this finding, we discuss the implications of PDAP being considered a COPC.

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.

Chronic Widespread Pain and Fibromyalgia Syndrome: Life-Course Risk Markers in Young People

Although the life-course concept of risk markers as potential etiological influences is well established in epidemiology, it has not featured in academic publications or clinical practice in the context of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS). Studies of risk markers are required considerations for evaluation of patients and for research because there is no single cause, pathological feature, laboratory finding, or biomarker for CWP or FMS. The early-life risk markers identified by extensive literature review with best evidence for potential causal influence on the development and progression of CWP and FMS include genetic factors, premature birth, female sex, early childhood adversity, cognitive and psychosocial influences, impaired sleep, primary pain disorders, multiregional pain, physical trauma, infectious illness, obesity and inactivity, hypermobility of joints, iron deficiency, and small-fiber polyneuropathy. The case history illustrates the potential etiological influence of multiple risk markers offset by personal resilience.

Autonomic neurophysiologic implications of disorders comorbid with bladder pain syndrome vs myofascial pelvic pain

AIMS

The neuropathophysiology of a debilitating chronic urologic pain condition, bladder pain syndrome (BPS), remains unknown. Our recent data suggests withdrawal of cardiovagal modulation in subjects with BPS, in contrast to sympathetic nervous system dysfunction in another chronic pelvic pain syndrome, myofascial pelvic pain (MPP). We evaluated whether comorbid disorders differentially associated with BPS vs MPP shed additional light on these autonomic differences.

METHODS

We compared the presence and relative time of onset of 27 other medical conditions in women with BPS, MPP, both syndromes, and healthy subjects. Analysis included an adjustment for multiple comparisons.

RESULTS

Among 107 female subjects (BPS alone = 32; BPS with MPP = 36; MPP alone = 9; healthy controls = 30), comorbidities differentially associated with BPS included irritable bowel syndrome (IBS), dyspepsia, and chronic nausea, whereas those associated with MPP included migraine headache and dyspepsia, consistent with the distinct autonomic neurophysiologic signatures of the two disorders. PTSD (earliest), anxiety, depression, migraine headache, fibromyalgia, chronic fatigue, and IBS usually preceded BPS or MPP. PTSD and the presence of both pelvic pain disorders in the same subject correlated with significantly increased comorbid burden.

CONCLUSIONS

Our study suggests a distinct pattern of comorbid conditions in women with BPS. These findings further support our hypothesis of primary vagal defect in BPS as compared with primary sympathetic defect in MPP, suggesting a new model for chronic these pelvic pain syndromes. Chronologically, PTSD, migraine, dysmenorrhea, and IBS occurred early, supporting a role for PTSD or its trigger in the pathophysiology of chronic pelvic pain.

Healthcare Utilization in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Analysis of US Ambulatory Healthcare Data, 2000-2009

Background: ME/CFS is a complex and disabling illness with substantial economic burden and functional impairment comparable to heart disease and multiple sclerosis. Many patients with ME/CFS do not receive appropriate healthcare, partially due to lack of diagnostic tests, and knowledge/attitudes/beliefs about ME/CFS. This study was to assess the utility of US ambulatory healthcare data in profiling demographics, co-morbidities, and healthcare in ME/CFS. Methods: Data came from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) in the U.S. Weighted analysis was performed. We examined 9.06 billion adult visits from 2000 to 2009 NAMCS/NHAMCS data. ME/CFS-related visits were identified by ICD-9-CM code, 780.71, up to tertiary diagnosis. Results: We estimated 2.9 million (95% CI: 1.8-3.9 million) ME/CFS-related visits during 2000-2009, with no statistical evidence (p-trend = 0.31) for a decline or increase in ME/CFS-related visits. Internists, general and family practitioners combined provided 52.12% of these visits. Patients with ME/CFS-related visits were mostly in their 40 and 50 s (47.76%), female (66.07%), white (86.95%), metropolitan/urban residents (92.05%), and insured (87.26%). About 71% of ME/CFS patients had co-morbidities, including depression (35.79%), hypertension (31.14%), diabetes (20.30%), and arthritis (14.11%). As one quality indicator, physicians spent more time on ME/CFS-related visits than non-ME/CFS visits (23.62 vs. 19.38 min, p = 0.065). As additional quality indicators, the top three preventive counseling services provided to patients with ME/CFS-related visits were diet/nutrition (8.33%), exercise (8.21%), and smoking cessation (7.24%). Compared to non-ME/CFS visits, fewer ME/CFS-related visits included counseling for stress management (0.75 vs. 3.14%, p = 0.010), weight reduction (0.88 vs. 4.02%, p = 0.002), injury prevention (0.04 vs. 1.64%, p < 0.001), and family planning/contraception (0.17 vs. 1.45%, p = 0.037). Conclusions: Visits coded with ME/CFS did not increase from 2000 to 2009. Almost three quarters of ME/CFS-related visits were made by ME/CFS patients with other co-morbid conditions, further adding to complexity in ME/CFS healthcare. While physicians spent more time with ME/CFS patients, a lower proportion of ME/CFS patients received preventive counseling for weight reduction, stress management, and injury prevention than other patients despite the complexity of ME/CFS. NAMCS/NHAMCS data are useful in evaluating co-morbidities, healthcare utilization, and quality indicators for healthcare in ME/CFS.

Endometriosis as a Comorbid Condition in Chronic Fatigue Syndrome (CFS): Secondary Analysis of Data From a CFS Case-Control Study

Background: Endometriosis (EM) is a recognized co-morbid condition in women with chronic fatigue syndrome (CFS). This analysis evaluates the impact of EM on the health of women with CFS by comparing selected health characteristics and laboratory parameters in women with CFS with and without EM (CFS+EM and CFS-only). Methods: This secondary analysis included all 36 women with CFS from a cross-sectional study of CFS in Wichita, KS, conducted between 2002 and 2003. The health characteristics and laboratory parameters of interest included functioning, fatigue, CFS-related symptoms, gynecologic history, routine laboratory parameters, inflammatory markers, cortisol levels, allostatic load, and sleep parameters (overnight polysomnography). We used parametric or non-parametric tests to compare group differences in the selected health characteristics and laboratory parameters. For examining the association between EM and variables of interest, logistic regression models were performed and odds ratios (OR) with 95% confidence intervals (CI) were reported for the magnitude of associations. Statistical significance was set at 0.05 (two-sided). Results: The mean age of this study sample was 50.9 years. Of women with CFS, 36.1% reported having EM. Age and body mass index (BMI) did not differ between CFS+EM and CFS-only groups. When examining the impact of EM, compared to women with CFS-only, women with both CFS and EM were more likely to report chronic pelvic pain [OR = 9.00 (95% CI, 1.47-55.25)] and hysterectomy [OR = 10.3 (1.82-58.39)], had more CFS symptoms (6.8 ± 0.3 vs. 5.5 ± 0.3, p = 0.02), younger mean age at menopause onset (36.4 ± 3.0 vs. 47.0 ± 2.7 years, p = 0.03), higher mean number of obstructive apnea episodes per hour (20.3 vs. 4.4, p = 0.05) and reported more negative life events (15.8 vs. 4.4, p = 0.05). Other parameters did not differ significantly between the two groups. Conclusions: We found more than a third of women with CFS reported endometriosis as a comorbid condition. The endometriosis comorbidity was associated with chronic pelvic pain, earlier menopause, hysterectomy, and more CFS-related symptoms. However, endometriosis in women with CFS did not appear to further impact functioning, fatigue, inflammatory markers, or other laboratory parameters. Further investigations including younger women are warranted.

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.

The associated features of multiple somatic symptom complexes

OBJECTIVE

To assess whether two or more functional somatic symptom complexes (SSCs) showed stronger association with psychosocial correlates than single or no SSC after adjustment for depression/anxiety and general medical disorders.

METHODS

In a population-based sample we identified, by standardised questionnaire, participants with chronic widespread pain, chronic fatigue and irritable bowel syndrome, excluding those with a medical cause for pain/fatigue. We compared psychosocial variables in three groups: multiple (>1), single or no FSS, adjusting for depression/anxiety and general medical disorders using ordinal logistic regression. We evaluated whether multiple SSCs predicted health status 1 year later using multiple regression to adjust for confounders.

RESULTS

Of 1443 participants (58.0% response) medical records were examined in 990: 4.4% (n = 44) had 2 or 3 symptom complexes, 16.2% a single symptom complex. Many psychosocial adversities were significantly associated with number of SSCs in the expected direction but, for many, statistical significance was lost after adjustment for depression/anxiety and medical illness. Somatic symptoms, health anxiety, impairment and number of prior doctor visits remained significantly associated. Impaired health status 1 year later was predicted by multiple somatic symptom complexes even after adjustment for depression, anxiety, medical disorders and number of symptoms.

CONCLUSIONS

Depression, anxiety, medical illness and health anxiety, demonstrated an exposure-response relationship with number of somatic symptom complexes. These may be core features of all Functional Somatic Syndromes and may explain why number of somatic symptom complexes predicted subsequent health status. These features merit inclusion in prospective studies to ascertain causal relationships.

Complex regional pain syndrome type 1 in the medico-legal setting: High rates of somatoform disorders, opiate use and diagnostic uncertainty

Objective The aim of this study was to review demographic and clinical characteristics of patients with complex regional pain syndrome type 1 (CRPS) seen in a UK medico-legal setting - particularly the relationship between CRPS and somatoform disorders. Methods Fifty consecutive cases of CRPS (interviewed 2005-2016) undergoing psychiatric assessment were reviewed. A systematic assessment of mental states was conducted via interview and examination of medical/psychiatric records. Thirty patients also completed the Brief Illness Perception Questionnaire (BIPQ). Results Sixty per cent of patients ( n = 30) were female, and the mean age was 43 years. Twenty-two per cent ( n = 11) were employed, and 60% ( n = 30) received disability benefits. Symptoms were reported in the upper limb (62%; n = 31), lower limb (30%; n = 15), both (6%; n = 3) or elsewhere (2%; n = 1). Eighty-four per cent ( n = 42) satisfied DSM-5 criteria for current somatoform disorder. A history of more than two pain-related functional somatic syndromes (e.g. non-cardiac chest pain) was found in 42% ( n = 21) and functional neurological symptoms (e.g. 'claw-hand') in 42% ( n = 21). BIPQ scores resembled those associated with somatoform disorders and disorders mediated by psychological factors (e.g. irritable bowel syndrome). In 38% ( n = 19), the CRPS diagnosis was disputed among experts. A history of depression was noted in 60% ( n = 30), panic attacks in 20% ( n = 10) and alcohol/substance misuse in 18% ( n = 9). Opiates were prescribed to 64% ( n = 32). Conclusions Patients diagnosed with CRPS involved in litigation have high rates of prior psychopathology (mainly somatoform disorders) and pain-related disability for which opiate use is common. They risk an adverse reaction to limb pain 'shaped' by maladaptive illness beliefs. The CRPS diagnosis lacks reliability in medico-legal settings and may cause iatrogenic harm.

Severe and enduring somatoform disorders: recognition and management

Patients with severe and enduring somatoform disorders (SESD) characteristically present with multiple, recurrent and frequently changing physical symptoms that have usually been present for several years before referral to a psychiatrist/psychologist. Many patients report long histories of contact with both primary and tertiary care services, have undergone repeated fruitless investigations and have high levels of disability. SESD are responsible for disproportionately high healthcare costs and are the third most common cause of workplace absence. Identification of patients with SESD by psychiatrists requires particular skills: collaboration with colleagues is vital and there are risks of iatrogenic harm. We describe the obstacles encountered in identifying these patients as well as methods of assessment and management. Treatment pathways best suited to managing this large and as yet untended group of patients are described.

Extracellular signal-regulated kinase activation in the spinal cord contributes to visceral hypersensitivity induced by craniofacial injury followed by stress

BACKGROUND

We previously developed an animal model to examine mechanisms that underlie the emergence of visceral hypersensitivity modeling pain characteristics of temporomandibular disorder (TMD) patients with comorbid irritable bowel syndrome (IBS). In ovariectomized (OVx) rats with estradiol (E2) replacement, visceral hypersensitivity developed subsequent to masseter muscle inflammation followed by repeated forced swim (FS) stress. The purpose of this study was to investigate whether activation of extracellular signal-regulated kinase (ERK) in the spinal cord contributes to visceral hypersensitivity in this overlapping pain model.

METHODS

In OVx with E2 replacement rats masseter muscle inflammation was followed by 3 day FS (comorbid condition). Depression-like behaviors were assessed by sucrose preference and in the elevated plus maze, and visceral sensitivity was measured by the visceromotor response (VMR) to colorectal distention. The protein level of ERK1/2 and phosphorylated ERK1/2 (p-ERK1/2) in the L6-S2 dorsal spinal cord was analyzed by western blot.

KEY RESULTS

FS stress decreased sucrose consumption in E2 replaced rats in sucrose preference test. The expression of p-ERK1/2 in the L6-S2 dorsal spinal cord increased significantly in E2 with comorbid rats. Intrathecal injection of mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor PD98059 blocked the visceral hypersensitivity induced by masseter muscle inflammation combined with FS stress.

CONCLUSIONS & INFERENCES

These data indicate that ERK1/2 activation contributes to the visceral hypersensitivity evoked by craniofacial inflammation pain combined with stress. The results may provide a new therapeutic avenue for alleviating overlapping pain conditions.

Longitudinal outcomes associated with significant other responses to chronic fatigue and pain

This study investigated significant others' behavior associated with fatigue, pain, and mental health outcomes among 68 individuals with chronic fatigue (43% also had fibromyalgia) over 18 months. More negative significant others' responses were associated with more pain, poorer physical and mental health, and more fatigue-related symptoms over time. More fibromyalgia tender points covaried with more solicitous significant others' responses over time. Better mental health covaried with more distracting significant others' responses over time. The results are discussed in terms of theoretical models of the role of perceived significant others' responses on patient outcomes and recommendations for future research.

Bladder Capacity is a Biomarker for a Bladder Centric versus Systemic Manifestation in Interstitial Cystitis/Bladder Pain Syndrome

PURPOSE

Interstitial cystitis/bladder pain syndrome presents a significant clinical challenge due to symptom heterogeneity and the myriad associated comorbid medical conditions. We recently reported that diminished bladder capacity may represent a specific interstitial cystitis/bladder pain syndrome subphenotype. The objective of this study was to investigate the relationship between anesthetic bladder capacity, and urological and nonurological clinical findings in a cohort of patients with interstitial cystitis/bladder pain syndrome who had undergone therapeutic urinary bladder hydrodistention.

MATERIALS AND METHODS

This is a retrospective chart review of prospectively collected data on women diagnosed with interstitial cystitis/bladder pain syndrome between 2011 and 2015 who underwent bladder hydrodistention. Assessments in each patient included a detailed history and physical examination, ICPI (Interstitial Cystitis Problem Index), ICSI (Interstitial Cystitis Symptom Index) and PUF (Pelvic Pain and Urgency/Frequency Patient Symptom Scale). Bladder capacity was determined during bladder hydrodistention with the patient under general anesthesia.

RESULTS

Mean age was 45.8 years and mean bladder capacity was 857 ml in the 110 enrolled patients. We found a significant inverse correlation between bladder capacity and scores on 3 gold standard interstitial cystitis/bladder pain syndrome metrics, including ICPI (p = 0.0014), ICSI (p = 0.0022) and PUF (p = 0.0009) as well as urination frequency (p = 0.0025). Women with higher bladder capacity were significantly more likely to report depression (p = 0.0059) and irritable bowel syndrome (p = 0.022).

CONCLUSIONS

Low bladder capacity while under anesthesia was significantly associated with high symptom scores on 3 validated interstitial cystitis/bladder pain syndrome questionnaires as well as with urinary frequency. However, it was not associated with depression or other common systemic pain problems. These results suggest that low bladder capacity is a marker for a bladder centric manifestation of interstitial cystitis/bladder pain syndrome.

Functional urological disorders: a sensitized defence response in the bladder-gut-brain axis

Functional urological and gastrointestinal disorders are interrelated and characterized by a chronic course and considerable treatment resistance. Urological disorders associated with a sizeable functional effect include overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Poor treatment outcomes might be attributable to untreated underlying psychological and psychiatric disorders, as the co-occurrence of functional urological and gastrointestinal disorders with mood and anxiety disorders is common. The hypothetical bladder-gut-brain axis (BGBA) is a useful framework under which this interaction can be studied, suggesting that functional disorders represent a sensitized response to earlier threats such as childhood adversity or previous traumatic events, resulting in perceived emotional and bodily distress - the symptoms of functional disorders. Psychological and physical stress pathways might contribute to such alarm falsification, and neuroticism could be a risk factor for the co-occurrence of functional disorders and affective conditions. Additionally, physical threat - either from external sources or internal sources such as infection - might contribute to alarm falsification by influencing body-brain crosstalk on homeostasis and, therefore, affecting mood, cognition, and behaviour. Multidisciplinary research and an integrated care approach is, therefore, required to further elucidate and remediate functional urological and gastrointestinal polymorphic phenotypes.

Does central sensitization help explain idiopathic overactive bladder?

The pathophysiological mechanisms underlying overactive bladder syndrome (OAB) can include dysfunction of sensory pathways of the peripheral and central nervous systems, resulting in bladder hypersensitivity. Central sensitization describes an induced state of spinal hypersensitivity that is associated with a variety of chronic pain disorders that share many attributes with OAB, albeit without the presence of pain. As such, the concept of central sensitization might be relevant to understanding the mechanisms and clinical manifestations of OAB syndrome. An understanding of the pathophysiology and clinical manifestations of central sensitization, and the evidence that supports a role of central sensitization in OAB, including the potential implications of mechanisms of central sensitization for the treatment of patients with OAB could provide a novel approach to the treatment of patients with this disease. Such an approach would be especially relevant to those patients with central sensitization-related comorbidities, and has the potential to improve the outcomes of these patients in particular.

Toll-like receptor 4 and comorbid pain in Interstitial Cystitis/Bladder Pain Syndrome: a multidisciplinary approach to the study of chronic pelvic pain research network study

BACKGROUND

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a condition characterized by pelvic pain and urinary symptoms. Some IC/BPS patients have pain confined to the pelvic region, while others suffer widespread pain. Inflammatory processes have previously been linked to pelvic pain in IC/BPS, but their association with widespread pain in IC/BPS has not been characterized.

METHODS

Sixty-six women meeting criteria for IC/BPS completed self-report measures of pain as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP), collected 3days of saliva for cortisol assays, and provided blood samples. Peripheral blood mononuclear cells (PBMCs) were stimulated with Toll-like Receptor (TLR) 2 and 4 agonists and cytokines were measured in supernatant; IL-6 was also measured in plasma. Associations between inflammatory variables and the likelihood of endorsing extra-pelvic pain, or the presence of a comorbid syndrome, were tested by logistic regression and General Linear Models, respectively. A subset of patients (n=32) completed Quantitative Sensory Testing.

RESULTS

A one standard deviation increase in TLR-4 inflammatory response was associated with a 1.59 greater likelihood of endorsing extra-pelvic pain (p=.019). Participants with comorbid syndromes also had higher inflammatory responses to TLR-4 stimulation in PBMCs (p=.016). Lower pressure pain thresholds were marginally associated with higher TLR-4 inflammatory responses (p=.062), and significantly associated with higher IL-6 in plasma (p=.031).

CONCLUSIONS

TLR-4 inflammatory responses in PBMCs are a marker of widespread pain in IC/BPS, and should be explored in other conditions characterized by medically unexplained pain.

Early menopause and other gynecologic risk indicators for chronic fatigue syndrome in women

OBJECTIVE

This study aims to examine whether gynecologic conditions are associated with chronic fatigue syndrome (CFS).

METHODS

This study includes a subset of 157 women from a population-based case-control study in Georgia, United States, conducted in 2004-2009. Gynecologic history was collected using a self-administered questionnaire. Crude odds ratios (ORs) with 95% CIs and ORs adjusted for body mass index and other covariates, where relevant, were estimated for gynecologic conditions between 84 CFS cases and 73 healthy controls.

RESULTS

Cases and controls were of similar age. Women with CFS reported significantly more gynecologic conditions and surgical operations than controls: menopause status (61.9% vs 37.0%; OR, 2.37; 95% CI, 1.21-4.66), earlier mean age at menopause onset (37.6 vs 48.6 y; adjusted OR, 1.22; 95% CI, 1.09-1.36), excessive menstrual bleeding (73.8% vs 42.5%; adjusted OR, 3.33; 95% CI, 1.66-6.70), bleeding between periods (48.8% vs 23.3%; adjusted OR, 3.31; 95% CI, 1.60-6.86), endometriosis (29.8% vs 12.3%; adjusted OR, 3.67; 95% CI, 1.53-8.84), use of noncontraceptive hormonal preparations (57.1% vs 26.0%; adjusted OR, 2.95; 95% CI, 1.36-6.38), nonmenstrual pelvic pain (26.2% vs 2.7%; adjusted OR, 11.98; 95% CI, 2.57-55.81), and gynecologic surgical operation (65.5% vs 31.5%; adjusted OR, 3.33; 95% CI, 1.66-6.67), especially hysterectomy (54.8% vs 19.2%; adjusted OR, 3.23; 95% CI, 1.46-7.17). Hysterectomy and oophorectomy occurred at a significantly younger mean age in the CFS group than in controls and occurred before CFS onset in 71% of women with records of date of surgical operation and date of CFS onset.

CONCLUSIONS

Menstrual abnormalities, endometriosis, pelvic pain, hysterectomy, and early/surgical menopause are all associated with CFS. Clinicians should be aware of the association between common gynecologic problems and CFS in women. Further work is warranted to determine whether these conditions contribute to the development and/or perpetuation of CFS in some women.

Mood and Anxiety Disorders in Chronic Fatigue Syndrome, Fibromyalgia, and Irritable Bowel Syndrome: Results From the LifeLines Cohort Study

OBJECTIVE

Functional somatic syndromes (FSSs) have often been linked to psychopathology. The aim of the current study was to compare prevalence rates of psychiatric disorders among individuals with chronic fatigue syndrome (CFS), fibromyalgia (FM), and irritable bowel syndrome (IBS).

METHODS

This study was conducted in 94,516 participants (mean [standard deviation] age = 44.6 [12.5] years, 58.7% women) of the general-population cohort LifeLines. FSSs were assessed by self-reports. Mood disorders (i.e., major depressive disorder and dysthymia) and anxiety disorders (i.e., generalized anxiety disorder, social phobia, panic disorder with/without agoraphobia, and agoraphobia) were assessed by means of the Mini International Neuropsychiatric Interview. Risks on psychiatric disorders were compared for individuals with CFS, FM, and IBS by using logistic regression analyses adjusted for age and sex.

RESULTS

Prevalence rates of CFS, FM, and IBS were 1.3%, 3.0%, and 9.7%, respectively. Individuals with CFS, FM, and IBS had significantly more mood (odds ratios [ORs] = 1.72-5.42) and anxiety disorders (ORs = 1.52-3.96) than did individuals without FSSs, but prevalence rates were low (1.6%-28.6%). Individuals with CFS more often had mood (ORs = 2.00-4.08) and anxiety disorders (ORs = 1.63-2.32) than did individuals with FM and IBS. Major depressive disorder was more common in FM than in IBS (OR = 1.58, 95% confidence interval = 1.24-2.01), whereas these groups did not differ on dysthymia or anxiety disorders.

CONCLUSIONS

Mood and anxiety disorders are more prevalent in individuals with FSSs, and particularly CFS, than in individuals without FSSs. However, most individuals with FSSs do not have mood or anxiety disorders.

Stress-induced visceral pain: toward animal models of irritable-bowel syndrome and associated comorbidities

Visceral pain is a global term used to describe pain originating from the internal organs, which is distinct from somatic pain. It is a hallmark of functional gastrointestinal disorders such as irritable-bowel syndrome (IBS). Currently, the treatment strategies targeting visceral pain are unsatisfactory, with development of novel therapeutics hindered by a lack of detailed knowledge of the underlying mechanisms. Stress has long been implicated in the pathophysiology of visceral pain in both preclinical and clinical studies. Here, we discuss the complex etiology of visceral pain reviewing our current understanding in the context of the role of stress, gender, gut microbiota alterations, and immune functioning. Furthermore, we review the role of glutamate, GABA, and epigenetic mechanisms as possible therapeutic strategies for the treatment of visceral pain for which there is an unmet medical need. Moreover, we discuss the most widely described rodent models used to model visceral pain in the preclinical setting. The theory behind, and application of, animal models is key for both the understanding of underlying mechanisms and design of future therapeutic interventions. Taken together, it is apparent that stress-induced visceral pain and its psychiatric comorbidities, as typified by IBS, has a multifaceted etiology. Moreover, treatment strategies still lag far behind when compared to other pain modalities. The development of novel, effective, and specific therapeutics for the treatment of visceral pain has never been more pertinent.

Bladder pain syndrome/interstitial cystitis as a functional somatic syndrome

PURPOSE

To determine whether bladder pain syndrome/interstitial cystitis (BPS/IC) has the characteristics of a functional somatic syndrome (FSS).

MATERIALS AND METHODS

There is no accepted definition of an FSS. Consequently, this paper reviewed the literature for common FSS characteristics and for reports that BPS/IC has these characteristics.

RESULTS

Eleven articles met inclusion and exclusion criteria and yielded 18 FSS characteristics. BPS/IC patients manifest all but two: the exceptions were normal light microscopic anatomy (after hydrodistention under anesthesia, some BPS/IC bladders have Hunner's lesions and most have petechial hemorrhages) and normal laboratory tests (many BPS/IC patients have hematuria). Petechial hemorrhages and hematuria are probably related and may appear during naturally-occurring bladder distention. Without such distention, then, the 90% of BPS/IC patients without a Hunner's lesion have all the characteristics of an FSS. Comparisons in the opposite direction were consistent: several additional features of BPS/IC were found in FSSs.

CONCLUSIONS

This systematic but untested method is consistent with but does not test the hypothesis that BPS/IC in some patients might best be understood as an FSS. Like most conditions, BPS/IC is probably heterogeneous; hence only a proportion of BPS/IC cases are likely to be manifestations of an FSS. This hypothesis has several implications. Explorations of processes that connect the FSSs might contribute to understanding the pathogenesis of BPS/IC. Patients with FSSs are at risk for BPS/IC and may benefit from future preventive strategies. Therapies that are useful in FSSs also may be useful in some cases of BPS/IC.

Functional somatic syndromes as risk factors for hysterectomy in early bladder pain syndrome/interstitial cystitis

OBJECTIVE

We tested the hypothesis that functional somatic syndromes (FSSs) are risk factors for hysterectomy in early bladder pain syndrome/interstitial cystitis (BPS/IC).

METHODS

In 312 women with incident BPS/IC, we diagnosed seven pre-BPS/IC syndromes: chronic pelvic pain (CPP), fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome (IBS), sicca syndrome, migraine, and panic disorder. Each was defined as present before 12 months (existing syndrome) or onset within 12 months (new syndrome) prior to BPS/IC onset. Retrospectively, we sought associations between prior hysterectomy and existing FSSs. Prospectively, we studied associations of existing and new syndromes with subsequent hysterectomy. Logistic regression analyses adjusted for age, race, menopause and education.

RESULTS

The retrospective study showed prior hysterectomy (N=63) to be associated with existing CPP and the presence of multiple existing FSSs. The prospective study revealed that 30/249 women with a uterus at baseline (12%) underwent hysterectomy in early BPS/IC. This procedure was associated with new CPP (OR 6.0; CI 2.0, 18.2), new IBS (OR 5.4; CI 1.3, 22.3), and ≥3 existing FSSs (OR 3.9; CI 1.1, 13.9).

CONCLUSION

Accounting for CPP and IBS, the presence of multiple FSSs (most without pelvic pain) was a separate, independent risk factor for hysterectomy in early BPS/IC. This suggests that patient features in addition to abdominopelvic abnormalities led to this procedure. Until other populations are assessed, a prudent approach to patients who are contemplating hysterectomy (and possibly other surgeries) for pain and who have IBS or numerous FSSs is first to try alternative therapies including treatment of the FSSs.

A clinically relevant animal model of temporomandibular disorder and irritable bowel syndrome comorbidity

Temporomandibular disorder and irritable bowel syndrome are comorbid functional chronic pain disorders of unknown etiology that are triggered/exacerbated by stress. Here we present baseline phenotypic characterization of a novel animal model to gain insight into the underlying mechanisms that contribute to such comorbid pain conditions. In this model, chronic visceral hypersensitivity, a defining symptom of irritable bowel syndrome, is dependent on 3 factors: estradiol, existing chronic somatic pain, and stress. In ovariectomized rats, estradiol replacement followed by craniofacial muscle injury and stress induced visceral hypersensitivity that persisted for months. Omission of any 1 factor resulted in a transient (1 week) visceral hypersensitivity from stress alone or no hypersensitivity (no inflammation or estradiol). Maintenance of visceral hypersensitivity was estradiol dependent, resolving when estradiol replacement ceased. Referred cutaneous hypersensitivity was concurrent with visceral hypersensitivity. Increased spinal Fos expression suggests induction of central sensitization. These data demonstrate the development and maintenance of visceral hypersensitivity in estradiol-replaced animals following distal somatic injury and stress that mimics some characteristics reported in patients with temporomandibular disorder and comorbid irritable bowel syndrome. This new animal model is a powerful experimental tool that can be employed to gain further mechanistic insight into overlapping pain conditions.

PERSPECTIVE

The majority of patients with temporomandibular disorder report symptoms consistent with irritable bowel syndrome. Stress and female prevalence are common to both conditions. In a new experimental paradigm in ovariectomized rats with estradiol replacement, masseter inflammation followed by stress induces visceral hypersensitivity that persists for months, modeling these comorbid pain conditions.

Incidence and risk factors for chronic pelvic pain after hysteroscopic sterilization

STUDY OBJECTIVE

To investigate the incidence of and preoperative risk factors for developing pelvic pain after hysteroscopic sterilization using the Essure microinserts.

DESIGN

Retrospective cohort study (Canadian Task Force classification II-2).

SETTING

University medical center.

PATIENTS

A total of 458 patients who underwent hysteroscopic sterilization using Essure between January 1, 2005, and June 30, 2012.

INTERVENTION

Hysteroscopic sterilization using Essure.

MEASUREMENTS AND MAIN RESULTS

The incidence of acute pelvic pain after hysteroscopic sterilization was 8.1%, and of persistent pain at 3 months after the procedure was 4.2%. The range of presence of pain was 1 to 469 days (mean, 56 days). Of patients who developed chronic pelvic pain after the procedure, 75% reported it within 130 days of the procedure. Patients with previous diagnoses of any chronic pain (chronic pelvic pain, chronic low back pain, chronic headache, and fibromyalgia) were more likely to report both acute pain (odds ratio, 6.81; 95% confidence interval, 2.95-15.73) and chronic pain (odds ratio, 6.15; 95% confidence interval, 2.10-18.10) after hysteroscopic sterilization.

CONCLUSIONS

Pelvic pain may develop after hysteroscopic sterilization. Patients with a diagnosis of preexisting chronic pain may be at increased risk of developing pelvic pain after the procedure. Fifty percent of new pelvic pain after Essure placement will resolve within 3 months.

Shared genetic factors underlie chronic pain syndromes

Chronic pain syndromes (CPS) are highly prevalent in the general population, and increasingly the evidence points to a common etiological pathway. Using a large cohort of twins (n=8564) characterized for chronic widespread musculoskeletal pain (CWP), chronic pelvic pain (PP), migraine (MIG), dry eye disease, and irritable bowel syndrome (IBS), we explored the underlying genetic and environmental factors contributing to CPS and the correlation between them. The sample was predominantly female (87.3%), with a mean age of 54.7 (±14.7) years. Prevalence of the different CPS ranged from 7.4% (PP) to 15.7% (MIG). For all CPS the within-twin correlation in monozygotic twin pairs was higher than in dizygotic pairs, suggesting a heritable component. Estimated heritability ranged from 19% (IBS) to 46% (PP). Except for MIG, we found significant pairwise phenotypic correlations between the CPS. The phenotypic correlation was highest between CWP and IBS (0.40; 95% confidence interval: 0.27 to 0.46). Excluding MIG from further analyses, cross-twin cross-trait correlations were higher in monozygotic compared with dizygotic twin pairs, suggestive of shared genetic factors between CWP, PP, IBS, and dry eye disease. Twin modeling analysis revealed the common pathway model as the model best explaining the observed pattern of correlation between the traits, with an estimated heritability of 66% of the underlying latent variable. These results are evidence of shared genetic factors in conditions manifesting chronic pain and justify the search for underlying genetic variants.

Predicting fibromyalgia, a narrative review: are we better than fools and children?

Fibromyalgia syndrome (FMS) is a common and intriguing condition, manifest by chronic pain and fatigue. Although the pathogenesis of FMS is not yet completely understood, predicting the future development of FMS and chronic pain is a major challenge with great potential advantages, both from an individual as well as an epidemiological standpoint. Current knowledge indicates a genetic underpinning for FMS, and as increasing data are accumulated regarding the genetics involved, the prospect of utilizing these data for prediction becomes ever more attractive. The co-existence of FMS with multiple other functional disorders indicates that the clinical identification of such symptom constellations in a patient can alert the physician to the future development of FMS. Hypermobility syndrome is another clinical (as well as genetic) phenotype that has emerged as a risk factor for the development of FMS. Stressful events, including early life trauma, are also harbingers of the future development of FMS. Functional neuroimaging may help to elucidate the neural processes involved in central sensitization, and may ultimately also evolve into markers of predictive value. Last but not least, obesity and disturbed sleep are clinical (inter-related) features relevant for this spectrum. Future efforts will aim at integrating genetic, clinical and physiological data in the prediction of FMS and chronic pain.

Before the onset of interstitial cystitis/bladder pain syndrome, the presence of multiple non-bladder syndromes is strongly associated with a history of multiple surgeries

OBJECTIVE

Certain functional somatic syndromes (FSSs) such as fibromyalgia and irritable bowel syndrome are accompanied by diffuse pain amplification. Women with interstitial cystitis/bladder pain syndrome (IC/BPS) have numerous FSSs, as well as other non-bladder syndromes (NBSs) that are linked to the FSSs. They also report multiple surgeries. Since pain is a common indication for surgery, we tested the hypothesis that NBSs were associated with surgeries.

METHODS

We interviewed 312 incident IC/BPS cases and controls on NBSs and number of surgeries before the index date (for cases, IC/BPS onset date). Poisson and logistic regression analyses adjusted for age, race, educational level, and menopause.

RESULTS

Number of surgeries increased with number of NBSs in both cases and controls whether chronic pelvic pain (CPP), the only NBS generally accepted as an indication for surgery, was present or not. Logistic regression analysis showed that among cases CPP was the only individual NBS associated with a history of multiple surgeries, and then only modestly [odds ratio (OR) 1.9, confidence intervals (CI) 1.06, 3.2]. By far the strongest association was the number of NBSs. The OR for multiple surgeries increased with number of NBSs: for cases with 4-5 NBSs the OR was 14.1 (1.8, 113) and with 6-9 NBSs, 33.1 (3.9, 279). Controls had fewer syndromes and fewer surgeries and this linkage was less prominent.

CONCLUSION

Among IC/BPS cases, the number of NBSs was strongly correlated with the number of surgeries. Understanding temporal relationships will be necessary to explore causal linkages and may modify surgical practice.