The IASP classification of chronic pain for ICD-11: chronic secondary visceral pain

Ultrasound characteristics and risk factors of female patients with pelvic varicose veins and concomitant chronic pelvic pain

OBJECTIVE

The study aims to elucidate clinical and ultrasonographic characteristics of female patients diagnosed with pelvic varicose veins (PVVs) and to assess potential risk factors associated with incidences of chronic pelvic pain (CPP) in this population.

METHODS

Clinical and ultrasound data were retrospectively collected from female patients with PVVs at Beijing Shijitan Hospital between December 2017 and October 2022. Patient cohorts were divided into two groups based on whether they had been experiencing non-periodic pelvic pain over 6 months, consistent with the symptoms of CPP. Comparative analyses were conducted between the two groups, utilizing both univariate and multivariate logistic regression methodologies to identify risk factors for CPP.

RESULTS

The study included a total of 236 patients: 89 patients in the CPP group and 147 patients in the non-CPP group. No statistically significant differences were found between the two groups with regard to demographic parameters including age, height, weight, age of menarche, and number of pregnancies and births. However, the CPP group showed a higher menstrual volume score and a greater incidence of varicose veins, coupled with a lower body mass index. Transabdominal ultrasonography revealed that patients with CPP had a significantly larger diameter in the left ovarian vein (LOV) (6.2 ± 1.9 mm vs 5.0 ±2.3 mm; P < .05), and a higher prevalence of left internal iliac vein incompetence (21.3% vs 8.8%). Moreover, positive rates for LOV incompetence were markedly higher (94.4% vs 23.1%; P < .05), even in the absence of left common iliac vein compression and nutcracker phenomenon. Multivariate logistic regression analysis discerned that the LOV reflux (odds ratio [OR], 9.102; 95% confidence interval [CI], 4.578-18.099; P < .05), lower body mass index (OR, 0.646; 95% CI, 0.502-0.83; P < .05), elevated menstrual bleeding (OR, 1.182; 95% CI, 1.131-1.234; P < .05), and concomitant varicose veins (OR, 3.140; 95% CI, 1.067-9.273; P < .05) are independent risk factors for the manifestations of CPP in our patient cohorts.

CONCLUSIONS

Ultrasonography serves as an efficacious modality for evaluating abdomino-pelvic vascular pathology in patients with PVVs. Notably, LOV and internal iliac vein incompetence emerge as independent risk factors for CPP, thus offering a pivotal point of reference for clinical diagnosis and therapeutic management of PVVs.

Classification systems for chronic pelvic pain in males: a systematic review

OBJECTIVE

To systematically review the classification systems for male chronic pelvic pain (CPP).

METHODS

The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), and Web of Science were searched. Any publication, with no restriction to publication date, was eligible. Publications had to propose a classification system for CPP in males or provide additional information of a system that had been identified. Systems were assessed with an adapted Critical Appraisal of Classification Systems tool.

RESULTS

A total of 33 relevant publications were identified, with 22 proposing an original classification system. Systems aimed to: (i) diagnose CPP and/or differentially diagnose CPP from other conditions, (ii) differentially diagnose subtypes within CPP, or (iii) identify features that could inform underlying mechanisms and/or treatment selection. Conditions referred to as chronic prostatitis/chronic pelvic pain syndrome and interstitial cystitis/bladder pain syndrome were most represented. Clinical signs/symptoms, pathoanatomical investigations, and presumed pain mechanisms were used for classification. Quality of systems was low to moderate, implying limitations to consider for their interpretation.

CONCLUSIONS

Many classification systems for CPP in males exist. Careful consideration of their intended purpose is required. Future work should examine whether outcomes for patients are improved when decisions are guided by their use.

Abdominal Pain in Inflammatory Bowel Disease-Epidemiology, Pathophysiology, and Management: A Narrative Review

Abdominal pain is a major symptom of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, and has a significant impact on patients' quality of life. Given the evolving understanding of IBD pathology and management strategies, there is an urgent need to review the recent research findings. In this review, we have analyzed the epidemiology, pathophysiology, and management of abdominal pain in IBD over the past decade. We draw on the current literature and highlight emerging trends, challenges, and advances in this field. By synthesizing key findings, this review provides insights into the complex interplay between abdominal pain, disease progression, and therapeutic interventions for IBD.

Patients' perspective on the chronic pain classification in the 11th revision of the International Classification of Diseases (ICD-11): results from an international web-based survey

ABSTRACT

The 11th revision of the International Classification of Diseases and Related Health Problems (ICD-11) aims at improving the lives of persons with the lived experience of chronic pain by providing clearly defined and clinically useful diagnoses that can reduce stigma, facilitate communication, and improve access to pain management, among others. The aim of this study was to assess the perspective of people with chronic pain on these diagnoses. An international web-based survey was distributed among persons with the lived experience of chronic pain. After having seen an information video, participants rated the diagnoses on 8 endorsement scales (eg, diagnostic fit, stigma) that ranged from -5 to +5 with 0 representing the neutral point of no expected change. Overall ratings and differences between participants with chronic primary pain (CPP) and chronic secondary pain (CSP) were analyzed. N = 690 participants were included in the data analysis. The ratings on all endorsement scales were significantly higher than the neutral point of 0. The highest ratings were obtained for "openness" (2.95 ± 1.93) and "overall opinion" (1.87 ± 1.98). Participants with CPP and CSP did not differ in their ratings; however, those with CSP indicated an improved diagnostic fit of the new diagnoses, whereas participants with CPP rated the diagnostic fit of the new diagnoses similar to the fit of their current diagnoses. These results show that persons with the lived experience of chronic pain accept and endorse the new diagnoses. This endorsement is an important indicator of the diagnoses' clinical utility and can contribute to implementation and advocacy.

Clinicians diagnosing virtual patients with the classification algorithm for chronic pain in the ICD-11 (CAL-CP) achieve better diagnoses and prefer the algorithm to standard tools: An experimental validation study

BACKGROUND

The ICD-11 classification of chronic pain comprises seven categories, each further subdivided. In total, it contains over 100 diagnoses each based on 5-7 criteria. To increase diagnostic reliability, the Classification Algorithm for Chronic Pain in the ICD-11 (CAL-CP) was developed. The current study aimed to evaluate the CAL-CP regarding the correctness of assigned diagnoses, utility and ease of use.

METHODS

In an international online study, n = 195 clinicians each diagnosed 4 out of 8 fictitious patients. The clinicians interacted via chat with the virtual patients to collect information and view medical histories and examination findings. The patient cases differed in complexity: simple patients had one chronic pain diagnosis; complex cases had two. In a 2 × 2 repeated-measures design with the factors tool (algorithm/standard browser) and diagnostic complexity (simple/complex), clinicians used either the algorithm or the ICD-11 browser for their diagnoses. After each case, clinicians indicated the pain diagnoses and rated the diagnostic process. The correctness of the assigned diagnoses and the ratings of the algorithm's utility and ease of use were analysed.

RESULTS

The use of the algorithm resulted in more correct diagnoses. This was true for chronic primary and secondary pain diagnoses. The clinicians preferred the algorithm over the ICD-11 browser, rating it easier to work with and more useful. Especially novice users benefited from the algorithm.

CONCLUSIONS

The use of the algorithm increases the correctness of the diagnoses for chronic pain and is well accepted by clinicians. The CAL-CP's use should be considered in routine care and research contexts.

SIGNIFICANCE STATEMENT

The ICD-11 has come into effect in January 2022. Clinicians and researchers will soon begin using the new classification of chronic pain. To facilitate clinicians training and diagnostic accuracy, a classification algorithm was developed. The paper investigates whether clinicians using the algorithm-as opposed to the generic tools provided by the WHO-reach more correct diagnoses when they diagnose standardized patients and how they rate the comparative utility of the diagnostic instruments available.

Factors associated with chronic abdominal pain in patients with inflammatory bowel disease in remission: A pilot cross-sectional study

BACKGROUND

Patients (20%-50%) with inflammatory bowel disease (IBD) experience chronic abdominal pain during remission. The clinical features of IBD patients with abdominal pain during remission remain poorly characterized. This cross-sectional pilot study aimed to assess patient recruitment, adherence, and feedback to optimize questionnaires for future use and to determine the clinical features that distinguish IBD patients in remission with and without abdominal pain.

METHODS

Online validated questionnaires about disease activity, symptoms, and psychological factors were sent to participants of the UK National Institute for Health and Care Research (NIHR) IBD BioResource, which is a national research platform consisting of re-callable IBD patients designed to expedite research into Crohn's and colitis. Inclusion/exclusion criteria of the IBD BioResource main cohort were applied. Descriptive and inferential statistics were applied to participants in remission. p-values ≤0.01 were considered significant.

KEY RESULTS

A total of 2050 patients were approached; 291 (14.2%) of these agreed to participate. In 35 patients, technical problems, length, and poor understanding of the relevance of some questionnaires affected completion as confirmed by feedback. In total, 244 patients were full responders with 122 (50%) in remission; 33 (27%) of these had chronic abdominal pain. Comparison of those with versus without (n = 89) chronic abdominal pain yielded higher scores in patients with pain for the following: somatization (p < 0.001); gastrointestinal symptoms rating scale score (p = <0.001); highly sensitive person scale (p = 0.007); catastrophizing score (p = 0.010). Trends were observed for azathioprine use (p = 0.021); coping resources inventory health in general (p = 0.046); neuroticism (p = 0.019); and poor sleep (p = 0.03).

CONCLUSIONS & INFERENCES

Differences in symptoms and psychological characteristics exist between IBD patients in remission with and without abdominal pain. Confirmation of findings in larger studies may facilitate development of personalized chronic pain treatments for IBD patients.

BNT12, a novel hybrid peptide of opioid and neurotensin pharmacophores, produces potent central antinociception with limited side effects

The development of multitarget opioid drugs has emerged as an attractive approach for innovative pain management with reduced side effects. In the present study, a novel hybrid peptide BNT12 containing the opioid and neurotensin (NT)-like fragments was synthesized and pharmacologically characterized. In acute radiant heat paw withdrawal test, intracerebroventricular (i.c.v.) administration of BNT12 produced potent antinociception in mice. The central antinociceptive activity of BNT12 was mainly mediated by μ-, δ-opioid receptor, neurotensin receptor type 1 (NTSR1) and 2 (NTSR2), supporting a multifunctional agonism of BNT12 in the functional assays. BNT12 also exhibited significant antinociceptive effects in spared nerve injury (SNI)-neuropathic pain, complete Freund's adjuvant (CFA)-induced inflammatory pain, acetic acid-induced visceral and formalin-induced pain after i.c.v. administration. Furthermore, BNT12 exhibited substantial reduction of acute antinociceptive tolerance, shifted the dose-response curve to the right by only 1.3-fold. It is noteworthy that BNT12 showed insignificant chronic antinociceptive tolerance at the supraspinal level. In addition, BNT12 exhibited reduced or no opioid-like side effects on conditioned place preference (CPP) response, naloxone-precipitated withdrawal response, acute hyperlocomotion, motor coordination, gastrointestinal transit, and cardiovascular responses. The present investigation demonstrated that the novel hybrid peptide BNT12 might serve as a promising analgesic candidate with limited opioid-like side effects.

Evaluating Sensitization-associated, Neuropathic-like Symptoms and Psychological Factors in Patients With Interstitial Lung Disease

The aims of this study were to phenotype pain in patients with interstitial lung disease (ILD) by investigating the association between sensitization-associated symptoms with quality of life, anxiety/depression, pain catastrophizing, and kinesiophobia levels and identifying those risk factors explaining the variance of quality of life in individuals with ILD and pain. One hundred and thirty-two (38.6% women, mean age: 70, standard deviation: 10.5 years) patients with ILD completed clinical (age, sex, height, weight), psychological (Hospital Anxiety and Depression Scale [HADS] and the Pittsburgh Sleep Quality Index), and health-related quality of life (EQ-5D-5L) variables, as well as the Central Sensitization Inventory (CSI), the Self-Report Leeds Assessment of Neuropathic Symptoms (S-LANSS), Pain Catastrophizing Scale, and Tampa Scale for Kinesiophobia (TSK-11) questionnaires. The prevalence of sensitization-associated symptomatology (CSI), neuropathic-like features (S-LANSS), anxiety symptoms, depressive symptoms, or poor sleep was 20.5%, 23.5%, 23.6%, 22.9%, or 51.6%. Significant associations between CSI, S-LANSS, HADS-A, HADS-D, Pain Catastrophizing Scale, TSK-11, and EQ-5D-5L (.220 < r < .716) were found. The regression analysis revealed that CSI, TSK-11, and HADS-D explained 44.8% of the variance of EQ-5D-5L (r2 adjusted: .448). This study found the presence of sensitization-associated and neuropathic-like symptoms as well as other central nervous system-derived symptoms, such as anxiety, depression, poor sleep, pain catastrophizing, and kinesiophobia in 25% of ILD patients with pain. Sensitization-associated symptoms, depression, and kinesiophobia were associated with a worse quality of life. These findings would support that individuals with ILD can exhibit different pain phenotypes, including nociplastic-like pain phenotype based on self-reported measurements. PERSPECTIVE: Pain in patients with ILD can fulfill features of different phenotypes, including nociplastic pain, when sensory, emotional, and cognitive mechanisms are involved at the same time.

Pain from Internal Organs and Headache: The Challenge of Comorbidity

Headache and visceral pain are common clinical painful conditions, which often co-exist in the same patients. Numbers relative to their co-occurrence suggest possible common pathophysiological mechanisms. The aim of the present narrative review is to describe the most frequent headache and visceral pain associations and to discuss the possible underlying mechanisms of the associations and their diagnostic and therapeutic implications based on the most recent evidence from the international literature. The conditions addressed are as follows: visceral pain from the cardiovascular, gastrointestinal, and urogenital areas and primary headache conditions such as migraine and tension-type headache. The most frequent comorbidities involve the following: cardiac ischemic pain and migraine (possible shared mechanism of endothelial dysfunction, oxidative stress, and genetic and hormonal factors), functional gastrointestinal disorders, particularly IBS and both migraine and tension-type headache, primary or secondary dysmenorrhea and migraine, and painful bladder syndrome and headache (possible shared mechanisms of peripheral and central sensitization processes). The data also show that the various visceral pain-headache associations are characterized by more than a simple sum of symptoms from each condition but often involve complex interactions with the frequent enhancement of symptoms from both, which is crucial for diagnostic and treatment purposes.

World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project: V. Physical examination standards in endometriosis research

OBJECTIVE

The World Endometriosis Research Foundation established the Endometriosis Phenome and Biobanking Harmonisation Project (EPHect) to create standardized documentation tools (with common data elements) to facilitate the comparison and combination of data across different research sites and studies. In 2014, 4 data research standards were published: clinician-reported surgical data, patient-reported clinical data, and fluid and tissue biospecimen collection. Our current objective is to create an EPHect standard for the clinician-reported physical examination (EPHect-PE) for research studies.

DESIGN

An international consortium involving 26 clinical and academic experts and patient partners from 11 countries representing 25 institutions and organizations. Two virtual workshops, followed by the development of the physical examination standards underwent multiple rounds of iterations and revisions.

SUBJECTS

N/A MAIN OUTCOME MEASURE(S): N/A RESULT(S): The EPHect-PE tool provides standardized assessment of physical examination characteristics and pain phenotyping. Data elements involve examination of back and pelvic girdle; abdomen including allodynia and trigger points; vulva including provoked vestibulodynia; pelvic floor muscle tone and tenderness; tenderness on unidigital pelvic examination; presence of pelvic nodularity; uterine size and mobility; presence of adnexal masses; presence of incisional masses; speculum examination; tenderness and allodynia at an extra-pelvic site (e.g., forearm); and recording of anthropometrics.

CONCLUSION(S)

The EPHect-PE standards will facilitate the standardized documentation of the physical examination, including the assessment and documentation of examination phenotyping of endometriosis-associated pelvic pain.

Fibromyalgia: A Review of the Pathophysiological Mechanisms and Multidisciplinary Treatment Strategies

Fibromyalgia is a syndrome characterized by chronic widespread musculoskeletal pain, which may or may not be associated with muscle or joint stiffness, accompanied by other symptoms such as fatigue, sleep disturbances, anxiety, and depression. It is a highly prevalent condition globally, being considered the third most common musculoskeletal disorder, following lower back pain and osteoarthritis. It is more prevalent in women than in men, and although it can occur at any age, it is more common between the ages of thirty and thirty-five. Although the pathophysiology and etiopathogenesis remain largely unknown, three underlying processes in fibromyalgia have been investigated. These include central sensitization, associated with an increase in the release of both excitatory and inhibitory neurotransmitters; peripheral sensitization, involving alterations in peripheral nociceptor signaling; and inflammatory and immune mechanisms that develop concurrently with the aforementioned processes. Furthermore, it has been determined that genetic, endocrine, psychological, and sleep disorders may influence the development of this pathology. The accurate diagnosis of fibromyalgia remains challenging as it lacks specific diagnostic biomarkers, which are still under investigation. Nonetheless, diagnostic approaches to the condition have evolved based on the use of scales and questionnaires for pain identification. The complexity associated with this pathology makes it difficult to establish a single effective treatment. Therefore, treatment is multidisciplinary, involving both pharmacological and non-pharmacological interventions aimed at alleviating symptoms. The non-pharmacological treatments outlined in this review are primarily related to physiotherapy interventions. The effectiveness of physical exercise, both on land and in water, as well as the application of electrotherapy combined with transcranial therapy and manual therapy has been highlighted. All of these interventions aim to improve the quality of life of patients highly affected by fibromyalgia.

Longitudinal multisite study of the chronobiological control of chronic pain: the CircaHealth CircaPain study protocol

INTRODUCTION

One in five Canadians lives with chronic pain. Evidence shows that some individuals experience pain that fluctuates in intensity following a circadian (24-hour) rhythm. Endogenous molecular rhythms regulate the function of physiological processes that govern pain mechanisms. Addressing chronic pain rhythmicity on a molecular and biopsychosocial level can advance understanding of the disease and identify new treatment/management strategies. Our CircaHealth CircaPain study uses an online survey combined with ecological momentary assessments and biosample collection to investigate the circadian control of chronic pain and identify potential biomarkers. Our primary objective is to understand interindividual variability in pain rhythmicity, by collecting biopsychosocial measures. The secondary objective accounts for seasonal variability and the effect of latitude on rhythmicity.

METHODS AND ANALYSIS

Following completion of a baseline questionnaire, participants complete a series of electronic symptom-tracking diaries to rate their pain intensity, negative affect, fatigue and stress on a 0-10 scale at 8:00, 14:00 and 20:00 daily over 10 days. These measures are repeated at 6 and 12 months postenrolment to account for potential seasonal changes. We aim to recruit ≥2500 adults with chronic pain within Canada. Infrastructure is being developed to facilitate the collection of blood samples from subgroups of participants (~800) two times per day over 24-48 hours to identify rhythmic expression of circulating genes and/or proteins.

ETHICS AND DISSEMINATION

Ethical approval for this study was obtained by the Queen's University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board (File No. 6038114). Participants provide informed consent to participate, and their data will not be identifiable in any publication or report. Findings will be published in a relevant scientific journal and disseminated at scientific meetings and online webinars. We maintain a website to post updated resources and engage with the community. We employ knowledge mobilisation in the form of direct data sharing with participants.

Novel endomorphin analogues CEMR-1 and CEMR-2 produce potent and long-lasting antinociception with a favourable side effect profile at the spinal level

BACKGROUND AND PURPOSE

Endomorphins have shown great promise as pharmaceutics for the treatment of pain. We have previously confirmed that novel endomorphin analogues CEMR-1 and CEMR-2 behaved as potent μ agonists and displayed potent antinociceptive activities at the supraspinal and peripheral levels. The present study was undertaken to evaluate the antinociceptive properties of CEMR-1 and CEMR-2 following intrathecal (i.t.) administration. Furthermore, their antinociceptive tolerance and opioid-like side effects were also determined.

EXPERIMENTAL APPROACH

The spinal antinociceptive effects of CEMR-1 and CEMR-2 were determined in a series of pain models, including acute radiant heat paw withdrawal test, spared nerve injury-induced neuropathic pain, complete Freund's adjuvant-induced inflammatory pain, visceral pain and formalin pain. Antinociceptive tolerance was evaluated in radiant heat paw withdrawal test.

KEY RESULTS

Spinal administration of CEMR-1 and CEMR-2 produced potent and prolonged antinociceptive effects in acute pain. CEMR-1 and CEMR-2 may produce their antinociception through distinct μ receptor subtypes. These two analogues also exhibited significant analgesic activities in neuropathic, inflammatory, visceral and formalin pain at the spinal level. It is noteworthy that CEMR-1 showed non-tolerance-forming analgesic properties, while CEMR-2 exhibited substantially reduced antinociceptive tolerance. Furthermore, both analogues displayed no or reduced side effects on conditioned place preference response, physical dependence, locomotor activity and gastrointestinal transit.

CONCLUSIONS AND IMPLICATIONS

The present investigation demonstrated that CEMR-1 and CEMR-2 displayed potent and long-lasting antinociception with a favourable side effect profile at the spinal level. Therefore, CEMR-1 and CEMR-2 might serve as promising analgesic compounds with minimal opioid-like side effects.

Pain as a disease in the new International Classification of Diseases (ICD-11): Latin American expert consensus

Aims: Pain diagnoses in the 10th version of the International Classification of Diseases (ICD-10) did not adequately support the current management of pain. Therefore, we aimed to review the new 11th revision (ICD-11) in order to analyze its usefulness for the management, coding, research and education of chronic pain from a Latin American perspective. Methods: The Latin American Federation of Associations for the Study of Pain convened a meeting of pain experts in Lima, Peru. Pain specialists from 14 Latin American countries attended the consensus meeting. Results: In ICD-11, chronic pain is defined as pain that persists or recurs longer than 3 months and is subdivided into seven categories: chronic primary pain and six types of chronic secondary pain. Chronic primary pain is now considered a disease in itself, and not a mere symptom of an underlying disease. Conclusion: The novel definition and classification of chronic pain in ICD-11 is helpful for better medical care, research and health statistics. ICD-11 will improve chronic pain management in Latin American countries, for both the pain specialist and the primary care physician.

Chronic pelvic pain; more than just the bladder

PURPOSE OF REVIEW

Chronic pelvic pain is much of a burden to those who suffer from it. Additionally, in many patients medical doctors, such as urologists are unable to identify a cause or clear pathology that can explain the pain. Still numerous patients and doctors keep on searching for a cause, focussing particularly on the pelvic organs. Lots of diagnostics and treatment methods are used but often without success. In recent years, we have gained increased insight into the mechanisms of pain and adapted the terminology accordingly.

RECENT FINDINGS

Two aspects of chronic pelvic pain have gained more attention. First, the myofascial aspects, especially the role of the pelvic floor muscles in maintaining the pain and as a therapeutic option. Second, the role of the brain and the psychological aspects intertwine with the pain and its consequences also open up for alternative management options. In terminology chronic pain is now included in the ICD-11, a historical change. Introducing chronic primary pain (no cause found) helps us to look away from the organ and deal with the patient as a whole human being.

SUMMARY

The findings reported here are helpful for your daily practice. Looking from a broad perspective gives the patient the feeling of being seen and heard. Working together in a multidisciplinary team makes your work easier and gives more satisfaction.

VIDEO ABSTRACT

http://links.lww.com/COU/A44.

Exercise Training for Chronic Pain: Available Evidence, Current Recommendations, and Potential Mechanisms

Chronic pain conditions pose a significant global burden of disability, with epidemiological data indicating a rising incidence. Exercise training is commonly recommended as a standalone or complementary approach for managing various chronic pain conditions like low back pain, osteoarthritis, rheumatoid arthritis, fibromyalgia syndrome, and neuropathic pain. Regardless of the specific condition or underlying cause (e.g., autoimmune disease, chronic inflammation), exercise training consistently leads to moderate to large reductions in pain. Moreover, exercise yields numerous benefits beyond pain alleviation, including small-to-moderate improvements in disability, quality of life, and physical function. Despite its efficacy, there is a lack of comprehensive research delineating the optimal intensity, duration, and type of exercise for maximal benefits; however, evidence suggests that sustained engagement in regular exercise or physical activity is necessary to achieve and maintain reductions in both clinical pain intensity ratings and the level that pain interferes with activities of daily living. Additionally, the precise mechanisms through which exercise mitigates pain remain poorly understood and likely vary based on the pathophysiological mechanisms underlying each condition.

Clinical Diagnosis and Treatment of Chronic Pain

More than 600 million people globally are estimated to be living with chronic pain. It is one of the most common complaints seen in an outpatient setting, with over half of patients complaining of pain during a visit. Failure to properly diagnose and manage chronic pain is associated with substantial morbidity and mortality, especially when opioids are involved. Furthermore, it is a tremendous financial strain on the healthcare system, as over USD 100 billion is spent yearly in the United States on healthcare costs related to pain management and opioids. This exceeds the costs of diabetes, heart disease, and cancer-related care combined. Being able to properly diagnose, manage, and treat chronic pain conditions can substantially lower morbidity, mortality, and healthcare costs in the United States. This review will outline the current definitions, biopsychosocial model, subclassifications, somatosensory assessments, imaging, clinical prediction models, and treatment modalities associated with chronic pain.

Do baseline patient reported outcome measures predict changes in self-reported function, following a chronic pain rehabilitation programme?

Background

Interdisciplinary pain management programmes, based on cognitive-behavioural principles, aim to improve physical and psychological functioning and enhance self-management in people living with chronic pain. Currently there is insufficient evidence about whether psychological, biological or social factors are predictive of positive outcomes following pain rehabilitation. This study aims to evaluate predictors of change in Brief Pain Inventory - pain interference score (BPI) in a clinical data set to determine whether age, sex and baseline outcome measures are predictive of improvement in pain interference following pain rehabilitation.

Methods

A retrospective, pragmatic observational analysis of routinely collected clinical data in two pain rehabilitation programmes, Balanced Life Programme (BLP) and Get Back Active (GBA) was conducted. Standard regression and hierarchical regression analyses were used to identify predictors of change to assess temporal changes in BPI. Responder analysis was also conducted.

Results

Standard regression analyses of 208 (BLP) and 310 (GBA) patients showed that higher baseline BPI and better physical performance measures predicted better improvement in BPI across both programmes. Hierarchical regression showed that age and sex accounted for 2.7% (BLP) and 0.002% (GBA) of the variance in change in BPI. After controlling for age and sex, the other measures explained an additional 23% (BLP) and 19% (GBA) of the variance, p = < .001 where BPI and physical performance measures were consistently statistically significant predictors, p < .05. Responder analysis also showed that pain interference and physical performance were significantly associated with improvement (p = < .0005).

Conclusions

The combination of high self-reported pain interference and better physical performance measures may be a useful indicator of who would benefit from interdisciplinary rehabilitation. Further validation of the results is required.

Comprehensive quantitative sensory testing shows altered sensory function in women with chronic pelvic pain: results from the Translational Research in Pelvic Pain (TRiPP) Study

ABSTRACT

Chronic pelvic pain (CPP), despite its high prevalence, is still relatively poorly understood mechanistically. This study, as part of the Translational Research in Pelvic Pain (TRiPP) project, has used a full quantitative sensory testing (QST) paradigm to profile n = 85 women with and without CPP (endometriosis or bladder pain specifically). We used the foot as a control site and abdomen as the test site. Across 5 diagnostically determined subgroups, we found features which are common across different aetiologies, eg, gain of function in pressure pain threshold (PPT) when assessing responses from the lower abdomen or pelvis (referred pain site). However, disease-specific phenotypes were also identified, eg, greater mechanical allodynia in endometriosis, despite there being large heterogeneities within diagnostic groups. The most common QST sensory phenotype was mechanical hyperalgesia (>50% across all the groups). A "healthy' sensory phenotype was seen in <7% of CPP participants. Specific QST measures correlated with sensory symptoms assessed by the painDETECT questionnaire (pressure-evoked pain [painDETECT] and PPT [QST] [ r = 0.47, P < 0.001]; mechanical hyperalgesia (painDETECT) and mechanical pain sensitivity [MPS from QST] [ r = 0.38, P = 0.009]). The data suggest that participants with CPP are sensitive to both deep tissue and cutaneous inputs, suggesting that central mechanisms may be important in this cohort. We also see phenotypes such as thermal hyperalgesia, which may be the result of peripheral mechanisms, such as irritable nociceptors. This highlights the importance of stratifying patients into clinically meaningful phenotypes, which may have implications for the development of better therapeutic strategies for CPP.

Making chronic pain count: empirical support for the ICD-11 classification of chronic pain

PURPOSE OF REVIEW

The purpose is to review the evidence that has been collected with regard to the new classification of chronic pain. In 2022, the World Health Assembly endorsed the 11 th revision of the International Classification of Diseases and Related Health Problems (ICD-11), and with it a new classification of chronic pain.

RECENT FINDINGS

The evidence from the formative field testing indicated that the categories were clearly delineated and the coverage of chronic pain excellent (<3% in remainder categories). Official WHO field tests showed that the classification works well within the technical parameters WHO classifications must conform to and outperformed the ICD-10 diagnoses in all respects. International field tests, in which clinicians diagnosed consecutive patients in settings of medium and high resources, showed substantial interrater reliability (κ = 0.596 to κ = 0.783) for the diagnoses and the clinicians rated their clinical utility as very high. Studies using complete hospital records demonstrated that with the information they contain, retrospective coding of the new diagnoses is possible and provides much more meaningful information than the ICD-10 diagnoses.

SUMMARY

The evidence supports the use of the new classification and highlights its informational gains - using it will contribute to making chronic pain count in many contexts.

Effectiveness of visceral fascial therapy targeting visceral dysfunctions outcome: systematic review of randomized controlled trials

BACKGROUND

Fascial Therapy is an ancient and widespread practice throughout the world. These approaches are very common in osteopathic practice and taught in workshops for professionals from different areas of health care, including Physiotherapy. This type of treatment is quite specialized and centered on the therapist. However, there is a lack of high-quality and low-risk bias studies that justify the use of this practice. Despite this, there is little scientific evidence about the effectiveness of Fascial Therapy to treat some visceral disorders. The purpose of this study was to critically appraise the scientific literature concerning the clinical efficacy of techniques used in Fascial Therapy targeting the visceral system.

METHODS

This systematic review included randomized controlled trials in any language or date of publication. All primary outcomes reported were included. The methodological quality and statistical reporting of each eligible trial were evaluated using the version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2). This systematic review provided a synthesis of current evidence on the effects of Fascial Therapy in patients with visceral disorders and/or pain. A total of 11 studies were included, with five of them covering gastrointestinal dysfunction, two covering cardiorespiratory dysfunction, two covering musculoskeletal dysfunction, and two covering urogenital dysfunction.

RESULTS

Fascial Therapy targeting the visceral system has been shown to be effective in reducing pain over the long term in people with low back pain when combined with standard physical therapy and effective in reducing gastroesophageal reflux symptoms over the short term. Considering the overall bias, six studies were at high risk of bias, two studies had some concerns and only three studies were at low risk of bias. Of the three studies with a low risk of bias, only two showed positive results and were effective in improving the studied outcome.

CONCLUSION

This systematic review shows that currently, there is poor evidence for the efficacy of the techniques used in Fascial Therapy targeting the visceral system, and this information can help healthcare professionals in decision-making related to the use of Fascial Therapy targeting the visceral system in patients with visceral disorders and/or pain.

Chronic Primary Pelvic Pain Syndrome in Men

BACKGROUND

Chronic primary pelvic pain syndrome in men (CPPPSm) can be associated with urogenital pain, urinary symptoms, sexual dysfunction, and emotional disturbance. Its clinical heterogeneity and incompletely understood pathogenesis make it more difficult to treat. This article is intended to familiarize the reader with basic aspects of the manifestations, pathophysiology, diagnostic evaluation, differential diagnosis, and treatment of this condition.

METHODS

This article is based on relevant publications retrieved by a selective search of the literature, including the current guidelines of the European Association of Urology. The features of this disease pertaining to urology, psychosomatic medicine, and pain medicine are illuminated from an interdisciplinary perspective.

RESULTS

Chronic pelvic pain appears to arise through a complex interaction of inflammatory, infectious, neurological, musculoskeletal, and psychosomatic factors. A comprehensive diagnostic work-up should be carried out to evaluate and exclude the numerous differential diagnoses. Treatment strategies are based on the clinical phenotype. Randomized controlled trials have shown that significant relief can be achieved with a variety of drugs and non-pharmacological treatments, selected according to the manifestations of the condition in the individual case. Attention must be paid to treatment-specific adverse effects.

CONCLUSION

The management of patients with CPPPSm should consist of a comprehensive differential diagnostic evaluation and an individually oriented treatment strategy.

Clinical profiling of specific diagnostic subgroups of women with chronic pelvic pain

Introduction

Chronic pelvic pain (CPP) is a common condition affecting up to 26.6% of women, with many suffering for several years before diagnosis and/or treatment. Its clinical presentation is varied and there are frequently comorbid conditions both within and outside the pelvis. We aim to explore whether specific subgroups of women with CPP report different clinical symptoms and differing impact of pain on their quality of life (QoL).

Methods

The study is part of the Translational Research in Pelvic Pain (TRiPP) project which is a cross-sectional observational cohort study. The study includes 769 female participants of reproductive age who completed an extensive set of questions derived from standardised WERF EPHect questionnaires. Within this population we defined a control group (reporting no pelvic pain, no bladder pain syndrome, and no endometriosis diagnosis, N = 230) and four pain groups: endometriosis-associated pain (EAP, N = 237), interstitial cystitis/bladder pain syndrome (BPS, N = 72), comorbid endometriosis-associated pain and BPS (EABP, N = 120), and pelvic pain only (PP, N = 127).

Results

Clinical profiles of women with CPP (13-50 years old) show variability of clinical symptoms. The EAP and EABP groups scored higher than the PP group (p < 0.001) on the pain intensity scales for non-cyclical pelvic pain and higher than both the BPS and PP groups (p < 0.001) on the dysmenorrhoea scale. The EABP group also had significantly higher scores for dyspareunia (p < 0.001), even though more than 50% of sexually active participants in each pain group reported interrupting and/or avoiding sexual intercourse due to pain in the last 12 months. Scores for the QoL questionnaire (SF-36) reveal that CPP patients had significantly lower QoL across all SF-36 subscales (p < 0.001). Significant effects were also observed between the pain groups for pain interference with their work (p < 0.001) and daily lives (p < 0.001), with the EABP suffering more compared to the EAP and PP groups (p < 0.001).

Discussion

Our results demonstrate the negative impact that chronic pain has on CPP patients' QoL and reveal an increased negative impact of pain on the comorbid EABP group. Furthermore, it demonstrates the importance of dyspareunia in women with CPP. Overall, our results demonstrate the need for further exploration of interventions targeting QoL more broadly and suggest that novel approaches to classifying women with CPP are needed.

The Unmet Needs for Studying Chronic Pelvic/Visceral Pain Using Animal Models

The different definitions of chronic pelvic/visceral pain used by international societies have changed over the years. These differences have a great impact on the way researchers study chronic pelvic/visceral pain. Recently, the role of systemic changes, including the role of the central nervous system, in the perpetuation and chronification of pelvic/visceral pain has gained weight. Consequently, researchers are using animal models that resemble those systemic changes rather than using models that are organ- or tissue-specific. In this review, we discuss the advantages and disadvantages of using bladder-centric and systemic models, enumerating some of the central nervous system changes and pain-related behaviors occurring in each model. We also present some drawbacks when using animal models and pain-related behavior tests and raise questions about possible, yet to be demonstrated, investigator-related bias. We also suggest new approaches to study chronic pelvic/visceral pain by refining existing animal models or using new ones.

Anxiety-related behaviors without observation of generalized pain in a mouse model of endometriosis

Endometriosis is a chronic, hormone-dependent, inflammatory disease, characterized by the presence and growth of endometrial tissue outside the uterine cavity. It is associated with moderate to severe pelvic and abdominal pain symptoms, subfertility and a marked reduction in health-related quality of life. Furthermore, relevant co-morbidities with affective disorders like depression or anxiety have been described. These conditions have a worsening effect on pain perception in patients and might explain the negative impact on quality of life observed in those suffering from endometriosis-associated pain. Whereas several studies using rodent models of endometriosis focused on biological and histopathological similarities with the human situation, the behavioral characterization of these models was never performed. This study investigated the anxiety-related behaviors in a syngeneic model of endometriosis. Using elevated plus maze and the novel environment induced feeding suppression assays we observed the presence of anxiety-related behaviors in endometriosis-induced mice. In contrast, locomotion or generalized pain did not differ between groups. These results indicate that the presence of endometriosis lesions in the abdominal cavity could, similarly to patients, induce profound psychopathological changes/impairments in mice. These readouts might provide additional tools for preclinical identification of mechanisms relevant for development of endometriosis-related symptoms.

Characterizing mechanism-based pain phenotypes in patients with chronic pancreatitis: a cross-sectional analysis of the PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translational StuDies

ABSTRACT

Pain is common in chronic pancreatitis (CP) and profoundly reduces quality of life (QoL). Multiple underlying mechanisms contribute to a heterogenous pain experience and reduce efficacy of pain management. This study was designed to characterize the distribution of mechanism-based pain phenotypes in painful CP. The data analyzed were collected as part of the PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translational StuDies, an NCI/NIDDK-funded longitudinal study of the natural history of CP. The PROspective Evaluation of Chronic pancreatitis for EpidEmiologic and translational stuDies includes patient-reported outcome (PRO) measures of pain, medication use, global health, and QoL. Of subjects (N = 681) with CP, 80% experienced abdominal pain within the year before enrollment. Subjects who experienced pain in the week before enrollment (N = 391) completed PROMIS Neuropathic and Nociceptive Pain Quality instruments which were then used to classify them by pain type: 40% had nociceptive, 5% had neuropathic-like, and 32% had both types of pain. The prevalence of having both types of pain was higher among women and subjects with diabetes mellitus, whereas nociceptive-only pain was more prevalent among men and those with pancreatic duct stricture. Other factors, including pain medication use and healthcare utilization, did not differ between groups based on pain type. Subjects in the Both group had significantly worse health and QoL scores relative to those with nociceptive-only pain, suggesting that using psychosocial pain surveys may be useful for understanding pain subtypes in patients with CP. Additional research is needed to identify biochemical and biophysical signatures that may associate with and predict responses to mechanism-specific interventions.

Wenn aus einem Bauchgefühl viszerale Schmerzen werden: Placebo- und Nocebo-Mechanismen entlang der Darm-Hirn-Achse

Das Erleben von Schmerz ist nach heutigem Verständnis durch eine Vielzahl biologischer, psychologischer und sozialer Faktoren geprägt und somit eine komplexe, von der Nozizeption abzugrenzende, psychologische Erfahrung. Entsprechend ist das Schmerzerleben durch psychologische Faktoren modulierbar und chronische Schmerzen werden als biopsychosoziale Erkrankungen verstanden. Dies gilt auch für den Viszeralschmerz, dem spezifische psychophysiologische Prinzipien und neurobiologische Mechanismen zugrunde liegen, was eine interdisziplinäre Betrachtung unter Einbeziehung der Psychologie und der Neurowissenschaften erforderlich macht. Ausgehend von den bidirektionalen Verbindungen zwischen Darm und Hirn und aufbauend auf einem biopsychosozialen Krankheitsmodell beschreibt dieser Übersichtsbeitrag psychologische Mechanismen, die bei der Entstehung, Aufrechterhaltung und Therapie viszeraler Schmerzen wichtig sind. Dabei liegt der Fokus auf positiven und negativen Erwartungseffekten im psychosozialen Behandlungskontext. Therapieerwartungen können Krankheitssymptome sowohl positiv als auch negativ beeinflussen. Diese gemeinhin als Placebo- und Noceboeffekte bekannten Phänomene, die durch die Arzt-Patient Kommunikation, Lernprozesse, Stress und Furcht vermittelt werden, sind auch für den Viszeralschmerz bei gastrointestinalen Erkrankungen zunehmend anerkannt und Gegenstand aktueller grundlagenwissenschaftlicher und klinischer Forschungsaktivitäten. Neue interdisziplinäre und translationale Forschungsansätze aus der Forschung zu Placebo- und Noceboeffekten liefern spannende Einblicke in die zahlreichen Verbindungen und Wechselbeziehungen zwischen Darm und Gehirn bei normalen wie auch pathologischen Darm-Hirn Interaktionen und können dazu beitragen, die Pathophysiologie von Erkrankungen, die mit viszeralen Schmerzen einhergehen, besser zu verstehen und wichtige Erkenntnisse für neue Therapieansätze zu gewinnen.

Assessment of visceral pain with special reference to chronic pancreatitis

A thorough pain assessment is of utmost importance when managing pain in clinical practice as it is the foundation for defining pain in need of treatment, either interventional or pharmacological. Pain characteristics can also guide interventional strategies and help evaluate the effect of treatment. In research settings, standardized pain assessment is crucial to improve comparability across studies and facilitate meta-analysis. Due to the importance of thorough visceral pain assessment, this manuscript describes the key elements of pain evaluation focusing on chronic pancreatitis. Most studies in pain assessment have focused on somatic pain, and although chronic pain often shares characteristics between etiologies, some differences must be addressed when assessing visceral pain. Especially differences between somatic and visceral pain are apparent, where visceral pain is diffuse and difficult to localize, with referred pain aspects and often autonomic symptoms dominating the clinical picture. These aspects need to be incorporated into the pain assessment instrument. The manuscript will discuss the different ways of assessing pain, including unidimensional measurement scales, multidimensional questionnaires, and quantitative sensory testing. The advantages and challenges linked to the different methods will be evaluated.

Chronic Pain in the ICD-11: New Diagnoses That Clinical Psychologists Should Know About

Background

In the 10th revision of the International Classification of Diseases and Related Health Problems (ICD-10), chronic pain was not represented adequately. Pain was left undefined and not recognized as a biopsychosocial phenomenon. Instead, a flawed dualism between psychological and somatic factors was implied. Individual diagnoses were ill-defined and scattered randomly through different chapters. Many patients received diagnoses in remainder categories devoid of meaningful clinical information.

Method

The International Association for the Study of Pain launched a Task Force to improve the diagnoses for the 11th revision of the ICD and this international expert team worked from 2013-2019 in cooperation with the WHO to develop a consensus based on available evidence and to improve the diagnoses.

Results

A new chapter on chronic pain was created with a biopsychosocial definition of pain. Chronic pain was operationalized as pain that persists or recurs longer than three months and subdivided into seven categories: Chronic primary pain and six types of chronic secondary pain. All diagnoses were based on explicit operationalized criteria. Optional extension codes allow coding pain-related parameters and the presence of psychosocial aspects together with each pain diagnosis.

Conclusion

First empirical studies demonstrated the integrity of the categories, the reliability, clinical utility, international applicability and superiority over the ICD-10. To improve reliability and ease of diagnosis, a classification algorithm is available. Clinical psychologists and other clinicians working with people with chronic pain should watch the national implementation strategies and advocate for multimodal and interdisciplinary treatments and adequate reimbursement for all providers involved.

What is the relationship between physical activity and chronic pain in older adults? A systematic review and meta-analysis protocol

INTRODUCTION

Chronic pain is highly prevalent in older adults and can cause functional limitations, negatively affecting health and quality of life. Physical activity is a non-pharmacological approach used to prevent chronic pain as it promotes the release of endogenous opioids that block pain sensitivity. Therefore, we developed a systematic review protocol to analyse the relationship between physical activity and the occurrence and intensity of chronic pain in older adults.

METHODS AND ANALYSES

The systematic review will search PubMed, Scopus and Embase databases. The inclusion criteria will be observational studies that had primary chronic pain as an outcome, including persistent and intermittent pain. The population will include older adults from the community, living in a long-stay institution, or in outpatient follow-up. There will be no restriction regarding the year of publication and articles published in Portuguese, English and Spanish will be analysed. Effect or impact measures will be quantified, including OR, HR, prevalence ratio, incidence ratio and relative risk with their 95% CIs. If the data allow, a meta-analysis will be performed. The results may help understand the impact of physical activity as a potential protection factor against the occurrence of pain later in life as well as promote strategic prevention plans and public policies that encourage this practice in older adults.

ETHICS AND DISSEMINATION

Ethical approval is not required. The results will be disseminated via submission for publication to a peer-reviewed journal when complete.

PROSPERO REGISTRATION NUMBER

CRD42021282898.

Determinants of Pain-Induced Disability in German Women with Endometriosis during the COVID-19 Pandemic

(1) Background: The main aim of this research was to examine the factors leading to pain-induced disability by assessing the impact of demographic, endometriosis-specific, pandemic-specific, and mental health factors. (2) Methods: Women with endometriosis who attended online support groups were invited to respond to an online survey during the first wave of the COVID-19 pandemic in Germany. The Pain Disability Index (PDI) was employed to assess disability-related daily functioning. Independent predictors of pain-induced disability were determined using univariate and multivariate logistic regression analyses. (3) Results: The mean PDI score of the study population was 31.61 (SD = 15.82), which was significantly higher (p < 0.001) than that reported in a previously published normative study of the German population. In the present study, a high level of pain-induced disability, as defined by scores equal to or higher than the median of the study population, older age (OR 1.063, 95% CI 1.010−1.120, p = 0.020), dysmenorrhea (OR 1.015, 95% CI 1.005−1.026, p = 0.005), dysuria (OR 1.014; 95% CI 1.001−1.027, p = 0.029), lower back pain (OR 1.018, 95% CI 1.007−1.029, p = 0.001), and impaired mental health (OR 1.271, 95% CI 1.134−1.425, p < 0.001) were found to be independent risk factors. Pandemic-specific factors did not significantly influence the pain-induced disability of the participants in this study. (4) Conclusions: The level of pain-induced disability was significantly higher among the women with endometriosis than among women in the normative German validation study. Our findings identified risk factors for experiencing a high level of pain-induced disability, such as demographic and specific pain characteristics. Pandemic-specific factors did not significantly and independently influence the pain-induced disability during the first wave of the COVID-19 pandemic in Germany. Impaired mental health negatively influenced functioning during daily activities. Thus, women with endometriosis should be managed by a multidisciplinary team of healthcare professionals to prevent negative effects of pain-induced disability on their quality of life.

Intermittent Fasting: Potential Utility in the Treatment of Chronic Pain across the Clinical Spectrum

Dietary behavior can have a consequential and wide-ranging influence on human health. Intermittent fasting, which involves intermittent restriction in energy intake, has been shown to have beneficial cellular, physiological, and system-wide effects in animal and human studies. Despite the potential utility in preventing, slowing, and reversing disease processes, the clinical application of intermittent fasting remains limited. The health benefits associated with the simple implementation of a 12 to 16 h fast suggest a promising role in the treatment of chronic pain. A literature review was completed to characterize the physiologic benefits of intermittent fasting and to relate the evidence to the mechanisms underlying chronic pain. Research on different fasting regimens is outlined and an overview of research demonstrating the benefits of intermittent fasting across diverse health conditions is provided. Data on the physiologic effects of intermittent fasting are summarized. The physiology of different pain states is reviewed and the possible implications for intermittent fasting in the treatment of chronic pain through non-invasive management, prehabilitation, and rehabilitation following injury and invasive procedures are presented. Evidence indicates the potential utility of intermittent fasting in the comprehensive management of chronic pain and warrants further investigation.

Repetitive Transcranial Magnetic Stimulation of the Primary Motor Cortex beyond Motor Rehabilitation: A Review of the Current Evidence

Transcranial magnetic stimulation (TMS) has emerged as a novel technique to stimulate the human brain through the scalp. Over the years, identifying the optimal brain region and stimulation parameters has been a subject of debate in the literature on therapeutic uses of repetitive TMS (rTMS). Nevertheless, the primary motor cortex (M1) has been a conventional target for rTMS to treat motor symptoms, such as hemiplegia and spasticity, as it controls the voluntary movement of the body. However, with an expanding knowledge base of the M1 cortical and subcortical connections, M1-rTMS has shown a therapeutic efficacy that goes beyond the conventional motor rehabilitation to involve pain, headache, fatigue, dysphagia, speech and voice impairments, sleep disorders, cognitive dysfunction, disorders of consciousness, anxiety, depression, and bladder dysfunction. In this review, we summarize the latest evidence on using M1-rTMS to treat non-motor symptoms of diverse etiologies and discuss the potential mechanistic rationale behind the management of each of these symptoms.

[From gut feeling to visceral pain : Effects of negative expectations in the context of the gut-brain axis]

Disturbances of the gut-brain axis are characterized by complex dysfunctions on peripheral and central nervous system levels, which can contribute to visceral hypervigilance and hyperalgesia and imprint visceral pain. Numerous cognitive, emotional and psychoneurobiological factors are involved in visceral pain modulation, which in the psychosocial treatment concept can have a positive as well as a negative impact on the experience of visceral pain. Nocebo effects induced by negative expectations are of high clinical relevance in acute and especially in chronic visceral pain but the underlying mechanisms remain insufficiently understood. Verbal instructions, previous experiences and learning processes as well as emotional factors, such as fear and stress contribute to the development and maintenance of negative expectation effects. Targeted communication strategies, a sensitive use of information in the clarification and positive environmental context conditions can contribute to establishing an adequate expectation management and minimize negative expectation effects in the clinical practice. At the same time, translational research approaches are required to gain further insights into the mediators and moderators of negative expectation effects and to transfer these into clinical practice. In this way the treatment of patients with disorders of the gut-brain communication can be improved.

Living with endometriosis: Comorbid pain disorders, characteristics of pain and relevance for daily life

BACKGROUND

Pain plays a central role in endometriosis. The complex relationship among pain characteristics, comorbid pain disorders and daily life represents a challenge for medical support. This multicentre cross-sectional case-control study analysed the association between endometriosis-related chronic pain and functions of daily life in 510 women with endometriosis, 265 (52%) who experienced chronic pain, either from endometriosis alone (N = 134, 26.3%) or in association with additional pain disorders (N = 131, 25.7%).

METHODS

Self-administered questionnaires from the Brief Pain Inventory and the Pain Disability Index were used to investigate associations between pain characteristics (frequency, duration, intensity) and daily life. Also, associations between different endometriosis characteristics (rASRM stage, presence of adhesions, localisation of lesions) and pain were evaluated.

RESULTS

Chronic pain is negatively associated with almost all (12/14) aspects of daily life investigated, including standing, walking, sitting, defaecation, sleep, sports activities, family and domestic responsibilities, sexuality, social functioning, professional life, mood, and joy of life. Altogether, 33.7% of women with chronic pain reported moderate and 27.5% severe limitations. Comorbid pain disorders resulted in significantly more limitations. The length of pain episodes showed a particularly important influence, especially for family/domestic responsibilities (OR 22.94, p < 0.001), professional life (OR 16.56, p < 0.001) and social functioning (OR 41.03, p < 0.001).

CONCLUSIONS

Our data confirm that despite treatment, about 50% of women experience pain. Pain was associated with at least moderate negative effects on almost all areas of daily life; additional pain comorbidities increased limitations. Improving pain management is essential for improving quality of life in women with endometriosis.

SIGNIFICANCE

The study provides an accurate overview of the impact of endometriosis-associated pain on daily life. This is important because pain plays a central role in women living with endometriosis, and despite modern therapies, many women continue to suffer from chronic pain. The detailed analysis of its impact with a comprehensive survey of all aspects of daily life in a very large study population is unique. We expect an improved understanding of consequences of pain to significantly advance medical support in these patients.

Health-related quality of life of Malaysian patients with chronic non-malignant pain and its associated factors: a cross-sectional study

Background

Chronic pain has a major impact on a patient’s quality of life, affecting physical and psychological functioning. It has debilitating consequences on social and economic aspects too. This study aimed to explore the status of health-related quality of life (HRQoL) of Malaysian patients suffering from chronic non-malignant pain.

Methods

Four hospitals offering pain clinic services were involved in this multicentre cross-sectional study conducted between June and September 2020. Adult patients who had been diagnosed with non-malignant chronic pain lasting for at least three months and able to communicate in English or Malay language were recruited in this study. Participants were informed about the study and were made aware that their participation was entirely voluntary. A battery of questionnaires consists of the EuroQol-5 dimensions-5 levels questionnaire (EQ-5D-5L) and the EuroQol visual analogue scale (EQ VAS), the Pain Self-Efficacy questionnaire (PSEQ) and the Pain Catastrophizing Scale (PCS) were self-administered by the patients. Besides, a structured questionnaire was used to collect their socio-demographic information, pain condition, sleep quality and working status. Participants’ usage of pain medications was quantified using the Quantitative Analgesic Questionnaire (QAQ).

Results

A total of 255 patients participated in this study. A median EQ-5D index value of 0.669 (IQR: 0.475, 0.799) and a median EQ VAS score of 60.0 (IQR: 50.0, 80.0) were recorded. Malay ethnicity (Adj. B: 0.77; 95% CI: 0.029, 0.126; p = 0.002) and a higher level of self-efficacy (Adj. B: 0.008; 95% CI: 0.006, 0.011; p < 0.001) were predictors of a better HRQoL, while suffering from pain in the back and lower limb region (Adj. B: -0.089; 95% CI: − 0.142, − 0.036; p = 0.001), the use of a larger amount of pain medications (Adj. B: -0.013; 95% CI: − 0.019, − 0.006; p < 0.001), and a higher degree of pain magnification (Adj. B: -0.015; 95% CI: − 0.023, − 0.008; p < 0.001) were associated with a poorer HRQoL.

Conclusions

These findings suggested that Malay ethnicity and a higher level of self-efficacy were predictors of a better HRQoL in patients with chronic pain, whereas pain-related factors such as higher usage of medication, specific pain site and pain magnification style were predictors of poorer HRQoL.

Pain severity ratings in the 11th revision of the International Classification of Diseases: a versatile tool for rapid assessment

ABSTRACT

An improved classification of chronic pain is included in the 11th revision of the International Classification of Diseases (ICD-11). For all diagnoses of chronic pain, an optional dimensional code for the chronic pain severity will supplement the categorical diagnoses. Pain severity combines pain intensity, pain-related interference, and pain-related distress. Each component is rated by the patient on a numerical rating scale (NRS) from 0 to 10, and subsequently translated into severity stages ('mild'/'moderate'/'severe'). The present study aimed to evaluate this severity code by comparing the ratings with established psychometric measures of pain-related interference and distress. An online survey was posted to self-help groups for chronic pain, and 595 participants (88.7% women, 59.5±13.5 years) rated each of the severity parameters (pain intensity, pain-related interference, pain-related distress) on an NRS from 0 to 10 and completed the Pain Disability Index (PDI) and the Pain Coping Questionnaire (FESV, 3 subscales). The participants reported a mean pain intensity of 6.4±1.9, mean pain-related interference of 6.7±2.1, and mean pain-related distress of 5.7±2.5. The respective NRS ratings showed substantial correlations with the PDI score (r=.65) and the FESV subscales (r=.65, r=.56, r=.37). The extension code for pain severity is a valid and efficient way of recording additional dimensional pain parameters, which can be used to monitor the course of chronic pain and its treatment. The specifier's efficiency makes it possible to use the code when a questionnaire would not be feasible due to time constraints, such as in primary care.

Spinal Microglia and Astrocytes: Two Key Players in Chronic Visceral Pain Pathogenesis

Chronic visceral pain (CVP) is one of the common symptoms of many diseases triggered by underlying diseases of the internal organs of the human body. Its causes include vascular mechanisms, mechanical factors, persistent inflammation, and unexplained functional mechanisms. Although the pathogenesis is unclear, more and more research has begun to shift from the neuronal aspect to the glial cells in recent years. Some data highlight that the spinal glial cells, particularly the microglia and astrocytes, play an essential role in CVP. Based on this, we highlight the mechanisms of microglia and astrocytes in CVP concerning the release of cytokines, chemokines, and neuroactive substances and alterations in intracellular signaling pathways during the process. Finally, because CVP is widespread in various diseases, we present future perspectives targeting microglia and astrocytes for treatment.

Current Challenges in the Management of Chronic Pelvic Pain in Women: From Bench to Bedside

Chronic pelvic pain (CPP) affects a significant proportion of women worldwide And has a negative impact on several aspects of these women’s lives including mental health, work, relationships and sexual function, among others. This set of factors ultimately reflects negatively on quality Of life. The physiopathology of CPP is complex and remains to be fully clarified; however, recent advances have increased understanding of the mechanisms involved in chronic pain in general, and more specifically, CPP. Nonetheless, even when a detailed clinical history is obtained, meticulous physical examination is performed and imaging resources are appropriately used, the organic cause of the pain may still fail to be identified in a substantial number of women with CPP. Management of CPP may therefore be challenging. This narrative review was aimed at adding to the available literature on the subject, presenting and discussing the principal characteristics of CPP in women. The paper highlights gaps in the literature while providing the most up-to-date evidence associated with the physiopathology and classification of pain, its diagnosis and treatment. In addition, current challenges in the management of women with CPP are discussed.

Classification of chronic pain for the International Classification of Diseases (ICD-11): results of the 2017 international World Health Organization field testing

ABSTRACT

Because chronic pain has been poorly represented in the International Statistical Classification of Diseases and Related Health Problems (ICD) despite its significant contribution to the burden of disease worldwide, the International Association for the Study of Pain (IASP) developed a classification of chronic pain that was included in the ICD-11 version as "MG30" and approved by the World Health Assembly in 2019. The objective of this field test was to determine how well the classification of chronic pain works in the context of the ICD-11. A web-based survey using the WHO-FiT platform recruited 177 healthcare professionals from all WHO regions. After a training on coding chronic pain hosted by the IASP Web site, participants evaluated 18 diagnostic codes (lines) of the 2017 frozen version of the ICD-11 and 12 vignettes (cases) describing chronic pain conditions. Correctness, ambiguity, and perceived difficulty of the coding were compared between the ICD-11 and the ICD-10 and the applicability of the morbidity rules for the ICD-11 verified. In the line coding, 43.0% of correct chronic pain diagnoses assigned with the ICD-10 contrasted with 63.2% with the ICD-11. Especially in cases in which the chronic pain is regarded as the symptom of an underlying disease, the ICD-11 (63.5%) commanded more correct diagnoses than the ICD-10 (26.8%). The case coding was on average 83.9% accurate, only in 1.6% of cases any difficulty was perceived. The morbidity rules were applied correctly in 74.1% of cases. From a coding perspective, the ICD-11 is superior to the ICD-10 in every respect, offering better accuracy, difficulty, and ambiguity in coding chronic pain conditions.

Chronic pain in the 11th revision of the International Classification of Diseases: users' questions answered

ABSTRACT

The upcoming 11th revision of the International Classification of Diseases (ICD-11) will include a comprehensive classification of chronic pain for the first time, which is based on the biopsychosocial definition of chronic pain. This presents a great opportunity for pain research and clinical practice. The new classification consists of seven main diagnostic categories of chronic pain, which are further divided into increasingly specific levels of diagnoses. Each diagnosis is characterized by clearly defined operationalized criteria. Future users will need to familiarize themselves with the new system and its application. The aim of the present publication is to provide users of the ICD-11 chronic pain classification with answers to frequently asked questions regarding the ICD-11 as a whole, the ICD-11 chronic pain classification, and its application to common pain syndromes. The questions compiled here reached the International Association for the Study of Pain Task Force via different routes (e.g., at conferences, by letter, or during field testing). Furthermore, the authors collected questions posted to the ICD-11 browser and contacted early users of the classification to enquire about their most frequent difficulties when applying the new diagnoses. The authors of the present publication prepared answers to these frequently asked questions. This publication intends to act as a guide for the future users of the new ICD-11 chronic pain classification, hence facilitating its implementation.

Altered Brain Structure in Chronic Visceral Pain: Specific Differences in Gray Matter Volume and Associations With Visceral Symptoms and Chronic Stress

Structural brain alterations in chronic pain conditions remain incompletely understood, especially in chronic visceral pain. Patients with chronic-inflammatory or functional bowel disorders experience recurring abdominal pain in concert with other gastrointestinal symptoms, such as altered bowel habits, which are often exacerbated by stress. Despite growing interest in the gut-brain axis and its underlying neural mechanisms in health and disease, abnormal brain morphology and possible associations with visceral symptom severity and chronic stress remain unclear. We accomplished parallelized whole-brain voxel-based morphometry analyses in two patient cohorts with chronic visceral pain, i.e., ulcerative colitis in remission and irritable bowel syndrome, and healthy individuals. In addition to analyzing changes in gray matter volume (GMV) in each patient cohort vs. age-matched healthy controls using analysis of covariance (ANCOVA), multiple regression analyses were conducted to assess correlations between GMV and symptom severity and chronic stress, respectively. ANCOVA revealed reduced GMV in frontal cortex and anterior insula in ulcerative colitis compared to healthy controls, suggesting alterations in the central autonomic and salience networks, which could however not be confirmed in supplemental analyses which rigorously accounted for group differences in the distribution of sex. In irritable bowel syndrome, more widespread differences from healthy controls were observed, comprising both decreased and increased GMV within the sensorimotor, central executive and default mode networks. Associations between visceral symptoms and GMV within frontal regions were altered in both patient groups, supporting a role of the central executive network across visceral pain conditions. Correlations with chronic stress, on the other hand, were only found for irritable bowel syndrome, encompassing numerous brain regions and networks. Together, these findings complement and expand existing brain imaging evidence in chronic visceral pain, supporting partly distinct alterations in brain morphology in patients with chronic-inflammatory and functional bowel disorders despite considerable overlap in symptoms and comorbidities. First evidence pointing to correlations with chronic stress in irritable bowel syndrome inspires future translational studies to elucidate the mechanisms underlying the interconnections of stress, visceral pain and neural mechanisms of the gut-brain axis.

Preclinical models of endometriosis and interstitial cystitis/bladder pain syndrome: an Innovative Medicines Initiative-PainCare initiative to improve their value for translational research in pelvic pain

ABSTRACT

Endometriosis (ENDO) and interstitial cystitis/bladder pain syndrome (IC/BPS) are chronic pain conditions for which better treatments are urgently needed. Development of new therapies with proven clinical benefit has been slow. We have conducted a review of existing preclinical in vivo models for ENDO and IC/BPS in rodents, discussed to what extent they replicate the phenotype and pain experience of patients, as well as their relevance for translational research. In 1009 publications detailing ENDO models, 41% used autologous, 26% syngeneic, 18% xenograft, and 11% allogeneic tissue in transplantation models. Intraperitoneal injection of endometrial tissue was the subcategory with the highest construct validity score for translational research. From 1055 IC/BPS publications, most interventions were bladder centric (85%), followed by complex mechanisms (8%) and stress-induced models (7%). Within these categories, the most frequently used models were instillation of irritants (92%), autoimmune (43%), and water avoidance stress (39%), respectively. Notably, although pelvic pain is a hallmark of both conditions and a key endpoint for development of novel therapies, only a small proportion of the studies (models of ENDO: 0.5%-12% and models of IC/BPS: 20%-44%) examined endpoints associated with pain. Moreover, only 2% and 3% of publications using models of ENDO and IC/BPS investigated nonevoked pain endpoints. This analysis highlights the wide variety of models used, limiting reproducibility and translation of results. We recommend refining models so that they better reflect clinical reality, sharing protocols, and using standardized endpoints to improve reproducibility. We are addressing this in our project Innovative Medicines Initiative-PainCare/Translational Research in Pelvic Pain.

Classification algorithm for the International Classification of Diseases-11 chronic pain classification: development and results from a preliminary pilot evaluation

ABSTRACT

The International Classification of Diseases-11 (ICD-11) chronic pain classification includes about 100 chronic pain diagnoses on different diagnostic levels. Each of these diagnoses requires specific operationalized diagnostic criteria to be present. The classification comprises more than 200 diagnostic criteria. The aim of the Classification Algorithm for Chronic Pain in ICD-11 (CAL-CP) is to facilitate the use of the classification by guiding users through these diagnostic criteria. The diagnostic criteria were ordered hierarchically and visualized in accordance with the standards defined by the Society for Medical Decision Making Committee on Standardization of Clinical Algorithms. The resulting linear decision tree underwent several rounds of iterative checks and feedback by its developers, as well as other pain experts. A preliminary pilot evaluation was conducted in the context of an ecological implementation field study of the classification itself. The resulting algorithm consists of a linear decision tree, an introduction form, and an appendix. The initial decision trunk can be used as a standalone algorithm in primary care. Each diagnostic criterion is represented in a decision box. The user needs to decide for each criterion whether it is present or not, and then follow the respective yes or no arrows to arrive at the corresponding ICD-11 diagnosis. The results of the pilot evaluation showed good clinical utility of the algorithm. The CAL-CP can contribute to reliable diagnoses by structuring a way through the classification and by increasing adherence to the criteria. Future studies need to evaluate its utility further and analyze its impact on the accuracy of the assigned diagnoses.

Comparing the ICD-11 chronic pain classification with ICD-10: how can the new coding system make chronic pain visible? A study in a tertiary care pain clinic setting

ABSTRACT

Pain is a frequent reason for patients to ask for medical services. However, systematic information about the extent and impact of pain, especially in developing countries, has not been available up to now. We evaluated whether the 11th edition of the International Statistical Classification of Diseases and Related Health Problems (ICD) can fill this gap by coding all electronic out-patient medical records of the pain clinic at Siriraj Hospital in Thailand in 2019 (8714 visits), using the ICD-10 and ICD-11 browsers referenced on the WHO websites. The 3 most frequent pain-related codes in ICD-10 were R52.2 "other chronic pain" (29%), M54.5 "low back pain" (18%), and M79.6 "pain in limb" (13%). In ICD-11, the 3 most frequent codes were MG30.31 "chronic secondary musculoskeletal pain associated with structural changes" (28%), MG30.51 "chronic peripheral neuropathic pain" (26%), and MG30.10 "chronic cancer pain" (23%). Thus, using the currently valid ICD-10 system, roughly one-third of patient encounters were coded as "other chronic pain," and the next 2 were specifying the pain region rather than any underlying cause. By contrast, ICD-11 coding of the same patients identified underlying causes (bones and joints, somatosensory nervous system, cancer, or surgery), which provide guidance towards differential patient management. In our pain clinic, most patients suffered from chronic cancer pain, chronic neuropathic pain, and chronic secondary musculoskeletal pain, which were poorly defined or nonexistent in the current ICD-10 coding system. Compared with the ICD-10, the ICD-11 provides more detailed diagnostic categories and is more informative for clinical use, research, and resource allocation for pain-related conditions.

Visceral pain, mechanisms, and implications in musculoskeletal clinical practice

The global impact of visceral pain is extremely high, representing a significant portion of all forms of chronic pain. In musculoskeletal practice, at least one-third of people with persistent noncancerous pain report recurrent abdominal, pelvic, or chest pain symptoms. Visceral pain can be felt in several different areas of the body and can migrate throughout a region, even though the site of origin does not appear to change. Traditionally, clinicians have examined musculoskeletal pain through a reductionist lens that ignores the influence of the visceral system on musculoskeletal pain. The hypothesis presented is that visceral pain has an important influence on developing and maintaining different types of musculoskeletal pain through processes within the peripheral or central nervous systems, as a result of a visceral nociceptive stimulus generated by pathoanatomical or functional alterations. The hypothesis predicts that a consideration of the function of the visceral system in musculoskeletal pain conditions will improve clinical outcomes, moving beyond a linear model and adopting a more holistic approach, especially in the more complex groups of patients.