The DABBEC phenotyping system: towards a mechanistic understanding of CP/CPPS

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.

Reproducible Microstructural Changes in the Brain Associated With the Presence and Severity of Urologic Chronic Pelvic Pain Syndrome (UCPPS): A 3-Year Longitudinal Diffusion Tensor Imaging Study From the MAPP Network

Microstructural alterations have been reported in patients with urologic chronic pelvic pain syndrome (UCPPS). However, it isn't clear whether these alterations are reproducible within 6 months or whether long-term symptom improvement is associated with specific microstructural changes. Using data from the MAPP-II Research Network, the current study performed population-based voxel-wise DTI and probabilistic tractography in a large sample of participants from the multicenter cohort with UCPPS (N = 364) and healthy controls (HCs, N = 61) over 36 months. While fractional anisotropy (FA) differences between UCPPS patients and HCs were observed to be unique at baseline and 6-month follow-up visits, consistent aberrations in mean diffusivity (MD) were observed between UCPPS and HCs at baseline and repeated at 6 months. Additionally, compared to HCs, UCPPS patients showed stronger structural connectivity (SC) between the left postcentral gyrus and the left precuneus, and weaker SC from the left cuneus to the left lateral occipital cortex and the isthmus of the left cingulate cortex at baseline and 6-month. By 36 months, reduced FA and MD aberrations in these same regions were associated with symptom improvement in UCPPS. Together, results suggest changes in white matter microstructure may play a role in the persistent pain symptoms in UCPPS. PERSPECTIVE: This longitudinal study identified reproducible, "disease-associated" patterns in altered mean diffusivity and abnormal microstructural connectivity in UCPPS comparing to HCs over 6 months. These differences were found in regions involved in sensory processing and integration and pain modulation, making it potentially amenable for clinical interventions that target synaptic and/or neuronal reorganization.

Urologic chronic pelvic pain syndrome: insights from the MAPP Research Network

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

Brain signature and functional impact of centralized pain: a multidisciplinary approach to the study of chronic pelvic pain (MAPP) network study

Chronic pain is often measured with a severity score that overlooks its spatial distribution across the body. This widespread pain is believed to be a marker of centralization, a central nervous system process that decouples pain perception from nociceptive input. Here, we investigated whether centralization is manifested at the level of the brain using data from 1079 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network (MAPP) study. Participants with a clinical diagnosis of urological chronic pelvic pain syndrome (UCPPS) were compared to pain-free controls and patients with fibromyalgia, the prototypical centralized pain disorder. Participants completed questionnaires capturing pain severity, function, and a body map of pain. A subset (UCPPS N = 110; fibromyalgia N = 23; healthy control N = 49) underwent functional and structural magnetic resonance imaging. Patients with UCPPS reported pain ranging from localized (pelvic) to widespread (throughout the body). Patients with widespread UCPPS displayed increased brain gray matter volume and functional connectivity involving sensorimotor and insular cortices (P < 0.05 corrected). These changes translated across disease diagnoses as identical outcomes were present in patients with fibromyalgia but not pain-free controls. Widespread pain was also associated with reduced physical and mental function independent of pain severity. Brain pathology in patients with centralized pain is related to pain distribution throughout the body. These patients may benefit from interventions targeting the central nervous system.

Resting-state functional connectivity predicts longitudinal pain symptom change in urologic chronic pelvic pain syndrome: a MAPP network study

Chronic pain symptoms often change over time, even in individuals who have had symptoms for years. Studying biological factors that predict trends in symptom change in chronic pain may uncover novel pathophysiological mechanisms and potential therapeutic targets. In this study, we investigated whether brain functional connectivity measures obtained from resting-state functional magnetic resonance imaging at baseline can predict longitudinal symptom change (3, 6, and 12 months after scan) in urologic chronic pelvic pain syndrome. We studied 52 individuals with urologic chronic pelvic pain syndrome (34 women, 18 men) who had baseline neuroimaging followed by symptom tracking every 2 weeks for 1 year as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study. We found that brain functional connectivity can make a significant prediction of short-term (3 month) pain reduction with 73.1% accuracy (69.2% sensitivity and 75.0% precision). In addition, we found that the brain regions with greatest contribution to the classification were preferentially aligned with the left frontoparietal network. Resting-state functional magnetic resonance imaging measures seemed to be less informative about 6- or 12-month symptom change. Our study provides the first evidence that future trends in symptom change in patients in a state of chronic pain may be linked to functional connectivity within specific brain networks.

Unique Microstructural Changes in the Brain Associated with Urological Chronic Pelvic Pain Syndrome (UCPPS) Revealed by Diffusion Tensor MRI, Super-Resolution Track Density Imaging, and Statistical Parameter Mapping: A MAPP Network Neuroimaging Study

Studies have suggested chronic pain syndromes are associated with neural reorganization in specific regions associated with perception, processing, and integration of pain. Urological chronic pelvic pain syndrome (UCPPS) represents a collection of pain syndromes characterized by pelvic pain, namely Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) and Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS), that are both poorly understood in their pathophysiology, and treated ineffectively. We hypothesized patients with UCPPS may have microstructural differences in the brain compared with healthy control subjects (HCs), as well as patients with irritable bowel syndrome (IBS), a common gastrointestinal pain disorder. In the current study we performed population-based voxel-wise DTI and super-resolution track density imaging (TDI) in a large, two-center sample of phenotyped patients from the multicenter cohort with UCPPS (N = 45), IBS (N = 39), and HCs (N = 56) as part of the MAPP Research Network. Compared with HCs, UCPPS patients had lower fractional anisotropy (FA), lower generalized anisotropy (GA), lower track density, and higher mean diffusivity (MD) in brain regions commonly associated with perception and integration of pain information. Results also showed significant differences in specific anatomical regions in UCPPS patients when compared with IBS patients, consistent with microstructural alterations specific to UCPPS. While IBS patients showed clear sex related differences in FA, MD, GA, and track density consistent with previous reports, few such differences were observed in UCPPS patients. Heat maps illustrating the correlation between specific regions of interest and various pain and urinary symptom scores showed clustering of significant associations along the cortico-basal ganglia-thalamic-cortical loop associated with pain integration, modulation, and perception. Together, results suggest patients with UCPPS have extensive microstructural differences within the brain, many specific to syndrome UCPPS versus IBS, that appear to be localized to regions associated with perception and integration of sensory information and pain modulation, and seem to be a consequence of longstanding pain.

Altered resting state neuromotor connectivity in men with chronic prostatitis/chronic pelvic pain syndrome: A MAPP: Research Network Neuroimaging Study

Brain network activity associated with altered motor control in individuals with chronic pain is not well understood. Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is a debilitating condition in which previous studies have revealed altered resting pelvic floor muscle activity in men with CP/CPPS compared to healthy controls. We hypothesized that the brain networks controlling pelvic floor muscles would also show altered resting state function in men with CP/CPPS. Here we describe the results of the first test of this hypothesis focusing on the motor cortical regions, termed pelvic-motor, that can directly activate pelvic floor muscles. A group of men with CP/CPPS (N = 28), as well as group of age-matched healthy male controls (N = 27), had resting state functional magnetic resonance imaging scans as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study. Brain maps of the functional connectivity of pelvic-motor were compared between groups. A significant group difference was observed in the functional connectivity between pelvic-motor and the right posterior insula. The effect size of this group difference was among the largest effect sizes in functional connectivity between all pairs of 165 anatomically-defined subregions of the brain. Interestingly, many of the atlas region pairs with large effect sizes also involved other subregions of the insular cortices. We conclude that functional connectivity between motor cortex and the posterior insula may be among the most important markers of altered brain function in men with CP/CPPS, and may represent changes in the integration of viscerosensory and motor processing.

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We studied men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

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First resting state neuroimaging comparison CP/CPPS and healthy controls (HC)

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Motor cortex connectivity to insula distinguishes CP/CPPS from HC.

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Motor cortex connectivity to insula is among largest changes in CP/CPPS resting brain.

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Results provide additional evidence of motor network changes in chronic pain.

Physical activity and chronic prostatitis/chronic pelvic pain syndrome

PURPOSE

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a prevalent urologic disorder among men, but its etiology is still poorly understood. Our objective was to examine the relation between physical activity and incidence of CP/CPPS in a large cohort of male health professionals.

METHODS

We conducted a prospective cohort study among men in the Health Professionals Follow-up Study followed from 1986 to 2008. The study population included 20,918 men who completed all CP/CPPS questions on the 2008 questionnaire. Leisure-time physical activity, including type and intensity of activity, was measured by questionnaire in 1986. A National Institute of Health Chronic Prostatitis Symptom Index pain score was calculated on the basis of the responses on the 2008 questionnaire. Participants with pain scores ≥8 were considered CP/CPPS cases (n = 689).

RESULTS

Higher leisure-time physical activity was associated with lower risk of CP/CPPS. The multivariable-adjusted odds ratio comparing >35.0 to ≤3.5 MET·h·wk of physical activity was 0.72 (95% confidence interval, 0.56-0.92; P for trend <0.001). Observed inverse associations between physical activity and CP/CPPS were similar for both moderate- and vigorous-intensity activities. Sedentary behavior, measured as time spent watching television, was not associated with risk of CP/CPPS (P for trend = 0.64).

CONCLUSIONS

Findings from this study, the first large scale and most comprehensive study to date on this association, suggest that higher levels of leisure-time physical activity may lower risk of CP/CPPS in middle-age and older men.

Reliability of superficial male pelvic floor structural measurements using linear-array transperineal sonography

This study evaluated reliability of measures for superficial structures of the male pelvic floor (PF) obtained via transperineal sonography. Two embalmed cadavers were dissected to identify positioning of muscles on and around the bulb of the penis and to confirm the PF protocol. Cross-sectional area (CSA) and linear thickness of the bulb of the penis, urethra, bulbospongiosus (BS) muscles, and ischiocavernosus (IC) muscles were measured on 38 transverse images from 20 male patients by three raters with varied study knowledge and sonographic experience. Intra- and inter-rater reliability were calculated with two-way, mixed effects intra-class correlation coefficients. Measures of the bulb of the penis had the best reliability. CSA of all muscles and sagittal thickness of the BS near the central tendon had good reliability. Reliability varied for rater-identified thickest muscle region and measures of the urethra. Our study suggests that structures of the male PF can be reliably evaluated using a transperineal sonographic approach.

Clinical phenotyping of urologic pain patients

PURPOSE OF REVIEW

Urologic pain conditions such as chronic prostatitis/chronic pelvic pain syndrome, interstitial cystitis/bladder pain syndrome and chronic orchialgia are common, yet diagnosis and treatment are challenging. Current therapies often fail to show efficacy in randomized controlled studies. Lack of efficacy may be due to multifactorial causes and heterogeneity of patient presentation. Efforts have been made to map different phenotypes in patients with urologic pain conditions to tailor more effective therapies. This review will look at current literature on phenotype classification in urologic pain patients and their use in providing effective therapy.

RECENT FINDINGS

There has been validation of the 'UPOINT' system (urinary symptoms, psychosocial dysfunction, organ specific findings, infection, neurologic/systemic and tenderness of muscle) to better categorize male chronic prostatitis/chronic pelvic pain syndrome and interstitial cystitis/bladder pain syndrome. Refinement of domain systems and recent cluster analysis has suggested possible central processes involved in urologic pain conditions similar to systemic pain syndromes such as fibromyalgia, chronic fatigue and irritable bowel syndrome.

SUMMARY

Domain characterization of urologic pain conditions via phenotype mapping can be used to better understand causes of chronic pain and hopefully provide more effective, targeted and multimodal therapy.

Chronic Fatigue Syndrome: The Current Status and Future Potentials of Emerging Biomarkers

Chronic fatigue syndrome (CFS) remains an incompletely characterized illness, in part due to controversy regarding its definition, biological basis and diagnosis. Biomarkers are objective measures that may lead to improvements in our understanding of CFS by providing a more coherent and consistent approach to study, diagnosis and treatment of the illness. Such metrics may allow us to distinguish between CFS subtypes - each defined by characteristic biomarkers - currently conflated under the single, heterogeneous condition of CFS. These delineations, in turn, may guide more granular, focused, and targeted treatment strategies based on more precise characterizations of the illness. Here, we review potential CFS biomarkers related to neurological and immunological components of the illness, and discuss how these biomarkers may be used to move the field of CFS forward, emphasizing clinical utility and potential routes of future research.

Transperineal Sonography Evaluation of Muscles and Vascularity in the Male Pelvic Floor

Idiopathic chronic male pelvic pain is difficult to diagnose and treat. Currently, diagnosis relies on subjective symptoms; objective measures of neuromuscular mechanisms have not been investigated. Sonographic imaging has been used to investigate these neuromuscular mechanisms in the female pelvic floor, but neither research nor books describe sonography evaluation of the male pelvic floor. The purpose of this study was to develop and evaluate a perineal sonographic technique for the examination of the male pelvic floor muscles. Anatomic landmarks were identified with images collected from two subjects, one with intermittent reports of pelvic pain and one with no history of pain in the pelvic region. A description of the equipment settings, the examination protocol, and the resulting comparative image analysis is included. A validated protocol such as this may be useful in documenting differences in the soft tissue structures between asymptomatic individuals and patients with chronic pelvic pain to aid in diagnosis and treatment. This is the first known study to report sonographic findings of the individual muscles in the male pelvic floor, and additional research is needed to validate the techniques that have been deemed feasible.

Pain, catastrophizing, and depression in chronic prostatitis/chronic pelvic pain syndrome

Persistent and disabling pain is the hallmark of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). However, disease severity (as measured by objective indexes such as those that use radiography or serology) is only marginally related to patients' reports of pain severity, and pain-related presentation can differ widely among individuals with CP/CPPS. Increasing evidence in support of the biopsychosocial model of pain suggests that cognitive and emotional processes are crucial contributors to inter-individual differences in the perception and impact of pain. This review describes the growing body of literature relating depression and catastrophizing to the experience of pain and pain-related sequelae in CP/CPPS. Depression and catastrophizing are consistently associated with the reported severity of pain, sensitivity to pain, physical disability, poor treatment outcomes, and inflammatory disease activity and potentially with early mortality. A variety of pathways, from cognitive to behavioral to neurophysiological, seem to mediate these deleterious effects. Collectively, depression and catastrophizing are critically important variables in understanding the experience of pain in patients with CP/CPPS. Pain, depression, and catastrophizing might all be uniquely important therapeutic targets in the multimodal management of a range of such conditions.

NGF - the TrkA to successful pain treatment

Chronic pain arising from various pathological conditions such as osteoarthritis, low back or spinal injuries, cancer, and urological chronic pelvic pain syndromes presents significant challenges in diagnosis and treatment. Specifically, since the underlying cause of these pain syndromes is unknown or heterogeneous, physicians diagnose and treat patients based on the symptoms presented. Nerve growth factor (NGF) has been recognized as an important mediator of chronic pain in many pathological conditions, and has been shown to be upregulated in a subset of individuals suffering from such pain syndromes. These findings have led to the development of anti-NGF monoclonal antibodies such as tanezumab as potentially effective therapeutics for chronic pain. Although tanezumab has reached Phase II and III clinical trials, the trials of anti-NGF antibodies were halted due to safety concerns. Some of these trials of anti-NGF treatment have had statistically significant decreases in pain, while others have yielded inconclusive results. These findings are suggestive of, though do not prove, target (NGF) neutralization in chronic pain syndromes. A biomarker-driven anti-NGF clinical study layout is proposed that incorporates NGF measurements in the relevant samples before and after treatment, in addition to collecting the pain scores. This approach might not only confirm the mechanism of tanezumab's action in these chronic pain patients, but should establish NGF levels as a predictive biomarker for patients who can benefit from anti-NGF treatment, thereby creating a personalized approach to pain treatment.

The role of phenotyping in chronic prostatitis/chronic pelvic pain syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a chronic pain syndrome identified by the presence of noninfectious pelvic or perineal pain lasting longer than 3 months. Current diagnoses and treatments for the syndrome solely depend on and target symptoms, respectively. Thus far, the mechanistic disturbances responsible for the pathogenesis of CP/CPPS have remained largely elusive and treatments, and therefore, continue to be ineffective. To move toward successful management and treatment of CP/CPPS, it is necessary to elicit the underlying biological mechanisms responsible for the syndrome. Therefore, a phenotyping system that is able to bridge the gap between current symptom-based diagnosis and future mechanistic approaches to diagnosis and treatment is needed. In this article, we examine current CP/CPPS phenotyping systems, analyze their utility, and make suggestions for changes in clinical approaches to the syndrome that would both promulgate a mechanistic understanding and advance treatment approaches.