Pain
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Pain with bladder filling remains an unexplained clinical presentation with limited treatment options. Here, we aim to establish the clinical significance of bladder filling pain using a standardized test and the associated neural signature. We studied individuals diagnosed with urologic chronic pelvic pain syndrome (UCPPS) recruited as part of the multidisciplinary approach to the study of chronic pelvic pain (MAPP) study. ⋯ The UCPPS subtype with bladder-filling pain (BFP+) had altered morphology and increased functional activity in brain areas involved in sensory and pain processing. Bladder-filling pain positive status predicted increased symptom flare-ups and healthcare utilization over the subsequent 18 months when controlling for symptom severity and a self-reported history of bladder-filling pain. These results both highlight the importance of assessing bladder filling pain in heterogeneous populations and demonstrate that persistent bladder-filling pain profoundly affects the brain.
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Chronic pain conditions frequently co-occur, suggesting common risks and paths to prevention and treatment. Previous studies have reported genetic correlations among specific groups of pain conditions and reported genetic risk for within-individual multisite pain counts (≤7). Here, we identified genetic risk for multiple distinct pain disorders across individuals using 24 chronic pain conditions and genomic structural equation modeling (Genomic SEM). ⋯ Annotation identified pathways associated with organogenesis, metabolism, transcription, and DNA repair, with overrepresentation of strongly associated genes exclusively in brain tissues. Cross-reference with previous GWASs showed genetic overlap with cognition, mood, and brain structure. These results identify common genetic risks and suggest neurobiological and psychosocial mechanisms that should be targeted to prevent and treat cross-condition chronic pain.
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Observational Study
Evidence of neuroinflammation in fibromyalgia syndrome: a [18F]DPA-714 positron emission tomography study.
This observational study aimed to determine whether individuals with fibromyalgia (FM) exhibit higher levels of neuroinflammation than healthy controls (HCs), as measured with positron emission tomography using [ 18 F]DPA-714, a second-generation radioligand for the translocator protein (TSPO). Fifteen women with FM and 10 HCs underwent neuroimaging. Distribution volume (V T ) was calculated for in 28 regions of interest (ROIs) using Logan graphical analysis and compared between groups using multiple linear regressions. ⋯ In support of our hypothesis, we found increased radioligand binding (V T ) in the FM group compared with HCs in several brain regions regardless of participants' TSPO binding status. The ROIs overlapped with prior reports of increased TSPO binding in FM. Overall, increasing evidence supports the hypothesis that FM involves microglia-mediated neuroinflammation in the brain.
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The neural mechanisms for the persistence of pain after a technically successful arthroplasty in osteoarthritis (OA) remain minimally studied, and direct evidence of the brain as a predisposing factor for pain chronicity in this setting has not been investigated. We undertook this study as a first effort to identify presurgical brain and clinical markers of postarthroplasty pain in knee OA. Patients with knee OA (n = 81) awaiting total arthroplasty underwent clinical and psychological assessment and brain magnetic resonance imagining. ⋯ Brain and clinical indices accounted for unique influences on postoperative pain. Our study demonstrates the presence of presurgical subcortical brain factors that relate to postsurgical persistence of OA pain. These preliminary results challenge the current dominant view that mechanisms of OA pain predominantly underlie local joint mechanisms, implying novel clinical management and treatment strategies.
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Endometriosis-related pain has been predominantly medically managed, which has hindered understanding of psychological factors involved in these pain experiences. Models of chronic pain highlight the biased interpretation of ambiguous information as health threat related (interpretation bias) as an important process in the development and maintenance of chronic pain. Whether interpretation bias may also be similarly implicated in endometriosis-related pain is unclear. ⋯ Within the endometriosis sample, interpretation bias was significantly associated with increases in pain-related interference, however, interpretation bias was not associated with any other pain outcomes and did not moderate the relationship between pain severity and pain interference. This study is the first to evidence biased interpretation styles among individuals with endometriosis and to show this bias is associated with pain interference. Whether interpretation bias varies over time and whether this bias can be modified through scalable and accessible interventions to alleviate pain-related interference are avenues for future research.