Pain
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Randomized Controlled Trial
Disentangling self from pain: mindfulness meditation-induced pain relief is driven by thalamic-default mode network decoupling.
For millenniums, mindfulness was believed to diminish pain by reducing the influence of self-appraisals of noxious sensations. Today, mindfulness meditation is a highly popular and effective pain therapy that is believed to engage multiple, nonplacebo-related mechanisms to attenuate pain. Recent evidence suggests that mindfulness meditation-induced pain relief is associated with the engagement of unique cortico-thalamo-cortical nociceptive filtering mechanisms. ⋯ Preregistered (NCT03414138) whole-brain analyses revealed that mindfulness meditation-induced analgesia was moderated by greater thalamus-precuneus decoupling and ventromedial prefrontal deactivation, respectively, signifying a pain modulatory role across functionally distinct neural mechanisms supporting self-referential processing. Two separate preregistered seed-to-seed analyses found that mindfulness meditation-based pain relief was also associated with weaker contralateral thalamic connectivity with the prefrontal and primary somatosensory cortex, respectively. Thus, we propose that mindfulness meditation is associated with a novel self-referential nociceptive gating mechanism to reduce pain.
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Neuropathic pain is a complex, debilitating disease that results from injury to the somatosensory nervous system. The presence of systemic chronic inflammation has been observed in patients with chronic pain but whether it plays a causative role remains unclear. This study aims to determine the perturbation of systemic homeostasis by an injury to peripheral nerve and its involvement in neuropathic pain. ⋯ Although transferring sham serum to naïve mice did not change their pain sensitivity, PSNL serum significantly lowered mechanical thresholds and induced cold hypersensitivity in naïve mice. With broad anti-inflammatory properties, bone marrow cell extracts not only partially restored serum proteomic homeostasis but also significantly ameliorated PSNL-induced mechanical allodynia, and serum from bone marrow cell extracts-treated PSNL mice no longer induced hypersensitivity in naïve mice. These findings clearly demonstrate that nerve injury has a long-lasting impact on systemic homeostasis, and nerve injury-associated systemic inflammation contributes to the development of neuropathic pain.
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Understanding chronic pain and disability requires a consideration of the lived experience of the patient. There is limited evaluation of the content validity of patient-reported outcome measures (PROMs) in chronic pain using a comprehensive biopsychosocial view of the patient's experience. To address this gap, this study aimed to evaluate the content validity of PROMs for patients with chronic pain. ⋯ The greatest number of items across PROMs were represented in the activities and participation category (44% of all total items), followed by body functions (41%), environmental factors (9%), personal factors (5%), and body structures (0.3%). There was a 41% to 78% match with the Core Set for Chronic Widespread Pain and the International Classification of Diseases-11 FP, respectively. 20% of items reflected the pain-experience attributes with the most items reflecting the concept of "control over pain." Content validity analysis suggests chronic widespread pain patient-reported outcome measures poorly address attributes of living with chronic pain that matter most to patients. Future development or refinement should consider a more comprehensive view of the patients' lived experience.
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Preliminary evidence suggests that there are sex differences in microstructural brain organization among individuals with irritable bowel syndrome (IBS). The aim of this study was to further investigate sex-dependent differences in brain microstructure and organization in a large sample of well-phenotyped participants with IBS compared with healthy controls. We hypothesized that female patients with IBS would show evidence for increased axonal strength and myelination within and between brain regions concerned with pain and sensory processing, when compared with males with IBS. ⋯ Whole brain voxel-wise differences in fractional anisotropy, mean, radial and axial diffusivity, and track density as differences in somatic awareness and sensory sensitivity were assessed using the general linear model. Female compared with male IBS participants showed extensive microstructural alterations in sensorimotor, corticothalamic, and basal ganglia circuits involved in pain processing and integration of sensorimotor information. Together with the observed increases in symptom severity, somatic awareness, and sensory sensitivity, the findings support the hypotheses that the etiology and maintenance of symptoms in females with IBS may be driven by greater central sensitivity for multiple sensory stimuli.
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There were no estimates of the prevalence of pain and its treatment in the older population of India obtained from face-to-face interviews with a nationally representative sample. We addressed this evidence gap by using data on 63,931 individuals aged 45 years and older from the 2017/2018 Longitudinal Ageing Study in India. We identified pain from an affirmative response to the question: Are you often troubled by pain? We also identified those who reported pain that limited usual activities and who received treatment for pain. ⋯ There was large variation in each outcome across states. Fully adjusted prevalence of pain and pain limiting usual activity were higher among individuals who were female, older, less educated, rural residents, and poorer. Prevalence of treatment among those troubled by pain was lower among socially disadvantaged groups.