Pain
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Establishing clinically meaningful changes in pain experiences remains important for clinical trials of chronic pain treatments. Regulatory guidance and pain measurement initiatives have recommended including patient-reported global assessment measures (eg, Patient-Global Impression of Change [PGIC]) to aid interpretation of within-patient differences in domain-specific clinical trial outcomes (eg, pain intensity). The objectives of this systematic review were to determine the frequency of global assessment measures inclusion, types of measures, domains assessed, number and types of response options, and how measures were analyzed. ⋯ Response options and reference periods even differed within the PGIC. Global assessment measures were most commonly analyzed as continuous variables (n = 24; 46.2%) or as dichotomous variables with positive categories combined to calculate the proportion of participants with a positive response to treatment (n = 18; 34.6%). This review highlights the substantial work necessary to clarify measurement and use of patient global assessment in chronic pain trials and provides short- and long-term considerations for measure selection, reporting and analysis, and measure development.
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Spinal cord injury (SCI) results in permanent neurological dysfunction and neuropathic pain. To address this pathology, we recently conducted a clinical study in which we transplanted neural precursor cells (NPCs) derived from human induced pluripotent stem cells into patients during the subacute phase of SCI. One of the therapeutic mechanisms of cell transplantation is the formation of synaptic connections with the host's neural tissues, which we demonstrated using a chemogenetic tool. ⋯ In animal models of SCI, we have established an effective rehabilitative training program in which NPCs were transplanted during the chronic phase. Robotic rehabilitation has demonstrated improvements in gait ability and trunk function in clinical situations. Therefore, regenerative medicine shows promise for chronic SCI, particularly when rehabilitation strategies are incorporated.
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Forty-five years ago, Patrick Wall published his John J Bonica lecture "On the relation of injury to pain."90 In this lecture, he argued that pain is better classified as an awareness of a need-state than as a sensation. This need state, he argued, serves more to promote healing than to avoid injury. Here I reframe Wall's prescient proposal to pain in early life and propose a set of different need states that are triggered when injury occurs in infancy. ⋯ The IASP definition of pain includes a key statement, "through their life experiences, individuals learn the concept of pain."69 But the relation between injury and pain is not fixed from birth. In early life, the links between nociception (the sense) and pain (the need state) are very different from those of adults, although no less important. I propose that injury evokes three pain need states in infancy, all of which depend on the state of maturity of the central nervous system: (1) the need to attract maternal help; (2) the need to learn the concept of pain; and (3) the need to maintain healthy activity dependent brain development.
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"Somehow scientists still pursue the same questions, if now on higher levels of theoretical abstraction rooted in deeper layers of empirical evidence… To paraphrase an old philosophy joke, science is more like it is today than it has ever been. In other words, science remains as challenging as ever to human inquiry. ⋯ In this paper, we will describe how transgenics, transcriptomics, optogenetics, calcium imaging, fMRI, neuroimmunology and in silico drug development have transformed the way we examine the complexity of pain processing. But does it all, as our founders hoped, help people with pain? Are voltage-gated Na channels the new holy grail for analgesic development, is there a pain biomarker, can we completely replace opioids, will proteomic analyses identify novel targets, is there a "pain matrix," and can it be targeted? Do the answers lie in our tangible discoveries, or in the seemingly intangible? Our founders could barely imagine what we know now, yet their questions remain.
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Endometriosis, a common cause for chronic pelvic pain, significantly affects quality of life, fertility, and overall productivity of those affected. Therapeutic options remain limited, and collating evidence on treatment efficacy is complicated. One reason could be the heterogeneity of assessed outcomes in nonsurgical clinical trials, impeding meaningful result comparisons. ⋯ The PROMs used showed an even broader heterogeneity across all studies. Our findings underscore the large heterogeneity of assessed domains and PROMs in clinical pain-related endometriosis trials. This highlights the urgent need for a standardized approach to both, assessed domains and high-quality PROMs ideally realized through development and implementation of a core outcome set, encompassing the most pivotal domains and PROMs for both, stakeholders and patients.