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To characterize the effects of blocking calcitonin gene-related peptide (CGRP) activity in a mouse model of gastrointestinal transport.
Learn More >Itch sensation provokes the scratch reflex to protect us from harmful stimuli in the skin. Although scratching transiently relieves acute itch through activation of mechanoreceptors, it propagates the vicious itch-scratch cycle in chronic itch by further aggravating itch over time. Although well recognized clinically, the peripheral mechanisms underlying the itch-scratch cycle remain poorly understood. Here, we show that mechanical stimulation of the skin results in activation of the Piezo2 channels on Merkel cells that pathologically promotes spontaneous itch in experimental dry skin. Three-dimensional reconstruction and immunoelectron microscopy revealed structural alteration of MRGPRA3 pruriceptor nerve endings directed toward Merkel cells in the setting of dry skin. Our results uncover a functional miswiring mechanism under pathologic conditions, resulting in touch receptors triggering the firing of pruriceptors in the skin to drive the itch-scratch cycle.
Learn More >Increasing evidence reveals the damaging impact of having one's chronic pain symptoms invalidated through disbelief, discrediting, and critical judgement. In other instances, a caregiver's over-attentiveness to the daily tasks of individuals with pain can be problematic, potentially undermining rehabilitation. The aim of this study was to develop an instrument to measure different aspects of invalidation perceived by people with chronic pain. Item generation was informed through literature review and a thematic analysis of narratives from 431 peer-reviewed articles. The crowdsourcing platform Prolific was used to distribute survey items to participants. In Study 1A, Principal Component Analysis was performed on data from 302 respondents, giving rise to 4 subscales, including: Invalidation by the Self, Invalidation by Immediate Others, Invalidation by Healthcare Professionals, and Invalidation by Over-attentive Others. Confirmatory Factor Analysis of data collected from aonther 308 individuals in Study 1B supported the 4-factor model of the Pain-Invalidation Scale (Pain-IS) and identified a best-fit model with 24 items. The Pain-IS was further validated in another 300 individuals in Study 2. The Pain-IS demonstrates sound psychometric properties and may serve as a valuable tool for use by clinicians in the detection of pain-invalidation issues, as a first step in patient pain management. Perspective. Links between pain-invalidation and pain levels, as well as functional detriment, highlight the importance of having one's chronic pain experience heard, believed and accepted. The Pain-Invalidation Scale is designed to identify domains where invalidation of the patient's pain should be addressed to promote emotional processing, treatment adherence and improved outcomes.
Learn More >There is some evidence that corticosteroids may have a beneficial effect in hand osteoarthritis. We examined the efficacy of corticosteroids on symptoms and structural outcomes in hand osteoarthritis.
Learn More >We aimed to examine the effects of repetitive cortical spreading depression on the responses of nociceptive trigeminal neurons with dural afferents and characterize the role of 5-HT and opioid receptors.
Learn More >The pathophysiology of cluster headache and how cluster episodes are triggered, are still poorly understood. Recurrent inflammation of the trigeminovascular system has been hypothesized. It was noted that some long-term attack-free cluster headache patients suddenly developed a new cluster episode shortly after COVID-19 vaccination.
Learn More >The modern management of chronic pain is largely focused on improving functional capacity (often despite ongoing pain) by using graded activation and exposure paradigms. However, many people with chronic pain find functional activation programs aversive, and dropout rates are high. Modern technologies such as virtual reality (VR) could provide a more enjoyable and less threatening way for people with chronic pain to engage in physical activity. Although VR has been successfully used for pain relief in acute and chronic pain settings, as well as to facilitate rehabilitation in conditions such as stroke and cerebral palsy, it is not known whether VR can also be used to improve functional outcomes in people with chronic pain.
Learn More >Although sleep quantity and quality appear to be interrelated, most previous studies have considered sleep duration and insomnia symptoms as distinct entities. We therefore examined whether there is a joint effect of sleep duration and long-term changes in insomnia symptoms on the risk of recurrent chronic spinal pain. We performed a prospective study of 8,788 participants who participated in three surveys over ∼22 years and reported chronic spinal pain at the first, second, or both surveys. Adjusted risk ratios (RRs) were calculated for the risk of recurrent spinal pain at the last survey associated with self-reported sleep duration at the first survey and changes in insomnia symptoms between the two first surveys. Compared to participants with normal sleep duration (7-9 h) and no insomnia symptoms at the two first surveys, participants with insomnia symptoms over the same period had RRs of spinal pain of 1.33 (95% CI 1.26-1.41) in the last survey if they reported normal sleep duration and 1.50 (95% CI 1.34-1.67) if they reported short sleep (≤6 h). The corresponding RRs for spinal pain for participants who improved their sleep symptoms were 1.09 (95% CI 1.00-1.19) for those with normal sleep and 1.13 (95% CI 0.88-1.45) for those with short sleep. In conclusion, people who reported insomnia symptoms over ∼10 years in combination with short sleep had a particularly increased risk of recurrent spinal pain. Improvement in insomnia symptoms was associated with a favorable prognosis.
Learn More >Fibromyalgia is a prevalent disorder manifesting with widespread musculoskeletal pain and central sensitization, as well as fatigue, sleep issues, psychologic distress, and poor quality of life. Patients with fibromyalgia also may be diagnosed with other painful conditions amenable to treatment with spinal cord stimulation (SCS), although it is unclear how these patients respond to SCS compared with patients without fibromyalgia.
Learn More >Pain is a warning signal for the body defense mechanisms and is a critical sensation for supporting life. However, orofacial pain is not a vital sensation, but a disease. However, there are still many unclear points about the pathophysiological mechanism of orofacial pain. This situation makes it difficult for many clinicians to treat orofacial pain hypersensitivity.
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