Articles: chronic.
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Central sensitization (CS) is believed to play a role in many chronic pain conditions. Direct non-invasive recording from single nociceptive neurons is not feasible in humans, complicating CS establishment. This review discusses how secondary hyperalgesia (SHA), considered a manifestation of CS, affects physiological measures in healthy individuals and if these measures could indicate CS. It addresses controversies about heat sensitivity changes, the role of tactile afferents in mechanical hypersensitivity and detecting SHA through electrical stimuli. Additionally, it reviews the potential of neurophysiological measures to indicate CS presence. ⋯ Gathering evidence for CS in humans is a crucial research focus, especially with the increasing interest in concepts such as 'central sensitization-like pain' or 'nociplastic pain'. This review clarifies which readouts, among the different behavioural and neurophysiological proxies tested in experimental settings, can be used to infer the presence of CS in humans.
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Extensive audio-motor training and psychological stress can cause professional musicians acute overstrain-injury and chronic pain, resulting in damaged careers and diminished quality of life. It has also been previously shown that musicians might perceive pain differently than non-musicians. Therefore, the aim of our study was to quantify differences between musicians and non-musicians regarding their subjective responses to painful contact heat stimuli and assess how emotional traits might influence these responses. ⋯ The findings of this report justify musicians' repetitive sensorimotor training as an important model for plasticity and contribute to a better understanding of pain perception in musicians.
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Low peak alpha frequency (PAF) is an electroencephalography (EEG) outcome associated reliably with high acute pain sensitivity. However, existing research suggests that the relationship between PAF and chronic pain is more variable. This variability could be attributable to chronic pain groups typically being examined as homogenous populations, without consideration being given to potential diagnosis-specific differences. Indeed, while emerging work has compared individuals with chronic pain to healthy controls, no previous studies have examined differences in PAF between diagnoses or across chronic pain subtypes. ⋯ Our work suggests that, contrary to previous hypotheses, inter-individual differences in PAF reflect diagnosis-specific mechanisms rather than the general presence of chronic pain, and therefore may have important implications for future work regarding individually-tailored pain management strategies.
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Repetitive ischemia with reperfusion (I/R) injury is a common cause of myalgia. Ischemia with reperfusion injuries occur in many conditions that differentially affect males and females including complex regional pain syndrome and fibromyalgia. Our preclinical studies have indicated that primary afferent sensitization and behavioral hypersensitivity caused by I/R injury may be due to sex-specific gene expression in the dorsal root ganglia (DRG) and distinct upregulation of growth factors and cytokines in the affected muscles. ⋯ AUF1 knockdown was able to specifically inhibit repeated I/R-induced gene expression in females potentially downstream of prolactin receptor signaling. Data suggest RNA-binding proteins such as pAUF1 may underlie the sex-specific effects on DRG gene expression that modulates behavioral hypersensitivity after repeated I/R injury through prolactin signaling. This study may aid in finding distinct receptor differences related to the evolution of acute to chronic ischemic muscle pain development between sexes.
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Supporting behavioural self-management is increasingly important in the care for chronic widespread pain (CWP), including fibromyalgia. Understanding peoples' experiences of these interventions may elucidate processes and mechanisms that lead to or hinder their intended impact. We conducted a systematic review and thematic synthesis of qualitative studies exploring peoples' experiences of self-management interventions for CWP, including fibromyalgia. ⋯ Lack of on-going support after interventions led to challenges in applying behavioural strategies, and some struggled without social support from the group. The experiences of self-management interventions for CWP reflect a complex, multifaceted process. Although many reported positive experiences, addressing issues with integration of physical activity, group dynamics and postintervention support may improve effectiveness for a broader range of people.