European journal of pain : EJP
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Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that often develops after injury, with a typical onset in adolescence. The impact of chronic pain is far-reaching, with many adolescents reporting atypical developmental trajectories compared with peers. Social Comparison Theory offers a framework for understanding how such comparisons influence well-being, whereby a heightened sense of disparity places adolescents at risk of poor cognitive, affective and social outcomes. Using a novel linguistic analysis programme, this study aims to investigate cognitive, affective and social language used by adolescents with CRPS in comparison to their peers during a task reflecting on their futures. ⋯ Social comparisons are commonly undertaken by adolescents with CRPS in relation to peers, increasing risk for poor cognitive, affective and social outcomes. Findings promote the potential importance of targeting psychosocial factors in treatments for paediatric chronic pain.
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The neural mechanism underlying the analgesic effect of acupuncture is largely unknown. We aimed at investigating the effect of abdominal acupuncture (AA) on the laser-evoked potential (LEP) amplitude and laser-pain rating to stimulation of body parts either homotopic or heterotopic to the treated acupoint. ⋯ Although abdominal acupuncture has demonstrated to be effective in the reduction in laser-evoked potential (LEP) amplitude and laser-pain rating, the exact mechanism of this analgesic effect is not known. In the current study, we found that treatment of an area in the "turtle representation" of the body led to a topographical pattern of LEP amplitude inhibition that can be mediated by a segmental spinal mechanism.
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The 'pain-inhibits-pain' effect stems from neurophysiological mechanisms involving endogenous modulatory systems termed diffuse noxious inhibitory controls (DNIC) or conditioned pain modulation (CPM). Laser-evoked potentials (LEPs) components, the N2/P2 complex, and the N1 wave, reflect the medial and lateral pain pathway, respectively: anatomically, the lateral thalamic nuclei (LT) project mainly to the somatosensory cortex (N1 generator), while the medial thalamic nuclei (MT) are bound to the limbic cortices (N2/P2 generators). ⋯ No reports have described the effect of DNIC on lateral and medial pain pathways. We studied the N1 wave and the N2/P2 complex to detect changes during a CPM protocol. We found a reduction in the amplitude of the N2/P2 complex and no change in the N1 wave. This suggests that the DNIC inhibitory effect on dorsal horns neurons affects only pain transmission via the SRT, whereas the neurons that give rise to the STT are not involved.
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The 'funnel effect' of Fibromyalgia (FM) assumes that as patients access healthcare services, they present greater severity and a more complex clinical situation than individuals with FM from the general population, but the studies comparing patients treated in different levels of healthcare are scarce. The aim of this study was to analyse the 'funnel effect' hypothesis by comparing patients from secondary and tertiary healthcare services. ⋯ The worst clinical and psychological status and poorer quality of life in the patients from tertiary healthcare (chronic pain clinics) in relation to the patients from secondary healthcare (rheumatology practices) must be taken into account to design studies that assess any of these aspects, to a proper analysis and interpretation of the data, and to define the scope of its generalization, as data from different clinical settings are not directly comparable.
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Fibromyalgia is characterized by widespread musculoskeletal pain and often accompanied by cognitive and emotional problems. Adaptation to fibromyalgia may therefore also rely on one's ability to regulate emotional problems. In this study, we examined two indices of emotion regulation, that is, (a) affective instability, involving frequent large fluctuations in self-reported affect, and (b) resting heart rate variability (HRV). ⋯ This study provides novel insight in the link between emotion regulation indices,that is, heart-rate variability and negative affective (NA) instability, in patients with fibromyalgia, and presents evidence for differences in both emotion regulation indices between patients with fibromyalgia and healthy people. Furthermore, results link increased NA instability with increased levels of daily disability in patients with fibromyalgia. Together, these findings offer support for a key role of emotion regulation in fibromyalgia outcomes, providing pathways for clinical practice.