Articles: function.
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Provoked vestibulodynia (PVD) is a common genital pain disorder in women that is associated with sexual dysfunction and lowered sexual satisfaction. A potentially applicable cognitive-behavioral model of chronic pain and disability is the fear-avoidance model (FAM) of pain. The FAM posits that cognitive variables, such as pain catastrophizing, fear, and anxiety lead to avoidance of pain-provoking behaviors (eg, intercourse), resulting in continued pain and disability. Although some of the FAM variables have been shown to be associated with PVD pain and sexuality outcomes, the model as a whole has never been tested in this population. An additional protective factor, pain self-efficacy (SE), is also associated with PVD, but has not been tested within the FAM model. ⋯ Changes in both cognitive and behavioral variables were significantly associated with improved pain and sexual satisfaction outcomes. However, it was the positive changes in SE that better predicted changes in avoidance behavior, pain, and sexual satisfaction. Cognitive-behavior therapy is often focused on changing negative pain-related cognitions to reduce avoidance and pain, but the present results demonstrate the potential importance of bolstering positive self-beliefs as well. Indeed, before engaging in exposure therapies, SE beliefs should be assessed and potentially targeted to improve adherence to exposure strategies.
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Acta Anaesthesiol Scand · Apr 2015
Clinical TrialPre-operative baroreflex sensitivity and efferent cardiac parasympathetic activity are correlated with post-operative pain.
A maladaptation of the autonomic nervous system may been seen in patients with chronic pain that includes persistent changes in the autonomic tone, increased heart rate, and reduced heart rate variability and baroreflex sensitivity. Baroreflex sensitivity and acute pain intensity have been reported to be inversely correlated. However, it is unknown whether the same correlation applies with regard to post-operative pain. In the present study, autonomic function was measured in patients scheduled for minor hand surgery and correlated with early and persistent pain after the procedure. Thus, the cause (autonomic imbalance) was present before the effect (post-operative pain). Our primary hypothesis was that a lower level of pre-operative baroreflex sensitivity is correlated with increased early post-operative pain. ⋯ The findings suggest that a low pre-operative level of baroreflex sensitivity is associated with higher post-operative pain intensity. To our knowledge, this is the first study to show the correlation between baroreflex sensitivity and post-operative pain.
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Hyperalgesia is one of the negative consequences following intraoperative analgesia with remifentanil. Peroxynitrite is a critical determinant in nociceptive process. Peroxynitrite inactivates iron-sulfur cluster that results in mitochondrial dysfunction and the release of iron, leading to mitochondrial iron accumulation. Iron accumulation mediated by divalent metal transporter 1 (DMT1) plays a key role in N-methyl-D-aspartate neurotoxicity. This study aims to determine whether peroxynitrite contributes to remifentanil-induced postoperative hyperalgesia via DMT1-mediated iron accumulation. ⋯ Our study identifies that spinal peroxynitrite activates DMT1(-)IRE, leading to abnormal iron accumulation in remifentanil-induced postoperative hyperalgesia, while providing the rationale for the development of molecular hydrogen and "iron-targeted" therapies.
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An important property of the nociceptive system is its plasticity, ie, the ability to change in an experience-dependent manner, which is implicated in the transition from acute pain to chronic pathological pain. Disease-induced plasticity can occur at both structural and functional levels and manifests as changes in individual molecules, synapses, cellular function, and network activity. In this short review, the author discusses how synaptic plasticity may mediate pathophysiological alterations linked to chronic pain by virtue of shifting the balance between excitation and inhibition, with a particular emphasis on the spinal dorsal horn. ⋯ Structural remodeling and reorganization represent another exciting area of advance in our understanding of pain. Here, new insights into maladaptive structural plasticity of spinal synapses and molecular determinants thereof will be discussed. Finally, the role of synapse-to-nucleus communication in mediating long-term changes in nociceptive sensitivity is discussed from the view point of pain chronicity.
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This review presents a general model for the understanding of pain, placebo, and chronification of pain in the framework of cognitive neuroscience. The concept of a computational cost-function underlying the functional imaging responses to placebo manipulations is put forward and demonstrated to be compatible with the placebo literature including data that demonstrate that placebo responses as seen on the behavioural level may be elicited on all levels of the neuroaxis. In the same vein, chronification of pain is discussed as a consequence of brain mechanisms for learning and expectation. ⋯ Women are greatly overrepresented in patients with chronic pain. Hence, both from a general standpoint and from reasons of health equity, it is of essence to advance research and care efforts. Success in these efforts will only be granted with better theoretical concepts of chronic pain mechanisms that maps into the framework of cognitive neuroscience.