Articles: hyperalgesia.
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Nocebo hyperalgesia is a phenomenon that is opposite to placebo analgesia and whereby expectation of pain increase plays a crucial role. In recent times, both the neuroanatomical and the neurochemical bases of the nocebo effect and of nocebo-related effects have begun to be explored. Here, we highlight recent advances in our understanding of the neurobiology of the nocebo hyperalgesic effect. ⋯ Since pain appears to be amplified by anxiety through the activation of cholecystokininergic systems, new therapeutic strategies, such as new cholecystokinin antagonists, can be envisaged whenever pain has an important anxiety component.
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Long-term consequences of early infant injury upon somatosensory processing were tested in school aged children. The aim was to test whether the long-term changes in sensitivity reported in animal models, in regions both local to and distant from the injury site, could be observed in humans. To do this we used quantitative sensory testing (QST) in children aged 9-12 years who had undergone cardiac surgery in infancy. ⋯ Questionnaires revealed perceived differences in pain perception, individual aberrant sensations and pain interfering with daily life that warrant further study. We conclude that tissue injured in early infancy remains measurably altered to mechanical and thermal stimulation in later life. These findings are consistent with the results of animal studies that early infant injury has not only local, but also global long-term consequences upon sensory processing.
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J Pain Symptom Manage · Oct 2007
Clinical TrialManaging the symptoms of neuropathic pain: an exploration of patients' experiences.
The debilitating effects of chronic neuropathic pain on everyday life are considerable, but little is known about how individual sufferers manage these effects. Virtually nothing is known about what patients prefer, what measures they take themselves and when, or in what combinations. The aim of this study was to explore patients' reports of how they managed their neuropathic pain symptoms. ⋯ Some had tried to accept their pain, but there was insufficient psychological, social, emotional, and practical support to allow them to do this successfully. This exploratory study provides a basis from which to develop a larger study to validate and extend the findings. Other issues meriting research are the effectiveness of cognitive-behavioral therapies for those with neuropathic pain, and an exploration and subsequent evaluation of different types of social, practical, and emotional support needed to help live with neuropathic pain.
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Diverging results exist regarding the connection between altered visceral perception and gastrointestinal (GI) symptoms, as well as the effects of psychological status on visceral sensitivity. We sought to investigate different aspects of rectal perception in irritable bowel syndrome (IBS) and the association with GI and psychological symptoms. ⋯ Altered rectal perception is common in IBS and seems to be one important pathophysiologic factor associated with GI symptom severity in general and pain and bloating in particular. It is not just a reflection of the psychological state of the patient.
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Neuropsychopharmacology · Oct 2007
Non-nociceptive environmental stress induces hyperalgesia, not analgesia, in pain and opioid-experienced rats.
It is well admitted that stress induces analgesia (SIA) via endogenous opioid release. However, there is evidence that stressful events play a role in the pathogenesis of pain, but little is known about mechanisms underlying such pain vulnerability. Previous studies reported that a single opioid exposure activates NMDA-dependent pronociceptive systems leading to long-term pain vulnerability after analgesia. ⋯ This indicates that low levels of opioids induce opposite effects, that is analgesia vs hyperalgesia dependent on prior life events. In pain and opioid-experienced rats, NMDA receptor antagonists, ketamine or BN2572, completely prevented hyperalgesia when injected just before NNES or fentanyl ULD. This latent pain sensitization model may be important for studying the transition from acute to chronic pain and individual differences in pain vulnerability associated with prior life events.