The journal of pain : official journal of the American Pain Society
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Avoidance is considered key in the development of chronic pain. However, little is known about how avoidance behavior subsequently affects pain-related fear and pain. We investigated this using a robotic arm reaching avoidance task. ⋯ PERSPECTIVE: Results indicate participants become more afraid of and sensitive to pain, when previously acquired avoidance is no longer effective. Also, participants continue to show avoidance behavior despite it being not adaptive anymore. These findings suggest that ineffective avoidance may play role in the maintenance and development of chronic pain.
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The brainstem has been discussed as the main player in the pathogenesis of migraine. Dysfunctional brainstem nuclei and their abnormal connections to other key brain centers may contribute to headache and other symptoms of migraine. In the present study, 32 patients with migraine without aura (MWoA) and 32 age- and sex-matched healthy controls (HCs) underwent resting-state fMRI scans. ⋯ Furthermore, patients with MWoA exhibited significantly decreased ReHo values in the posterior pons compared with HCs, and the posterior pons ReHo value was significantly negatively correlated with HIT-6 scores in the MWoA group. Patients with MWoA exhibited functional abnormalities in the posterior pons and weakened connections between the posterior pons and several key cortical brain areas involved in pain processing during the resting state. PERSPECTIVE: This study provided increased evidence that the pons is involved in the pathophysiological mechanism of migraine, and weakened connections suggest that the touch and pain sensation of migraine sufferers may not be properly relayed to cortical processing areas, which may be associated with the pathogenesis of MWoA.
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The development of multitarget opioid drugs has emerged as an attractive therapeutic strategy to eliminate opioid-related side effects. Our previous study developed a series of opioid and neuropeptide FF pharmacophore-containing chimeric peptides, including DN-9 (Tyr-D. Ala-Gly-NMe. ⋯ DN-9 might be a promising compound for developing multifunctional opioid analgesics with limited adverse effects. PERSPECTIVE: This article presents the potent and nontolerance forming analgesia effects of DN-9 in a series of preclinical pain models with less opioid related adverse effects at the spinal level in mice. This study also demonstrates that DN-9 has translational potential into an intrathecal analgesic.
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Randomized Controlled Trial
Effects of oxytocin on placebo and nocebo effects in a pain conditioning paradigm: a randomized controlled trial.
Oxytocin has been shown to increase trust, decrease anxiety, and affect learning as has been observed in conditioning paradigms. Trust, anxiety, and learning are important factors that influence placebo effects. In this study, we investigated whether oxytocin can increase placebo analgesia, decrease nocebo hyperalgesia, and influence extinction processes of both. ⋯ PERSPECTIVE: The present study demonstrated that placebo analgesia and nocebo hyperalgesia can be successfully induced by conditioning and verbal suggestions. We could not confirm the hypothesis that oxytocin affects either of these phenomena. Other pharmacological agents and behavioral manipulations for increasing placebo and decreasing nocebo effects should be investigated.
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Burn injuries are significantly painful and associated with physical and psychological impairment. However, little research to-date has examined the potential role of the subjective experience of pain in either physical or psychological impairment in this population. This may be particularly important to examine, given that the pain experience can often be a significant barrier to recovery in other pediatric populations. ⋯ Future research is needed to further examine these relationships. PERSPECTIVE: This study presents preliminary findings from a national database on pain-related outcomes both cross-sectionally and longitudinally in youth with a history of burn injury. To-date, pain-related outcomes are poorly understood in this population and the results of this study serve to inform future research and treatment-related efforts.