Pain
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Randomized Controlled Trial
Single vs composite measures of pain intensity: relative sensitivity for detecting treatment effects.
Assay sensitivity remains a significant issue in pain clinical trials. One possible method for increasing assay sensitivity for detecting changes in pain intensity is to increase the reliability of pain intensity assessment by increasing the number of intensity ratings obtained, and combining these ratings into composite scores. The current study performed secondary analyses from a published clinical trial to test this possibility. ⋯ If this finding replicates in other pain populations, it has significant implications for the design and conduct of pain clinical trials. Specifically, it suggests the possibility that assessment burden (and associated costs and problems related to missing data) might be greatly reduced by specifying a single recall rating as the primary outcome variable. Research is needed to explore this possibility further.
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Modern forms of music therapy are clinically established for various therapeutic or rehabilitative goals, especially in the treatment of chronic pain. However, little is known about the neuronal mechanisms that underlie pain modulation by music. Therefore, we attempted to characterize the effects of music therapy on pain perception by comparing the effects of 2 different therapeutic concepts, referred to as receptive and entrainment methods, on cortical activity recorded by magnetencephalography in combination with laser heat pain. ⋯ On the other hand, listening to self-composed "pain music" and "healing music" within the entrainment method exerted major effects on gamma-band activity in primary and secondary somatosensory cortices. Pain music, in contrast to healing music, increased pain ratings in parallel with an increase in gamma-band activity in somatosensory brain structures. In conclusion, our data suggest that the 2 music therapy approaches operationalized in this study seem to modulate pain perception through at least 2 different mechanisms, involving changes of activity in the delta and gamma bands at different stages of the pain processing system.
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The combined oral contraceptive pill (COCP) has been implicated in the development of a number of chronic pain conditions. Modern COCP formulations produce a low endogenous estradiol, low progesterone environment similar to the early follicular phase of the natural menstrual cycle, with a variable effect on serum androgen levels. We used behavioural measures and functional magnetic resonance imaging to investigate the response to experimental thermal stimuli in healthy women, in both a natural and COCP-induced low endogenous estradiol state, to investigate whether alterations in central pain processing may underlie these observations in COCP users. ⋯ Of particular interest, in COCP users, activity in the rostral ventromedial medulla increased with increasing testosterone and in those women with low testosterone, was significantly reduced compared to controls. These findings suggest that, in a low endogenous estradiol state, testosterone may be a key factor in modulating pain sensitivity via descending pathways. Specifically, failure to engage descending inhibition at the level of the rostral ventromedial medulla may be responsible for the reduction in temperature required by COCP users with low circulating testosterone.
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Facial expressions provide a primary source of inference about a child's pain. Although facial expressions typically appear spontaneous, children have some capacity to fake or suppress displays of pain, thereby potentially misleading caregiver judgments. The present study was designed to compare accuracy of different groups of caregivers in detecting deception in children's facial expressions of pain when voluntarily controlled. ⋯ A 3 (group: pediatrician vs pediatric nurse vs parent)×4 (condition: genuine vs faked vs suppressed vs neutral) mixed analysis of variance (ANOVA) of judgment accuracies revealed a significant main effect of group, with nurses demonstrating higher overall accuracy scores than parents, and pediatricians not differing from either group. As well, all caregivers, regardless of group, demonstrated the lowest accuracy when viewing the genuine condition, relative to the faked and suppressed conditions, with accuracy for the neutral condition not differing significantly from the other conditions. Overall, caregivers were more successful at identifying faked and suppressed than genuine expressions of pain in children, and pediatric nurses fared better overall in judgment accuracy than parents.