Pain
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Comparative Study
Readiness to change in pediatric chronic pain: initial validation of adolescent and parent versions of the Pain Stages of Change Questionnaire.
Despite the clinical importance of readiness to change in predicting treatment outcomes among adults, no studies have examined this construct among pediatric pain patients. Because parents play a key role in adolescent pain management, both adolescent and parent readiness to adopt a self-management approach to pain merit further study. The primary goal of the current study was to validate adolescent and parent-report adaptations of the adult Pain Stages of Change Questionnaire (PSOCQ). ⋯ Stability findings at 4 and 8 weeks after a multidisciplinary pain clinic evaluation are reported. Associations between pediatric PSOCQ scores and demographic, pain, and functional domains were explored to inform future research. Further validation of the PSOCQ-A and PSOCQ-P measures with new, separate samples of pediatric pain patients and parents are needed before use in clinical contexts.
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Randomized Controlled Trial
Randomized trial of a DVD intervention to improve readiness to self-manage joint pain.
A DVD (digital video disk) intervention to increase readiness to self-manage joint pain secondary to hemophilia was informed by a 2-phase, motivational-volitional model of readiness to self-manage pain, and featured the personal experiences of individuals with hemophilia. The DVD was evaluated in a randomized controlled trial in which 108 men with hemophilia completed measures of readiness to self-manage pain (Pain Stages of Change Questionnaire) before and 6 months after receiving the DVD plus information booklet (n=57) or just the booklet (n=51). The effect of the DVD was assessed by comparing changes in Pain Stages of Change Questionnaire scores (precontemplation, contemplation, and action/maintenance) between groups. ⋯ Significant use×time effects showed that benefits in terms of contemplation and action/maintenance were restricted to those who used the interventions at least once. The results show that low-intensity interventions in DVD format can improve the motivational impact of written information, and could be used to help prepare people with chronic pain for more intensive self-management interventions. The findings are consistent with a 2-phase, motivational-volitional model of pain self-management, and provide the first insights to our knowledge of readiness to self-manage pain in hemophilia.
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Comparative Study
Genotype-selective phenotypic switch in primary afferent neurons contributes to neuropathic pain.
Pain is normally mediated by nociceptive Aδ and C fibers, while Aβ fibers signal touch. However, after nerve injury, Aβ fibers may signal pain. Using a genetic model, we tested the hypothesis that phenotypic switching in neurotransmitters expressed by Aβ afferents might account for heritable differences in neuropathic pain behavior. ⋯ Substance P immunoreactivity was also upregulated in large-diameter neurons, but this change was similar in the 2 lines. Our findings suggest that phenotypic switching contributes to the heritable difference in pain behavior in HA vs LA rats. Specifically, we propose that in HA rats, but less so in LA rats, injured, spontaneously active Aβ afferents both directly drive CGRP-sensitive central nervous system pain-signaling neurons and also trigger and maintain central sensitization, hence generating spontaneous pain and tactile allodynia.
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The perception of pain is initiated by the transduction of noxious stimuli through specialized ion channels and receptors expressed by primary nociceptive neurons. The molecular mechanisms that orchestrate the expression and function of ion channels relevant for pain processing are poorly understood. We demonstrate here a central role of the transcription factor Smad-interacting protein 1 (Sip1/Zfhx1b/Zeb2), a 2-handed zinc finger DNA-binding protein with essential functions in neural crest and forebrain development, in controlling nociceptive neuron excitability and pain sensitivity. ⋯ Analysis of the voltage-gated currents underlying repetitive firing revealed a significant increase in persistent sodium currents and a reduction in delayed rectifier potassium currents. Modeling experiments in conjunction with experimental results suggest that these changes cause a depolarization-induced block of action potential propagation past the DRG axon T-junction. These data suggest that Sip1 controls the transduction properties of heat-sensitive primary sensory neurons and thus thermal pain sensitivity in a novel manner via coordinated changes in DRG-neuron voltage-gated ion channels.
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This study examined the influence of patients' likability on pain estimations made by observers. Patients' likability was manipulated by means of an evaluative conditioning procedure: pictures of patients were combined with either positive, neutral, or negative personal traits. Next, videos of the patients were presented to 40 observers who rated the pain. ⋯ The effect on pain estimations was only found with regard to patients expressing high-intensity pain. There was no effect on response bias (i.e., the overall tendency to indicate pain). These findings suggest that we take the pain of patients we do not like less seriously than the pain of patients we like.