Pain
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Wrist and ankle fractures are the most frequent causes of complex regional pain syndrome (CRPS type I). The current study examined the temporal development of vascular, nociceptive and bony changes after distal tibial fracture in rats and compared these changes to those observed after cast immobilization in intact normal rats. After baseline testing the right distal tibial was fractured and the hindlimb casted. ⋯ Postulating that facilitated substance P signaling may also contribute to the vascular and nociceptive abnormalities observed after tibial fracture or cast immobilization, we attempted to reverse these changes with LY303870. Hindpaw warmth, spontaneous extravasation, edema, and allodynia were inhibited by LY303870. Collectively, these data support the hypotheses that the distal tibial fracture model simulates CRPS, immobilization alone can generate a syndrome resembling CRPS, and substance P signaling contributes to the vascular and nociceptive changes observed in these models.
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Randomized Controlled Trial Comparative Study Clinical Trial
A randomized trial of electronic versus paper pain diaries in children: impact on compliance, accuracy, and acceptability.
Electronic diary assessment of pain and disability has become increasingly popular in adult chronic pain research but use of this methodology with children has received limited attention. The aim of this study was to compare two formats of a prospective daily diary (handheld computer=e-diary; paper diary=p-diary) on children's compliance, accuracy, and acceptability ratings. Sixty children, ages 8-16 (M=12.3) with headaches or juvenile idiopathic arthritis, were randomized to receive either e-diaries administered via home visits (n=30) or p-diaries (n=30) handed out during clinic visits for return by mail. ⋯ Children rated both diary formats as highly acceptable and easy to use. A significant gender x diary format interaction (P<0.01) was found for compliance where boys demonstrated greater compliance with the e-diary format. Findings demonstrated that the e-diary was feasible to use with children and showed significantly greater compliance and accuracy in diary recording compared to traditional paper diaries in a population of children with recurrent pain.
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Randomized Controlled Trial Comparative Study Clinical Trial
Communicative dimensions of pain catastrophizing: social cueing effects on pain behaviour and coping.
The study was designed to assess whether the social context of a pain experience impacted on the relation between catastrophizing and duration of pain behaviour. Based on a communal coping model, the prediction was that the presence of an observer during a pain procedure would differentially influence the display of pain behaviour in high and low catastrophizers. University undergraduates taking part in a cold pressor procedure were randomly assigned to one of two conditions: (1) participant alone (n=30), or (2) observer present (n=34). ⋯ When the observer was present, high catastrophizers also reported using fewer cognitive coping strategies than low catastrophizers. The pattern of findings suggests that in the presence of an observer, high pain catastrophizers show a propensity to engage in strategies that more effectively communicate their pain, and are less likely to engage in strategies that might minimize pain. Theoretical implications of the findings are discussed.
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Comparative Study
Effects of stimulus duration on heat induced pain: the relationship between real-time and post-stimulus pain ratings.
Pain is a temporally dynamic experience. Yet, in most instances, pain ratings are acquired in a static fashion and frequently require subjects to retrospectively evaluate the pain experience that occurred in a preceding interval of time. In order to determine which components of the real-time experience of pain contribute to static pain ratings, we obtained real-time (dynamic) and post-stimulus (static) ratings using a visual analogue scale during various of durations (5-30 s) of noxious thermal stimulation (43-49 degrees C). ⋯ Regression analyses examining both pain-intensity and pain-unpleasantness revealed that the mean response and the peak response of real-time ratings significantly contributed to post-stimulus ratings, while temporal components such as perceived duration of pain contributed minimally. Additional regression analyses revealed that mean and peak responses of real-time intensity ratings accounted for much of the variability of post-stimulus unpleasantness ratings whereas real-time unpleasantness ratings accounted for somewhat less of the variability of post-stimulus intensity ratings. Taken together, the close relationship between real-time and post-stimulus ratings of pain across stimulus conditions evoking both adaptation and temporal summation further confirms that post-stimulus, retrospective ratings of pain are valid measures of the real-time experience of pain.