Pain
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Postoperative pain significantly impacts patient recovery. However, postoperative pain management remains suboptimal, perhaps because treatment strategies are based mainly on studies using inflammatory pain models. We used a recently developed mouse model of incisional pain to investigate peripheral and spinal mechanisms contributing to heat hyperalgesia after incision. ⋯ Finally, heat hyperalgesia after incision was reversed by antagonism of spinal non-NMDA receptors, unlike inflammatory hyperalgesia, which is mediated via NMDA receptors. Thus, TRPV1 is important for the generation of thermal hyperalgesia after incision. Our observations suggest that all experimental pain models may not be equally appropriate to guide the development of postoperative pain therapies.
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The relationship between temporo-spatial stimulus parameters and evoked pain intensity as well as duration was examined in patients with peripheral neuropathy and brush-evoked allodynia, i.e. dynamic mechanical allodynia. Brush-evoked allodynia was induced in the innervation territory of the lesioned nervous structure in 18 patients by lightly stroking different distances of the skin (20, 40, 60 mm) two or four times with brushes of different widths (4, 8, 16 mm). Pain intensity and duration of brush-evoked allodynia was recorded using a computerized visual analogue scale. ⋯ Significantly increased duration of aftersensation was demonstrated only following increased brushing length (P<0.008). The most commonly used sensory-discriminative pain descriptors were pricking, burning and sore and for the affective descriptors, annoying and troublesome. This is the first study demonstrating a relationship between evoked pain and some temporo-spatial stimulus parameters during brush-evoked allodynia.
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The alpha2A and alpha2C adrenergic receptor (AR) subtypes mediate antinociception when activated by the endogenous ligand norepinephrine. These receptors also produce antinociceptive synergy when activated concurrently with opioid receptor activation. The involvement of the opioid receptors in the mechanisms governing transcutaneous electrical nerve stimulation (TENS) has been well described. ⋯ The alpha2 adrenergic receptor selective antagonist, SK&F 86466, reversed TENS-mediated antihyperalgesia when delivered intra-articularly, but not when delivered intrathecally or intracerebroventricularly. These data suggest that peripheral alpha2 ARs contribute, in part, to TENS antihyperalgesia. This pharmacodynamic response is consistent with previous anatomical observations that alpha2A ARs are expressed on primary afferent neurons and macrophages near injured tissue.
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Relative readiness to assume a self-management approach to chronic pain can be conceptualised as a stage model. Although both initial stage (precontemplation, action) and changes in attitudes reflecting stage orientation have been shown to predict treatment outcome, the joint contributions of these factors need to be examined. Sixty-five chronic pain patients, participating in a 4-week multidisciplinary pain program, completed the Pain Stages of Change Questionnaire (PSOCQ), subscales of the Multidimensional Pain Inventory, and the Beck Depression Inventory at pre-, mid- and post-treatment. ⋯ Results showed that: (a) stage group interacted with pre- to mid-treatment Precontemplation subscale changes to predict mid- to late-treatment pain severity and interference changes such that precontemplation attitude decreases were related to reduced pain and interference only among patients who were already action stage at pre-treatment; (b) stage group interacted with pre- to mid-treatment Action subscale changes to predict mid- to late-treatment interference and activity changes such that action attitude increases were related to reduced interference and increased activity only among patients at the action stage at pre-treatment; (c) pre- to mid-treatment decreases in depression did not account for these effects. Results suggest that any advantage enjoyed by patients with predominant action attitudes at pre-treatment may be enhanced by consolidating a pain self-management approach during treatment. In contrast, late-treatment gains of patients initially taking a predominant precontemplation stance were unaffected by their degree of early-treatment attitude changes.
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Little is known about how other than cancer pain related issues are represented in medical education. A standardised questionnaire was mailed to all medical students who graduated from the five Finnish medical schools in 2001. A total of 387 students received the questionnaire and 41% responded. ⋯ The clinical problems were excellently solved. In conclusion, the IASP curriculum is well covered in the present programmes in the Finnish medical faculties. However, the quality and the methods of teaching still need improvement.