Pain
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Post-injury inflammation activates nociceptive systems and recruits normally non-nociceptive afferents into a pain processing role. During inflammation, Abeta low threshold mechanoreceptor afferents that usually mediate tactile sensation acquire properties of nociceptors, allowing them to participate in post-injury spontaneous pain and evoked abnormalities such as tenderness and pain to light touch. This study assessed the sensory consequences of post-injury inflammation following extraction of a single, lower third molar tooth. ⋯ Thermal detection and pain thresholds were not altered at any location in patients, and no effects were observed in control subjects receiving only local anesthetic injections. These results in humans are consistent with recent experimental evidence that inflammatory processes alter the central consequence of activity in large-diameter Abeta touch primary afferents evoked under natural conditions by gentle mechanical stimulation. These effects result in hyperesthesia, increased sensitivity to light touch, and mechanical allodynia, pain evoked by normally innocuous stimulation of Abeta primary afferents.
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Randomized Controlled Trial Clinical Trial
Sex differences in response to cutaneous anesthesia: a double blind randomized study.
The existing literature on experimentally induced pain indicates that there are sex differences, with females displaying greater sensitivity. In epidemiological studies, sex differences are also noted in the prevalence of a number of pain syndromes, with females reporting more severe pain, more frequent pain, and pain of longer duration. Complicating the interpretation of pain differences between men and women in clinical samples are reports of sex differences in response to pain-reducing medications. ⋯ This study did not show sex differences in the placebo condition. These results are particularly interesting in light of previous work that has shown similar pain stimuli (pressure pain) to be the stimulation most sensitive to sex differences. Results of this study suggest that the protocol employed (pressure pain stimulus with magnitude matching task) is sensitive to both anesthetic treatment and sex differences and represents an improvement in pain assessment methodology for use in experimental studies and in the clinic.
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The inability to predict outcome in patients with low back/neck pain leads to inappropriate or unnecessary treatment. The aims of the study were to identify prognostic factors for disability at 1-year follow-up in patients with back pain visiting primary care, and to compare the effect of these in two treatment strategies--chiropractic and physiotherapy. Data were taken from a randomised trial on patients with back/neck pain visiting the general practitioner, in which patients were allocated to chiropractic and physiotherapy as primary management. ⋯ Twelve per cent of the patients had poor prognostic factors (duration > or = 1 month, more than one localisation, low expectations of treatment and low well-being) at entry. These patients had a mean Oswestry score above 20% at 1-year follow-up. Clinical decision models for the management of patients with back pain visiting primary care that consider prognostic factors need to be implemented and prospectively evaluated.