Articles: hyperalgesia.
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Randomized Controlled Trial Multicenter Study
Sensory profiles of patients with neuropathic pain based on the neuropathic pain symptoms and signs.
This manuscript aimed to characterize the clinical profile of various neuropathic pain (NeP) disorders and to identify whether patterns of sensory symptoms/signs exist, based on baseline responses on the Neuropathic Pain Symptom Inventory (NPSI) questionnaire and the quantitative sensory testing (QST). These post hoc analyses were based on data from 4 randomized, double-blind, placebo-controlled clinical studies of pregabalin (150-600mg/day) in patients with NeP syndromes: central poststroke pain, posttraumatic peripheral pain, painful HIV neuropathy, and painful diabetic peripheral neuropathy. The NPSI questionnaire includes 10 different pain symptom descriptors. ⋯ Based on QST signs, PCA identified 2 pain dimensions: evoked by cold and evoked by touch. A hierarchical cluster analysis identified 4 clusters with distinct pain characteristics profiles. These "trans-etiological" profiles may reflect distinct pathophysiological mechanisms and therefore, potential differential responses to treatment.
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Randomized Controlled Trial
Negative expectations facilitate mechanical hyperalgesia after high-frequency electrical stimulation of human skin.
High-frequency electrical stimulation (HFS) of human skin induces not only an increased pain sensitivity in the conditioning area but also an increased pain sensitivity to mechanical punctate stimuli in the non-conditioned surrounding skin area. The aim of the present study was to investigate whether this heterotopically increased mechanical pain sensitivity can be facilitated through the induction of negative expectations. ⋯ This study shows for the first time that brain mechanisms, via the induction of negative expectations, can facilitate heterotopic mechanical hyperalgesia after HFS of human skin.
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Randomized Controlled Trial Comparative Study
Comparison of postoperative pain in the first and second knee in staged bilateral total knee arthroplasty: clinical evidence of enhanced pain sensitivity following surgical injury.
Staged bilateral total knee arthroplasty (TKA) may provide an ideal clinical model for the study of central sensitization. In staged TKA, hyperalgesia may be induced as a result of repeated surgical injury possibly via central sensitization, which can decrease functional outcomes. Therefore, we hypothesized that in staged bilateral TKA, patients would have greater pain in the second operated knee than in the first. ⋯ Patients undergoing staged bilateral TKA experience greater postoperative pain in the second operated knee than the first. This suggests extension of hyperalgesia beyond the initially injured site to remote regions after surgical injury, in which central sensitization may be involved. Therapeutic approaches to reduce such hyperalgesia induced in the course of staged operations are required.
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Randomized Controlled Trial
The Effect of Repeated Intramuscular Alfentanil Injections on Experimental Pain and Abuse Liability Indices in Healthy Males.
Opioid-induced hyperalgesia (OIH), increased sensitivity to noxious stimuli after repeated opioid exposures, has been demonstrated in preclinical studies. However, there is no accepted, prospective model of OIH after repeated opioid exposures currently available in humans. This study assessed a potential prospective OIH model. ⋯ Repeated alfentanil exposures over 4 to 5 weeks resulted in within session decreases in cold pain tolerance from baseline but these differences were not substantially different from diphenhydramine controls. The results did not support the phenomenon of OIH in this model, although definitive conclusions regarding the existence of OIH in humans likely requires a larger sample size or an alternative model.
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Randomized Controlled Trial Multicenter Study
The analgesic efficiency of combined pregabalin and ketamine for total hip arthroplasty: a randomised, double-blind, controlled study.
Pregabalin and ketamine given together have a small, additive effect in reducing post-operative pain after total hip arthroplasty.
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