Articles: hyperalgesia.
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The aim of the study was to evaluate the analgesic/antihyperalgesic efficacy and to establish the dose-response relationship of morphine immediate release (IR) and oxycodone IR in a human experimental algesimetric model. Calculated effect ratios for peak-to-peak (PtP) amplitudes of laser-evoked potentials (LEPs) and visual analog scales (VAS) postlaser pain on UVB-irradiated skin (main target variables) were 1.68 and 1.18 respectively for oxycodone 10mg/morphine 20mg, 3.00 and 1.63 respectively for oxycodone 15 mg/morphine 30 mg, and 1.12 and 1.25 respectively for oxycodone 20mg/morphine 40 mg. The effect on the laser-PtP amplitude of morphine at the highest dose (40 mg) and of oxycodone at all doses (10, 15, 20mg) was considered to be clinically relevant based on a difference from placebo of ≥ 2.5 μV. ⋯ Hyperalgesia developed over time vs baseline due to acute exposure to UVB irradiation and to topical/occlusive 1% capsaicin solution. For both compounds, the principal onset of analgesic/antihyperalgesic drug effects was around 0.5 hours with an average peak at about 1 to 2 hours and the effect lasting for more than 3 hours (morphine 20 and 30 mg) or 6 hours (morphine 40 mg and oxycodone all doses). In conclusion, the study demonstrated a solid outcome of a mixed objective/subjective human experimental algesimetric model to approach dose-response relationships and analgesic/antihyperalgesic effects of 2 opioids.
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The purpose of this study was to examine differences in heat pain threshold (HPTh) and heat pain tolerance (HPTo) between temporomandibular joint disorder (TMJD) patients and healthy controls. Using suprathreshold heat pain, this study also examined between-group (i.e. TMJD vs. healthy controls) differences in hyperalgesia and temporal summation (TS) of heat pain. ⋯ Data analysis revealed a significant simple mediation effect whereby the presence of TMJD was strongly associated with poorer self-reported sleep quality, which, in turn, was related to enhanced hyperalgesia at 46 °C. These findings support the hypothesis that the thermal hyperalgesia demonstrated by TMJD patients may be related to poor quality of their self-reported sleep. The ability of interventions that improve sleep quality to also affect pain sensitivity is currently the topic of ongoing investigation.
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Comparative Study
Ankle joint mobilization decreases hypersensitivity by activation of peripheral opioid receptors in a mouse model of postoperative pain.
Investigate whether ankle joint mobilization (AJM) decreases hypersensitivity in the mouse plantar incision (PI) model of postoperative pain as well as to analyze the possible mechanisms involved in this effect. ⋯ Our results indicate that joint mobilization reduces postoperative pain by activation of the peripheral opioid pathway. However, antihypersensitivity induced by AJM is apparently not limited by the number of opioid-containing leukocytes but by opioid receptors availability in sensory neurons. A better understanding of the peripheral mechanisms of AJM could stimulate therapists to integrate joint mobilization with strategies also known to influence endogenous pain control, such as exercise, acupuncture, and transcutaneous electrical nerve stimulation to potentiate endogenous analgesia.
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Individual differences in interoceptive sensitivity are associated with differences in reported intensity of emotional experience, vulnerability to anxiety and mood disorder and capacity for emotional self-regulation. Enhanced sensitivity to autonomic state is often accompanied by increased autonomic reactivity. Here we tested the hypothesis that healthy people classified as more interoceptively sensitive, by their performance of a heartbeat monitoring task, will demonstrate enhanced perception of pain. ⋯ We observed significant relationships between heightened interoceptive sensitivity and both enhanced sensitivity and decreased tolerance to pain. These effects were accompanied by a more pronounced parasympathetic decrease and a change in sympathovagal balance during pain assessment in the high, compared to the low, interoceptively sensitive group. Our study provides novel evidence that interoceptive sensitivity is associated with the experience and tolerability of pain in conjunction with reactive changes in autonomic balance.