Pain
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Comparative Study
Increased bias to report heat or pain following emotional priming of pain-related fear.
Emotional and attentional factors have been identified to play a significant role in modulating pain perception with negative emotions increasing pain sensitivity. Recent studies suggest that fearful images may activate the attentional components of fear driven behaviours and facilitate an attentional bias or sensitivity toward noxious stimuli. The current investigation examines whether priming of pain-related fear will affect performance by increasing sensitivity to punctuate heat stimuli. ⋯ The results indicated a significant facilitation of heat and pain perception at varying temperatures following emotional priming. In particular, there was an increase in the bias toward reporting a heat stimulus following emotional priming. The findings emphasise the efficacy of the visual dot probe task as a method of priming and provide a possible method for probing hypervigilance in chronic pain patients.
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Comparative Study
Selective stimulation of GalR1 and GalR2 in rat substantia gelatinosa reveals a cellular basis for the anti- and pro-nociceptive actions of galanin.
Galanin modulates spinal nociceptive processing by interacting with two receptors, GalR1 and GalR2. The underlying neurophysiological mechanisms were examined by whole-cell recording from identified neurons in the substantia gelatinosa of young adult rats. GalR1 was activated with a 'cocktail' containing the GalR1/2 agonist, AR-M 961 (0.5 microM), in the presence of the GalR2 antagonist, M871 (1.0-2.5 microM). ⋯ GalR2 was also located presynaptically, as AR-M 1896 increased the interevent interval of spontaneous EPSCs in both delay and tonic cells. By contrast, the 'GalR1 agonist cocktail' had little effect on spontaneous EPSCs, suggesting that presynaptic terminals do not express GalR1. These diverse actions of GalR1 and GalR2 activation on both inhibitory and excitatory neurons are discussed in relation to the known spinal antinociceptive and pro-nociceptive actions of galanin, to the possible association of GalR1 with the inhibitory G-protein, G(i/o) and to report that GalR2 activation suppresses Ca2+ channel currents.
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Randomized Controlled Trial Comparative Study
Is pain relief equally efficacious and free of side effects with repeated doses of oral sucrose in preterm neonates?
The aim of the present study was to examine the efficacy and potential side effects of repeated doses of oral sucrose for pain relief during procedures in NICU. Thirty-three preterm neonates were randomly allocated in blind fashion into two groups, the sucrose group (SG=17) and the control group (CG=16). The responses of neonates to pain and distress were assessed during blood collection on four consecutive assessment (ass.) days. ⋯ There were significantly fewer SG neonates crying during A (ass.2), P (ass.2 and ass.4), and D (ass.3). There was no statistical difference between-groups for physiological response. The efficacy of sucrose was maintained for pain relief in preterm neonates with no side effects.
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Multicenter Study Comparative Study
Neurophysiological characterization of postherniotomy pain.
Inguinal herniotomy is one of the most frequent surgical procedures and chronic pain affecting everyday activities is reported in approximately 10% of patients. However, the neurophysiological changes and underlying pathophysiological mechanisms of postherniotomy pain are not known in detail, thereby precluding advances in treatment strategies and prophylaxis. Therefore, we examined forty-six patients reporting moderate to severe postherniotomy pain affecting daily activities for more than a year postoperatively, and compared them with a control group of patients without pain 1 yr postoperatively. ⋯ The specific finding of reduced pain detection threshold over the external inguinal annulus is consistent with damage to the cutaneous innervation territory of nervous structures in the inguinal region. The correspondence between pain location and sensory disturbance suggests that the pain is neuropathic in nature. Whether the underlying pathophysiological mechanisms are related to direct intraoperative nerve injury or nerve injury due to an inflammatory mesh response remains to be determined.
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Pain is common in patients with multiple sclerosis (MS), but estimates of its prevalence have varied widely. The literature describing pain in MS patients spans four decades and has employed a range of different methodologies. We undertook a systematic review in order to summarize current understanding of the association between MS and pain and provide a basis for the design and interpretation of future studies. ⋯ Putative mechanisms of pain in patients with MS are discussed, and a classification of pain in MS is proposed. Few randomized clinical trials of treatments for MS pain have been conducted, and the limitations of current knowledge regarding approaches for treating MS pain are discussed. Suggestions for future studies that would increase understanding of the natural history, mechanisms, and treatment of pain in patients with MS are presented.