Pain
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We studied the effect of unilateral ligation of two spinal nerves on behavioral pain responses evoked by various types of cutaneous stimuli in the adult rat. Furthermore, we determined the effect of spinal nerve ligation on morphology of the peripheral nerves. The most consistent behavioral finding (83%) was a marked decrease in monofilament-induced hindlimb withdrawal thresholds (mechanical allodynia) ipsilateral to the spinal nerve ligation. ⋯ However, this mechanical allodynia may differentially dissociate from mechanical and thermal hyperalgesia at various post-operative time points. The marked mechanical allodynia together with a dramatic decrease in the number of myelinated nerve fibers is paradoxical, since the activation of myelinated nerve fibers by monofilaments produced abnormally strong behavioral responses. This paradox may be explained by spinal nerve ligation-induced amplification or disinhibition of tactile signals at central levels.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of 50, 100 and 200 mg of intra-articular pethidine during knee joint surgery, a controlled study with evidence for local demethylation to norpethidine.
Pethidine (meperidine) is a compound with both local anaesthetic and opioid agonist properties. We have in a recent study demonstrated that pethidine could be an interesting alternative to prilocaine in arthroscopy with local anaesthetic technique. Therefore, we investigated, in a controlled randomized double-blind study, the effect of three doses of pethidine compared with a standard local anaesthetic, in patients subjected to arthroscopic knee joint surgery. ⋯ This site of drug oxidation has not earlier been demonstrated neither in vitro nor in vivo. The results suggest that pethidine given i.a. in the dose range of 50 to 200 mg results in analgesia due to both peripheral and central mechanisms. The significant systemic uptake of pethidine can cause unwanted side-effects.
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Clinical Trial Controlled Clinical Trial
Nefopam strongly depresses the nociceptive flexion (R(III)) reflex in humans.
Nefopam hydrochloride has been commercialized as an analgesic drug in most Western European countries for 20 years. It has been shown to possess analgesic activity with a profile distinct from that of opioids or anti-inflammatory drugs. In order to define the mechanisms of action of this pharmacological agent, we studied, in a double-blind and cross-over fashion, its effects on the nociceptive flexion (R(III)) reflex and the corresponding pain sensation in ten healthy volunteers. ⋯ However, complementary peripheral mechanisms cannot be excluded on the basis of the present study. In view of these results, it seems that new clinical studies will have to be undertaken to revisit this potent analgesic agent and try to limit its adverse effects (i.e. nausea, vomiting, sweating). Its fast onset of action could clearly be an advantage, notably in the treatment of post-operative pain.
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Randomized Controlled Trial Clinical Trial
Patient utilities in chronic musculoskeletal pain: how useful is the standard gamble method?
The main goal of current pain management approaches is to increase the patients' quality of life by improving pain coping skills and by reducing the levels of disability in daily life, often despite persistent pain. Direct measurement of quality of life is of crucial importance in economic evaluation research, in which not only is the estimation of financial costs and benefits included, but so is the evaluation of costs and benefits in terms of changes in health states. The purpose of this study is to compare the psychometric qualities of two instruments for assessing patients' utilities, the rating scale (RS) and the standard gamble (SG). ⋯ It is therefore recommended to include in economic evaluation studies both domain-specific measures and valuation measures. Finally, in chronic musculoskeletal pain patients, RS scores were found to be more responsive in detecting significant changes in preferences than SG scores. For use in patients with chronic musculoskeletal pain, the RS is preferred to the SG for establishing accurate decisions about the impact of new interventions on their health outcomes.
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This study tests whether facial pain or associated symptoms and disorders aggregates in first degree relatives of those with myofascial temporomandibular disorders (M/TMD). We randomly selected one first degree relative of 106 probands with a lifetime history of M/TMD and one first degree relative of 118 acquaintance control probands with no history of M/TMD. ⋯ In addition, proband descriptors of facial pain severity or disability did not significantly predict the likelihood of having a first degree relative with one or more TMD-related symptoms. These results indicate that M/TMD is not a familial disorder.