Pain
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Randomized Controlled Trial Comparative Study
Motor cortex stimulation for long-term relief of chronic neuropathic pain: a 10 year experience.
Chronic subthreshold stimulation of the contralateral precentral gyrus is used in patients with intractable neuropathic pain for more than 15 years. The aim of this study was to analyse retrospectively our own patient group with long term follow-up of 10 years. Seventeen patients with chronic neuropathic pain were treated with contralateral epidural stimulation electrodes. ⋯ Double-blind testing can identify non-responders. Patients with TNP profit more than patients with PSP. The positive effect can last for ten years in long-term follow-up.
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Symptom duration is integral to clinical and epidemiological research on pain. It is widely used for sample selection and commonly assessed in clinical practice. However, there has been little specific investigation of the link between duration and outcome. ⋯ In conclusion, memory of LBP episode duration is associated with pain, disability and psychological status, and is an independent predictor of time to improvement. There are important differences between people who recall more or less than 3 years' duration. Mechanisms for these associations are poorly understood, but this research suggests that duration itself is an important focus for research.
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Comparative Study
Glucocorticoid inhibition of vascular abnormalities in a tibia fracture rat model of complex regional pain syndrome type I.
Tibia fracture in rats evokes chronic hindpaw warmth, spontaneous extravasation, edema, allodynia, and periarticular bone loss, a syndrome resembling complex regional pain syndrome type I (CRPS I). Glucocorticoids such as methylprednisolone (MP) are probably effective analgesic and anti-edematous agents in patients suffering from CRPS and this study examined the effects of chronic MP treatment in the rat CRPS I model. Bilateral hindpaw thickness, temperature, and nociceptive thresholds were determined, and the hindlimb bone density was measured using dual-energy X-ray absorptiometry (DXA). ⋯ Furthermore, there was an increase in spontaneous protein extravasation and an enhanced substance P evoked extravasation and edema response in the hindpaw at 4 weeks that was inhibited by MP infusion. Glucocorticoid treatment had no effect on the allodynia, hindpaw unweighting, or the periarticular bone loss observed after tibia fracture. We postulate that post-junctional facilitation of substance P signaling contributes to the hindpaw warmth, edema, and the enhanced spontaneous protein extravasation observed in this CRPS I model, and that the anti-edematous effects of glucocorticoid treatment are due to inhibition of post-junctional neuropeptide signaling.
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Comparative Study
Localization of touch versus heat pain in the human hand: a dissociative effect of temporal parameters on discriminative capacity and decision strategy.
We studied the influence of temporal parameters on localization of monofilament-evoked touch versus thulium laser-induced and C fiber-mediated pain in human subjects. Stimuli were applied at interstimulus intervals (ISIs) varying from 1 to 9 s to determine discrimination between successive stimulus sites in the palmar skin. Localization threshold was about two times higher for heat pain than touch. ⋯ Additionally, temporal factors dissociatively influence the response strategy in the tactile versus pain localization task with the prolongation of the ISI from 1 to 9 s. Due to this strategy change, localization threshold for touch remains constant at prolonged ISIs, in spite of a decrease in discriminative capacity. In a cutaneous localization task, the subject's accuracy and response strategy vary with the modality and temporal parameters of sequential test stimulation.
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Comparative Study
Synergism between paracetamol and nonsteroidal anti-inflammatory drugs in experimental acute pain.
The antinociception induced by the intraperitoneal coadministration of combinations of paracetamol with the nonsteroidal anti-inflammatory drugs (NSAIDs) diclofenac, ibuprofen, ketoprofen, meloxicam, metamizol, naproxen, nimesulide, parecoxib and piroxicam was studied by isobolographic analysis in the acetic acid abdominal constriction test of mice (writhing test). The effective dose that produced 50% antinociception (ED50) was calculated from the log dose-response curves of fixed ratio combinations of paracetamol with each NSAID. ⋯ As shown by isobolographic analysis, all the combinations were synergistic, the experimental ED50s being significantly smaller than the theoretically calculated ED50s. The results of this study demonstrate potent interactions between paracetamol and NSAIDs and validate the clinical use of combinations of these drugs in the treatment of pain conditions.