Pain
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No pain scale is available for stroke patients due to the presence of language or cognitive disorders. However, the Faces Pain Scale (FPS), which was initially developed for children, has been used with success in adults with cognitive impairments. The aim of this study is to test whether the FPS could be used in left or right hemispheric stroke patients (LHSP, RHSP). ⋯ The present study provides preliminary support for the validity and the reliability of FPS in LHSP. However, we do not recommend its sole use in stroke patients. Further studies are needed to determine whether FPS can be used in stroke patients for assessing changes in severity of pain over time.
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Noxious C-fibre stimulation produces increased sensitivity within the injured area (primary hyperalgesia), and a surrounding zone of secondary hyperalgesia. As significant changes in nociceptive processing occur during development, we compared C-fibre induced primary and secondary hyperalgesia in rat pups aged 3, 10 and 21 postnatal (P) days. Hyperalgesia was measured by electromyography flexion reflex recordings following mustard oil or capsaicin at the site of (primary hyperalgesia), or distant to (secondary hyperalgesia) hindpaw mechanical stimuli. ⋯ These results provide evidence that primary and secondary hyperalgesia are differentially modulated during development. Furthermore, since ERK activation is required for secondary hyperalgesia, phosphoERK expression can be used to map the spatial distribution of neuronal activation in the spinal cord. Understanding changing responses to injury in the developing nervous system is important for clinical paediatric practice, and will enhance our ability to target the most effective site with a developmentally appropriate analgesic regime.
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Sympathetically maintained pain could either be mediated by ephaptic interactions between sympathetic efferent and afferent nociceptive fibers or by catecholamine-induced activation of nociceptive nerve endings. We report here single fiber recordings from C nociceptors in a patient with sympathetically maintained pain, in whom sympathetic blockade had repeatedly eliminated the ongoing pain in both legs. We classified eight C-fibers as mechano-responsive and six as mechano-insensitive nociceptors according to their mechanical responsiveness and activity-dependent slowing of conduction velocity (latency increase of 0.5+/-1.1 vs. 7.1+/-2.0 ms for 20 pulses at 0.125 Hz). ⋯ Moreover, their activity-dependent slowing was typical for mechano-insensitive nociceptors. We conclude that sensitized mechano-insensitive nociceptors can be activated by endogenously released catecholamines and thereby may contribute to sympathetically maintained pain. No evidence for ephaptic interaction between sympathetic efferent and nociceptive afferent fibers was found.