Articles: peripheral-nerve-injuries-physiopathology.
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J Plast Reconstr Aesthet Surg · Jun 2012
Comparative StudyThermoregulation in peripheral nerve injury-induced cold-intolerant rats.
Cold intolerance is defined as pain after exposure to non-painful cold. It is suggested that cold intolerance may be related to dysfunctional thermoregulation in upper extremity nerve injury patients. The purpose of this study was to examine if the re-warming of a rat hind paw is altered in different peripheral nerve injury models and if these patterns are related to severity of cold intolerance. ⋯ There is no direct correlation between cold intolerance and re-warming patterns in different peripheral nerve injury rat models. This is an important finding for future developing treatments for this common problem, since treatment focussing on vaso-regulation may not help diminish symptoms of cold-intolerant patients.
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Neuropathic pain is a chronic debilitating disease characterized by mechanical allodynia and spontaneous pain. Because symptoms are often unresponsive to conventional methods of pain treatment, new therapeutic approaches are essential. Here, we describe a strategy that not only ameliorates symptoms of neuropathic pain but is also potentially disease modifying. ⋯ Underlying this improvement is a remarkable integration of the MGE transplants into the host spinal cord circuitry, in which the transplanted cells make functional connections with both primary afferent and spinal cord neurons. By contrast, MGE transplants were not effective against inflammatory pain. Our findings suggest that MGE-derived GABAergic interneurons overcome the spinal cord hyperexcitability that is a hallmark of nerve injury-induced neuropathic pain.
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Anasthesiol Intensivmed Notfallmed Schmerzther · May 2012
Review[Nerve injury due to peripheral nerve blocks: Pathophysiology and aetiology].
Permanent nerve injury as a complication of peripheral regional anaesthesia is fortunately rare with an estimated incidence of 0,03%. However, transient neurological symptoms are more frequent with an occurrence of 3-8%. ⋯ Regarding pathophysiology, trauma-related inflammation should be acknowledged as an important interference during nerve recovery. Needle-nerve contacts, nerve perforation and local cytotoxicity of local anaesthetics should be reduced to a minimum by application of nerve stimulation, ultrasound and an adequate dosage of local anaesthetics with less locotoxicity.
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Peripheral nerve injuries can trigger neuropathic pain in adults but cause little or no pain when they are sustained in infancy or early childhood. This is confirmed in rodent models where neonatal nerve injury causes no pain behaviour. However, delayed pain can arise in man some considerable time after nerve damage and to examine this following early life nerve injury we have carried out a longer term follow up of rat pain behaviour into adolescence and adulthood. ⋯ We report a novel consequence of early life nerve injury whereby mechanical hypersensitivity only emerges later in life. This delayed adolescent onset in mechanical pain thresholds is accompanied by neuroimmune activation and NMDA dependent central sensitization of spinal nociceptive circuits. This delayed onset in mechanical pain sensitivity may provide clues to understand the long term effects of early injury such as late onset phantom pain and the emergence of complex adolescent chronic pain syndromes.