Articles: peripheral-nerve-injuries.
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The authors report on a series of patients with severely painful disorders of peripheral nerves--they review the modern theories on the nature of causalgia and reflex sympathetic dystrophy. Peripheral causes include spontaneous discharges from neuroma sprouts, their sensitivity to adrenergic compounds, ectopic generator activity in abnormally myelinated fires and increased firing in dorsal root ganglia. Central causes include spontaneous activity of deafferented nerves in the dorsal horn and development of response to new receptive fields. ⋯ Recurrences depend on the degree of initial response. Those who obtained virtually complete relief of pain had a lower recurrence rate but a high proportion needed repeated sessions of treatment at yearly intervals. Follow-ups must therefore be indefinite.
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Pain to light touching of the skin is a hallmark sign of causalgia. The purpose of this study was to determine whether myelinated or unmyelinated afferent fibers signal this hyperalgesia. Sensory testing was performed in 17 patients with long-standing hyperalgesia after nerve injury. ⋯ The mean latency for detection of pain in the hyperalgesic region was 414 +/- 18 msec, compared to 458 +/- 16 msec for the detection of touch to the same stimuli applied to the opposite normal foot. These 3 lines of evidence indicate that myelinated primary afferents, perhaps A beta fibers, signal the hyperalgesic pain in causalgia. These fibers may be sensitized A beta nociceptors or low-threshold mechanoreceptors.
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The imaging of peripheral nerve lesions remains limited to the radiographic demonstration of secondary skeletal lesions in birth trauma, reflex sympathetic dystrophy, neuropathic arthropathy, leprosy, and congenital indifference to pain. Nerve root avulsions can be imaged directly and the newer imaging modalities now allow delineation of lesions that previously could not be studied using conventional radiography. ⋯ Imaging of peripheral nerve lesions remains in its infancy. With further refinement in the signal-to-noise ratio made possible by advances in MRI technology, we may be optimistic about future imaging of peripheral nerve pathology.
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Injury to a mammalian peripheral nerve is accompanied by a restorative process that is manifested after a delay. This process is expressed morphologically by the emergence of new nerve fibers. Restoration of function occurs when the regenerating fibers reconnect with the target organ. ⋯ The studies include follow-up for 1 year after the injury. This electrophysiological manifestation of the effect of laser treatment on injured nerves was accompanied by a diminution of the size of the scar tissue from these nerves. Yet to be resolved is whether these two phenomena (i.e., electrophysiological and morphological responses) coincide or whether they relate to each other.(ABSTRACT TRUNCATED AT 250 WORDS)
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On the one hand, out of 115 patients admitted to hospital with 162 various fractures of the cervical spine without injury to the spinal cord, only 3 (2.6%) had an associated lesion to the brachial plexus or nerves in the vicinity. On the other hand, among 500 consecutive patients with injuries to the brachial plexus, 55 (11%) presented fractures of the cervical spine (including T1 and the 1st rib), whiplash injuries, severe distortions and dislocations, and contusions of that vertebral segment. ⋯ Fractures around the shoulder-girdle as well as arterial ruptures are also significant for this severe nerve injury. Of these patients 39 (71%), were victims of motorcycle accidents.