Spinal Hyperexcitability in Sympathetically Maintained Pain
Anesthetic block of sympathetic postganglionic neurons relieves both spontaneous pain and mechanical allodynia in some individuals without blocking painful responses to noxious stimuli. A similar effect is obtained in many cases by regional infusion of guanethidine, which depletes norepinephrine from peripheral tissues. These responses to sympathetic block indicate that the pain and allodynia are sympathetically maintained--that they are dependent on sympathetic efferent activity. One syndrome characterized by sympathetically maintained pain is reflex sympathetic dystrophy.
KeywordsMechanical Allodynia Spinal Neuron Primary Afferents Sympathetic Stimulation Reflex Sympathetic Dystrophy
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- 2.Roberts, W.J., Lindsay, A.D. Sympathetic activity shown to have no short-term effect on polymodal nociceptors in cats. Society for Neuroscience Abstracts, 7: 227, 1973.Google Scholar
- 3.Shea, V.K, Perl, E.E. Failure of sympathetic stimulation to effect responsiveness of rabbit polymodal nociceptors. J. of Neurophysiology, 54: 513–520, 1985.Google Scholar
- 14.Price, D.D., Bennett, G.J., Rafii, A.Psycho-physical observation patients with neuropathic pain relieved by a sympathetic block.Plain (in press)Google Scholar