Neurogenic hyperalgesia: psychophysical studies of underlying mechanisms

作者：Robert H. LaMotte, C. N. Shain, Donald A. Simone, Eling Tsai · 发表于：Journal of Neurophysiology · 年份：1991 · DOI：10.1152/jn.1991.66.1.190 · 被引用次数：942 · 研究领域：Pain Mechanisms and Treatments、Pain Management and Placebo Effect、Acupuncture Treatment Research Studies

1. Psychophysical studies were made, in humans, of the sensory characteristics and underlying mechanisms of the hyperalgesia (often termed "secondary hyperalgesia") that occurs in uninjured skin surrounding a local cutaneous injury. The hyperalgesia was characterized by lowered pain thresholds and enhanced magnitude of pain to normally painful stimuli. The "injury" was produced by a single intradermal injection of 10 microliters of 100 micrograms of capsaicin, the algesic substance in hot chili peppers. 2. On injection of capsaicin into the volar forearm, the subjects experienced intense burning pain, accompanied immediately by the formation of three areas of hyperalgesia surrounding the injection site. The largest mean area (55 cm2) was hyperalgesic to a normally painful punctate stimulation of the skin. Nested within this was an area of tenderness to gentle stroking (38 cm2) and a much smaller area of hyperalgesia to heat (2 cm2). An area of analgesia to pinprick, approximately 4 mm in diameter and centered on the injection site, developed within minutes and typically disappeared within 24 h. The hyperalgesia to heat and to stroking disappeared within 1-2 h, whereas the hyperalgesia to punctate stimuli, although gradually decreasing in area, lasted from 13 to 24 h. 3. The radial spread of the mechanical hyperalgesia (to punctate and stroking stimuli) away from the injury was dependent on neural activity and not produced, for example, by algesic substances transported away f...