Nociceptor modulated central sensitization causes mechanical hyperalgesia in acute chemogenic and chronic neuropathic pain

作者：Martin Koltzenburg, H. E. Torebjörk, Lis Karin Wahren · 发表于：Brain · 年份：1994 · DOI：10.1093/brain/117.3.579 · 被引用次数：472 · 研究领域：Pain Mechanisms and Treatments、Botulinum Toxin and Related Neurological Disorders、Musculoskeletal pain and rehabilitation

Brush-evoked pain (mechanical allodynia, dynamic mechanical hyperalgesia) is a hallmark of neuropathic and inflammatory pain states. Here we have examined the neural mechanisms that induce and maintain this component of mechanical hyperalgesis. The principle finding of these experiments is that the severity of brush-evoked pain correlates with the intensity of backgound pain in patients suffering from chronic painful neuropathies and in normal subjkects with acute experimental chemogenic pain. In experiments on nine normal subjects topical application of mustrard oil for 5 min evoked strong buring pain and hyperalgesia to light mechanical stimuli. Differential nerve blocks (by comparession of the superficial radial nerve) revealed that the brush-evoked pain was transmitted by Aβ-fibers, which normally encode non-painful tactile sensations, while the buring pain was signalled by C-fibers. Psychophysical measurements showed that mustard oil treatment resulted in a pronounced sensitization of nociceptors to heat so that subsequent innocuous changes of skin temperature from 35 to 40°C resulted in a proprotional rincrease of buring background pain. Changes in the magnitucde of ongoing buring pain were closely correlated (r = 0.81) to the intensity of brush-evoked pain. While conduction block of A-fibers eliminated only touch-evoked pain, blocked of C-fibre exciation instantaneously abolished both ongoing and touch-evoked pain. In nine patients with chronic neuralgia (15 years mean...