M Granot1, I Weissman-Fogel. 1. Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.
Abstract
BACKGROUND: Surgery-induced neuroplasticity at spinal and supra-spinal levels is assumed to evoke a clinical acute post-operative pain (cAPOP) experience, which is expressed by allodynia and/or hyperalgesia. It remains unclear whether the systemic pain perception measured outside the incision area remains unchanged and whether it is affected by the presence of cAPOP. AIMS: This study explored whether the systemic perception of experimental pain would be altered towards hypersensitivity following elective gynecological surgery unmasked by opioids. METHODS: A perioperative psychophysical evaluation of heat pain thresholds (HPT) and pain estimations were obtained in a remote bodily area before and after surgery among 35 women. RESULTS: The ratings for both pain dimensions of intensity and unpleasantness remained stable following surgery. However, there was a reduction found in HPT the day after surgery (43.6 ± 2.2 °C to 42.2 ± 3.1 °C, p = 0.002). This reduction was associated with lower HPT measured before surgery (r = .56, p < 0.000) and with higher cAPOP intensity obtained at rest (r = -.44, p = 0.008). CONCLUSIONS: This post-surgical allodynia, as reflected by the systemic enhancement of pain perception, may represent plasticity in the central pain pathways at the supra-spinal level. Pre-surgical assessment of a patient's pain perception profile may predict certain pain dimensions of post-surgical pain plasticity. The evaluation of individual pain profiles may contribute to a mechanism-based approach aimed to attenuate the cAPOP.
BACKGROUND: Surgery-induced neuroplasticity at spinal and supra-spinal levels is assumed to evoke a clinical acute post-operative pain (cAPOP) experience, which is expressed by allodynia and/or hyperalgesia. It remains unclear whether the systemic pain perception measured outside the incision area remains unchanged and whether it is affected by the presence of cAPOP. AIMS: This study explored whether the systemic perception of experimental pain would be altered towards hypersensitivity following elective gynecological surgery unmasked by opioids. METHODS: A perioperative psychophysical evaluation of heat pain thresholds (HPT) and pain estimations were obtained in a remote bodily area before and after surgery among 35 women. RESULTS: The ratings for both pain dimensions of intensity and unpleasantness remained stable following surgery. However, there was a reduction found in HPT the day after surgery (43.6 ± 2.2 °C to 42.2 ± 3.1 °C, p = 0.002). This reduction was associated with lower HPT measured before surgery (r = .56, p < 0.000) and with higher cAPOP intensity obtained at rest (r = -.44, p = 0.008). CONCLUSIONS: This post-surgical allodynia, as reflected by the systemic enhancement of pain perception, may represent plasticity in the central pain pathways at the supra-spinal level. Pre-surgical assessment of a patient's pain perception profile may predict certain pain dimensions of post-surgical pain plasticity. The evaluation of individual pain profiles may contribute to a mechanism-based approach aimed to attenuate the cAPOP.
Authors: Rogelio A Coronado; Corey B Simon; Carolina Valencia; Jeffrey J Parr; Paul A Borsa; Steven Z George Journal: PLoS One Date: 2014-09-29 Impact factor: 3.240