1. Evaluation of Postsurgical Hyperalgesia and Sensitization After Open Inguinal Hernia Repair: A Useful Model for Neuropathic Pain?
- Author
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Wheeler DW, Bhatia A, Mani V, Kinna S, Bell A, Boyle Y, Chizh BA, Menon DK, and Lee MC
- Subjects
- Adult, Aged, Follow-Up Studies, Humans, Male, Middle Aged, Neuralgia diagnosis, Pain Measurement, Pain, Postoperative diagnosis, Central Nervous System Sensitization physiology, Hernia, Inguinal surgery, Hyperalgesia physiopathology, Neuralgia physiopathology, Pain, Postoperative physiopathology
- Abstract
Cutaneous mechanical hyperalgesia can be induced in healthy volunteers in early phase analgesic studies to model central sensitization, a key mechanism of persistent pain. However, such hyperalgesia is short-lived (a matter of hours), and is used only for assessing only single drug doses. In contrast, postsurgical peri-incisional hyperalgesia may be more persistent and hence be a more useful model for the assessment of the efficacy of new analgesics. We undertook quantitative sensory testing in 18 patients at peri-incisional and nonoperated sites before open inguinal hernia repair and up to the 24th postsurgical week. The spatial extent of punctate hyperalgesia and brush allodynia at the peri-incisional site were greatest at weeks 2 and 4, but had resolved by week 24. Heat allodynia, suggestive of local inflammation or peripheral sensitization, was not observed; instead, there were deficits in cold and heat sensory detection that persisted until week 24. The findings suggest that central sensitization contributes significantly to mechanical hyperalgesia at the peri-incisional site. The prolonged duration of hyperalgesia would be advantageous as a pain model, but there was considerable variability of mechanical hyperalgesia in the cohort; the challenges of recruitment may limit its use to small, early phase analgesic studies. PERSPECTIVE: Peri-incisional mechanical hyperalgesia persists for ≥4 weeks after open inguinal hernia repair and reflects central sensitization; this may have usefulness as a model of chronic pain to assess the potential of antineuropathic analgesics., (Copyright © 2019 the American Pain Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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