Korean J Pain 2016; 29(1): 3-11
Published online January 31, 2016 https://doi.org/10.3344/kjp.2016.29.1.3
Copyright © The Korean Pain Society.
Eun Ji Choi, Yun Mi Choi, Eun Jung Jang, Ju Yeon Kim, Tae Kyun Kim, and Kyung Hoon Kim*
Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea.
Correspondence to: Kyung Hoon Kim. Pain Clinic, Pusan National University Yangsan Hospital, 20 Geumo-ro, Mulgeum-eup, Yangsan 50612, Korea. Tel: +82-55-360-1422, Fax: +82-55-360-2149, email@example.com
Received: June 10, 2015; Revised: November 26, 2015; Accepted: December 22, 2015
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
A nerve block is an effective tool for diagnostic and therapeutic methods. If a diagnostic nerve block is successful for pain relief and the subsequent therapeutic nerve block is effective for only a limited duration, the next step that should be considered is a nerve ablation or modulation. The nerve ablation causes iatrogenic neural degeneration aiming only for sensory or sympathetic denervation without motor deficits. Nerve ablation produces the interruption of axonal continuity, degeneration of nerve fibers distal to the lesion (Wallerian degeneration), and the eventual death of axotomized neurons. The nerve ablation methods currently available for resection/removal of innervation are performed by either chemical or thermal ablation. Meanwhile, the nerve modulation method for interruption of innervation is performed using an electromagnetic field of pulsed radiofrequency. According to Sunderland's classification, it is first and foremost suggested that current neural ablations produce third degree peripheral nerve injury (PNI) to the myelin, axon, and endoneurium without any disruption of the fascicular arrangement, perineurium, and epineurium. The merit of Sunderland's third degree PNI is to produce a reversible injury. However, its shortcoming is the recurrence of pain and the necessity of repeated ablative procedures. The molecular mechanisms related to axonal regeneration after injury include cross-talk between axons and glial cells, neurotrophic factors, extracellular matrix molecules, and their receptors. It is essential to establish a safe, long-standing denervation method without any complications in future practices based on the mechanisms of nerve degeneration as well as following regeneration.
Keywords: Axon, Chemical Neurolysis, Denervation, Electromagnetic field, Myelin, Nerve degeneration, Nerve regeneration, Peripheral nerve injury, Pulsed radiofrequency treatment, Wallerian degeneration