Pulsed Radiofrequency Application at Some Dorsal Root Ganglions Could Cause Drastic Neuromodulation throughout the Whole Body

Background: The modified technique, pulsed radiofrequency (PRF) procedure, applied to nervous tissue has been providing anecdotal benefits for the management of chronic and intractable pain conditions. Although PRF has a neuromodulatory effect instead of thermally lesioning nervous tissue, the mechanism underlying the analgesic effect of PRF has not been fully clarified yet. Objectives: To see the changes of electricallyevoked responses of peripheral A-δ and A-β nerve fibers and the analgesic effect induced by PRF. Study Design: Case series. Setting: Inpatient. Methods: This study investigated how dorsal root ganglion (DRG) PRF influenced electricallyevoked responses of peripheral A-δ and A-β nerve fibers at the treated root ganglion dominating areas in five patients with intractable vertebral metastatic pain. Results: DRG PRF provided sound pain relief for patients with intractable vertebral metastatic pain. PRF application at DRGs had a different effect on electrically-evoked responses of peripheral A-δ and A-β nerve fibers at not only the treated root ganglion dominating areas but also the nontreated root ganglion dominating areas far from the treated root ganglion dominating areas in each patient. Limitation: This report is a case series. Conclusions: PRF application at some peripheral nerves could cause drastic neuromodulation throughout the whole body. Key words: Pulsed radiofrequency, dorsal root ganglion block, neuromodulation