rTMS for Suppressing Neuropathic Pain: A Meta-Analysis

Leung, Albert; Donohue, Michael; Xu, Ronghui; Lee, Ryan; Lefaucheur, Jean-Pascal; Khedr, Eman M.; Saitoh, Youichi; André-Obadia, Nathalie; Rollnik, Jens; Wallace, Mark; Chen, Robert

doi:10.1016/j.jpain.2009.03.010

« Previous Next »The Journal of Pain
Volume 10, Issue 12 , Pages 1205-1216, December 2009

rTMS for Suppressing Neuropathic Pain: A Meta-Analysis

Albert Leung
- Department of Anesthesiology, The University of California, San Diego, School of Medicine, VA San Diego Healthcare System
- Address reprint requests to Dr Albert Leung, 9500 Gilman Drive, #0924, La Jolla, CA 92093-0924.
Michael Donohue
- Department of Family and Preventive Medicine, The University of California, San Diego, School of Medicine
Ronghui Xu
- Department of Family and Preventive Medicine, and Department of Mathematics, The University of California, San Diego, School of Medicine
Ryan Lee
- The University of California, San Diego
Jean-Pascal Lefaucheur
- Department of Physiology, Henri Mondor University Hospital, Créteil, France
Eman M. Khedr
- Department of Neurology, Assiut University Hospital, Assiut, Egypt
Youichi Saitoh
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Osaka, Japan
Nathalie André-Obadia
- Department of Neurology, University Hospital Lyon Sud, Lyon, France
Jens Rollnik
- Department of Neurology and Clinical Neurophysiology, Medical School of Hannover, Germany
Mark Wallace
- Department of Anesthesiology, The University of California, San Diego, School of Medicine
Robert Chen
- Division of Neurology, Department of Medicine, Toronto Western Research Institute, University of Toronto, Toronto, Canada

published online 25 May 2009.

Abstract

This pooled individual data (PID)-based meta-analysis collectively assessed the analgesic effect of repetitive transcranial magnetic stimulation (rTMS) on various neuropathic pain states based on their neuroanatomical hierarchy. Available randomized controlled trials (RCTs) were screened. PID was coded for age, gender, pain neuroanatomical origins, pain duration, and treatment parameters analyses. Coded pain neuroanatomical origins consist of peripheral nerve (PN); nerve root (NR); spinal cord (SC); trigeminal nerve or ganglion (TGN); and post-stroke supraspinal related pain (PSP). Raw data of 149 patients were extracted from 5 (1 parallel, 4 cross-over) selected (from 235 articles) RCTs. A significant (P < .001) overall analgesic effect (mean percent difference in pain visual analog scale (VAS) score reduction with 95% confidence interval) was detected with greater reduction in VAS with rTMS in comparison to sham. Including the parallel study (Khedr et al), the TGN subgroup was found to have the greatest analgesic effect (28.8%), followed by PSP (16.7%), SC (14.7%), NR (10.0%), and PN (1.5%). The results were similar when we excluded the parallel study with the greatest analgesic effect observed in TGN (33.0%), followed by SC (14.7%), PSP (10.5%), NR (10.0%), and PN (1.5%). In addition, multiple (vs single, P = .003) sessions and lower (>1 and ≤10 Hz) treatment frequency range (vs >10 Hz) appears to generate better analgesic outcome. In short, rTMS appears to be more effective in suppressing centrally than peripherally originated neuropathic pain states.

Perspective

This is the first PID-based meta-analysis to assess the differential analgesic effect of rTMS on neuropathic pain based on the neuroanatomical origins of the pain pathophysiology and treatment parameters. The derived information serves as a useful resource in regards to treatment parameters and patient population selection for future rTMS-pain studies.

Key words: Transcranial magnetic stimulation, TMS, rTMS, neuropathic pain, neuromodulation, meta-analysis