Objective: Our objective was to assess transcranial magnetic stimulation (TMS) in the treatment of chronic widespread pain.
Methods: Nineteen participants were randomized into 2 groups: one group receiving active TMS (n = 7) and another group receiving sham stimulation (n = 11) applied to the left dorsolateral prefrontal cortex. During sham stimulation, subjects heard a sound similar to the sound heard by those receiving the active treatment and received an active electrical stimulus to the scalp. The stimulation protocol consisted of 15 sessions completed within a 4-week period. Blind assessments were done at baseline and after each 5 sessions followed by blind assessments at 1 week, 1 month, and 3 months after the last TMS sessions. The primary outcome variable was a pain measure, the Gracely Box Intensity Scale (BIRS).
Results: The percentage of subjects who guessed that they were receiving TMS was similar in the 2 groups. Both the TMS group and the sham group showed a statistically significant reduction in the BIRS scores from baseline during the acute phase of treatment and the follow-up phase. However, the TMS and sham groups did not differ in the change in the BIRS scores.
Discussion: Although some previous clinical studies and basic science studies of TMS in treating pain are promising, this study found no difference in the analgesic effect of TMS and sham stimulation. Future studies should use a sham condition that attempts to simulate the sound and sensation of the TMS stimulation. Stimulus location and other stimulus parameters should be explored in future studies.
From the *Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine; †Psychiatric Medicine Associates; ‡Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA; §Department of Psychiatry of Catholic University of Korea College of Medicine, Seoul, South Korea; ∥Department of Radiology, University of Washington School of Medicine; and ¶Department of Internal Medicine, University of Washington School of Medicine, Seattle, WA.
Received for publication January 1, 2014; accepted February 7, 2014.
Reprints: David H. Avery, MD, Psychiatric Medicine Associates, 1505 Westlake Ave N, Suite 920, Seattle, WA 98109 (e-mail: firstname.lastname@example.org).
The study was funded by the National Institute for Arthritis, Musculoskeletal and Skin Diseases, R21 AR053963, and the Bipolar Illness Fund. Neuronetics, Inc. loaned the TMS machine to the study.
Dr. Avery was a consultant for Neuronetics, Inc. for one day, is a member of the Data and Safety Monitoring Board for Cervel Neurotech, Inc., was on the speakers’ bureau for Eli Lilly and Takeda, was a consultant for Takeda, and received a grant from the National Institute of Mental Health. Dr. Roy-Byrne is editor for Journal Watch, Depression and Anxiety, and UpToDate and has stock in Valant Medical Systems. None of the other authors has potential conflicts of interest or financial disclosures to report.