P74-S A randomized clinical trial of repetitive transcranial magnetic stimulation for neuropathic pain

Abstract

Background Treatment of neuropathic pain (NP) remains a challenge. We compared repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex with sham stimulation for the treatment of NP. Methods In our multicenter, randomized, patient and assessor-blind, sham-controlled, parallel trial, NP patients were randomly assigned to receive five daily sessions of active rTMS of the primary motor cortex somatotopically corresponding to the worst pain (5 Hz, 90% motor threshold, 500 pulses/session) or sham treatment. Responders were invited to enroll in a continuous trial involving four weekly sessions of active rTThe primary outcome was a mean decrease in a visual analogue scale (VAS) measured daily in an intention-to-treat population. Secondary outcomes were the short-form McGill pain questionnaire 2 (SF-MPQ2), quality-of-life measures, and depression score. Results 144 patients were assigned to the active or sham stimulation groups. The primary outcome, mean VAS decreases, was not significantly different (p = 0.58) between the active stimulation group (8.0 ± 12.1) and the sham group (9.2 ± 13.6). The mean SF-MPQ2 decreases in the active stimulation and sham groups were 21.7 ± 24.1 and 16.2 ± 19.7, respectively (p = 0.14). The secondary outcomes were not significantly different between both groups. Active stimulation group patients tended to achieve additional pain relief with continuous weekly rTNo serious adverse events were observed. Conclusions Patients given five daily sessions of rTMS with stimulus conditions used in this trial showed no improvements in pain relief in various types of NP. The findings of this study may reflect the importance of further optimization of enrolled subjects, trial protocol, and stimulus procedure.