Papers of the Week

We conducted a multicenter, randomized, patient and assessor-blinded, sham-controlled trial to investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) in patients with neuropathic pain. Patients were randomly assigned to receive five daily sessions of active or sham rTMS of M1 corresponding to the part of the body experiencing the worst pain (500 pulses per session at 5 Hz). Responders were invited to enroll in an open-label continuous trial involving four weekly sessions of active rTMS. The primary outcome was a mean decrease in a visual analogue scale (VAS) of pain intensity (scaled 0-100 mm) measured daily during the daily sessions in an intention-to-treat population. Secondary outcomes were other pain scores, quality-of-life measures, and depression score. 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 (mean, 8.0) and the sham group (9.2) during the daily sessions. The secondary outcomes were not significantly different between two groups. The patients enrolled in the continuous weekly rTMS achieved more pain relief in the active stimulation group compared with the sham (p<0.01). No serious adverse events were observed. Five daily sessions of rTMS with stimulus conditions used in this trial were ineffective in short-term pain relief in the whole study population with various neuropathic pain. Long-term administration to the responders should be investigated for the clinical use of rTMS on neuropathic pain in the future trials.