Effect of Repetitive Transcranial Magnetic Stimulation Over the Hand Motor Cortical Area on Central Pain After Spinal Cord Injury

Kang BS, Shin HI, Bang MS. Effect of repetitive transcranial magnetic stimulation over the hand motor cortical area on central pain after spinal cord injury.ObjectiveTo evaluate the analgesic effect of repetitive transcranial magnetic stimulation (rTMS) applied on the hand motor cortical area in patients with spinal cord injury (SCI) who have chronic neuropathic pain at multiple sites in the body, including the lower limbs, trunk, and pelvis.DesignBlinded, randomized crossover study.SettingUniversity hospital outpatient setting.ParticipantsPatients (N=13) with motor complete or incomplete SCI and chronic central pain (11 completed the study).InterventionsrTMS was applied on the hand motor cortical area using a figure-of-eight coil. One thousand stimuli were applied daily on 5 consecutive days. Real and sham rTMS were separated by 12 weeks.Main Outcome MeasuresNumeric rating scale (NRS) for average and worst pain and the Brief Pain Inventory (BPI).ResultsAt 1 week after the end of the rTMS period, the average NRS scores changed from 6.45±2.25 to 5.45±1.81 with real stimulation and from 6.18±1.83 to 5.91±2.07 with sham stimulation, and did not differ between treatments. The interference items of the BPI also did not differ between the real and sham rTMS. The effect of time on the NRS score for worst pain was significant with real stimulation but not with sham stimulation.ConclusionsThe therapeutic efficacy of rTMS was not demonstrated when rTMS was applied to the hand motor cortical area in patients with chronic neuropathic pain at multiple sites in the body, including the lower limbs, trunk, and pelvis. However, the results for worst pain reduction suggest that further studies are required in which rTMS is applied with a more intensive stimulation protocol.