Journal international de médecine physique et de réadaptation
Libre accès

Abstrait

Optimum Stimulation Frequency of High-Frequency Repetitive Transcranial Magnetic Stimulation for Upper-Limb Function in Healthy Subjects

Motoyuki Watanabe, Toshiki Matsunaga, Yoshihiko Okudera, Mineyoshi Sato, Kazutoshi Hatakeyama, Satoaki Chida, Yusuke Takahashi and Yoichi Shimada

Objective: Because rTMS requires the subject’s head to be immobilized and the subject to maintain the same posture throughout stimulation, stimulation of long duration may induce discomfort. If changing the stimulation parameters can allow the duration of rTMS to be shortened, physical discomfort may decrease. The purpose of this study was to identify the most beneficial stimulation parameters for high-frequency rTMS in terms of the effect on upper-limb function in healthy subjects. Materials and Methods: Forty right-handed healthy volunteers were divided into four groups: three real rTMS groups (5, 10, and 20 Hz rTMS) and one sham group. In the real rTMS groups, 600 impulses were applied at a frequency of 5, 10, or 20 Hz and an intensity of 90% of resting motor threshold. Performance on a peg-board task, tapping task, and grip strength were measured before stimulation, immediately after stimulation, and 20 min after stimulation. Results: All real rTMS groups showed a significant increase in performance on the peg-board task and tapping task after rTMS. There was no significant increase in grip strength in any group. Conclusions: 10-Hz rTMS may improve upper-limb function with a shorter duration of stimulation than rTMS at 5 or 20 Hz. 10-Hz rTMS had the shortest stimulation time, and is recommended as beneficial setting to use with a little discomfort. These results can be used when deciding rTMS stimulation frequency.