Repetitive transcranial magnetic stimulation (rTMS)
Repetitive magnetic stimuli were delivered for 15 min at a rate of 1 Hz and with an intensity of 115% rMT to the contralateral (e.g. left) hemisphere of M1 via an air-cooled figure of eight coil (MCF-B65, Tonica Elektronik A/S, Farum, Denmark) connected to a Magstim stimulator (MagPro X100 with MagOption, MagVenture A/S, Farum, Denmark). The hot-spot to elicit motor evoked potentials (MEPs) in the SOL was marked (with color directly on the scalp) and the coil was fixed tangentially to the scalp by a mechanical mount. To facilitate the mounting, the coil was aligned straight over the head and the current flow had an anterior–posterior direction. RMT was afterwards defined in a seated position as the intensity that triggered MEPs peak-to-peak amplitudes greater than 50 µV in at least 5 out of 10 trials. For the sham-rTMS group the procedure was the same except that the coil was placed orthogonally to the scalp. Thus, the side of one winding touched the scalp but the TMS pulses were not able to stimulate the brain. All TMS measurements were conducted in compliance with safety recommendations