Dataset of ipsilateral motor-evoked potentials induced by transcranial magnetic stimulation

The dataset includes 4244 trials of EMG recordings after ipsilateral TMS under muscle contraction. This data was used for the evaluation of the DiMEP toolbox https://pypi.org/project/dimep/

All subjects provided written, informed consent before participation and following approval by the local ethics committee. Subjects had no contraindications to TMS. TMS was delivered with a MagVenture MagPro-R30 with MagOption and a MCF-B70 figure 8-coil at an orientation of 45° to the midsagittal plane (see figure 1A). First, the motor hotspot of the contralateral, i.e., right, extensor digitorum communis (EDC) was determined by applying 40 stimuli to the left hemisphere. 40% MSO was used as the starting intensity and increased in steps of 5% MSO in case no MEPs could be elicited. Next, at the locations of the three stimuli that resulted in the greatest MEP, i.e., the largest MEP peak-to-peak amplitude, additional three stimuli were applied. The stimulation location that consistently elicited the largest MEPs in the contralateral EDC was then selected as the hotspot. A neuro-navigation system (TMS Navigator, Localite GmbH, Germany) supported coil positioning throughout the measurements. In order to measure ipsilateral MEPs, TMS pulses were applied to the motor hotspot with 5s ± 1.25 s between pulses (at an intensity of 90% MSO). To increase the likelihood of exhibiting ipsilateral MEPs, subjects were requested to isometrically contract their left biceps brachii (BB) to 30% of its maximum voluntary contraction while receiving visual feedback of the BB activity relative to the required target level of contraction on a computer display. The electromyographical response (EMG) to TMS was recorded with a BrainProducts ExG bipolar amplifier from the ipsilateral EDC. All trials were divided into 1s segments, i.e., 500 ms before and after each TMS pulse, and sampled at 1000 Hz.