Figure 3

Visualization and analysis of MEPs with a custom-made MATLAB® algorithm. (A) Both ipsi- and contralateral MEPs were recorded for left and right motor cortex stimulation. Per limb, 4 stimuli were given and consequently 4 MEPs were recorded. Stimulation intensities ranged between 0–60 V for the forelimbs and 0–100 V for the hindlimbs. Based on the guidelines, the motor threshold was defined as the lowest stimulus intensity of motor cortex stimulation required to elicit at least 3 MEPs of similar shape⁵. (B) At motor threshold, response onset (point 1), maximal and minimal peaks (point 2 and 3) and the end of the response (point 4) were defined by 3 independent and blinded observers. These measurements were then used to calculate latency, area-under-the-curve, peak-to-peak and duration of each MEP at the motor threshold.