Fig. 1

CMCT and CSP. a To calculate central motor conduction time (CMCT), motor-evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) and magnetic-motor-root stimulation were analyzed. The onset latency of reproducible MEPs was measured for cortical latency and root latency (Cortex and Root). CMCT was calculated according to the following formula: CMCT = cortical latency − root latency. b To measure the cortical silent period (CSP), MEPs elicited by TMS were analyzed, and the figure shows the superimposed MEPs for demonstration. To analyze CSP, peak-to-peak MEP amplitude and CSP ranging from MEP onset to reappearance of electromyographic activities reflecting voluntary contraction were measured for each MEP. A total of eight MEPs were analyzed at each stimulus intensity. All recordings are from the right first dorsal interosseous (FDI) muscle