Effects of anodal transcranial direct current stimulation on motor evoked potentials variability in humans

In this study, 32 healthy subjects received anodal tDCS stimulation over the left M1 for three durations (tDCS ‐T5, tDCS‐T10, and tDCS‐T20 min) on separate days in a crossover‐randomized order. After the resting motor threshold (RMT) was determined for the contralateral first dorsal interosseous muscle, 15 single pulses 4–8 sec apart at an intensity of 120% RMT were delivered to the left M1 to de termine the baseline MEP amplitude at T0, T5, T10, T20, T30, T40, T50, and T60 min after stimulation for each durations. During TMS delivery, 3D images of the participant's cortex and hot spot were visualized for obtaining MEPs from same position. Our findings revealed that there was a significant MEPs improvement at T0 (P = 0.01) after 10 min of anodal stimulation. After the 20‐min stimulation duration, MEPs differed specifically at T0, T5, T30 min (P <  0.05). This indicates that tDCS is a promising tool to improve MEPs. Our observed variability in response to the tDCS protocol is consistent with other noninvasive brain stimulation studies.

Source: Physiological Reports - July 11, 2019 Category: Physiology Authors: Shahid Bashir, Shafiq Ahmad, Moath Alatefi, Ali Hamza, Mohamed Sharaf, Shirely Fecteau, Woo Kyoung Yoo Tags: Original Research Source Type: research