AUTHOR=Yu Fengyun , Tang Xinwei , Hu Ruiping , Liang Sijie , Wang Weining , Tian Shan , Wu Yi , Yuan Ti-Fei , Zhu Yulian 

TITLE=The After-Effect of Accelerated Intermittent Theta Burst Stimulation at Different Session Intervals

JOURNAL=Frontiers in Neuroscience

VOLUME=14

YEAR=2020

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2020.00576

DOI=10.3389/fnins.2020.00576

ISSN=1662-453X

ABSTRACT=<sec><title>Objective</title><p>The study aims to investigate the after-effect of three sessions of intermittent theta-burst stimulation (iTBS) on motor cortical excitability. The iTBS was induced over the primary motor cortex (M1) at different time intervals.</p></sec><sec><title>Methods</title><p>The study has a crossover design. Sixteen participants were assigned to three groups and received different accelerated iTBS (aiTBS) protocols during each visit: (1) three continuous sessions with no interval (iTBS18000); (2) three iTBS sessions with 10-min intervals (iTBS600 × 3<sup>∗</sup>10); and (3) three iTBS sessions with 30-min intervals (iTBS600 × 3<sup>∗</sup>30). As washout period, each visit is separated by at least 7 days. We measured the motor cortical excitability changes and intracortical inhibition.</p></sec><sec><title>Results</title><p>A dose of 1,800 pulses of aiTBS per day is tolerable. The iTBS1800 led to a reduced cortical excitability; whereas iTBS600 × 3<sup>∗</sup>10 and iTBS600 × 3<sup>∗</sup>30 enhanced cortical excitability to a differential extent. After a total dose of 1,800 pulses, iTBS600 × 3<sup>∗</sup>30 exhibited the longer effect and highest percentage of individuals with enhanced cortical excitability.</p></sec><sec><title>Conclusion</title><p>The results suggest that aiTBS protocols at different time intervals result in different motor cortical excitability after-effects.</p></sec>