The Modulatory Effect of Low-intensity Priming Intermittent Theta Burst Stimulation on Motor Cortex Poststroke: a Concurrent TMS-EEG Study

Background: The optimization of the intensity of priming theta burst stimulation increases the probability of success in a randomized controlled trial. We hypothesize that priming intermittent theta burst stimulation (iTBS) with a low-intensity continuous theta burst stimulation (cTBS) will yield superior effects than our original priming protocol in healthy adults and patients after stroke. Methods: 15 healthy adults and 15 stroke patients will undergo three separate experimental conditions: a low-intensity priming stimulation (55% resting motor threshold \[RMT\] cTBS+70% RMT iTBS), a conventional-intensity priming stimulation (70% RMT cTBS+70% RMT iTBS), and a nonpriming control. The alterations in cortical excitation/inhibition and its impacts on motor behaviors will be evaluated following stimulation. Significance: The findings will inform future clinical trials investigating the optimized priming iTBS in promoting poststroke recovery.