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

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

doi:10.3389/fnins.2020.00576

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

Front Neurosci. 2020 Jun 25:14:576. doi: 10.3389/fnins.2020.00576. eCollection 2020.

Authors

Fengyun Yu^{1

2}, Xinwei Tang¹, Ruiping Hu¹, Sijie Liang², Weining Wang², Shan Tian¹, Yi Wu¹, Ti-Fei Yuan^{3

4}, Yulian Zhu¹

Affiliations

¹ Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China.
² School of Kinesiology, Shanghai University of Sport, Shanghai, China.
³ Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
⁴ Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.

Abstract

Objective: 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.

Methods: 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^∗10); and (3) three iTBS sessions with 30-min intervals (iTBS600 × 3^∗30). As washout period, each visit is separated by at least 7 days. We measured the motor cortical excitability changes and intracortical inhibition.

Results: A dose of 1,800 pulses of aiTBS per day is tolerable. The iTBS1800 led to a reduced cortical excitability; whereas iTBS600 × 3^∗10 and iTBS600 × 3^∗30 enhanced cortical excitability to a differential extent. After a total dose of 1,800 pulses, iTBS600 × 3^∗30 exhibited the longer effect and highest percentage of individuals with enhanced cortical excitability.

Conclusion: The results suggest that aiTBS protocols at different time intervals result in different motor cortical excitability after-effects.

Keywords: accelerated; cortical plasticity; motor cortex; stimulation interval; theta burst stimulation.