Predicting Long-Term After-Effects of Theta-Burst Stimulation on Supplementary Motor Network Through One-Session Response.

Gong-Jun Ji,Chunyan Zhu,Lei Zhang,Tongjian Bai,Jinmei Sun,Junjie Wei,Yanghua Tian,Fengqiong Yu,Xingqi Wu,Pingping Liu,Kai Wang,Dandan Li

doi:10.3389/fnins.2020.00237

Abstract

To understand the neural mechanism of repetitive transcranial magnetic stimulation (rTMS), the after-effects following one session or multiple days of stimulation have been widely investigated. However, the relation between the short-term effect (STE) and long-term effect (LTE) of rTMS is largely unknown. This study aims to explore whether the after-effects of 5-day rTMS on supplementary motor area (SMA) network could be predicted by one-session response. A primary cohort of 38 healthy participants underwent five daily sessions of real or sham continuous theta-burst stimulation (cTBS) on the left SMA. Resting-state functional magnetic resonance imaging (fMRI) data were acquired at the first (before and after the first stimulation) and sixth experimental day. The SMA connectivity changes after the first cTBS and after 5 days of stimulation were defined as STE and LTE, respectively. Compared to the baseline, significant STE and LTE were found in the bilateral paracentral gyrus (ParaCG) after real stimulation, suggesting shared neural correlates of short- and long-term stimulations. Region-of-interest analysis indicated that the resting-state functional connectivity between SMA and ParaCG increased after real stimulation, while no significant change was found after sham stimulation. Leave-one-out cross-validation indicated that the LTE in ParaCG could be predicted by the STE after real but not sham stimulations. In an independent cohort, the after-effects of rTMS on ParaCG and short- to long-term prediction were reproduced at the region-of-interest level. These imaging evidences indicate that one-session rTMS can aid to predict the regions responsive to long-term stimulation and the individualized response degree.

Highlights

Repetitive transcranial magnetic stimulation is a powerful technique that could noninvasively modulate neural activity in human brain (Allen et al, 2007)
Five measures at baseline were compared within the primary cohort, and no significant difference was found (Table 1)
This study associated the after-effects of short- and long-term Repetitive transcranial magnetic stimulation (rTMS) on supplementary motor area (SMA) network

Summary

Introduction

Repetitive transcranial magnetic stimulation (rTMS) is a powerful technique that could noninvasively modulate neural activity in human brain (Allen et al, 2007). It has been widely used to map brain function of healthy subjects or alleviate clinical symptoms for neuropsychological patients. High variability of rTMS after-effects has been reported in both. Predicting Long-Term rTMS After-Effect neuroscientific and clinical studies (Hamada et al, 2013; Yesavage et al, 2018). Electroencephalography might represent a more thorough reflection of cortical excitability than motor evoked potentials (MEP) (Rocchi et al, 2018). Consistent with this variability in healthy subjects, another study observed that less than half of patients with major depression could achieve symptom remission after days of rTMS treatment (Yesavage et al, 2018). Before rTMS could be recommended as a conventional therapy, more investigations are required to elucidate the neural mechanism and individualized aftereffect prediction

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