Different effects of I-wave periodicity repetitive TMS on motor cortex interhemispheric interaction

Frontiers in Neuroscience

Neuroscience

Dongting Tian¹  Shin-Ichi Izumi² 

[1] Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Japan;Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Japan;Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan;

关键词: I-wave;    neural plasticity;    interhemispheric interaction;    neural circuits;    motor cortex;    transcranial magnetic stimulation;    neuromodulation;   

DOI  :  10.3389/fnins.2023.1079432

 received in 2022-10-26, accepted in 2023-06-12,  发布年份 2023

来源: Frontiers

【 摘 要 】

BackgroundActivity of the neural circuits in the human motor cortex can be probed using transcranial magnetic stimulation (TMS). Changing TMS-induced current direction recruits different cortical neural circuits. I-wave periodicity repetitive TMS (iTMS) substantially modulates motor cortex excitability through neural plasticity, yet its effect on interhemispheric interaction remains unclear.ObjectiveTo explore the modulation of interhemispheric interaction by iTMS applied in different current directions.Materials and MethodsTwenty right-handed healthy young volunteers (aged 27.5 ± 5.0 years) participated in this study with three visits. On each visit, iTMS in posterior–anterior/anterior–posterior direction (PA-/AP-iTMS) or sham-iTMS was applied to the right hemisphere, with corticospinal excitability and intracortical facilitation of the non-stimulated left hemisphere evaluated at four timepoints. Ipsilateral silent period was also measured at each timepoint probing interhemispheric inhibition (IHI).ResultsPA- and AP-iTMS potentiated cortical excitability concurrently in the stimulated right hemisphere. Corticospinal excitability of the non-stimulated left hemisphere increased 10 min after both PA- and AP-iTMS intervention, with a decrease in short-interval intracortical facilitation (SICF) observed in AP-iTMS only. Immediately after the intervention, PA-iTMS tilted the IHI balance toward inhibiting the non-stimulated hemisphere, while AP-iTMS shifted the balance toward the opposite direction.ConclusionsOur findings provide systematic evidence on the plastic modulation of interhemispheric interaction by PA- and AP-iTMS. We show that iTMS induces an interhemispheric facilitatory effect, and that PA- and AP-iTMS differs in modulating interhemispheric inhibition.

【 授权许可】

Unknown   
Copyright © 2023 Tian and Izumi.