Cerebellar Repetitive Transcranial Magnetic Stimulation and Noisy Galvanic Vestibular Stimulation Change Vestibulospinal Function

Akiyoshi Matsugi; Shinya Douchi; Rikiya Hasada; Nobuhiko Mori; Yohei Okada; Naoki Yoshida; Satoru Nishishita; Koichi Hosomi; Youichi Saitoh

doi:10.3389/fnins.2020.00388

Cerebellar Repetitive Transcranial Magnetic Stimulation and Noisy Galvanic Vestibular Stimulation Change Vestibulospinal Function

Front Neurosci. 2020 Apr 28:14:388. doi: 10.3389/fnins.2020.00388. eCollection 2020.

Authors

Akiyoshi Matsugi¹, Shinya Douchi², Rikiya Hasada³, Nobuhiko Mori^{4

5}, Yohei Okada^{6

7}, Naoki Yoshida^{8

9}, Satoru Nishishita^{8

9}, Koichi Hosomi^{4

5}, Youichi Saitoh^{4

5}

Affiliations

¹ Faculty of Rehabilitation, Shijonawate Gakuen University, Daito, Japan.
² Department of Rehabilitation, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
³ Department of Rehabilitation, Nagahara Hospital, Higasiosaka, Japan.
⁴ Department of Neuromodulation and Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan.
⁵ Department of Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan.
⁶ Faculty of Health Sciences, Kio University, Koryo, Japan.
⁷ Neurorehabilitation Research Center, Kio University, Koryo, Japan.
⁸ Institute of Rehabilitation Science, Tokuyukai Medical Corporation, Toyonaka, Japan.
⁹ Kansai Rehabilitation Hospital, Toyonaka, Japan.

Abstract

Background: The cerebellum strongly contributes to vestibulospinal function, and the modulation of vestibulospinal function is important for rehabilitation. As transcranial magnetic stimulation (TMS) and electrical stimulation may induce functional changes in neural systems, we investigated whether cerebellar repetitive TMS (crTMS) and noisy galvanic vestibular stimulation (nGVS) could modulate vestibulospinal response excitability. We also sought to determine whether crTMS could influence the effect of nGVS.

Methods: Fifty-nine healthy adults were recruited; 28 were randomly allocated to a real-crTMS group and 31 to a sham-crTMS group. The crTMS was conducted using 900 pulses at 1 Hz, while the participants were in a static position. After the crTMS, each participant was allocated to either a real-nGVS group or sham-nGVS group, and nGVS was delivered (15 min., 1 mA; 0.1-640 Hz) while patients were in a static position. The H-reflex ratio (with/without bilateral bipolar square wave pulse GVS), which reflects vestibulospinal excitability, was measured at pre-crTMS, post-crTMS, and post-nGVS.

Results: We found that crTMS alone and nGVS alone have no effect on H-reflex ratio but that the effect of nGVS was obtained after crTMS.

Conclusion: crTMS and nGVS appear to act as neuromodulators of vestibulospinal function.

Keywords: H-reflex; cerebellum; galvanic vestibular stimulation; transcranial magnetic stimulation; vestibular.