Relationships between changes in lateral vestibulospinal tract excitability and postural control by dynamic balance intervention in healthy individuals: A preliminary study

Tomoyuki Shiozaki; Yohei Okada; Junji Nakamura; Kozo Ueta; Hiroaki Tanaka; Mako Moritani; Tadashi Kitahara

doi:10.3389/fnhum.2023.1109690

Relationships between changes in lateral vestibulospinal tract excitability and postural control by dynamic balance intervention in healthy individuals: A preliminary study

Front Hum Neurosci. 2023 Feb 1:17:1109690. doi: 10.3389/fnhum.2023.1109690. eCollection 2023.

Authors

Tomoyuki Shiozaki¹, Yohei Okada^{2

3}, Junji Nakamura^{3

4}, Kozo Ueta^{3

5}, Hiroaki Tanaka^{6

7}, Mako Moritani⁸, Tadashi Kitahara¹

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, Kashihara, Japan.
² Neurorehabilitation Research Center of Kio University, Nara, Japan.
³ Graduate School of Health Sciences, Kio University, Nara, Japan.
⁴ Department of Rehabilitation, Nishiyamato Rehabilitation Hospital, Nara, Japan.
⁵ Department of Rehabilitation, Shiga Hospital, Shiga, Japan.
⁶ Department of Physical Medicine and Rehabilitation, Kansai Medical University, Osaka, Japan.
⁷ KMU Day-Care Center Hirakata, Kansai Medical University Hospital, Osaka, Japan.
⁸ Department of Faculty of Medicine, Nara Medical University, Nara, Japan.

Abstract

Introduction: We conducted dynamic balance or static intervention on healthy young adults to examine the changes in lateral vestibulospinal tract (LVST) excitability and postural control that ensued following dynamic balance intervention and to investigate the correlation between these changes.

Methods: Twenty-eight healthy young adults were randomly assigned to either the dynamic balance group or the control group. They performed either a dynamic balance or static intervention for 10 trials of 30 s each and were assessed for head jerks during the intervention to confirm adaptation to the intervention. The dynamic balance intervention consisted of maintaining balance on a horizontally unstable surface, whereas the control intervention involved standing in the same foot position as the dynamic balance intervention on a stable surface while completing a maze task. LVST excitability and postural stability were assessed before and after the interventions. LVST excitability was assessed as the change rate in the soleus H-reflex amplitude with galvanic vestibular stimulation (GVSH). The velocity and area of the center of pressure (COP) were examined in the eyes closed/foam rubber condition.

Results: No significant main and interaction effects (task, time) were observed for GVSH and COP variables. In the dynamic balance intervention, head jerk significantly decreased, and GVSH-change and changes in head jerk and COP area were significantly negatively correlated.

Discussion: The LVST excitability change for the dynamic balance intervention varied among the participants, although increased LVST excitability may have been related to increased postural stability.

Keywords: H-reflex; dynamic balance intervention; galvanic vestibular stimulation (GVS); lateral vestibulospinal tract (LVST); postural control.

Grants and funding

This research was funded by the JSPS KAKENHI (Grant no. 19K19800) and the Health Labour Sciences Research (Grant no. 20FC1048). The funding source had no role in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.