Observational Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Apr 26, 2020; 12(4): 144-154
Published online Apr 26, 2020. doi: 10.4330/wjc.v12.i4.144
Autonomic laterality in caloric vestibular stimulation
Mohammadreza Aghababaei Ziarati, Mohammad Hosein Taziki, Seyed Mehran Hosseini
Mohammadreza Aghababaei Ziarati, Department of Internal Medicine, Medical Faculty, Golestan University of Medical Sciences, Gorgan 4934174515, Golestan, Iran
Mohammad Hosein Taziki, Department of Otolaryngology, Medical Faculty, Golestan University of Medical Sciences, Gorgan 4934174515, Golestan, Iran
Seyed Mehran Hosseini, Department of Physiology, Medical Faculty, Golestan University of Medical Sciences, Gorgan 4934174515, Golestan, Iran
Seyed Mehran Hosseini, Neuroscience Research Center, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan 4934174515, Golestan, Iran
Author contributions: Hosseini SM designed the research, performed the data collection, analysed data, wrote the paper; Aghababaei Ziarati M searched the literature, performed the data collection, contributed to manuscript preparation; Taziki MH did clinical examination of the participants, contributed to data collection and edited the manuscript.
Supported by the Golestan University of Medical Sciences of Iran, No. 961103.
Institutional review board statement: This observational study was confirmed by the institutional review board standards at the Golestan University of Medical Sciences, Gorgan, Iran.
Informed consent statement: All participants were informed about the study and assigned the informed consent.
Conflict-of-interest statement: All authors declare that they have no competing interests.
Data sharing statement: No additional data are available.
STROBE statement: This study is presented as suggested by the STROBE statement, i.e., according to the guidelines for reporting observational studies.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Seyed Mehran Hosseini, MD, PhD, Associate Professor, Department of Physiology, Neuroscience Research Center, Gorgan Faculty of Medicine, Golestan University of Medical Sciences, Shastkola, Gorgan 4934174515, Golestan, Iran. hosseini@goums.ac.ir
Received: December 24, 2019
Peer-review started: December 24, 2019
First decision: February 20, 2020
Revised: March 12, 2020
Accepted: March 26, 2020
Article in press: March 26, 2020
Published online: April 26, 2020
ARTICLE HIGHLIGHTS
Research background

The caloric vestibular stimulation provides the opportunity for isolated and unilateral activation of the vestibular system. Therefore, it may be very helpful as a model for comparison of the effect of vestibulo-autonomic reflex on cardiovascular system and for exploration of differences between the right and the left sides.

Research motivation

There is very limited information about the autonomic laterality. The autonomic effects of vestibular system are well documented but the reports about the laterality of vestibular effect on cardiovascular system is rare.

Research objectives

To compare the effect of the caloric test on the cardiac sympathovagal tone and to study any difference between the autonomic effects of the right and the left side caloric vestibular stimulations.

Research methods

This self-control study was conducted on 12 healthy male volunteers. The minimal ice water caloric test was applied for vestibular stimulation in the optimum and in the pessimum positions for each side. The time domain and the frequency domain indices of the heart rate variability were used as markers of cardiac sympathovagal tone.

Research results

Caloric test induced nystagmus and vestibular stimulation in the optimum positions but had no effect on blood pressure, average heart rate and heart rate variability.

Research conclusions

The minimal ice water caloric test was well tolerable, provided inadequate vestibular autonomic stimulation and may have introduced a model for studying the concept of the laterality of vestibulo-autonomic reflex.

Research perspectives

The vestibular and the autonomic system may have different sensitivity to caloric stimulation and the irritation with more volume of cold water or in longer duration e.g., more than a few seconds may cause adequate autonomic vestibular stimulation.