Original Research ARTICLE
Rebalancing the Vestibular System by Unidirectional Rotations in Patients with Chronic Vestibular Dysfunction
- 1Shaheed Beheshti University, Iran
- 2Day General Hospital, Iran
- 3Department of Communicative Disorders and Sciences, University at Buffalo, United States
Vestibular dysfunction is a common disorder that results in debilitating symptoms. Even after full compensation, the vestibulo-ocular reflex (VOR) could be further improved by using rehabilitation exercises and visual-vestibular adaptation. Here, we describe a rehabilitation method that uses a unidirectional rotation in the dark (i.e., vestibular stimulation) toward the less active side (i.e., low response or LR side) in patients with chronic vestibular dysfunction. We show that the unidirectional rotation rebalances the activity in the vestibular pathway by increasing VOR responses during rotations in the LR direction and simultaneously decreasing the VOR for rotations in the high response (HR) direction. Originally, subjects had VOR asymmetry as measured by a high directional preponderance (DP). To study the short term effect, VOR responses to a sinusoidal rotation were measured before and 10, 40, and 70 min after a single unidirectional rotational rehabilitation session, which took ~ 7 minutes. We observed a significant decrease in VOR asymmetry at all times, as quantified by DP. Long term effects were studied in a second group of patients that were subjected to the rehabilitation 6 times over a 4 week period. Our results show a significant decrease in DP after rehabilitation, which occurred in the first 2 sessions in the majority of cases and was maintained for > 4 weeks in most cases. The improvement in DP over time was due to a decrease in VOR responses during HR rotations and an increase in the responses during LR rotations. Our results show that unidirectional rotation can significantly decrease asymmetries between the two sides even in chronically compensated patients and could be used as an effective supervised method for vestibular rehabilitation.
Keywords: Compensation, Vestibulo-ocluar reflex, Rehabilitation, Directional preponderance, Unidirectional Rotation
Received: 30 Sep 2018;
Accepted: 31 Dec 2018.
Edited by:Alexis Bozorg Grayeli, Centre Hospitalier Regional Universitaire De Dijon, France
Reviewed by:Kathleen Cullen, McGill University, Canada
Eric Anson, University of Rochester, United States
Copyright: © 2018 Sadeghi, Sabet Azad, Rassaian and Sadeghi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Soroush G. Sadeghi, University at Buffalo, Department of Communicative Disorders and Sciences, Buffalo, United States, email@example.com