AUTHOR=Geisinger Dario , Elyoseph Zohar , Zaltzman Roy , Mintz Matti , Gordon Carlos R. 

TITLE=Functional impact of bilateral vestibular loss and the unexplained complaint of oscillopsia

JOURNAL=Frontiers in Neurology

VOLUME=Volume 15 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1365369

DOI=10.3389/fneur.2024.1365369

ISSN=1664-2295

ABSTRACT=Introduction. The vestibulo-ocular reflex (VOR) stabilizes vision during head movements. VOR disorders lead to symptoms like imbalance, dizziness, and oscillopsia. Despite similar VOR dysfunction, patients display diverse complaints. This study analyses saccades, balance, and spatial orientation in chronic peripheral and central VOR disorders, specifically examining oscillopsia's impact. Methods. Participants were 15 peripheral bilateral vestibular loss (pBVL), 21 clinically and genetically confirmed Machado-Joseph disease (MJD) patients which also have bilateral vestibular deficit, and 22 healthy controls. All pBVL and MJD participants were tested at least 9 months after the onset of symptoms and underwent a detailed clinical neuro-otological evaluation at the Dizziness and Eye Movements Clinic of the Meir Medical Center.Results. Out of the 15 pBVL and 21 MJD, only 5 pBVL complained about chronic oscillopsia while none of MJD participants reported this complaint. Comparison between groups showed significant differences in vestibular, eye movements, balance and spatial orientation. When comparing oscillopsia with no oscillopsia subjects, significant differences were found in dynamic visual acuity, saccade latency of eye movements and triangle completion test.Discussion. Even though there is a significant VOR gain impairment in MJD with some subjects having less VOR gain than pBVL with reported oscillopsia, no individuals with MJD reported suffering from oscillopsia. This study further supports that subjects suffering from oscillopsia present a real impairment to stabilize the image on the retina, while those without oscillopsia may utilize saccade strategies to cope with it and may also rely on visual information for spatial orientation. Finding objective differences will help understand the causes of the oscillopsia experience and develop coping strategies to overcome it.