The effect of previous spaceflight on otolith-mediated ocular counter-roll in Cosmonauts after long duration spaceflight

Paper number

IAC-21,B3,9-GTS.2,8,x66413

Author

Mrs. Catho Schoenmaekers, Belgium, University of Antwerp

Coauthor

Prof. Ludmila Kornilova, Russian Federation, Institute of Biomedical Problems (IBMP), Russian Academy of Sciences (RAS)

Coauthor

Mr. Dmitrii Glukhikh, Russian Federation, Institute of Biomedical Problems (IBMP), Russian Academy of Sciences (RAS)

Coauthor

Dr. Gilles Clement, France, Centre National de La Recherche Scientifique (CNRS)

Coauthor

Dr. Hamish MacDougall, Australia, The University of Sydney

Coauthor

Prof. Steven Moore, Australia, Central Queensland University

Coauthor

Mr. Steven Jillings, Belgium

Coauthor

Mrs. Chloe De Laet, Belgium, University of Antwerp

Coauthor

Mr. Leander Wille, Belgium, University of Antwerp

Coauthor

Prof.Dr. Floris Wuyts, Belgium, University of Antwerp

Year

2021

Abstract

INTRODUCTION The otolith system plays an essential role in the estimation of verticality, where an otolith driven eye movement, the Ocular Counter-Roll (OCR), is important to ensure gaze stabilization, as the eyes tilt in the opposite direction to the direction of the head tilt. Long duration exposure to microgravity, as experienced aboard the International Space Station (ISS), will cause a deconditioning of the otolith system. As a result, cosmonauts will experience balance disorders and problems with gaze stabilization after returning on Earth. The aim of this study is to measure the effect of long-term spaceflight on the otolith-mediated OCR, in cosmonauts, with focus on the difference between first time flyers versus frequent flyers.

MATERIAL AND METHODS 44 cosmonaut experiments were performed, first time flyers (1F, N=14) and frequent flyers (FF, N=30), were exposed to off-axis centrifugation before and after their 6-month space mission to the ISS. The OCR induced by the Visual and Vestibular Investigation System (VVIS) mini centrifuge was assessed and recorded for 20 seconds at a maximal velocity of 254°/s, out of a total duration of 5 minutes centrifugation. The OCR measurements were further statistically analyzed in SPSS, with p<0,05 as significance threshold. 

RESULTS We found a significant decrease in OCR early postflight (R3/5, three to five days after return) for both the 1F group and the FF group. The post-flight OCR decrease in the 1F group was significantly different from the FF group with a greater reduction in the 1F group. A full recovery was seen nine to eleven days after their return (R9/11).

CONCLUSION The FF group suffered less from a deconditioning of the otoliths, because they may have acquired an adaptation from previous space missions, demonstrating a learning effect. The results argue for that for important missions, e.g. to the Moon or Mars, it is more advisable to send experienced cosmonauts or astronauts because they are noticeably less affected by microgravity regarding the vestibular system.

Abstract document

IAC-21,B3,9-GTS.2,8,x66413.brief.pdf

Manuscript document

IAC-21,B3,9-GTS.2,8,x66413.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.