Dynamic Ocular Counterrolling

Vestibular and Visual Control on Posture and Locomotor Equilibrium ◽

10.1159/000410334 ◽

2015 ◽

pp. 246-250 ◽

Cited By ~ 2

Author(s):

Charles H. Markham ◽

Shirley G. Diamond

Keyword(s):

Ocular Counterrolling

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Ocular counterrolling as an indicator of vestibular otolith function

Neurology ◽

10.1212/wnl.33.11.1460 ◽

1983 ◽

Vol 33 (11) ◽

pp. 1460-1460 ◽

Cited By ~ 121

Author(s):

S. G. Diamond ◽

C. H. Markham

Keyword(s):

Otolith Function ◽

Ocular Counterrolling

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Decreased otolith-mediated vestibular response in 25 astronauts induced by long-duration spaceflight

Journal of Neurophysiology ◽

10.1152/jn.00065.2016 ◽

2016 ◽

Vol 115 (6) ◽

pp. 3045-3051 ◽

Cited By ~ 23

Author(s):

Emma Hallgren ◽

Ludmila Kornilova ◽

Erik Fransen ◽

Dmitrii Glukhikh ◽

Steven T. Moore ◽

...

Keyword(s):

Orthostatic Intolerance ◽

Balance Control ◽

Head Tilt ◽

Otolith Organs ◽

Negative Effects ◽

Spatial Disorientation ◽

Long Duration ◽

Before And After ◽

Ocular Counterrolling ◽

Otolith System

The information coming from the vestibular otolith organs is important for the brain when reflexively making appropriate visual and spinal corrections to maintain balance. Symptoms related to failed balance control and navigation are commonly observed in astronauts returning from space. To investigate the effect of microgravity exposure on the otoliths, we studied the otolith-mediated responses elicited by centrifugation in a group of 25 astronauts before and after 6 mo of spaceflight. Ocular counterrolling (OCR) is an otolith-driven reflex that is sensitive to head tilt with regard to gravity and tilts of the gravito-inertial acceleration vector during centrifugation. When comparing pre- and postflight OCR, we found a statistically significant decrease of the OCR response upon return. Nine days after return, the OCR was back at preflight level, indicating a full recovery. Our large study sample allows for more general physiological conclusions about the effect of prolonged microgravity on the otolith system. A deconditioned otolith system is thought to be the cause of several of the negative effects seen in returning astronauts, such as spatial disorientation and orthostatic intolerance. This knowledge should be taken into account for future long-term space missions.

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