Markham CH, Diamond SG.
Aviat Space Environ Med. 1991 May; 62: 459.
Department of Neurology, UCLA School of Medicine 90024-1769.
INTRODUCTION: The hypothesis of asymmetric otolith function asserts that physiological or anatomical differences in the two sides of the bilateral gravity-sensing otolith apparatus of the inner ear may be well compensated on earth, but when such a system is exposed to novel gravitational states, the prior compensatory strategems may be ineffective, leading to unstable vestibular responses and causing the phenomenon of space motion sickness (SMS). METHODS: Spontaneous eye torsion, a reflex governed by the otolith organs, was examined in the upright position during the hypo- and hypergravity of parabolic flight aboard NASA's KC-135 aircraft in 12 former astronauts whose history of SMS was revealed after data analysis had been completed. Eye torsion was measured with a photographic method accurate to 0.1 degree. RESULTS: Astronauts who had been sick in space had significantly higher scores (p = 0.01) of disconjugate eye torsion in parabolic flight, and their responses were consistently different in 1.8 G relative to 0 G compared to astronauts [correction of astronautes] who had not been sick in space. In 1 G testing, there were no differences in disconjugate eye torsion between the subjects. CONCLUSIONS: The highly significant differences in disconjugate eye torsion aboard the KC-135 in astronauts who had been sick in space and those who had not offers a practical method of determining which prospective astronauts would benefit from preflight adaptation training or anti-motion sickness medication. The support of the asymmetry hypothesis provides insight into the etiology of SMS and its differences from ground-based motion sickness.
Publication Types:
Keywords:
- Astronauts
- Ear, Inner
- Eye
- Eye Diseases
- Eye Movements
- Gravity Perception
- Hypergravity
- Longitudinal Studies
- Motion Sickness
- Otolithic Membrane
- Reflex
- Research Design
- Space Motion Sickness
- instrumentation
- methods
- NASA Discipline Neuroscience
- NASA Discipline Number 16-10
- NASA Program Space Physiology and Countermeasures
- Non-NASA Center
Other ID:
UI: 102212715
From Meeting Abstracts