Yonago Acta medica 2003;46:18
Effects of Microgravity on Cerebral Hemodynamics
Yasuaki Kawai, Mitsuru Doi, Akira Setogawa, Reiko Shimoyama, Keigo Ueda, Yasumasa Asai and Kyoko Tatebayashi
Division of Adaptation Physiology, Department of Functional, Morphological and Regulatory
Science, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503 Japan
After centuries of wonder, human being finally realized the decisive possibility of going to the moon a little more than 50 years ago, and in 1969 this became a reality, no longer a dream. The human body, however, is designed to live under 1 g as on Earth. Thus, it is important to understand what happens in the human body under microgravity in order to make rapid progress in space development. One of the most serious problems produced by microgravity is a fluid shift from lower to upper body. This cephalad fluid shift may change the hemodynamics in the brain. In this review, effects of actual or simulated microgravity on cerebral blood flow, intracranial pressure, formation of brain edema, and orthostatic intolerance will be discussed. These studies provide us lots of information not only to maintain the health of astronauts but also to treat senile persons who, on rare occasions, sit or stand up.
Key words: brain edema; cerebral circulation; head-down tilt; intracranial pressure; microgravity