Floating in zero gravity can put quite the squeeze on the human brain, according to a study published in the New England Journal of Medicine on Wednesday.
Researchers scanned astronauts’ brains using magnetic resonance imaging before and after varying lengths of space missions. The MRI scans revealed brain changes in a majority of the astronauts who returned from long-term spaceflight missions.
“There appears to be increased cerebrospinal fluid and an upward shift of the brain within the skull,” wrote Rachael Seidler, a professor at the University of Florida’s department of applied physiology and kinesiology, in an email.
“Similar to our recent findings, there are spaceflight duration effects,” she said. “This additional cerebrospinal fluid ‘squeezes’ the brain, making the space between brain regions appear smaller. It will be important to follow this up with additional studies to examine how long lasting these changes are.”
She said, “We hypothesize that upward brain shift and expansion of tissue along the top of the brain may in result in compression of adjacent venous structures along the top of the head,” she said.
“We suspect that this may ultimately result in a decrease in the outflow of (cerebrospinal fluid) and blood from the head.”