A new study by the Medical University of South Carolina suggests long periods of time in space can affect the brains of astronauts.

For the study, published in the New England Journal of Medicine, participants stayed in bed for 90 days with their heads tilted in a downward position to simulate the effects of microgravity.

Neuroradiologist Dr. Donna Roberts used MRIs to examine their brains and muscular responses before, during and after the period of bed rest.

She found “crowding” at the top and back of the brain, in which the bumps and depressions in the brain narrowed. The crowding was more pronounced during longer periods of bed rest.

Roberts then got scans of astronauts from NASA and saw similar narrowing and shifting in the brains of many of those who had been in long-duration space missions.

During extended periods of time without gravity, fluids in the body shift toward the head, explained Lauren Sergio, a professor at the School of Kinesiology and Health Science at Toronto’s York University. She was not affiliated with the study.

Sergio said on Earth, gravity “pulls things down to our toes,” but in space things move more freely. Without gravity to hold down the brain and its fluids, it gathers at the top and back, creating pressure on parts of the brain that control vision, spatial awareness and hand-eye co-ordination.

She uses the analogy of being in a skiing accident and bumping your head, with internal bleeding putting pressure on the brain.

But that said, “the human body is really good at adapting,” Sergio noted.

Many astronauts — including Scott Kelly, who spent 340 days in space — have complained about vision problems upon return to Earth.

More research is needed to determine whether the changes in the brain stabilize or progress, the study notes. Increased understanding of how the human body, including the brain, is affected by long-term space travel is especially relevant as scientists work toward the possibility of a journey to Mars, which could take up to six months.
Photo: NASA astronaut Sunita Williams raises her hand during a mission in space. Researchers are trying to better understand the effects of staying in space for long periods of time on the brain. (NASA via Getty Images)

http://www.cbc.ca/news/health/second-opinion-november-4-2017-1.4387438Original article at: