Tuesday, 12 December, 2017

Spending time in space may cause astronauts' brains to float upward

Using MRI scans Dr Roberts evaluated brain changes both during and after long-term bed rest. Results confirmed brain changes occurred during bed rest Spending time in space may cause astronauts' brains to float upward
Theresa Hayes | 02 November, 2017, 14:34

Researchers continue to study the cognitive effects of the narrowing of the central sulcus and suggest we might have to fake gravity during interplanetary missions to avoid affecting health.

In the 55 years since NASA astronaut John Glenn became the first American to orbit the Earth, technological advancements and public-private commercial partnerships have boosted the public's confidence in both discovery missions and space tourism.

The New England Journal of Medicine study examined 34 astronauts, looking at their brains through an MRI before and after space travel.

Cerebrospinal fluid helps the brain maintain normal function, and any disruptions in its balance can causes changes in brain function, said Donna Roberts, lead author of the study and associate professor at the Medical University of SC. Astronauts often complain of increased pressure in the head during missions, as well as changes in vision. NASA has dubbed the phenomenon "visual impairment and intracranial pressure" syndrome, or VIIP. Though scientists believe the syndrome is related to the flow of body fluid toward the head that results from prolonged exposure to microgravity, the exact cause is unclear. Roberts' research aimed to get to the bottom of what the cause of VIIP actually is.

Roberts, who previously worked at NASA, was anxious about the lack of data on how the human brain adapts to microgravity. "These are the questions that we are interested in addressing, especially what happens to the human brain and brain function", Dr Roberts said.

And since a round-trip to Mars is likely to take at least three years, scientists are now questioning whether such a mission would be desirable - or even possible, if the astronauts were inflicted by severe brain damage.

Dr Roberts used MRI scans to evaluate the motor cortex - which controls voluntary muscular activity - before, during and after the bed rest.

And a narrowing of the cerebrospinal fluid spaces at the vertex, the top of the skull, was apparent in 12 long-term astronauts but only one of the short-term astronauts. "What's going on?" Dorit Donoviel, the interim director of the Translational Research Institute for Space Health, who was not involved in the study, tells The Verge.

"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.

In further tests, Roberts acquired brain MRI scans and related data from NASA on two groups of astronauts: 18 who had been in space for short periods of time, and 16 who had been in space for longer durations - typically three months.

Brain images taken before and after spaceflight. Second, participants' brains were shifting, and the space between the top of the brain and the skull decreased.

While astronauts make up only a tiny percent of VIIP patients in the world, knowing about the impact of space travel on the brain does have some practical function. "Our results highlight the importance of brain imaging of astronauts on long-duration missions, not only when they return to Earth but also over time back on Earth to assess whether or not these structural changes are persistent or return to baseline".