Expert with first aerospace neurology program in US talks astronaut health as two return

The long-awaited return of astronauts Butch Wilmore and Suni Williams from the International Space Station means they can start recovering from the physical effects of their time in zero gravity. The impact of space travel on the human body is an area of intense focus for some scientists and physicians, including those at the Medical University of South Carolina’s Aerospace and Human Performance Neurology Program. 

Mark Rosenberg, M.D., leads that effort.He was watching closely as Wilmore and Williams’ trip, which was expected to last about a week, turned into a stay of more than 280 days on the space station after their spacecraft developed technical problems. “From a physiologic standpoint, there are things to consider when you go from a mission that's less than two weeks to something that was much, much longer in duration,” Rosenberg said.

He described some of the changes the body undergoes in space. “The extra height is probably the first thing that people complain about. Without gravity pulling you down, the little gel between the bones and your back actually stretches. So when astronauts get up there, one of the very first things they complain about is back pain. The other thing is the puffy face,” Rosenberg said.

“So puffy face and chicken leg syndrome is what happens when you don't have gravity acting on the cardiovascular system and pulling all this blood down to your legs. And so that blood starts traveling upward. Eventually over time, your body actually starts getting rid of that extra fluid. So astronauts will start urinating quite a bit more.”

 

Astronauts can also undergo vision changes. “We've been doing a lot of research for a number of years at MUSC on this. Donna Roberts, now a deputy chief scientist with ISS National Labs, and I have looked into this vision issue, which is called SANS, or spaceflight-associated neuro-ocular syndrome. It's a blurring of your vision that is variable in intensity that happens in around 70% of astronauts that have been in space for at least two weeks. It's a commonly accepted complication that can happen to the point where astronauts are sent with multiple pairs of glasses, in fact.”

Other areas of research in the Aerospace and Human Performance Neurology Program at MUSC include circadian dysregulation, musculoskeletal injury, issues with vessels that supply blood to the brain and the effects of microgravity on the nervous system.

Rosenberg said his team knows that the makeup of the people who go into space is changing. 

“Previous astronauts have been fighter pilots, you know, five-minute-mile types. But now we're looking at, especially in the commercial space flight realm, people who might be relatively healthy, but they're not going to be tip-of-the-spear fitness folks like before.”

That means some of them may have underlying health conditions that could be affected by their time in space. 

“There's a necessity to make sure that we have appropriate standards now that we're starting to have increased players in space flight, especially transport services with commercial entities starting to send people up. We need to make sure that there's standardization so that we don't have potential fatalities or complications that might affect human health. Ultimately, we need to make something that is inherently dangerous as safe as possible.”

Inherently dangerous – and important and amazing enough to keep attracting top-notch astronauts such as Wilmore and Williams. For now, the focus is on their health. 

“There's a couple of different phases as far as coming back to Earth goes. The first is the immediate, and that is making sure that their vitals, like heart rate, are OK. And one of the big reasons for that is their cardiovascular system just decompensates in space. It's not dealing with the push and the pull of gravity. And of course, going along with that is your brain not getting adequate blood flow,” Rosenberg said.

“Then once they get their typical numbers checked off as far as all their blood work and their vitals, the hard work of rehabilitation begins. That's going to be cardiovascular rehabilitation; neuro vestibular rehabilitation, where you work on the coordination centers in the inner ear; and musculoskeletal rehabilitation because astronauts will lose bone density and muscle density, despite best practices of weightlifting with what's called the ARED, which is this weightlifting device that's on the ISS, they still have a loss of muscle and bone.”

Rosenberg said he’s glad Wilson and Williams’ journey has finally come to an end. “Anytime we're able to recover from an unexpected mission is always a good thing, right? Yeah. Of course there's an opportunity to learn no matter what you do. And that's one of the beauties of space. Because it is still science-based. Of course, the circumstances by which it occurred weren’t ideal. But the fact that they were able to head home safely is great.”