A new study sheds light on the potentially severe effects long term space flight can have on the human brain, the consequences of which could affect an astronaut’s vision and more. The study was recently published in the New England Journal of Medicine; it details the brain changes that happen in most astronauts who spend a prolonged amount of time in space. Among those changes is an upward shifting of the brain, as well as greater levels of cerebrospinal fluid.
The changes are most apparent in astronauts who spend a large of amount of time in space versus those who only briefly leave our planet. The cause of the problems is the microgravity environment the astronauts live in, which changes the way fluids work in the body. Fluids from the lower body begin moving upwards to the top of the body; that can result in symptoms in a matter of days.
Those earlier and most apparent symptoms include a thinning of the legs and a puffiness in the face. Astronauts may feel like they have a congested nose, among other things, including temporary symptoms like nausea and dizziness. The bigger effects, though, include a shifting of the brain upward in the skull, leaving less space between the two and causing an expansion of the tissue.
This shifting could cause compression on structures that existence in the top of the brain, possibly disrupting cerebrospinal fluid and blood movements in the region.
Specifically, researchers have noted a narrowing of the central sulcus in affected astronauts’ brains. The majority of long-term space travelers experienced this, whereas only a small number of short-term space travelers had the same results.
Big questions about the effects remain, though, such as whether this narrowing and upward shift would continue to worsen the longer someone spends in a microgravity environment, or whether it will eventually settle and stop progressing. Potential ramifications of these brain changes include something known as VIIP syndrome, otherwise called visual impairment and intracranial pressure. As the name suggestions, affected astronauts suffer altered vision that has been described as similar to advanced aging.