MRI Shows How Astronauts’ Brains Change While in Space

Astronauts go through a variety of physical changes while up in space, like losing bone density, but a new study has found that they also experience changes in the brain after spaceflight.

Researchers at the University of South Carolina, Charleston used MRI to evaluate 18 astronauts’ brains before and after long expeditions, and 16 astronauts’ brains before and after short expeditions. The images were interpreted by researchers who were unaware of the flight time. The researchers compared preflight ventricular volumes to postflight ventricular volumes through “automated analysis of T1-weighted MRI.” The objective was to determine the change in volume of the central nucleus, the volume of the CSF spaces at the vertex, and analyze the “vertical displacement of the brain.”

Seventeen of the 18 long-flight astronauts (who, on average, were in space for 164.8 days) and three out of the 16 astronauts who participated in shorter flights (average flight time was 13.6 days) experienced narrowing of the central nucleus. Cine clips demonstrated an upward shift of the brain after long flights but not in shorter ones. After all long flights, astronauts had narrowed CSF spaces at the vertex, whereas this only occurred in 16 percent of short-flight astronauts. Three of the long-flight astronauts also experienced optic-disk edema and narrowing of the central sulcus.

Although these findings illuminate space’s influence on brain functioning, the researchers emphasize that “further investigation, including repeated post-flight imaging conducted after some time on Earth, is required to determine the duration and clinical significance of these changes.”