The work was led by Donna Roberts, Associate Professor at the Medical University of South Carolina and aimed to understand the effects of spaceflight on the structure of the brain. 

MRI scans were used to look at the brains of 18 astronauts on long duration missions aboard the International Space Station, and 16 astronauts on shorter missions aboard the Space Shuttle Program.  

Before and after brain images were used to compare:

• the change in the volume of the central sulcus (the central fissure of the brain separating the parietal lobe from the frontal lobe and the primary motor cortex from the primary somatosensory cortex)
• the change in volume of cerebrospinal fluid (CSF) spaces at the vertex (upper surface of the head)
• and vertical displacement of the brain

The results showed a narrowing of the central sulcus in 94% of astronauts on long duration space flights. This occurred in only 19% of astronauts on shorter missions.

There was also evidence of an upward shift of the brain towards the top of the skull and narrowing of CSF spaces after all long duration flights, but not after short duration flights.

These findings suggest that long duration space flight significantly alters the structure of the human brain. Further work will help to determine the clinical significance of these changes.  

Russian cosmonaut Valery Polyakov holds the record for the longest continuous time in space: 438 days. A mission to Mars would be more than double this.

The research was published last week in the New England Journal of Medicine.

Poster image: MRI scanner, NIMH