MY CONTENT

Brain MR imaging scans of National Aeronautics and Space Administration astronauts were retrospectively analyzed to quantify pre- to postflight changes in brain structure. Local structural changes were assessed using the Jacobian determinant. Structural changes were compared with clinical findings and cognitive and motor function. Long-duration spaceflights aboard the International Space Station, but not short-duration Space Shuttle flights, resulted in a significant increase in the percentage of total ventricular volume change (10.7% versus 0%). The percentage of total ventricular volume change was significantly associated with mission duration but negatively associated with age. Pre- to postflight structural changes of the left caudate correlated significantly with poor postural control, and the right primary motor area/midcingulate correlated significantly with a complex motor task completion time. These findings suggest that brain structural changes are associated with changes in cognitive and motor test scores and with the development of spaceflight-associated neuro-optic syndrome.