Spaceflight experience, in particular longer missions and shorter inter-mission recovery time, induce fluid changes in the brain that may not return to normal before subsequent flights, reports a study published in Scientific Reports. Ventricles — cavities in the brain filled with cerebrospinal fluid — expand increasingly with longer spaceflight missions up to six months, and inter-mission intervals of less than three years may not allow sufficient time for the ventricles to fully recover.
Spaceflight induces widespread changes in the human brain including ventricle volume expansion, but it is unclear if these changes differ with varying mission duration or number of previous spaceflight missions. Rachael Seidler and colleagues scanned the brains of 30 astronauts using MRI, pre- and post-spaceflight, including those on two-week missions (eight astronauts), six-month missions (18 astronauts) and longer (four astronauts). They found that longer spaceflight missions resulted in greater ventricular enlargement, which tapered off after six months in space.
They found that there were no statistically reliable associations between the number of previous missions completed and post-fight gray matter volume (GMv) shifts or ventricular volume changes.
