Inglesby DC, Antonucci MU, Spampinato MV, et al. - Researchers conducted this cohort study to quantify preflight to postflight changes in the opacification of the paranasal sinuses and mastoid air cells in Space Shuttle astronauts and International Space Station (ISS) astronauts and to ascertain if there are variations between the two groups of astronauts. Participants in the study were 35 NASA astronauts who had flown missions on either the Space Shuttle (n = 17) or the ISS (n = 18). They discovered that exposure to spaceflight conditions on the ISS is correlated with an increased probability for mastoid effusions formation. No connection was found between exposure to spaceflight conditions and changes in paranasal sinus opacification. The drawbacks of this research include lack of knowledge about medical history and mission-specific operational experience for individual astronauts.