# Preliminary evidence of high prevalence of cerebral microbleeds in astronauts with spaceflight experience

## TL;DR

Astronauts who have spent time in space may have a higher risk of cerebral microbleeds, which could be linked to long-term health effects.

## Contribution

This study provides preliminary evidence of increased cerebral microbleed prevalence in astronauts after spaceflight.

## Key findings

- Astronauts with prior spaceflight experience showed higher-than-expected microbleed prevalence.
- No statistically significant increase in microbleed burden was observed up to 7 months post-flight.
- Spaceflight may indirectly influence microbleed burden over time periods longer than 1 year.

## Abstract

Long-duration spaceflight poses a variety of health risks to astronauts, largely resulting from extended exposure to microgravity and radiation. Here, we assessed the prevalence and incidence of cerebral microbleeds in sixteen astronauts before and after a typical 6-month mission on board the International Space Station Cerebral microbleeds are microhemorrhages in the brain, which are typically interpreted as early evidence of small vessel disease and have been associated with cognitive impairment. We identified evidence of higher-than-expected microbleed prevalence in astronauts with prior spaceflight experience. However, we did not identify a statistically significant increase in microbleed burden up to 7 months after spaceflight. Altogether, these preliminary findings suggest that spaceflight exposure may increase microbleed burden, but this influence may be indirect or occur over time courses that exceed 1 year. For health monitoring purposes, it may be valuable to acquire neuroimaging data that are able to detect the occurrence of microbleeds in astronauts following their spaceflight missions.