Prevention of Cerebrovascular Emergencies in Spaceflight: A Review and a Proposal for Enhanced Medical Screening Guidelines.

Abstract

Purpose of review: A growing number of opportunities for paying customers to travel to space are becoming available. Preflight medical screening of these potential private astronauts will likely be performed by local physicians, with referral to specialists in aerospace medicine as required for more in-depth evaluation before flight qualification. Neurologic concerns contribute a portion of the potential medical risks for these private astronauts, especially with the participation of more diversified crews than traditional governmental astronauts. The objective of this article was to review the current knowledge base concerning cerebrovascular adaptation to spaceflight to inform risk factor assessment for flight-associated cerebrovascular emergencies by the neurologic community when performing initial medical screening of potential private astronauts.

Recent findings: A review of published human spaceflight studies and medical guidelines regarding cerebrovascular risks for spaceflight was conducted. Most of the available literature describes cohorts of a small number of astronauts undergoing spaceflight missions of various flight profiles. While there are gaps in the literature, cerebrovascular adaptation to spaceflight occurs, which may alter the medical risk profile in susceptible individuals. The occurrence of an inflight cerebrovascular emergency could have devastating consequences; therefore, additional screening tests may be required, based on risk level and mission profile, in assessing the more diverse commercial spaceflight population expected over the next decade.

Summary: With increasing interest in commercial space tourism among diverse participant populations, the stroke risk in microgravity/reduced gravity environments is unknown. Furthermore, stresses of rocket ascent/descent, abnormal fluid dynamics in microgravity, altered atmospheric conditions, and other unknown occupational hazards add additional complexity. Because inflight emergency management protocols have yet to be developed, the most effective tool to ensure spaceflight participant safety is comprehensive preflight preventative screenings. Determining neurologic risk factors is critical for developing evidence-based guidelines for preventative measures and treatment protocols in the future.