Neurological complications in microgravity and long duration spaceflight

Long-duration spaceflight produces structural, functional, and hemodynamic brain changes driven by microgravity, radiation, elevated CO2, and isolation. Consequences include Spaceflight-Associated Neuro-Ocular Syndrome, vestibular imbalance, orthostatic intolerance, and cognitive disturbance. We consolidate current evidence, present a cerebrovascular physiologic framework, and discuss emerging countermeasures-including lower body negative pressure, artificial gravity, advanced neuromonitoring, and synthetic torpor-needed to safeguard neurological health on exploration-class missions.