[Effect of long-term microgravity on the vestibular function].

Comprehensive computerized oculomotor testing was used to investigate the vestibular function in 9 Russian members of ISS crews 3-9 on days 1 (2), 4 (5) and 8 (9) of return from long-term stay in microgravity (126 to 195 days). The vestibular function was assessed by the static otolith-cervical-ocular reflex, dynamic otolith-cervical-ocular reactions, vestibular reactivity, and spontaneous oculomotor activity. The postflight investigations revealed functional disorders in the peripheral (an increased vestibular reactivity, absent or damped otolith-cervical-ocular reflex), and central (spontaneous typical and atypical nystagmus, gaze nystagmus) vestibular analyzer. The pattern and extent of vestibular disorders after long-term exposure in microgravity were individual by character; however, some of the vestibular reactions, including disappearance or considerable damping of the static otolith-cervical-ocular reflex, exaggerated vestibular reactivity and spontaneous eye movements, displayed consistency.