Vertical Spatial Orientation in Patients with Parkinsonism under the State of Single “Dry” Immersion and a Course of Immersions

The aim of this study was to characterize the vertical spatial orientation of the body in patients with Parkinson’s disease (PD) and healthy young (HY) controls after a single and course action of simulated microgravity in the form of “dry” immersion (DI) using computer stabilometry. After a single 45-min DI session, the trajectory parameters of the common center of pressure (CCP) in PD ( n = 9) and HY ( n = 12) did not change ( p > 0.05), although a slight tendency for them to decrease was noted. The course of seven DI sessions (each 45 min long, within 30 days) in PD patients ( n = 17) did not affect the stabilometry parameters either. The effect of a single DI session did not become more significant by the end of the DI course. The use of Romberg’s test with closing the eyes did not exercise the influence of DI on the stabilometry parameters. At the same time, after the DI session in PD patients, the score on the UPDRS -III scale decreased by 33% ( p < 0.05); muscle rigidity, by 37% ( p < 0.05); tremor, by 27% ( p < 0.05); akinesia, by 30% ( p < 0.05). Thus, there is a discrepancy between the effect of DI on clinimetrically and instrumentally measured variables, which may be due to (1) insufficient complexity of the task, (2) unaccounted influence of DI on the stabilogram trajectory separately in the frontal and sagittal planes, and (3) unaccounted factor in the development of the stabilometric signal in time.