The relation of motion sickness to the spatial–temporal properties of velocity storage

摘要: Tilting the head in roll to or from upright while rotating at a constant velocity (roll rotating, RWR) alters position of semicircular canals relative axis rotation. This produces vertical and horizontal nystagmus, disorientation, vertigo, nausea. With recurrent exposure, subjects habituate can make more movements before experiencing overpowering motion sickness. We questioned whether promethazine lessened vertigo delayed habituation, habituation was related central vestibular time constant, i.e., storage, severity sickness deviation eye gravity. Sixteen received placebo double-blind, crossover study two consecutive 4-day test series 1 month apart, termed I II. Horizontal were recorded with video-oculography performed approx. 45° over 2 s being rotated 138°/s around axis. Motion scaled (no sickness) an endpoint 20, which subject too sick continue about vomit. Habituation determined by number that made reaching maximum score 20. Head increased steadily each session repeated testing, there no difference between groups. angular vestibulo-ocular reflex (aVOR) constants declined test, declines closely correlated increase movements. The strength vertiginous sensation associated amount gravity; larger gravity, severe Thus, neither reduced nausea RWR, nor retarded hastened habituation. inverse relationship aVOR sickness, association extent, strength, gravity supports postulate spatiotemporal properties are processed nodulus uvula vestibulocerebellum nuclei, likely represent source conflict responsible for producing