Age-dependent perturbation of the perceptual and postural vertical by visual roll vection and susceptibility to motion sickness in children

Background The visual contribution to the perceptual and postural vertical is mediated by a multisensory integration process and may relate to children's susceptibility to motion sickness that is hypothesized to arise from intersensory conflicts. Objective To analyze the maturation of visual contribution to the perceptual and postural vertical in conjunction with the motion sickness susceptibility in childhood. Methods In 81 healthy children (aged 2-17 years;57 females), adjustments of the subjective visual vertical and posturographically tested mediolateral displacements of body sway were measured during free upright stance and large-field visual motion stimulation in the roll plane (roll vection). Motion sickness susceptibility was assessed by taking the history of parents and children. Results Vection-induced tilts of the visual vertical showed a linear age-dependent decrease with largest tilts in the youngest (2-7 years;median of 20 degrees) and smallest tilts in the oldest age group (13-17 years;median of 9-10 degrees). Analogously, postural tilts as measured by mediolateral body sway were greatest in the youngest and smallest in the oldest age group. In contrast, motion sickness susceptibility was lowest in the youngest and highest in the oldest age group and exhibited an inverse correlation with vection-induced tilts of the visual vertical. Conclusion Roll vection-induced tilts of the visual and postural vertical exhibited a similar age-dependent course with the greatest effects in the youngest and the least effects in the oldest age group, the latter of which exhibited the highest susceptibility to motion sickness