Temporary Unilateral Caloric Vestibular Stimulation Affects Balance and Gait Control During Walking in Healthy Young Adults

OBJECTIVE: This study aimed to examine the individual differences and factors affecting balance and gait control during walking (i.e., dynamic equilibrium) in healthy young adults subjected to unilateral caloric vestibular stimulation (CVS). METHODS: Sixty-six participants completed questionnaires related to motion sickness. All participants were subjected to the head-up tilt test (HUT), which assesses orthostatic dysregulation, followed by inner ear stimulation with cold water (20°C) for 60 s. Subsequently, all participants performed a 6 m walking test with their eyes open. RESULTS: CVS resulted in horizontal nystagmus. The measured distance of sway from the centerline on the goal line ranged from 0 to 600 cm. Both motion sickness and orthostatic dysregulation (OD) were associated with the distance of sway from the centerline. CONCLUSIONS: Autonomic dysfunction affects the dynamic equilibrium and might cause individual gait differences. Further study is warranted to quantify the autonomic function and clarify individual variations in dynamic equilibrium, after unilateral CVS.