Sensory feedback curbs the impact of nGVS on postural control in older adults.

Abstract

Noisy galvanic vestibular stimulation (nGVS) has been shown to improve postural control. However, the focus has been on the vestibular system, failing to account for other sensory inputs. The aim of the present study was thus to examine the relative impact of the various sensory feedback sources on the improvement of postural control following nGVS in older adults. Fourty-seven participants (20 controls; 27 older adults) were recruited for this study. Participants performed the modified clinical test of sensory integration as part of the postural control assessment. Older adults received an nGVS or sham stimulation which was compared to their baseline measurements and to an optimal performance (control group comprised of young adults). Results suggest that the nGVS-induced improvement of postural control in older individuals is significant only in conditions where visual and somatosensory feedback were hindered.The data also suggest that improvements in these conditions is more significant in individuals with reduced vestibular feedback. The study confirms the potential impact of nGVS for the rehabilitation of balance difficulties in the elderly population, most particularly in conditions with less reliable somatosensory and visual inputs. nGVS effects are thus modulated by sensory feedback with a dominant effect of somatosensory and visual sensory cues.