A wide-ranging review of galvanic vestibular stimulation: from its genesis to basic science and clinical applications

Galvanic vestibular stimulation (GVS) involves applying small electrical currents to the vestibular organs via electrodes placed on the mastoids, providing a powerful tool for investigating vestibular function. Despite its long history, GVS remains highly relevant for researchers due to its ability to probe the vestibular system's role in posture, gaze control, perception, and cortical processing. Recent technical advances have considerably expanded its application in both basic research and clinical practice. Despite the fact it is not realistic to cover all aspects of GVS within the constraints of a manuscript, this narrative review summarizes the history and neurophysiological mechanisms of GVS and provides new insights and perspectives for current and future studies, both in fundamental and clinical applications. We synthesize the main findings from neurophysiological, behavioral, and neuroimaging studies, focusing on the effects of GVS on postural control, ocular responses, cortical activity, and self-motion perception. Then diagnostic and therapeutic applications are explored in balance disorders, stroke rehabilitation, and neurodegenerative diseases. Clinical approaches could benefit from greater reliance on laboratory research to refine stimulation protocols, for maximum efficacy in its therapeutic use. A final discussion summarizes what is currently well-established with regard to GVS and opens up new and exciting perspectives in basic science and clinical applications.