Electrical stimulation of the peripheral and central vestibular system

Abstract

Purpose of review Electrical stimulation of the peripheral and central vestibular system using noninvasive (galvanic vestibular stimulation, GVS) or invasive (intracranial electrical brain stimulation, iEBS) approaches have a long history of use in studying self-motion perception and balance control. The aim of this review is to summarize recent electrophysiological studies of the effects of GVS, and functional mapping of the central vestibular system using iEBS in awake patients. Recent findings The use of GVS has become increasingly common in the assessment and treatment of a wide range of clinical disorders including vestibulopathy and Parkinson's disease. The results of recent single unit recording studies have provided new insight into the neural mechanisms underlying GVS-evoked improvements in perceptual and motor responses. Furthermore, the application of iEBS in patients with epilepsy or during awake brain surgery has provided causal evidence of vestibular information processing in mostly the middle cingulate cortex, posterior insula, inferior parietal lobule, amygdala, precuneus, and superior temporal gyrus. Summary Recent studies have established that GVS evokes robust and parallel activation of both canal and otolith afferents that is significantly different from that evoked by natural head motion stimulation. Furthermore, there is evidence that GVS can induce beneficial neural plasticity in the central pathways of patients with vestibular loss. In addition, iEBS studies highlighted an underestimated contribution of areas in the medial part of the cerebral hemispheres to the cortical vestibular network.

Dynamics of sensorimotor reweighting: How light touch alters vestibular-evoked balance responses

“…However, the frequencies where EVS-CoP coherence were different between NO-TOUCH and TOUCH fall within the realm of natural vestibular stimulation, since people can experience vestibular inputs up to 20 Hz in situations like walking, stair climbing, running, jumping, sports, and riding the bus (50). Furthermore, leg and trunk muscles show responses to EVS up to 25 Hz during standing posture (51), postural transitions (31), and gait cycle (29, 46), while neck muscles show responses up to 150 Hz (52) independent of task demands (25, 53). While our experimental task had participants stand as still as possible, the vestibular system can operate at higher frequencies during dynamic balance situations to affect control of limb or segmental postural control and/or balance stabilization (29, 31, 46, 51, 52).…”

“…However, the frequencies where EVS-CoP coherence were different between NO-TOUCH and TOUCH fall within the realm of natural vestibular stimulation, since people can experience vestibular inputs up to 20 Hz in situations like walking, stair climbing, running, jumping, sports, and riding the bus (50). Furthermore, leg and trunk muscles show responses to EVS up to 25 Hz during standing posture (51), postural transitions (31), and gait cycle (29,46), while neck muscles show responses up to 150 Hz (52) independent of task demands (25,53).…”

Appropriate Vestibular Stimulation in Children and Adolescents—A Prerequisite for Normal Cognitive, Motor Development and Bodily Homeostasis—A Review

“…Not all of the functions of the above-mentioned cortical areas and their possible interactions and pathways are known [71]. Studies assessing vestibular-associated networks use electrical, caloric, visual or sound stimulation to induce the vestibular response [86][87][88][89][90]. The current testing methods lack the possibility of functional brain imaging during head and body movement.…”

“…As Wilkinson et al showed, electrical vestibular stimulation positively affects the speed of visual memory recollection [86]. Recent studies have indicated that non-invasive electrical stimulation causes simultaneous activation of semicircular canals and otolith systems and can improve neuronal plasticity in the central pathways [88].…”