Dissociation between subjective vertical and subjective body orientation elicited by galvanic vestibular stimulation

The present work reinvestigated the influence of bimastoidal galvanic vestibular stimulation (0.4 mA during 10 sec.) on subjective vertical. We tested the hypothesis that deviations are directed towards the anode side, like postural tilt evoked by galvanic vestibular stimulation. 15 subjects were instructed to orient vertically in darkness a light-rod during 3 experimental conditions of control, anode right, and anode left. The statistical analysis showed that the perception of the vertical was modified according to the experimental conditions and the subjects. Angular deviations occurred towards the anode side. The results are interpreted as a consequence of a modification of the central representation of the vertical or of ocular torsion directed towards the anode side and likely to induce an apparent displacement of the rod towards the cathode side.

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Effects of galvanic vestibular stimulation on postural limb reflexes and neurons of spinal postural network

Journal of Neurophysiology ◽

10.1152/jn.00041.2012 ◽

2012 ◽

Vol 108 (1) ◽

pp. 300-313 ◽

Cited By ~ 10

Author(s):

L.-J. Hsu ◽

P. V. Zelenin ◽

G. N. Orlovsky ◽

T. G. Deliagina

Keyword(s):

Vestibular Stimulation ◽

Afferent Input ◽

Galvanic Vestibular Stimulation ◽

Dorsal Side ◽

Body Orientation ◽

Cathode Side ◽

Body Sway ◽

Postural Control System ◽

Opposite Pattern ◽

Neuronal Mechanisms

Quadrupeds maintain the dorsal side up body orientation due to the activity of the postural control system driven by limb mechanoreceptors. Binaural galvanic vestibular stimulation (GVS) causes a lateral body sway toward the anode. Previously, we have shown that this new position is actively stabilized, suggesting that GVS changes a set point in the reflex mechanisms controlling body posture. The aim of the present study was to reveal the underlying neuronal mechanisms. Experiments were performed on decerebrate rabbits. The vertebral column was rigidly fixed, whereas hindlimbs were positioned on a platform. Periodic lateral tilts of the platform caused postural limb reflexes (PLRs): activation of extensors in the loaded and flexing limb and a decrease in extensor activity in the opposite (unloaded and extending) limb. Putative spinal interneurons were recorded in segments L4–L5 during PLRs, with and without GVS. We have found that GVS enhanced PLRs on the cathode side and reduced them on the anode side. This asymmetry in PLRs can account for changes in the stabilized body orientation observed in normal rabbits subjected to continuous GVS. Responses to platform tilts (frequency modulation) were observed in 106 spinal neurons, suggesting that they can contribute to PLR generation. Two neuron groups were active in opposite phases of the tilt cycle of the ipsi-limb: F-neurons in the flexion phase, and E-neurons in the extension phase. Neurons were driven mainly by afferent input from the ipsi-limb. If one supposes that F- and E-neurons contribute, respectively, to excitation and inhibition of extensor motoneurons, one can expect that the pattern of response to GVS in F-neurons will be similar to that in extensor muscles, whereas E-neurons will have an opposite pattern. We have found that ∼40% of all modulated neurons meet this condition, suggesting that they contribute to the generation of PLRs and to the GVS-caused changes in PLRs.

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Effects of galvanic vestibular stimulation on subjective visual vertical and static eye deviation

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(97)88208-2 ◽

1997 ◽

Vol 103 (1) ◽

pp. 67

Author(s):

R Zink

Keyword(s):

Vestibular Stimulation ◽

Galvanic Vestibular Stimulation ◽

Subjective Visual Vertical ◽

Visual Vertical

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Effect of noisy galvanic vestibular stimulation on dynamic posture sway under visual deprivation in patients with bilateral vestibular hypofunction

Scientific Reports ◽

10.1038/s41598-021-83206-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Po-Yin Chen ◽

Ying-Chun Jheng ◽

Chien-Chih Wang ◽

Shih-En Huang ◽

Ting-Hua Yang ◽

...

Keyword(s):

Clinical Trial ◽

Light Exposure ◽

Light Condition ◽

Vestibular Stimulation ◽

Galvanic Vestibular Stimulation ◽

Lateral Deviation ◽

Clinical Trial Registration ◽

Vestibular Hypofunction ◽

Dark Conditions ◽

Bilateral Vestibular Hypofunction

AbstractA single-blind study to investigate the effects of noisy galvanic vestibular stimulation (nGVS) in straight walking and 2 Hz head yaw walking for healthy and bilateral vestibular hypofunction (BVH) participants in light and dark conditions. The optimal stimulation intensity for each participant was determined by calculating standing stability on a force plate while randomly applying six graded nGVS intensities (0–1000 µA). The chest–pelvic (C/P) ratio and lateral deviation of the center of mass (COM) were measured by motion capture during straight and 2 Hz head yaw walking in light and dark conditions. Participants were blinded to nGVS served randomly and imperceivably. Ten BVH patients and 16 healthy participants completed all trials. In the light condition, the COM lateral deviation significantly decreased only in straight walking (p = 0.037) with nGVS for the BVH. In the dark condition, both healthy (p = 0.026) and BVH (p = 0.017) exhibited decreased lateral deviation during nGVS. The C/P ratio decreased significantly in BVH for 2 Hz head yaw walking with nGVS (p = 0.005) in light conditions. This study demonstrated that nGVS effectively reduced walking deviations, especially in visual deprived condition for the BVH. Applying nGVS with different head rotation frequencies and light exposure levels may accelerate the rehabilitation process for patients with BVH.Clinical Trial Registration This clinical trial was prospectively registered at www.clinicaltrials.gov with the Unique identifier: NCT03554941. Date of registration: (13/06/2018).

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