scholarly journals Vertical torque responses to vestibular stimulation in standing humans

2011 ◽  
Vol 589 (16) ◽  
pp. 3943-3953 ◽  
Author(s):  
Raymond F. Reynolds
Keyword(s):  
Vestibular Stimulation ◽  
Standing Humans

Effects of Galvanic Vestibular Stimulation on Perception of Subjective Vertical in Standing Humans

1998 ◽  
Vol 86 (3_suppl) ◽  
pp. 1155-1161 ◽  
Author(s):  
Marie-Françoise Tardy-Gervet ◽  
Alexandra Séverac-Cauquil
Keyword(s):  
Vestibular Stimulation ◽  
Galvanic Vestibular Stimulation ◽  
Cathode Side ◽  
Anode Side ◽  
Ocular Torsion ◽  
Apparent Displacement ◽  
Experimental Conditions ◽  
Subjective Vertical ◽  
Central Representation ◽  
Standing Humans

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.

scholarly journals Caloric vestibular stimulation in aphasic syndrome

2013 ◽  
Vol 7 ◽  
Author(s):  
David Wilkinson ◽  
Rachael Morris ◽  
William Milberg ◽  
Mohamed Sakel
Keyword(s):  
Vestibular Stimulation ◽  
Caloric Vestibular Stimulation

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

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).

scholarly journals Qualitative and quantitative assessment of magnetic vestibular stimulation in humans

2020 ◽  
Vol 30 (6) ◽  
pp. 353-361
Author(s):  
Rebecca S. Dewey ◽  
Rachel Gomez ◽  
Chris Degg ◽  
David M. Baguley ◽  
Paul M. Glover
Keyword(s):  
Magnetic Field ◽  
Objective Measure ◽  
Quantitative Measure ◽  
Vestibular Stimulation ◽  
Initial Study ◽  
Clinical Test ◽  
Healthy Control ◽  
Student’S T ◽  
The Impact ◽  
The Magnetic Field

The sensation of phantom motion or exhibition of bodily sway is often reported in the proximity of an MR scanner. It is proposed that the magnetic field stimulates the vestibular system. There are a number of possible mechanisms responsible, and the relative contributions of susceptibility on the otolithic receptors and the Lorentz force on the cupulae have not yet been explored. This exploratory study aims to investigate the impact of being in the proximity of a 7.0 T MR scanner. The modified clinical test of sensory interaction on balance (mCTSIB) was used to qualitatively ascertain whether or not healthy control subjects who passed the mCTSIB in normal conditions 1) experienced subjective sensations of dizziness, vertigo or of leaning or shifting in gravity when in the magnetic field and 2) exhibited visibly increased bodily sway whilst in the magnetic field compared to outside the magnetic field. Condition IV of the mCTSIB was video recorded outside and inside the magnetic field, providing a semi-quantitative measure of sway. For condition IV of the mCTSIB (visual and proprioceptive cues compromised), all seven locations/orientations around the scanner yielded significantly more sway than at baseline (p < 0.01 FDR). A Student’s t-test comparing the RMS velocity of a motion marker on the upper arm during mCTSIB condition IV showed a significant increase in the amount of motion exhibited in the field (T = 2.59; d.f. = 9; p = 0.029) compared to outside the field. This initial study using qualitative measures of sway demonstrates that there is evidence for MR-naïve individuals exhibiting greater sway while performing the mCTSIB in the magnetic field compared to outside the field. Directional polarity of sway was not significant. Future studies of vestibular stimulation by magnetic fields would benefit from the development of a sensitive, objective measure of balance function, which can be performed inside a magnetic field.

Derealization and motion-perception related to repeated exposure to 3T Magnetic Resonance Image scanner in healthy adults

2020 ◽  
pp. 1-12
Author(s):  
Sergio Martínez-Gallardo ◽  
José A. Miguel-Puga ◽  
Davis Cooper-Bribiesca ◽  
Adolfo M. Bronstein ◽  
Kathrine Jáuregui-Renaud
Keyword(s):  
Magnetic Resonance ◽  
Motion Perception ◽  
State Anxiety ◽  
Random Order ◽  
Vestibular Stimulation ◽  
Psychological Effects ◽  
Psychological Reactions ◽  
Exposure Effect ◽  
Individual Susceptibility ◽  
Magnetic Exposure

BACKGROUND: Magnetic Resonance Imaging (MRI) scanning can induce psychological effects. No studies have investigated the role of magnetic vestibular stimulation (MVS) in 3TMRI scanner-induced psychological reactions. OBJECTIVE: To assess depersonalization/derealization(DD), state anxiety and motion-perception in a 3TMRI scanner, acutely and long-term. PARTICIPANTS: 48 healthcare professionals and students were included, after preliminary rejection of claustrophobes and neuro-otology and psychiatry assessments. PROCEDURES: Participants completed questionnaires on personal habits, dissociation, anxiety/depression and motion sickness susceptibility. Validated DD and state anxiety questionnaires were administered before and after magnetic exposure twice, entering the bore head and feet first in random order, one week apart. During the following week, dizziness/disorientation was reported daily. One month later, 11 subjects repeated the procedure to assess reproducibility. RESULTS: Considerable individual susceptibility was observed, circa 40% of the subjects reported self-motion perception related to the exposure, with variable increase on DD symptoms. Multivariate analysis showed that DD scores after any exposure were influenced by entering the bore “feet first”, motion-perception, and the mean sleep hours/week (MANCOVA, R = 0.58, p = 0.00001). There was no clear effect of scanner exposure on state anxiety, which was related to trait anxiey but not to DD scores. During repeated exposures, about half of all subjects re-entering the scan reported motion-perception, but DD or anxiety symptoms were not consistent. CONCLUSION: Psychological effects during 3TMRI scanning result from multiple, interacting factors, including novelty of the procedure (first-exposure effect), motion-perception due to MVS, head/body orientation, sleeping habits and individual susceptibility. Forewarning subjects of these predisposing factors may increase tolerance to MRI scanning.

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