scholarly journals No evidence for after-effects of noisy galvanic vestibular stimulation on motion perception

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aram Keywan ◽  
Hiba Badarna ◽  
Klaus Jahn ◽  
Max Wuehr
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Po-Yin Chen ◽  
Ying-Chun Jheng ◽  
Chien-Chih Wang ◽  
Shih-En Huang ◽  
Ting-Hua Yang ◽  
...  

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).


2020 ◽  
pp. 1-12
Author(s):  
Sergio Martínez-Gallardo ◽  
José A. Miguel-Puga ◽  
Davis Cooper-Bribiesca ◽  
Adolfo M. Bronstein ◽  
Kathrine Jáuregui-Renaud

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.


2004 ◽  
Vol 124 (8) ◽  
pp. 941-945 ◽  
Author(s):  
Susan G. T. Balter ◽  
Robert J. Stokroos ◽  
Rosemiek M. A. Eterman ◽  
Sophie A. B. Paredis ◽  
Joep Orbons ◽  
...  

2003 ◽  
Vol 12 (2-3) ◽  
pp. 77-85
Author(s):  
Anthony P. Scinicariello ◽  
J. Timothy Inglis ◽  
J.J. Collins

Galvanic vestibular stimulation (GVS) is a technique in which small currents are delivered transcutaneously to the afferent nerve endings of the vestibular system through electrodes placed over the mastoid bones. The applied current alters the firing rates of the peripheral vestibular afferents, causing a shift in a standing subject's vestibular perception and a corresponding postural sway. Previously, we showed that in subjects who are facing forward, stochastic bipolar binaural GVS leads to coherent stochastic mediolateral postural sway. The goal of this pilot study was to extend that work and to test the hypothesis that in subjects who are facing forward, stochastic monopolar binaural GVS leads to coherent stochastic anteroposterior postural sway. Stochastic monopolar binaural GVS was applied to ten healthy young subjects. Twenty-four trials, each containing a different galvanic input stimulus from among eight different frequency ranges, were conducted on each subject. Postural sway was evaluated through analysis of the center-of-pressure (COP) displacements under each subject's feet. Spectral analysis was performed on the galvanic stimuli and the COP displacement time series to calculate the coherence spectra. Significant coherence was found between the galvanic input signal and the anteroposterior COP displacement in some of the trials (i.e., at least one) in nine of the ten subjects. In general, the coherence values were highest for the mid-range frequencies that were tested, and lowest for the low- and high-range frequencies. However, the coherence values we obtained were lower than those we previously reported for stochastic bipolar binaural GVS and mediolateral sway. These differences may be due to fundamental characteristics of the vestibular system such as lower sensitivity to symmetric changes in afferent firing dynamics, and/or differences between the biomechanics of anteroposterior and mediolateral sway.


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