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Peto D, Schmidmeier F, Katzdobler S, Fietzek UM, Levin J, Wuehr M, Zwergal A. No evidence for effects of low-intensity vestibular noise stimulation on mild-to-moderate gait impairments in patients with Parkinson's disease. J Neurol 2024; 271:5489-5497. [PMID: 38884790 PMCID: PMC11319499 DOI: 10.1007/s00415-024-12504-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/05/2024] [Accepted: 06/07/2024] [Indexed: 06/18/2024]
Abstract
BACKGROUND Gait impairment is a key feature in later stages of Parkinson's disease (PD), which often responds poorly to pharmacological therapies. Neuromodulatory treatment by low-intensity noisy galvanic vestibular stimulation (nGVS) has indicated positive effects on postural instability in PD, which may possibly be conveyed to improvement of dynamic gait dysfunction. OBJECTIVE To investigate the effects of individually tuned nGVS on normal and cognitively challenged walking in PD patients with mild-to-moderate gait dysfunction. METHODS Effects of nGVS of varying intensities (0-0.7 mA) on body sway were examined in 32 patients with PD (ON medication state, Hoehn and Yahr: 2.3 ± 0.5), who were standing with eyes closed on a posturographic force plate. Treatment response and optimal nGVS stimulation intensity were determined on an individual patient level. In a second step, the effects of optimal nGVS vs. sham treatment on walking with preferred speed and with a cognitive dual task were investigated by assessment of spatiotemporal gait parameters on a pressure-sensitive gait carpet. RESULTS Evaluation of individual balance responses yielded that 59% of patients displayed a beneficial balance response to nGVS treatment with an average optimal improvement of 23%. However, optimal nGVS had no effects on gait parameters neither for the normal nor the cognitively challenged walking condition compared to sham stimulation irrespective of the nGVS responder status. CONCLUSIONS Low-intensity nGVS seems to have differential treatment effects on static postural imbalance and continuous gait dysfunction in PD, which could be explained by a selective modulation of midbrain-thalamic circuits of balance control.
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Affiliation(s)
- Daniela Peto
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, Ludwig-Maximilians-Universität München, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Florian Schmidmeier
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, Ludwig-Maximilians-Universität München, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Sabrina Katzdobler
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Urban M Fietzek
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Schön Klinik München Schwabing, Munich, Germany
| | - Johannes Levin
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Max Wuehr
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, Ludwig-Maximilians-Universität München, Marchioninistrasse 15, 81377, Munich, Germany.
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany.
| | - Andreas Zwergal
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, Ludwig-Maximilians-Universität München, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
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Wuehr M, Peto D, Fietzek UM, Katzdobler S, Nübling G, Zaganjori M, Brendel M, Levin J, Höglinger GU, Zwergal A. Low-intensity vestibular noise stimulation improves postural symptoms in progressive supranuclear palsy. J Neurol 2024; 271:4577-4586. [PMID: 38722328 PMCID: PMC11233287 DOI: 10.1007/s00415-024-12419-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/01/2024] [Accepted: 04/29/2024] [Indexed: 07/10/2024]
Abstract
BACKGROUND Postural imbalance and falls are an early disabling symptom in patients with progressive supranuclear palsy (PSP) of multifactorial origin that may involve abnormal vestibulospinal reflexes. Low-intensity noisy galvanic vestibular stimulation (nGVS) is a non-invasive treatment to normalize deficient vestibular function and attenuate imbalance in Parkinson's disease. The presumed therapeutic mode of nGVS is stochastic resonance (SR), a mechanism by which weak sensory noise stimulation can enhance sensory information processing. OBJECTIVE To examine potential treatment effects of nGVS on postural instability in 16 patients with PSP with a clinically probable and [18F]PI-2620 tau-PET-positive PSP. METHODS Effects of nGVS of varying intensity (0-0.7 mA) on body sway were examined, while patients were standing with eyes closed on a posturographic force plate. We assumed a bell-shaped response curve with maximal sway reductions at intermediate nGVS intensities to be indicative of SR. An established SR-curve model was fitted on individual patient outcomes and three experienced human raters had to judge whether responses to nGVS were consistent with the exhibition of SR. RESULTS We found nGVS-induced reductions of body sway compatible with SR in 9 patients (56%) with optimal improvements of 31 ± 10%. In eight patients (50%), nGVS-induced sway reductions exceeded the minimal clinically important difference (improvement: 34 ± 5%), indicative of strong SR. CONCLUSION nGVS yielded clinically relevant reductions in body sway compatible with the exhibition of SR in vestibular sensorimotor pathways in at least half of the assessed patients. Non-invasive vestibular noise stimulation may be thus a well-tolerated treatment strategy to ameliorate postural symptoms in PSP.
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Affiliation(s)
- Max Wuehr
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany.
| | - Daniela Peto
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Urban M Fietzek
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Schön Klinik München Schwabing, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
| | - Sabrina Katzdobler
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Georg Nübling
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
| | - Mirlind Zaganjori
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Matthias Brendel
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
| | - Johannes Levin
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Günter U Höglinger
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE) E.V., Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Andreas Zwergal
- German Center for Vertigo and Balance Disorders (DSGZ), LMU University Hospital, LMU Munich, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, LMU University Hospital, LMU Munich, Munich, Germany
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Wuehr M, Eder J, Kellerer S, Amberger T, Jahn K. Mechanisms underlying treatment effects of vestibular noise stimulation on postural instability in patients with bilateral vestibulopathy. J Neurol 2024; 271:1408-1415. [PMID: 37973635 PMCID: PMC10896912 DOI: 10.1007/s00415-023-12085-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND Previous studies indicate that imbalance in patients with bilateral vestibulopathy (BVP) may be reduced by treatment with low-intensity noisy galvanic vestibular stimulation (nGVS). OBJECTIVE To elucidate the potential mechanisms underlying this therapeutic effect. In particular, we determined whether nGVS-induced balance improvements in patients are compatible with stochastic resonance (SR)-a mechanism by which weak noise stimulation can paradoxically enhance sensory signal processing. METHODS Effects of nGVS of varying intensities (0-0.7 mA) on body sway were examined in 19 patients with BVP standing with eye closed on a posturographic force plate. We assumed a bell-shaped response curve with maximal sway reductions at intermediate nGVS intensities to be indicative of SR. An established SR curve model was fitted on individual patient outcomes, and three experienced human raters had to judge whether responses to nGVS were consistent with the exhibition of SR. RESULTS nGVS-induced reductions of body sway compatible with SR were found in 12 patients (63%) with optimal improvements of 31 ± 21%. In 10 patients (53%), nGVS-induced sway reductions exceeded the minimally important clinical difference (optimal improvement: 35 ± 21%), indicative of strong SR. This beneficial effect was more likely in patients with severe vestibular loss (i.e. lower video head impulse test gain; R = 0.663; p = 0.002) and considerable postural imbalance (baseline body sway; R = 0.616; p = 0.005). CONCLUSIONS More than half of the assessed patients showed robust improvements in postural balance compatible with SR when treated with nGVS. In particular, patients with a higher burden of disease may benefit from the non-invasive and well-tolerated treatment with nGVS.
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Affiliation(s)
- Max Wuehr
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377, Munich, Germany.
| | - Josefine Eder
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377, Munich, Germany
| | - Silvy Kellerer
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377, Munich, Germany
| | - Tamara Amberger
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377, Munich, Germany
| | - Klaus Jahn
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377, Munich, Germany
- Schön Klinik Bad Aibling, Bad Aibling, Germany
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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.
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Affiliation(s)
- Christophe Lopez
- Aix Marseille Univ, CNRS, Laboratory of Cognitive Neuroscience (LNC), FR3C, Marseille, France
| | - Kathleen E. Cullen
- Department of Biomedical Engineering, Johns Hopkins University
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University
- Department of Neuroscience, Johns Hopkins University
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore 21205 MD, USA
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Sherman SO, Greenstein M, Basner M, Clark TK, Anderson AP. Effects of additive sensory noise on cognition. Front Hum Neurosci 2023; 17:1092154. [PMID: 37333835 PMCID: PMC10270290 DOI: 10.3389/fnhum.2023.1092154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
Background Adding noise to a system to improve a weak signal's throughput is known as stochastic resonance (SR). SR has been shown to improve sensory perception. Some limited research shows noise can also improve higher order processing, such as working memory, but it is unknown whether SR can broadly improve cognition. Objective We investigated cognitive performance while applying auditory white noise (AWN) and/or noisy galvanic vestibular stimulation (nGVS). Methods We measured cognitive performance (n = 13 subjects) while completing seven tasks in the cognition test battery (CTB). Cognition was assessed with and without the influence of AWN, nGVS, and both simultaneously. Performance in speed, accuracy, and efficiency was observed. A subjective questionnaire regarding preference for working in noisy environments was collected. Results We did not find broad cognitive performance improvement under the influence of noise (p > 0.1). However, a significant interaction was found between subject and noise condition for accuracy (p = 0.023), indicating that some subjects exhibited cognitive changes with the addition of noise. Across all metrics, noisy environment preference may trend to be a potential indicator of whether subjects will exhibit SR cognitive benefits with a significant predictor in efficiency (p = 0.048). Conclusion This study investigated using additive sensory noise to induce SR in overall cognition. Our results suggest that using noise to improve cognition is not applicable for a broad population; however, the effect of noise differs across individuals. Further, subjective questionnaires may be a means to identify which individuals are sensitive to SR cognitive benefits, but further investigation is needed.
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Affiliation(s)
- Sage O. Sherman
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
| | - Maya Greenstein
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
| | - Mathias Basner
- Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Torin K. Clark
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
| | - Allison P. Anderson
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
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Lacquaniti F, La Scaleia B, Zago M. Noise and vestibular perception of passive self-motion. Front Neurol 2023; 14:1159242. [PMID: 37181550 PMCID: PMC10169592 DOI: 10.3389/fneur.2023.1159242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 03/29/2023] [Indexed: 05/16/2023] Open
Abstract
Noise defined as random disturbances is ubiquitous in both the external environment and the nervous system. Depending on the context, noise can degrade or improve information processing and performance. In all cases, it contributes to neural systems dynamics. We review some effects of various sources of noise on the neural processing of self-motion signals at different stages of the vestibular pathways and the resulting perceptual responses. Hair cells in the inner ear reduce the impact of noise by means of mechanical and neural filtering. Hair cells synapse on regular and irregular afferents. Variability of discharge (noise) is low in regular afferents and high in irregular units. The high variability of irregular units provides information about the envelope of naturalistic head motion stimuli. A subset of neurons in the vestibular nuclei and thalamus are optimally tuned to noisy motion stimuli that reproduce the statistics of naturalistic head movements. In the thalamus, variability of neural discharge increases with increasing motion amplitude but saturates at high amplitudes, accounting for behavioral violation of Weber's law. In general, the precision of individual vestibular neurons in encoding head motion is worse than the perceptual precision measured behaviorally. However, the global precision predicted by neural population codes matches the high behavioral precision. The latter is estimated by means of psychometric functions for detection or discrimination of whole-body displacements. Vestibular motion thresholds (inverse of precision) reflect the contribution of intrinsic and extrinsic noise to perception. Vestibular motion thresholds tend to deteriorate progressively after the age of 40 years, possibly due to oxidative stress resulting from high discharge rates and metabolic loads of vestibular afferents. In the elderly, vestibular thresholds correlate with postural stability: the higher the threshold, the greater is the postural imbalance and risk of falling. Experimental application of optimal levels of either galvanic noise or whole-body oscillations can ameliorate vestibular function with a mechanism reminiscent of stochastic resonance. Assessment of vestibular thresholds is diagnostic in several types of vestibulopathies, and vestibular stimulation might be useful in vestibular rehabilitation.
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Affiliation(s)
- Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Systems Medicine, Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
| | - Barbara La Scaleia
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Myrka Zago
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Civil Engineering and Computer Science Engineering, Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
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Noisy galvanic vestibular stimulation improves vestibular perception in bilateral vestibulopathy. J Neurol 2023; 270:938-943. [PMID: 36324034 PMCID: PMC9886588 DOI: 10.1007/s00415-022-11438-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Patients with bilateral vestibulopathy (BVP) suffer from impaired vestibular motion perception that is linked to deficits in spatial memory and navigation. OBJECTIVE To examine the potential therapeutic effect of imperceptible noisy galvanic vestibular stimulation (nGVS) on impaired vestibular perceptual performance in BVP. METHODS In 11 patients with BVP (mean age: 54.0 ± 8.3 years, 7 females), we initially determined the nGVS intensity that optimally stabilizes balance during a static posturographic assessment. Subsequently, effects of optimal nGVS vs. sham stimulation on vestibular motion perception were examined in randomized order. Vestibular perceptual performance was determined as direction recognition thresholds for head-centered roll tilt motion on a 6DOF motion platform in the absence of any visual or auditory motion cues. RESULTS For each patient, an nGVS intensity that optimally stabilized static balance compared to sham stimulation could be identified (mean 0.36 ± 0.16 mA). nGVS at optimal intensity resulted in lowered vestibular perceptual thresholds (0.94 ± 0.30 deg/s) compared to sham stimulation (1.67 ± 1.11 deg/s; p = 0.040). nGVS-induced improvements in vestibular perception were observed in 8 of 11 patients (73%) and were greater in patients with poorer perceptual performance during sham stimulation (R = - 0.791; p = 0.007). CONCLUSIONS nGVS is effective in improving impaired vestibular motion perception in patients with BVP, in particular in those patients with poor baseline perceptual performance. Imperceptible vestibular noise stimulation might thus offer a non-invasive approach to target BVP-related impairments in spatial memory, orientation, and navigation.
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La Scaleia B, Lacquaniti F, Zago M. Enhancement of Vestibular Motion Discrimination by Small Stochastic Whole-body Perturbations in Young Healthy Humans. Neuroscience 2023; 510:32-48. [PMID: 36535577 DOI: 10.1016/j.neuroscience.2022.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 12/05/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
Noisy galvanic vestibular stimulation has been shown to improve vestibular perception in healthy subjects. Here, we sought to obtain similar results using more natural stimuli consisting of small-amplitude motion perturbations of the whole body. Thirty participants were asked to report the perceived direction of antero-posterior sinusoidal motion on a MOOG platform. We compared the baseline perceptual thresholds with those obtained by applying small, stochastic perturbations at different power levels along the antero-posterior axis, symmetrically distributed around a zero-mean. At the population level, we found that the thresholds for all but the highest level of noise were significantly lower than the baseline threshold. At the individual level, the threshold was lower with at least one noise level than the threshold without noise in 87% of participants. Thus, small, stochastic oscillations of the whole body can increase the probability of recognizing the direction of motion from low, normally subthreshold vestibular signals, possibly due to stochastic resonance mechanisms. We suggest that, just as the external noise of the present experiments, also the spontaneous random oscillations of the head and body associated with standing posture are beneficial by enhancing vestibular thresholds with a mechanism similar to stochastic resonance.
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Affiliation(s)
- Barbara La Scaleia
- Laboratory of Visuomotor Control and Gravitational Physiology, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy.
| | - Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; Department of Systems Medicine and Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy.
| | - Myrka Zago
- Laboratory of Visuomotor Control and Gravitational Physiology, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy; Department of Civil Engineering and Computer Science Engineering and Center of Space Biomedicine, University of Rome Tor Vergata, 00133 Rome, Italy.
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McLaren R, Smith PF, Taylor RL, Niazi IK, Taylor D. Scoping out noisy galvanic vestibular stimulation: a review of the parameters used to improve postural control. Front Neurosci 2023; 17:1156796. [PMID: 37205050 PMCID: PMC10187481 DOI: 10.3389/fnins.2023.1156796] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/04/2023] [Indexed: 05/21/2023] Open
Abstract
Objective Noisy galvanic vestibular stimulation (nGVS) has been used to facilitate vestibular function and improve gait and balance in people with poor postural control. The aim of this scoping review is to collate, summarize and report on the nGVS parameters that have been used to augment postural control. Method A systematic scoping review was conducted up to December 2022. Data were extracted and synthesized from 31 eligible studies. Key nGVS parameters were identified, and the importance of these parameters and their influence on postural control evaluated. Results A range of nGVS parameters have been used to augment postural control, including; noise waveform, amplitude, frequency band, duration of stimulation, method of amplitude optimization, size and composition of electrodes and the electrode skin interface. Conclusion Systematic evaluation of the individual parameters that can be manipulated in the nGVS waveform identified that a broad array of settings have been utilized in each parameter across the studies. Choices made around the electrode and electrode-skin interface, as well as the amplitude, frequency band, duration and timing of the waveform are likely to influence the efficacy of nGVS. The ability to draw robust conclusions about the selection of optimal nGVS parameters to improve postural control, is hindered by a lack of studies that directly compare parameter settings or consider the variability in individuals' response to nGVS. We propose a guideline for the accurate reporting of nGVS parameters, as a first step toward establishing standardized stimulation protocols.
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Affiliation(s)
- Ruth McLaren
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Sciences, Auckland University of Technology, Auckland, New Zealand
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
- *Correspondence: Ruth McLaren,
| | - Paul F. Smith
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Rachael L. Taylor
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Imran Khan Niazi
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Sciences, Auckland University of Technology, Auckland, New Zealand
- Centre of Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
- Centre for Sensory-Motor Interactions, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Denise Taylor
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Sciences, Auckland University of Technology, Auckland, New Zealand
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
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Eder J, Kellerer S, Amberger T, Keywan A, Dlugaiczyk J, Wuehr M, Jahn K. Combining vestibular rehabilitation with noisy galvanic vestibular stimulation for treatment of bilateral vestibulopathy. J Neurol 2022; 269:5731-5737. [PMID: 35212789 PMCID: PMC9553809 DOI: 10.1007/s00415-022-11033-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/10/2022] [Accepted: 02/15/2022] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Noisy galvanic vestibular stimulation (nGVS) has been shown to partly restore vestibular function and to stabilize stance and gait in patients with incomplete bilateral vestibulopathy (BVP). Here, we examined potential synergistic effects of nGVS when combined with standardized vestibular rehabilitation training (VRT). METHODS 23 patients with confirmed BVP received a 30-min vestibular rehabilitation training (VRT) program three times a week for 2 weeks. The intervention group (n = 12) was stimulated with nGVS (at individually determined optimal amplitudes) during training, whereas the control group (n = 11) received zero-amplitude nGVS (sham stimulation) during training. Outcome measurements assessed at baseline, after 2 weeks of training, and at 2-week follow-up included quantitative posturography, instrumented gait analysis, Timed Up and Go Test (TUG), Functional Gait Assessment (FGA), and clinical scores related to quality of life and balance confidence. RESULTS After 2 weeks of VRT, all patients showed moderate improvement in balance. Irrespective of nGVS treatment, performance improved in the TUG (p < 0.013), and in the FGA (p < 0.040). Furthermore, base of support when walking with closed eyes was reduced after 2-week training (p < 0.003). Postural sway did not change. There was no difference between groups and thereby no evidence for an additional influence of nGVS on the VRT treatment effects. CONCLUSION nGVS does not induce synergistic treatment effects in combination with VRT in patients with BVP when applied during treatment sessions. Hence, rather than being applied in parallel, nGVS and VRT might be complementary therapeutic options with nGVS being used during postural activities in daily life, e.g., walking.
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Affiliation(s)
- Josefine Eder
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
| | - Silvy Kellerer
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
| | - Tamara Amberger
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
- Department of Neurology, Schoen Clinic Bad Aibling, Bad Aibling, Germany
| | - Aram Keywan
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
| | - Julia Dlugaiczyk
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
- Clinic for Ear, Nose, Throat and Facial Surgery, Interdisciplinary Center for Vertigo and Neurological Disorders, University of Zurich, Zurich, Switzerland
| | - Max Wuehr
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany
| | - Klaus Jahn
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians University of Munich (LMU), University Hospital Grosshadern, Marchioninistrasse 15, 81377, Munich, Germany.
- Department of Neurology, Schoen Clinic Bad Aibling, Bad Aibling, Germany.
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11
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McLaren R, Smith PF, Taylor RL, Ravindran S, Rashid U, Taylor D. Efficacy of nGVS to improve postural stability in people with bilateral vestibulopathy: A systematic review and meta-analysis. Front Neurosci 2022; 16:1010239. [PMID: 36248647 PMCID: PMC9553993 DOI: 10.3389/fnins.2022.1010239] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 08/24/2022] [Indexed: 11/25/2022] Open
Abstract
Objective Noisy galvanic vestibular stimulation (nGVS) has been used to boost vestibular afferent information to the central nervous system. This has the potential to improve postural control for people for whom vestibular signals are weak, such as in bilateral vestibulopathy (BVP). The aim of this systematic review and meta-analysis is to investigate the evidence for nGVS as a modality to improve postural control in people with BVP. Methods A comprehensive systematic search was conducted of five databases up to July 2022 to find studies applying nGVS to people with BVP, with the aim of improving postural control. Two independent reviewers screened and identified eligible studies, completed a risk of bias evaluation (Cochrane) and extracted relevant data. The standardized mean difference (SMD) based on Hedges' g was calculated as a measure of effect size for the primary outcome measure that best identified postural control, and a forest plot generated. Results Seven studies met the eligibility criteria, with five being suitable for meta-analysis. Meta-analysis revealed a moderate effect in favor of nGVS improving postural control during standing and walking [pooled SMD = 0.47 95% CI (0.25, 0.7)]. nGVS-mediated improvements in postural control were most evident in observations of reduced sway velocity when standing on a firm surface with eyes closed, and in the reduced variability of gait parameters, particularly those measuring lateral stability. Conclusions Coincident nGVS in people with BVP improves postural control during standing and walking. This improvement appears to be context specific, in that vestibular augmentation is most effective in situations where visual inputs are limited, and where reliable context specific proprioceptive cues are available. Further research is warranted investigating additional circumstances in which nGVS improves postural control, including investigating the residual, and sustained effects of nGVS. Systematic review registration https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=342147, identifier: 342147.
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Affiliation(s)
- Ruth McLaren
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Science, Auckland University of Technology, Auckland, New Zealand
- *Correspondence: Ruth McLaren
| | - Paul F. Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
| | - Rachael L. Taylor
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Shobika Ravindran
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Science, Auckland University of Technology, Auckland, New Zealand
| | - Usman Rashid
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Science, Auckland University of Technology, Auckland, New Zealand
| | - Denise Taylor
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, School of Clinical Science, Auckland University of Technology, Auckland, New Zealand
- Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
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12
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Wuehr M, Schmidmeier F, Katzdobler S, Fietzek UM, Levin J, Zwergal A. Effects of Low-Intensity Vestibular Noise Stimulation on Postural Instability in Patients with Parkinson's Disease. JOURNAL OF PARKINSON'S DISEASE 2022; 12:1611-1618. [PMID: 35491798 DOI: 10.3233/jpd-213127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Postural instability is a major disabling factor in patients with advanced Parkinson's disease (PD) and often resistant to treatment. Previous studies indicated that imbalance in PD may be reduced by low-intensity noisy galvanic vestibular stimulation (nGVS). OBJECTIVE To investigate the potential mode of action of this therapeutic effect. In particular, we examined whether nGVS-induced reductions of body sway in PD are compatible with stochastic resonance (SR), a mechanism by which weak sensory noise stimulation can paradoxically enhance sensory information transfer. METHODS Effects of nGVS of varying intensities (0-0.7 mA) on body sway were examined in 15 patients with PD standing with eye closed on a posturographic force plate. We assumed a bell-shaped response curve with maximal reductions of sway at intermediate nGVS intensities to be indicative of SR. An established SR-curve model was fitted on individual patient outcomes and three experienced human raters had to judge whether responses to nGVS were consistent with the exhibition of SR. RESULTS nGVS-induced reductions of body sway compatible with SR were found in 10 patients (67%) with optimal improvements of 23±13%. In 7 patients (47%), nGVS-induced sway reductions exceeded the minimally important clinical difference (optimal improvement: 30±10%), indicative of strong SR. This beneficial effect was more likely in patients with advanced PD (R = 0.45; p = 0.045). CONCLUSIONS At least half of the assessed patients showed robust improvements in postural balance compatible with SR when treated with low-intensity nGVS. In particular, patients with more advanced disease stages and imbalance may benefit from the non-invasive and well-tolerated treatment with nGVS.
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Affiliation(s)
- Max Wuehr
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Florian Schmidmeier
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Sabrina Katzdobler
- Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Munich, Germany
| | - Urban M Fietzek
- Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany.,Department of Neurology and Clinical Neurophysiology, Schön Klinik München Schwabing, Munich, Germany
| | - Johannes Levin
- Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) e.V., Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Andreas Zwergal
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-University of Munich, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
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13
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Voros J, Rise R, Sherman S, Durell A, Anderson AP, Clark TK. A Machine Learning Approach to Identify Stochastic Resonance in Human Perceptual Thresholds. J Neurosci Methods 2022; 374:109559. [DOI: 10.1016/j.jneumeth.2022.109559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/30/2022] [Accepted: 03/06/2022] [Indexed: 11/26/2022]
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14
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Putman EJ, Galvan-Garza RC, Clark TK. The Effect of Noisy Galvanic Vestibular Stimulation on Learning of Functional Mobility and Manual Control Nulling Sensorimotor Tasks. Front Hum Neurosci 2021; 15:756674. [PMID: 34803637 PMCID: PMC8595260 DOI: 10.3389/fnhum.2021.756674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) is a non-invasive method of electrically stimulating the vestibular system. We investigated whether the application of GVS can alter the learning of new functional mobility and manual control tasks and whether learning can be retained following GVS application. In a between-subjects experiment design, 36 healthy subjects performed repeated trials, capturing the learning of either (a) a functional mobility task, navigating an obstacle course on a compliant surface with degraded visual cues or (b) a manual control task, using a joystick to null self-roll tilt against a pseudo-random disturbance while seated in the dark. In the “learning” phase of trials, bilateral, bipolar GVS was applied continuously. The GVS waveform also differed between subjects in each task group: (1) white noisy galvanic vestibular stimulation (nGVS) at 0.3 mA (2) high-level random GVS at 0.7 mA (selected from pilot testing as destabilizing, but not painful), or (3) with the absence of stimulation (i.e., sham). Following the “learning” trials, all subjects were blindly transitioned to sham GVS, upon which they immediately completed another series of trials to assess any aftereffects. In the functional mobility task, we found nGVS significantly improved task learning (p = 0.03, mean learning metric 171% more than the sham group). Further, improvements in learning the functional mobility task with nGVS were retained, even once the GVS application was stopped. The benefits in learning with nGVS were not observed in the manual control task. High level GVS tended to inhibit learning in both tasks, but not significantly so. Even once the high-level stimulation was stopped, the impaired performance remained. Improvements in learning with nGVS may be due to increased information throughput resulting from stochastic resonance. The benefit of nGVS for functional mobility, but not manual control nulling, may be due to the multisensory (e.g., visual and proprioceptive), strategic, motor coordination, or spatial awareness aspects of the former task. Learning improvements with nGVS have the potential to benefit individuals who perform functional mobility tasks, such as astronauts, firefighters, high performance athletes, and soldiers.
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Affiliation(s)
- Esther J Putman
- Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
| | | | - Torin K Clark
- Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
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15
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Diaz-Artiles A, Karmali F. Vestibular Precision at the Level of Perception, Eye Movements, Posture, and Neurons. Neuroscience 2021; 468:282-320. [PMID: 34087393 PMCID: PMC9188304 DOI: 10.1016/j.neuroscience.2021.05.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 11/18/2022]
Abstract
Precision and accuracy are two fundamental properties of any system, including the nervous system. Reduced precision (i.e., imprecision) results from the presence of neural noise at each level of sensory, motor, and perceptual processing. This review has three objectives: (1) to show the importance of studying vestibular precision, and specifically that studying accuracy without studying precision ignores fundamental aspects of the vestibular system; (2) to synthesize key hypotheses about precision in vestibular perception, the vestibulo-ocular reflex, posture, and neurons; and (3) to show that groups of studies that are thoughts to be distinct (e.g., perceptual thresholds, subjective visual vertical variability, neuronal variability) are actually "two sides of the same coin" - because the methods used allow results to be related to the standard deviation of a Gaussian distribution describing the underlying neural noise. Vestibular precision varies with age, stimulus amplitude, stimulus frequency, body orientation, motion direction, pathology, medication, and electrical/mechanical vestibular stimulation, but does not vary with sex. The brain optimizes precision during integration of vestibular cues with visual, auditory, and/or somatosensory cues. Since a common concern with precision metrics is time required for testing, we describe approaches to optimize data collection and provide evidence that fatigue and session effects are minimal. Finally, we summarize how precision is an individual trait that is correlated with clinical outcomes in patients as well as with performance in functional tasks like balance. These findings highlight the importance of studying vestibular precision and accuracy, and that knowledge gaps remain.
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Affiliation(s)
- Ana Diaz-Artiles
- Bioastronautics and Human Performance Laboratory, Department of Aerospace Engineering, Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843-3141, USA. https://bhp.engr.tamu.edu
| | - Faisal Karmali
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston MA, USA.
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16
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van Stiphout L, Lucieer F, Pleshkov M, Van Rompaey V, Widdershoven J, Guinand N, Pérez Fornos A, Kingma H, van de Berg R. Bilateral vestibulopathy decreases self-motion perception. J Neurol 2021; 269:5216-5228. [PMID: 34263351 PMCID: PMC9467944 DOI: 10.1007/s00415-021-10695-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 03/19/2021] [Accepted: 06/29/2021] [Indexed: 11/25/2022]
Abstract
Objective Current diagnostic criteria for bilateral vestibulopathy (BV) primarily involve measurements of vestibular reflexes. Perceptual self-motion thresholds however, are not routinely measured and their clinical value in this specific population is not yet fully determined. Objectives of this study were (1) to compare perceptual self-motion thresholds between BV patients and control subjects, and (2) to explore patterns of self-motion perception performance and vestibular function in BV patients. Methods Thirty-seven BV patients and 34 control subjects were included in this study. Perceptual self-motion thresholds were measured in both groups using a CAREN platform (Motek Medical BV, Amsterdam, The Netherlands). Vestibular function was evaluated (only in BV patients) by the caloric test, torsion swing test, video head impulse test of all semicircular canals, and cervical- and ocular vestibular-evoked myogenic potentials. Differences in thresholds between both groups were analyzed. Hierarchical cluster analysis was performed to visualize patterns between self-motion perception and vestibular function within the group of BV patients. Results Perceptual self-motion thresholds were significantly higher in BV patients compared to control subjects, regarding nearly all rotations and translations (depending on the age group) (p ≤ 0.001). Cluster analysis showed that within the group of BV patients, higher perceptual self-motion thresholds were generally associated with lower vestibular test results (significant for yaw rotation, caloric test, torsion swing test, and video head impulse test (p ≤ 0.001)). Conclusion Self-motion perception is significantly decreased in BV patients compared to control subjects regarding nearly all rotations and translations. Furthermore, decreased self-motion perception is generally associated with lower residual vestibular function in BV patients. Trial registration Trial registration number NL52768.068.15/METC Supplementary Information The online version contains supplementary material available at 10.1007/s00415-021-10695-3.
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Affiliation(s)
- Lisa van Stiphout
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
| | - Florence Lucieer
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Maksim Pleshkov
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Faculty of Physics, Tomsk State Research University, Tomsk, Russian Federation
| | - Vincent Van Rompaey
- Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Josine Widdershoven
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Nils Guinand
- Service of Otorhinolaryngology Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland
| | - Angélica Pérez Fornos
- Service of Otorhinolaryngology Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland
| | - Herman Kingma
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Faculty of Physics, Tomsk State Research University, Tomsk, Russian Federation
| | - Raymond van de Berg
- Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Faculty of Physics, Tomsk State Research University, Tomsk, Russian Federation
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17
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Assländer L, Giboin LS, Gruber M, Schniepp R, Wuehr M. No evidence for stochastic resonance effects on standing balance when applying noisy galvanic vestibular stimulation in young healthy adults. Sci Rep 2021; 11:12327. [PMID: 34112904 PMCID: PMC8192540 DOI: 10.1038/s41598-021-91808-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/28/2021] [Indexed: 11/24/2022] Open
Abstract
Noisy galvanic vestibular stimulation (nGVS) at imperceptible levels has been shown to reduce body sway. This reduction was commonly attributed to the mechanism of stochastic resonance (SR). However, it has never been explicitly tested whether nGVS-induced effects on body sway consistently follow a SR-like bell-shaped performance curve with maximal reductions in a particular range of noise intensities. To test this, body sway in 21 young healthy participants was measured during varying nGVS amplitudes while standing with eyes closed in 3 conditions (quiet stance, sway referencing, sinusoidal platform tilts). Presence of SR-like response dynamics in each trial was assessed (1) by a goodness-of-fit analysis using an established SR-curve model and (2) by ratings from 3 human experts. In accordance to theory, we found reductions of body sway at one nGVS amplitude in most trials (75–95%). However, only few trials exhibited SR-like bell-shaped performance curves with increasing noise amplitudes (10–33%). Instead, body sway measures rather fluctuated randomly across nGVS amplitudes. This implies that, at least in young healthy adults, nGVS effects on body sway are incompatible with SR. Thus, previously reported reductions of body sway at particular nGVS intensities more likely result from inherent variations of the performance metric or by other yet unknown mechanisms.
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Affiliation(s)
- L Assländer
- Human Performance Research Centre, University of Konstanz, Konstanz, Germany.
| | - L S Giboin
- Human Performance Research Centre, University of Konstanz, Konstanz, Germany
| | - M Gruber
- Human Performance Research Centre, University of Konstanz, Konstanz, Germany
| | - R Schniepp
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-University, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| | - M Wuehr
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-University, Munich, Germany
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18
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Voros JL, Sherman SO, Rise R, Kryuchkov A, Stine P, Anderson AP, Clark TK. Galvanic Vestibular Stimulation Produces Cross-Modal Improvements in Visual Thresholds. Front Neurosci 2021; 15:640984. [PMID: 33867923 PMCID: PMC8044370 DOI: 10.3389/fnins.2021.640984] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 03/03/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Stochastic resonance (SR) refers to a faint signal being enhanced with the addition of white noise. Previous studies have found that vestibular perceptual thresholds are lowered with noisy galvanic vestibular stimulation (i.e., "in-channel" SR). Auditory white noise has been shown to improve tactile and visual thresholds, suggesting "cross-modal" SR. OBJECTIVE We investigated galvanic vestibular white noise (nGVS) (n = 9 subjects) to determine the cross-modal effects on visual and auditory thresholds. METHODS We measured auditory and visual perceptual thresholds of human subjects across a swath of different nGVS levels in order to determine if some individual-subject determined best nGVS level elicited a reduction in thresholds as compared the no noise condition (sham). RESULTS We found improvement in visual thresholds (by an average of 18%, p = 0.014). Subjects with higher (worse) visual thresholds with no stimulation (sham) improved more than those with lower thresholds (p = 0.04). Auditory thresholds were unchanged by vestibular stimulation. CONCLUSION These results are the first demonstration of cross-modal improvement with galvanic vestibular stimulation, indicating galvanic vestibular white noise can produce cross-modal improvements in some sensory channels, but not all.
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Affiliation(s)
- Jamie L. Voros
- Ann & H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado-Boulder, Boulder, CO, United States
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19
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Lajoie K, Marigold DS, Valdés BA, Menon C. The potential of noisy galvanic vestibular stimulation for optimizing and assisting human performance. Neuropsychologia 2021; 152:107751. [PMID: 33434573 DOI: 10.1016/j.neuropsychologia.2021.107751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/17/2022]
Abstract
Noisy galvanic vestibular stimulation (nGVS) is an emerging non-invasive brain stimulation technique. It involves applying alternating currents of different frequencies and amplitudes presented in a random, or noisy, manner through electrodes on the mastoid bones behind the ears. Because it directly activates vestibular hair cells and afferents and has an indirect effect on a variety of brain regions, it has the potential to impact many different functions. The objective of this review is twofold: (1) to review how nGVS affects motor, sensory, and cognitive performance in healthy adults; and (2) to discuss potential clinical applications of nGVS. First, we introduce the technique. We then describe the regions receiving and processing vestibular information. Next, we discuss the effects of nGVS on motor, sensory, and cognitive function in healthy adults. Subsequently, we outline its potential clinical applications. Finally, we highlight other electrical stimulation technologies and discuss why nGVS offers an alternative or complementary approach. Overall, nGVS appears promising for optimizing human performance and as an assistive technology, though further research is required.
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Affiliation(s)
- Kim Lajoie
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Daniel S Marigold
- Sensorimotor Neuroscience Lab, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Bulmaro A Valdés
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Carlo Menon
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada.
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20
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Keywan A, Dietrich H, Wuehr M. Subliminal Passive Motion Stimulation Improves Vestibular Perception. Neuroscience 2020; 441:1-7. [DOI: 10.1016/j.neuroscience.2020.05.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/02/2020] [Accepted: 05/28/2020] [Indexed: 12/30/2022]
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21
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Effects of perceptible and imperceptible galvanic vestibular stimulation on the postural control of patients with bilateral vestibulopathy. J Neurol 2020; 267:2383-2397. [DOI: 10.1007/s00415-020-09852-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 01/01/2023]
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22
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Keywan A, Badarna H, Jahn K, Wuehr M. No evidence for after-effects of noisy galvanic vestibular stimulation on motion perception. Sci Rep 2020; 10:2545. [PMID: 32054910 PMCID: PMC7018946 DOI: 10.1038/s41598-020-59374-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 01/27/2020] [Indexed: 11/09/2022] Open
Abstract
Noisy galvanic vestibular stimulation (nGVS) delivered at imperceptible intensities can improve vestibular function in health and disease. Here we evaluated whether nGVS effects on vestibular function are only present during active stimulation or may exhibit relevant post-stimulation after-effects. Initially, nGVS amplitudes that optimally improve posture were determined in 13 healthy subjects. Subsequently, effects of optimal nGVS amplitudes on vestibular roll-tilt direction recognition thresholds (DRT) were examined during active and sham nGVS. Ten of 13 subjects exhibited reduced DRTs during active nGVS compared to sham stimulation (p < 0.001). These 10 participants were then administered to 30 mins of active nGVS treatment while being allowed to move freely. Immediately post-treatment , DRTs were increased again (p = 0.044), reverting to baseline threshold levels (i.e. were comparable to the sham nGVS thresholds), and remained stable in a follow-up assessment after 30 min. After three weeks, participants returned for a follow-up experiment to control for learning effects, in which DRTs were measured during and immediately after 30 min application of sham nGVS. DRTs during both assessments did not differ from baseline level. These findings indicate that nGVS does not induce distinct post-stimulation effects on vestibular motion perception and favor the development of a wearable technology that continuously delivers nGVS to patients in order to enhance vestibular function.
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Affiliation(s)
- Aram Keywan
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University of Munich, University Hospital Grosshadern, Munich, Germany.
| | - Hiba Badarna
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University of Munich, University Hospital Grosshadern, Munich, Germany
| | - Klaus Jahn
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University of Munich, University Hospital Grosshadern, Munich, Germany.,Schoen Clinic Bad Aibling, Department of Neurology, Bad Aibling, Germany
| | - Max Wuehr
- German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University of Munich, University Hospital Grosshadern, Munich, Germany
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23
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Dlugaiczyk J, Gensberger KD, Straka H. Galvanic vestibular stimulation: from basic concepts to clinical applications. J Neurophysiol 2019; 121:2237-2255. [DOI: 10.1152/jn.00035.2019] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) plays an important role in the quest to understand sensory signal processing in the vestibular system under normal and pathological conditions. It has become a highly relevant tool to probe neuronal computations and to assist in the differentiation and treatment of vestibular syndromes. Following its accidental discovery, GVS became a diagnostic tool that generates eye movements in the absence of head/body motion. With the possibility to record extracellular and intracellular spikes, GVS became an indispensable method to activate or block the discharge in vestibular nerve fibers by cathodal and anodal currents, respectively. Bernie Cohen, in his attempt to decipher vestibular signal processing, has used this method in a number of hallmark studies that have added to our present knowledge, such as the link between selective electrical stimulation of semicircular canal nerves and the generation of directionally corresponding eye movements. His achievements paved the way for other major milestones including the differential recruitment order of vestibular fibers for cathodal and anodal currents, pronounced discharge adaptation of irregularly firing afferents, potential activation of hair cells, and fiber type-specific activation of central circuits. Previous disputes about the structural substrate for GVS are resolved by integrating knowledge of ion channel-related response dynamics of afferents, fiber type-specific innervation patterns, and central convergence and integration of semicircular canal and otolith signals. On the basis of solid knowledge of the methodology, specific waveforms of GVS are currently used in clinical diagnosis and patient treatment, such as vestibular implants and noisy galvanic stimulation.
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Affiliation(s)
- Julia Dlugaiczyk
- German Center for Vertigo and Balance Disorders, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Hans Straka
- Department Biology II, Ludwig-Maximilians-Universität München, Planegg, Germany
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Kwan A, Forbes PA, Mitchell DE, Blouin JS, Cullen KE. Neural substrates, dynamics and thresholds of galvanic vestibular stimulation in the behaving primate. Nat Commun 2019; 10:1904. [PMID: 31015434 PMCID: PMC6478681 DOI: 10.1038/s41467-019-09738-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/21/2019] [Indexed: 11/09/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) uses the external application of electrical current to selectively target the vestibular system in humans. Despite its recent popularity for the assessment/treatment of clinical conditions, exactly how this non-invasive tool activates the vestibular system remains an open question. Here we directly investigate single vestibular afferent responses to GVS applied to the mastoid processes of awake-behaving monkeys. Transmastoid GVS produces robust and parallel activation of both canal and otolith afferents. Notably, afferent activation increases with intrinsic neuronal variability resulting in constant GVS-evoked neuronal detection thresholds across all afferents. Additionally, afferent tuning differs for GVS versus natural self-motion stimulation. Using a stochastic model of repetitive activity in afferents, we largely explain the main features of GVS-evoked vestibular afferent dynamics. Taken together, our results reveal the neural substrate underlying transmastoid GVS-evoked perceptual, ocular and postural responses-information that is essential to advance GVS applicability for biomedical uses in humans.
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Affiliation(s)
- Annie Kwan
- Department of Biomedical Engineering, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Patrick A Forbes
- Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands.,Department of BioMechanical Engineering, Delft University of Technology, Delft, 2628 CD, The Netherlands.,School of Kinesiology, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Diana E Mitchell
- Department of Physiology, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Kathleen E Cullen
- Department of Physiology, McGill University, Montreal, QC, H3G 1Y6, Canada. .,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, 21205, MD, USA.
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