1
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Lee S, Liu A, McKeown MJ. Current perspectives on galvanic vestibular stimulation in the treatment of Parkinson's disease. Expert Rev Neurother 2021; 21:405-418. [PMID: 33621149 DOI: 10.1080/14737175.2021.1894928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Galvanic vestibular stimulation (GVS) is a noninvasive technique that activates vestibular afferents, influencing activity and oscillations in a broad network of brain regions. Several studies have suggested beneficial effects of GVS on motor symptoms in Parkinson's Disease (PD).Areas covered: A comprehensive overview of the stimulation techniques, potential mechanisms of action, challenges, and future research directions.Expert opinion: This emerging technology is not currently a viable therapy. However, a complementary therapy that is inexpensive, easily disseminated, customizable, and portable is sufficiently enticing that continued research and development is warranted. Future work utilizing biomedical engineering approaches, including concomitant functional neuroimaging, have the potential to significantly increase efficacy. GVS could be explored for other PD symptoms including orthostatic hypotension, dyskinesia, and sleep disorders.
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Affiliation(s)
- Soojin Lee
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.,Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford UK
| | - Aiping Liu
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, China
| | - Martin J McKeown
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.,Department of Medicine, University of British Columbia, Vancouver, Canada
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2
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Direct comparison of activation maps during galvanic vestibular stimulation: A hybrid H2[15 O] PET-BOLD MRI activation study. PLoS One 2020; 15:e0233262. [PMID: 32413079 PMCID: PMC7228124 DOI: 10.1371/journal.pone.0233262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 05/01/2020] [Indexed: 12/17/2022] Open
Abstract
Previous unimodal PET and fMRI studies in humans revealed a reproducible vestibular brain activation pattern, but with variations in its weighting and expansiveness. Hybrid studies minimizing methodological variations at baseline conditions are rare and still lacking for task-based designs. Thus, we applied for the first time hybrid 3T PET-MRI scanning (Siemens mMR) in healthy volunteers using galvanic vestibular stimulation (GVS) in healthy volunteers in order to directly compare H215O-PET and BOLD MRI responses. List mode PET acquisition started with the injection of 750 MBq H215O simultaneously to MRI EPI sequences. Group-level statistical parametric maps were generated for GVS vs. rest contrasts of PET, MR-onset (event-related), and MR-block. All contrasts showed a similar bilateral vestibular activation pattern with remarkable proximity of activation foci. Both BOLD contrasts gave more bilateral wide-spread activation clusters than PET; no area showed contradictory signal responses. PET still confirmed the right-hemispheric lateralization of the vestibular system, whereas BOLD-onset revealed only a tendency. The reciprocal inhibitory visual-vestibular interaction concept was confirmed by PET signal decreases in primary and secondary visual cortices, and BOLD-block decreases in secondary visual areas. In conclusion, MRI activation maps contained a mixture of CBF measured using H215O-PET and additional non-CBF effects, and the activation-deactivation pattern of the BOLD-block appears to be more similar to the H215O-PET than the BOLD-onset.
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3
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Colebatch JG, Rosengren SM. Investigating short latency subcortical vestibular projections in humans: what have we learned? J Neurophysiol 2019; 122:2000-2015. [PMID: 31596627 DOI: 10.1152/jn.00157.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Vestibular evoked myogenic potentials (VEMPs) are now widely used for the noninvasive assessment of vestibular function and diagnosis in humans. This review focuses on the origin, properties, and mechanisms of cervical VEMPs and ocular VEMPs; how these reflexes relate to reports of vestibular projections to brain stem and cervical targets; and the physiological role of (otolithic) cervical and ocular reflexes. The evidence suggests that both VEMPs are likely to represent the effects of excitation of irregularly firing otolith afferents. While the air-conducted cervical VEMP appears to mainly arise from excitation of saccular receptors, the ocular VEMP evoked by bone-conducted stimulation, including impulsive bone-conducted stimuli, mainly arises from utricular afferents. The surface responses are generated by brief changes in motor unit firing. The effects that have been demonstrated are likely to represent otolith-dependent vestibulocollic and vestibulo-ocular reflexes, both linear and torsional. These observations add to previous reports of short latency otolith projections to the target muscles in the neck (sternocleidomastoid and splenius) and extraocular muscles (the inferior oblique). New insights have been provided by the investigation and application of these techniques.
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Affiliation(s)
- James G Colebatch
- Prince of Wales Hospital Clinical School, University of New South Wales, Sydney, New South Wales, Australia.,Neuroscience Research Australia, University of New South Wales, Sydney, New South Wales, Australia
| | - Sally M Rosengren
- Department of Neurology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.,Central Clinical School, The University of Sydney, Sydney, New South Wales, Australia
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4
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Khosravi‐Hashemi N, Forbes PA, Dakin CJ, Blouin J. Virtual signals of head rotation induce gravity‐dependent inferences of linear acceleration. J Physiol 2019; 597:5231-5246. [DOI: 10.1113/jp278642] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
| | - Patrick A. Forbes
- Department of NeuroscienceErasmus MCUniversity Medical Center Rotterdam Rotterdam The Netherlands
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5
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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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6
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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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7
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Keywan A, Jahn K, Wuehr M. Noisy Galvanic Vestibular Stimulation Primarily Affects Otolith-Mediated Motion Perception. Neuroscience 2019; 399:161-166. [DOI: 10.1016/j.neuroscience.2018.12.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 10/27/2022]
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8
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Is hippocampal neurogenesis modulated by the sensation of self-motion encoded by the vestibular system? Neurosci Biobehav Rev 2017; 83:489-495. [DOI: 10.1016/j.neubiorev.2017.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/10/2017] [Accepted: 09/10/2017] [Indexed: 01/26/2023]
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9
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Hammam E, Macefield VG. Vestibular Modulation of Sympathetic Nerve Activity to Muscle and Skin in Humans. Front Neurol 2017; 8:334. [PMID: 28798718 PMCID: PMC5526846 DOI: 10.3389/fneur.2017.00334] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 06/26/2017] [Indexed: 12/19/2022] Open
Abstract
We review the existence of vestibulosympathetic reflexes in humans. While several methods to activate the human vestibular apparatus have been used, galvanic vestibular stimulation (GVS) is a means of selectively modulating vestibular afferent activity via electrodes over the mastoid processes, causing robust vestibular illusions of side-to-side movement. Sinusoidal GVS (sGVS) causes partial entrainment of sympathetic outflow to muscle and skin. Modulation of muscle sympathetic nerve activity (MSNA) from vestibular inputs competes with baroreceptor inputs, with stronger temporal coupling to the vestibular stimulus being observed at frequencies remote from the cardiac frequency; “super entrainment” was observed in some individuals. Low-frequency (<0.2 Hz) sGVS revealed two peaks of modulation per cycle, with bilateral recordings of MSNA or skin sympathetic nerve activity, providing evidence of lateralization of sympathetic outflow during vestibular stimulation. However, it should be noted that GVS influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. To identify the specific source of vestibular input responsible for the generation of vestibulosympathetic reflexes, we used low-frequency (<0.2 Hz) sinusoidal linear acceleration of seated or supine subjects to, respectively, target the utricular or saccular components of the otoliths. While others had discounted the semicircular canals, we showed that the contributions of the utricle and saccule to the vestibular modulation of MSNA are very similar. Moreover, that modulation of MSNA occurs at accelerations well below levels at which subjects are able to perceive any motion indicates that, like vestibulospinal control of posture, the vestibular system contributes to the control of blood pressure through potent reflexes in humans.
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Affiliation(s)
- Elie Hammam
- School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Vaughan G Macefield
- School of Medicine, Western Sydney University, Sydney, NSW, Australia.,Neuroscience Research Australia, Sydney, NSW, Australia
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10
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Ueberfuhr MA, Braun A, Wiegrebe L, Grothe B, Drexl M. Modulation of auditory percepts by transcutaneous electrical stimulation. Hear Res 2017; 350:235-243. [DOI: 10.1016/j.heares.2017.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/10/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
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11
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Cohen B, Martinelli GP, Xiang Y, Raphan T, Yakushin SB. Vestibular Activation Habituates the Vasovagal Response in the Rat. Front Neurol 2017; 8:83. [PMID: 28360882 PMCID: PMC5350135 DOI: 10.3389/fneur.2017.00083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/24/2017] [Indexed: 12/16/2022] Open
Abstract
Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long–Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated activation of the vestibulosympathetic reflex (VSR) with ±2 and ±3 mA, 0.025 Hz sinusoidal galvanic vestibular stimulation (sGVS) caused incremental changes in blood pressure (BP) and heart rate (HR) that blocked further generation of vasovagal responses. Initially, BP and HR fell ≈20–50 mmHg and ≈20–50 beats/min (bpm) into a vasovagal response when stimulated with Sgv\S in susceptible rats. As the rats were continually stimulated, HR initially rose to counteract the fall in BP; then the increase in HR became more substantial and long lasting, effectively opposing the fall in BP. Finally, the vestibular stimuli simply caused an increase in BP, the normal sequence following activation of the VSR. Concurrently, habituation caused disappearance of the low-frequency (0.025 and 0.05 Hz) oscillations in BP and HR that must be present when vasovagal responses are induced. Habituation also produced significant increases in baroreflex sensitivity (p < 0.001). Thus, repeated low-frequency activation of the VSR resulted in a reduction and loss of susceptibility to development of vasovagal responses in rats that were previously highly susceptible. We posit that reactivation of the baroreflex, which is depressed by anesthesia and the disappearance of low-frequency oscillations in BP and HR are likely to be critically involved in producing resistance to the development of vasovagal responses. SGVS has been widely used to activate muscle sympathetic nerve activity in humans and is safe and well tolerated. Potentially, it could be used to produce similar habituation of vasovagal syncope in humans.
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Affiliation(s)
- Bernard Cohen
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Giorgio P Martinelli
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Yongqing Xiang
- Department of Computer and Information Science, Brooklyn College, City University of New York , New York, NY , USA
| | - Theodore Raphan
- Department of Computer and Information Science, Brooklyn College, City University of New York , New York, NY , USA
| | - Sergei B Yakushin
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
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12
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Forbes PA, Vlutters M, Dakin CJ, van der Kooij H, Blouin J, Schouten AC. Rapid limb-specific modulation of vestibular contributions to ankle muscle activity during locomotion. J Physiol 2017; 595:2175-2195. [PMID: 28008621 PMCID: PMC5350434 DOI: 10.1113/jp272614] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 12/16/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The vestibular influence on human walking is phase-dependent and modulated across both limbs with changes in locomotor velocity and cadence. Using a split-belt treadmill, we show that vestibular influence on locomotor activity is modulated independently in each limb. The independent vestibular modulation of muscle activity from each limb occurs rapidly at the onset of split-belt walking, over a shorter time course relative to the characteristic split-belt error-correction mechanisms (i.e. muscle activity and kinematics) associated with locomotor adaptation. Together, the present results indicate that the nervous system rapidly modulates the vestibular influence of each limb separately through processes involving ongoing sensory feedback loops. These findings help us understand how vestibular information is used to accommodate the variable and commonplace demands of locomotion, such as turning or navigating irregular terrain. ABSTRACT During walking, the vestibular influence on locomotor activity is phase-dependent and modulated in both limbs with changes in velocity. It is unclear, however, whether this bilateral modulation is due to a coordinated mechanism between both limbs or instead through limb-specific processes that remain masked by the symmetric nature of locomotion. Here, human subjects walked on a split-belt treadmill with one belt moving at 0.4 m s-1 and the other moving at 0.8 m s-1 while exposed to an electrical vestibular stimulus. Muscle activity was recorded bilaterally around the ankles of each limb and used to compare vestibulo-muscular coupling between velocity-matched and unmatched tied-belt walking. In general, response magnitudes decreased by ∼20-50% and occurred ∼13-20% earlier in the stride cycle at the higher belt velocity. This velocity-dependent modulation of vestibular-evoked muscle activity was retained during split-belt walking and was similar, within each limb, to velocity-matched tied-belt walking. These results demonstrate that the vestibular influence on ankle muscles during locomotion can be adapted independently to each limb. Furthermore, modulation of vestibular-evoked muscle responses occurred rapidly (∼13-34 strides) after onset of split-belt walking. This rapid adaptation contrasted with the prolonged adaptation in step length symmetry (∼128 strides) as well as EMG magnitude and timing (∼40-100 and ∼20-70 strides, respectively). These results suggest that vestibular influence on ankle muscle control is adjusted rapidly in sensorimotor control loops as opposed to longer-term error correction mechanisms commonly associated with split-belt adaptation. Rapid limb-specific sensorimotor feedback adaptation may be advantageous for asymmetric overground locomotion, such as navigating irregular terrain or turning.
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Affiliation(s)
- Patrick A. Forbes
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials EngineeringDelft University of TechnologyDelftThe Netherlands
- Department of NeuroscienceErasmus Medical CentreRotterdamThe Netherlands
- School of KinesiologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Mark Vlutters
- Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA)University of TwenteEnschedeThe Netherlands
| | - Christopher J. Dakin
- Sobell Department of Motor Neuroscience and Movement DisordersUniversity College London Institute of NeurologyLondonUK
- Department of Kinesiology and Health ScienceUtah State UniversityLoganUtahUSA
| | - Herman van der Kooij
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials EngineeringDelft University of TechnologyDelftThe Netherlands
- Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA)University of TwenteEnschedeThe Netherlands
| | - Jean‐Sébastien Blouin
- School of KinesiologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Institute for Computing, Information and Cognitive SystemsUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Alfred C. Schouten
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials EngineeringDelft University of TechnologyDelftThe Netherlands
- Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA)University of TwenteEnschedeThe Netherlands
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13
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Kim G, Kim KS, Lee S. The integration of neural information by a passive kinetic stimulus and galvanic vestibular stimulation in the lateral vestibular nucleus. Med Biol Eng Comput 2017; 55:1621-1633. [PMID: 28176264 DOI: 10.1007/s11517-017-1618-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 01/25/2017] [Indexed: 02/07/2023]
Abstract
Despite an easy control and the direct effects on vestibular neurons, the clinical applications of galvanic vestibular stimulation (GVS) have been restricted because of its unclear activities as input. On the other hand, some critical conclusions have been made in the peripheral and the central processing of neural information by kinetic stimuli with different motion frequencies. Nevertheless, it is still elusive how the neural responses to simultaneous GVS and kinetic stimulus are modified during transmission and integration at the central vestibular area. To understand how the neural information was transmitted and integrated, we examined the neuronal responses to GVS, kinetic stimulus, and their combined stimulus in the vestibular nucleus. The neuronal response to each stimulus was recorded, and its responding features (amplitude and baseline) were extracted by applying the curve fitting based on a sinusoidal function. Twenty-five (96.2%) comparisons of the amplitudes showed that the amplitudes decreased during the combined stimulus (p < 0.001). However, the relations in the amplitudes (slope = 0.712) and the baselines (slope = 0.747) were linear. The neuronal effects by the different stimuli were separately estimated; the changes of the amplitudes were mainly caused by the kinetic stimulus and those of the baselines were largely influenced by GVS. Therefore, the slopes in the comparisons implied the neural sensitivity to the applied stimuli. Using the slopes, we found that the reduced amounts of the neural information were transmitted. Overall, the comparisons of the responding features demonstrated the linearity and the subadditivity in the neural transmission.
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Affiliation(s)
- Gyutae Kim
- Institute for Information and Electronics Research, Inha University, High-Tech Center #716, 100 Inharo, Namgu, Incheon, 402-751, Republic of Korea.
| | - Kyu-Sung Kim
- Institute for Information and Electronics Research, Inha University, High-Tech Center #716, 100 Inharo, Namgu, Incheon, 402-751, Republic of Korea.,Department of Otolaryngology, School of Medicine, Inha University, 27 Inhang-ro, Jung-Gu, Incheon, 400-711, Republic of Korea
| | - Sangmin Lee
- Institute for Information and Electronics Research, Inha University, High-Tech Center #716, 100 Inharo, Namgu, Incheon, 402-751, Republic of Korea.,School of Electronic/Electrical Engineering, Inha University, High-Tech Center #704, 100 Inharo, Namgu, Incheon, 402-751, Republic of Korea
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14
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Phillips JO, Ling L, Nie K, Jameyson E, Phillips CM, Nowack AL, Golub JS, Rubinstein JT. Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects. J Neurophysiol 2015; 113:3866-92. [PMID: 25652917 DOI: 10.1152/jn.00171.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 02/02/2015] [Indexed: 11/22/2022] Open
Abstract
Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0-400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear.
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Affiliation(s)
- James O Phillips
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; National Primate Research Center, University of Washington, Seattle, Washington; and Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington
| | - Leo Ling
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; National Primate Research Center, University of Washington, Seattle, Washington; and
| | - Kaibao Nie
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington
| | - Elyse Jameyson
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington
| | - Christopher M Phillips
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; National Primate Research Center, University of Washington, Seattle, Washington; and
| | - Amy L Nowack
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; National Primate Research Center, University of Washington, Seattle, Washington; and
| | - Justin S Golub
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington
| | - Jay T Rubinstein
- Department of Otolaryngology-HNS, University of Washington, Seattle, Washington; Department of Bioengineering, University of Washington, Seattle, Washington; National Primate Research Center, University of Washington, Seattle, Washington; and Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington
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15
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Holstein GR, Friedrich VL, Martinelli GP. Projection neurons of the vestibulo-sympathetic reflex pathway. J Comp Neurol 2015; 522:2053-74. [PMID: 24323841 DOI: 10.1002/cne.23517] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 12/20/2022]
Abstract
Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminates on cells in the vestibular nuclear complex, which in turn project to brainstem sites involved in the regulation of cardiovascular activity, including the rostral and caudal ventrolateral medullary regions (RVLM and CVLM, respectively). In the present study, sinusoidal galvanic vestibular stimulation was used to activate this pathway, and activated neurons were identified through detection of c-Fos protein. The retrograde tracer Fluoro-Gold was injected into the RVLM or CVLM of these animals, and immunofluorescence studies of vestibular neurons were conducted to visualize c-Fos protein and Fluoro-Gold concomitantly. We observed activated projection neurons of the vestibulo-sympathetic reflex pathway in the caudal half of the spinal, medial, and parvocellular medial vestibular nuclei. Approximately two-thirds of the cells were ipsilateral to Fluoro-Gold injection sites in both the RVLM and CVLM, and the remainder were contralateral. As a group, cells projecting to the RVLM were located slightly rostral to those with terminals in the CVLM. Individual activated projection neurons were multipolar, globular, or fusiform in shape. This study provides the first direct demonstration of the central vestibular neurons that mediate the vestibulo-sympathetic reflex.
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Affiliation(s)
- Gay R Holstein
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, 10029; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
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Forbes PA, Siegmund GP, Schouten AC, Blouin JS. Task, muscle and frequency dependent vestibular control of posture. Front Integr Neurosci 2015; 8:94. [PMID: 25620919 PMCID: PMC4288134 DOI: 10.3389/fnint.2014.00094] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/04/2014] [Indexed: 11/13/2022] Open
Abstract
The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwidth of vestibular input on neck muscles is much broader than appendicular muscles (up to a factor of 3). This result challenges the notion that vestibular reflexes only contribute to postural control across the behavioral and physiological frequency range of the vestibular organ (i.e., 0-20 Hz). In this review, we explore and integrate these task-, muscle- and frequency-related differences in the vestibular system's contribution to posture, and propose that the human nervous system has adapted vestibular signals to match the mechanical properties of the system that each group of muscles controls.
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Affiliation(s)
- Patrick A Forbes
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology Delft, Netherlands ; School of Kinesiology, University of British Columbia Vancouver, B. C., Canada
| | - Gunter P Siegmund
- School of Kinesiology, University of British Columbia Vancouver, B. C., Canada ; MEA Forensic Engineers & Scientists Richmond, B. C., Canada
| | - Alfred C Schouten
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology Delft, Netherlands ; Laboratory of Biomechanical Engineering, Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente Twente, Netherlands
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia Vancouver, B. C., Canada ; Institute for Computing, Information and Cognitive Systems (ICICS), University of British Columbia Vancouver, B. C., Canada ; Brain Research Centre, University of British Columbia Vancouver, B. C., Canada
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Yakushin SB, Martinelli GP, Raphan T, Xiang Y, Holstein GR, Cohen B. Vasovagal oscillations and vasovagal responses produced by the vestibulo-sympathetic reflex in the rat. Front Neurol 2014; 5:37. [PMID: 24772102 PMCID: PMC3983498 DOI: 10.3389/fneur.2014.00037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/14/2014] [Indexed: 12/17/2022] Open
Abstract
Sinusoidal galvanic vestibular stimulation (sGVS) induces oscillations in blood pressure (BP) and heart rate (HR), i.e., vasovagal oscillations, as well as transient decreases in BP and HR, i.e., vasovagal responses, in isoflurane-anesthetized rats. We determined the characteristics of the vasovagal oscillations, assessed their role in the generation of vasovagal responses, and determined whether they could be induced by monaural as well as by binaural sGVS and by oscillation in pitch. Wavelet analyses were used to determine the power distributions of the waveforms. Monaural and binaural sGVS and pitch generated vasovagal oscillations at the frequency and at twice the frequency of stimulation. Vasovagal oscillations and vasovagal responses were maximally induced at low stimulus frequencies (0.025-0.05 Hz). The oscillations were attenuated and the responses were rarely induced at higher stimulus frequencies. Vasovagal oscillations could occur without induction of vasovagal responses, but vasovagal responses were always associated with a vasovagal oscillation. We posit that the vasovagal oscillations originate in a low frequency band that, when appropriately activated by strong sympathetic stimulation, can generate vasovagal oscillations as a precursor for vasovagal responses and syncope. We further suggest that the activity responsible for the vasovagal oscillations arises in low frequency, otolith neurons with orientation vectors close to the vertical axis of the head. These neurons are likely to provide critical input to the vestibulo-sympathetic reflex to increase BP and HR upon changes in head position relative to gravity, and to contribute to the production of vasovagal oscillations and vasovagal responses and syncope when the baroreflex is inactivated.
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Affiliation(s)
- Sergei B Yakushin
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Giorgio P Martinelli
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Theodore Raphan
- Department of Computer and Information Sciences, Brooklyn College of the City University of New York , Brooklyn, NY , USA
| | - Yongqing Xiang
- Department of Computer and Information Sciences, Brooklyn College of the City University of New York , Brooklyn, NY , USA
| | - Gay R Holstein
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Bernard Cohen
- Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA
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Zheng Y, Geddes L, Sato G, Stiles L, Darlington CL, Smith PF. Galvanic vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory. Hippocampus 2014; 24:541-52. [DOI: 10.1002/hipo.22247] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Yiwen Zheng
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
| | - Lisa Geddes
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
| | - Go Sato
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
- Department of Otolaryngology; University of Tokushima; Tokushima Japan
| | - Lucy Stiles
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
| | - Cynthia L. Darlington
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
| | - Paul F. Smith
- Department of Pharmacology and Toxicology; School of Medical Sciences; and the Brain Health Research Centre; University of Otago; New Zealand
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Cohen B, Martinelli GP, Raphan T, Schaffner A, Xiang Y, Holstein GR, Yakushin SB. The vasovagal response of the rat: its relation to the vestibulosympathetic reflex and to Mayer waves. FASEB J 2013; 27:2564-72. [PMID: 23504712 PMCID: PMC3688754 DOI: 10.1096/fj.12-226381] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/04/2013] [Indexed: 12/15/2022]
Abstract
Vasovagal responses (VVRs) are characterized by transient drops in blood pressure (BP) and heart rate (HR) and increased amplitude of low-frequency oscillations in the Mayer wave frequency range. Typical VVRs were induced in anesthetized, male, Long-Evans rats by sinusoidal galvanic vestibular stimulation (sGVS). VVRs were also produced by single sinusoids that transiently increased BP and HR, by 70-90° nose-up tilts, and by 60° tilts of the gravitoinertial acceleration vector using translation while rotating (TWR). The average power of the BP signal in the Mayer wave range increased substantially when tilts were >70° (0.91 g), i.e., when linear accelerations in the x-z plane were ≥0.9-1.0 g. The standard deviations of the wavelet-filtered BP signals during tilt and TWR overlaid when they were normalized to 1 g. Thus, the amplitudes of the Mayer waves coded the magnitude of the linear acceleration ≥1 g acting on the head and body, and the average power in this frequency range was associated with the generation of VVRs. These data show that VVRs are a natural outcome of stimulation of the vestibulosympathetic reflex and are not a disease. The results also demonstrate the usefulness of the rat as a small animal model for studying human VVRs.
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Affiliation(s)
- Bernard Cohen
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, Brooklyn 10029-6574, USA.
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