1
|
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.
Collapse
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
| |
Collapse
|
2
|
McCulloch E, Kumar Goothy SS, McKeown J. Electrical vestibular nerve stimulation (VeNS): a follow-up safety assessment of long-term usage. J Basic Clin Physiol Pharmacol 2022; 33:645-648. [PMID: 35285589 DOI: 10.1515/jbcpp-2021-0395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/02/2022] [Indexed: 12/25/2022]
Abstract
OBJECTIVES This retrospective, open-label study was undertaken to assess the safety of repeated, long-term electrical vestibular nerve stimulation (VeNS). The primary outcome for this study was assessment of hearing function as reported by formal audiometry testing. METHODS Assessments were conducted on n=25 long-term users of daily 1.5 mA VeNS. Skin inspection of the mastoid area, otoscope examination of the inner ear, and formal audiometry testing was conducted on n=18 users. All participants completed a survey-based assessment to determine usage of the device, adverse events, and long-term outcomes. RESULTS Mean duration of use was 22 months, with approximately 80% of users reporting 1 h of daily, or 1 h of regular (2-3 times per week) VeNS usage. No adverse events were reported. There were no significant findings during examination of the mastoid areas, ear canal, or tympanic membranes. There were no significant findings reported from the formal audiogram assessments. CONCLUSIONS This appears to be the first study to provide formal assessment to show that repeated, long-term VeNS usage has not generated any significant side effects or adverse events. Results from this study further support previous literature that electrical vestibular stimulation is both safe and well-tolerated.
Collapse
Affiliation(s)
| | | | - Jason McKeown
- Neurovalens Ltd., Belfast, UK.,Wellcome-Wolfson Institute for Experimental Medicine, Queen's University, Belfast, UK.,Center for Brain and Cognition, UC San Diego, San Diego, USA
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Valdés BA, Menon C. Effects of Noisy Galvanic Vestibular Stimulation During a Bimanual Tracking Robotic Task. Front Neurosci 2019; 13:1132. [PMID: 31749673 PMCID: PMC6843009 DOI: 10.3389/fnins.2019.01132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/07/2019] [Indexed: 12/21/2022] Open
Abstract
Background Noisy galvanic vestibular stimulation (nGVS) has been shown to improve motor performance in people with and without disabilities. Previous investigations on the use of nGVS to improve upper-limb motor performance have focused on unimanual fine motor movements, nevertheless, bimanual gross movements are also essential for conducting activities of daily living and can be affected as a result of cerebral dysfunction. Consequently, in this study we investigated the effects of nGVS on bimanual gross motor performance. Methods Twelve healthy participants completed a visuomotor task in which they performed bimanual upper-limb movements using two robots. During the task, participants tracked a target that oscillated following a sinusoidal amplitude-modulated trajectory. In half of the trials, participants received subthreshold nGVS, in the other half, they received sham stimulation. Primary outcome measure: percent improvement in root mean square error (RMSE) between the target’s and cursors’ trajectories. Secondary outcome measures: percent improvement in lag between the cursors and target; and percent improvement in RMSE between the cursors’ trajectories. A post-test questionnaire was administered to evaluate the experience of participants. Results Tracking error was not affected by nGVS: left −2.6(5.5)%, p = 0.128; right −0.9(6.2)%, p = 0.639; nor was bimanual coordination −1.5(9.6)%, p = 0.590. When comparing if one hand was affected more than the other, we did not find a statistically significant difference (−1.7(3.3)%, p = 0.098). Similar results were found for the lag. Questionnaire results indicated that the robotic devices did not limit participants’ movements, did not make participants feel unsafe, nor were they difficult to control. Furthermore, participants did not feel unsafe with the nGVS device, nor did they report any discomfort due to nGVS. Conclusion Results suggest that nGVS applied to people without disabilities do not affect bimanual gross motor performance. However, as this was the first study to investigate such effects, stimulation parameters were based on previous unimanual fine motor studies. Future studies should investigate optimal stimulation parameters for improving upper-limb gross motor performance. Overall, participants felt safe using the robotic devices and receiving the noisy electrical stimulation. As such, a similar setup could potentially be employed for subsequent studies investigating the relation between upper-limb performance and nGVS.
Collapse
Affiliation(s)
- Bulmaro A Valdés
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Carlo Menon
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| |
Collapse
|
5
|
Sluydts M, Curthoys I, Vanspauwen R, Papsin BC, Cushing SL, Ramos A, Ramos de Miguel A, Borkoski Barreiro S, Barbara M, Manrique M, Zarowski A. Electrical Vestibular Stimulation in Humans: A Narrative Review. Audiol Neurootol 2019; 25:6-24. [PMID: 31533097 DOI: 10.1159/000502407] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/29/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND In patients with bilateral vestibulopathy, the regular treatment options, such as medication, surgery, and/or vestibular rehabilitation, do not always suffice. Therefore, the focus in this field of vestibular research shifted to electrical vestibular stimulation (EVS) and the development of a system capable of artificially restoring the vestibular function. Key Message: Currently, three approaches are being investigated: vestibular co-stimulation with a cochlear implant (CI), EVS with a vestibular implant (VI), and galvanic vestibular stimulation (GVS). All three applications show promising results but due to conceptual differences and the experimental state, a consensus on which application is the most ideal for which type of patient is still missing. SUMMARY Vestibular co-stimulation with a CI is based on "spread of excitation," which is a phenomenon that occurs when the currents from the CI spread to the surrounding structures and stimulate them. It has been shown that CI activation can indeed result in stimulation of the vestibular structures. Therefore, the question was raised whether vestibular co-stimulation can be functionally used in patients with bilateral vestibulopathy. A more direct vestibular stimulation method can be accomplished by implantation and activation of a VI. The concept of the VI is based on the technology and principles of the CI. Different VI prototypes are currently being evaluated regarding feasibility and functionality. So far, all of them were capable of activating different types of vestibular reflexes. A third stimulation method is GVS, which requires the use of surface electrodes instead of an implanted electrode array. However, as the currents are sent through the skull from one mastoid to the other, GVS is rather unspecific. It should be mentioned though, that the reported spread of excitation in both CI and VI use also seems to induce a more unspecific stimulation. Although all three applications of EVS were shown to be effective, it has yet to be defined which option is more desirable based on applicability and efficiency. It is possible and even likely that there is a place for all three approaches, given the diversity of the patient population who serves to gain from such technologies.
Collapse
Affiliation(s)
- Morgana Sluydts
- European Institute for Otorhinolaryngology, GZA Hospitals Antwerp, Wilrijk, Belgium,
| | - Ian Curthoys
- Vestibular Research Laboratory, University of Sydney, Sydney, New South Wales, Australia
| | - Robby Vanspauwen
- European Institute for Otorhinolaryngology, GZA Hospitals Antwerp, Wilrijk, Belgium
| | - Blake Croll Papsin
- Department of Otolaryngology - Head and Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sharon Lynn Cushing
- Department of Otolaryngology - Head and Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Angel Ramos
- Hearing Loss Unit, Otorhinolaryngology, Head and Neck Department, Complejo Hospitalario Universitario Insular Materno Infantil, Las Palmas of Gran Canaria, Spain
| | - Angel Ramos de Miguel
- Hearing Loss Unit, Otorhinolaryngology, Head and Neck Department, Complejo Hospitalario Universitario Insular Materno Infantil, Las Palmas of Gran Canaria, Spain
| | - Silvia Borkoski Barreiro
- Hearing Loss Unit, Otorhinolaryngology, Head and Neck Department, Complejo Hospitalario Universitario Insular Materno Infantil, Las Palmas of Gran Canaria, Spain
| | | | - Manuel Manrique
- Otorhinolaryngology Department, Clinica Universidad de Navarra, Pamplona, Spain
| | - Andrzej Zarowski
- European Institute for Otorhinolaryngology, GZA Hospitals Antwerp, Wilrijk, Belgium
| |
Collapse
|
6
|
Noisy galvanic vestibular stimulation: an emerging treatment option for bilateral vestibulopathy. J Neurol 2017; 264:81-86. [DOI: 10.1007/s00415-017-8481-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 01/22/2023]
|
7
|
Grabherr L, Macauda G, Lenggenhager B. The Moving History of Vestibular Stimulation as a Therapeutic Intervention. Multisens Res 2016; 28:653-87. [PMID: 26595961 DOI: 10.1163/22134808-00002495] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although the discovery and understanding of the function of the vestibular system date back only to the 19th century, strategies that involve vestibular stimulation were used long before to calm, soothe and even cure people. While such stimulation was classically achieved with various motion devices, like Cox's chair or Hallaran's swing, the development of caloric and galvanic vestibular stimulation has opened up new possibilities in the 20th century. With the increasing knowledge and recognition of vestibular contributions to various perceptual, motor, cognitive, and emotional processes, vestibular stimulation has been suggested as a powerful and non-invasive treatment for a range of psychiatric, neurological and neurodevelopmental conditions. Yet, the therapeutic interventions were, and still are, often not hypothesis-driven as broader theories remain scarce and underlying neurophysiological mechanisms are often vague. We aim to critically review the literature on vestibular stimulation as a form of therapy in various selected disorders and present its successes, expectations, and drawbacks from a historical perspective.
Collapse
|
8
|
Hashimoto T, Taoka M, Obayashi S, Hara Y, Tanaka M, Iriki A. Modulation of cortical vestibular processing by somatosensory inputs in the posterior insula. Brain Inj 2014; 27:1685-91. [PMID: 24266797 PMCID: PMC3854664 DOI: 10.3109/02699052.2013.831128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Primary objective To study the mechanism of somatosensory-vestibular interactions, this study examined the effects of somatosensory inputs on body sway induced by galvanic vestibular stimulation (GVS) in healthy participants and persons with brain injury in the posterior insula, a region constituting a part of the parietoinsular vestibular cortex. Research design This study adopted an experimental, controlled, repeated measures design. Methods and procedures Participants were 11 healthy individuals, two persons with unilateral posterior insular injury and two age-matched controls. Bipolar GVS was applied to the mastoid processes while participants were sitting with their eyes closed, either lightly touching a stable surface with their index finger or not touching the surface with their index finger. Main outcomes and results In healthy participants, tilting was greater with right hemispheric stimulation than with left hemispheric stimulation. Moreover, with right hemispheric stimulation, tilting was greater with a right finger touch than with no touch. The person with right-brain injury showed tilting induced by GVS; however, finger touch had no modulatory effect. In contrast, finger touch enhanced tilting in the person with left-brain injury. Conclusions These preliminary results are discussed in light of a hypothesis of right hemispheric dominance of somatosensory-vestibular interactions in the posterior insula.
Collapse
Affiliation(s)
- Teruo Hashimoto
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute , Wako , Japan and
| | | | | | | | | | | |
Collapse
|
9
|
Kim DJ, Yogendrakumar V, Chiang J, Ty E, Wang ZJ, McKeown MJ. Noisy galvanic vestibular stimulation modulates the amplitude of EEG synchrony patterns. PLoS One 2013; 8:e69055. [PMID: 23874865 PMCID: PMC3715484 DOI: 10.1371/journal.pone.0069055] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/02/2013] [Indexed: 11/18/2022] Open
Abstract
Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson’s disease; yet, the mechanism of action is unclear. Since Parkinson’s and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4–7.5 Hz), low alpha (8–10 Hz), high alpha (10.5–12 Hz), beta (13–30 Hz) and gamma (31–50 Hz) bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents – at 10, 26, 42, 58, 74 and 90% of sensory threshold – to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20–25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously-described cognitive and motor effects of vestibular stimulation, and noisy galvanic vestibular stimulation may provide an additional non-invasive means for neuromodulation of functional brain networks.
Collapse
Affiliation(s)
- Diana J. Kim
- Neuroscience, University of British Columbia, Vancouver, Canada
| | | | - Joyce Chiang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
| | - Edna Ty
- Pacific Parkinson’s Research Centre, Vancouver, Canada
| | - Z. Jane Wang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
| | - Martin J. McKeown
- Pacific Parkinson’s Research Centre, Vancouver, Canada
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
- Department of Medicine (Neurology), University of British Columbia, Vancouver, Canada
- Brain Research Centre, University of British Columbia, Vancouver, Canada
- * E-mail:
| |
Collapse
|
10
|
Zubko O, Wilkinson D, Langston D, Sakel M. The effect of repeated sessions of galvanic vestibular stimulation on target cancellation in visuo-spatial neglect: preliminary evidence from two cases. Brain Inj 2013; 27:613-9. [PMID: 23473288 DOI: 10.3109/02699052.2013.767938] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE In recent years it has emerged that the attentional disorder of visuo-spatial neglect can be overcome via artificial stimulation of the balance system. One means of achieving this is via galvanic vestibular stimulation (GVS), a simple procedure in which tiny, electrical currents are discharged to the part of the scalp overlying the vestibular nerves. Attempts to remediate neglect with GVS have utilized only a single session of stimulation and, although this can induce spontaneous recovery, symptoms resurface soon after stimulation. This study assessed whether repeated sessions induce longer carry-over. METHODS Two individuals diagnosed with neglect post-stroke received 5 days of sub-sensory, left anodal GVS. Performance was assessed via the letter and star cancellation tasks of the Behavioural Inattention Test on four occasions; 3 days before the start of stimulation, on the first and last day of stimulation and 3-days after stimulation. RESULTS Analyses of variance indicated that both participants missed significantly fewer targets in both tasks on the fifth day of stimulation compared to baseline. More so, this improvement was still evident at follow-up 3 days later. CONCLUSION The results strengthen the need for a larger, sham-controlled trial to establish whether repeated GVS provides lasting relief from neglect.
Collapse
Affiliation(s)
- Olga Zubko
- School of Psychology, University of Kent, UK
| | | | | | | |
Collapse
|
11
|
Carmona S, Ferrero A, Pianetti G, Escolá N, Arteaga MV, Frankel L. Galvanic vestibular stimulation improves the results of vestibular rehabilitation. Ann N Y Acad Sci 2012; 1233:E1-7. [PMID: 22360772 DOI: 10.1111/j.1749-6632.2011.06269.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Here, we present findings from a three-step investigation of the effect of galvanic vestibular stimulation (GVS) in normal subjects and in subjects undergoing vestibular rehabilitation (VR). In an initial study, we examined the body sway of 10 normal subjects after one minute of 2 mA GVS. The effect of the stimulation lasted for at least 20 minutes in all subjects and up to two hours in 70% of the subjects. We then compared a group of patients who received conventional VR (40 patients) with a group that received a combination of VR and GVS. Results suggest a significant improvement in the second group. Finally, we attempted to establish the optimal number of GVS sessions and to rule out a placebo effect. Fifteen patients received "systematic" GVS: five sessions, once a week. Five patients received "nonsystematic" galvanic stimulation in a sham protocol, which included two stimulations of the clavicle. These data were analyzed with Fisher's exact test and indicated that the best results were obtained after three sessions of GVS and no placebo effect was observed.
Collapse
Affiliation(s)
- Sergio Carmona
- Neurotology Department, Instituto San Lucas Neurociencias, Rosario, Argentina.
| | | | | | | | | | | |
Collapse
|
12
|
Utz KS, Korluss K, Schmidt L, Rosenthal A, Oppenländer K, Keller I, Kerkhoff G. Minor adverse effects of galvanic vestibular stimulation in persons with stroke and healthy individuals. Brain Inj 2011; 25:1058-69. [DOI: 10.3109/02699052.2011.607789] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|