scholarly journals Electrical Vestibular Stimulation in Humans: A Narrative Review

2019 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 6-24 ◽  
Author(s):  
Morgana Sluydts ◽  
Ian Curthoys ◽  
Robby Vanspauwen ◽  
Blake Croll Papsin ◽  
Sharon Lynn Cushing ◽  
...  
Keyword(s):  
Treatment Options ◽  
Electrode Array ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Bilateral Vestibulopathy ◽  
Regular Treatment ◽  
Surface Electrodes ◽  
Different Types ◽  
Spread Of Excitation ◽  
Stimulation Method

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.

Intraoperative transimpedance and spread of excitation profile correlations with a lateral-wall cochlear implant electrode array

2021 ◽  
Vol 405 ◽  
pp. 108235
Author(s):  
Samuel Söderqvist ◽  
Satu Lamminmäki ◽  
Antti Aarnisalo ◽  
Timo Hirvonen ◽  
Saku T. Sinkkonen ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Lateral Wall ◽  
Excitation Profile ◽  
Spread Of Excitation

Assessing head acceleration to identify a motor threshold to galvanic vestibular stimulation

2021 ◽  
Author(s):  
Youstina Mikhail ◽  
Jonathan Charron ◽  
Jean-Marc Mac Thiong ◽  
Dorothy Barthélemy
Keyword(s):  
Center Of Pressure ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Galvanic Vestibular Stimulation ◽  
Head Acceleration ◽  
Motor Threshold ◽  
Recruitment Curve ◽  
Eyes Closed ◽  
Postural Responses ◽  
Significant Difference

Galvanic vestibular stimulation (GVS) is used to assess vestibular function, but vestibular responses can exhibit variability depending on protocols or intensities used. We measured head acceleration in healthy subjects to identify an objective motor threshold on which to base GVS intensity when assessing postural responses. Thirteen healthy right-handed subjects stood on a force platform, eyes closed, head facing forward. An accelerometer was placed on the vertex to detect head acceleration, and electromyography activity of the right soleus was recorded. GVS (200 ms; current steps 0.5;1-4mA) was applied in a binaural and bipolar configuration. 1) GVS induced a biphasic accelerometer response at a latency of 15 ms. Based on response amplitude, we constructed a recruitment curve for all participants and determined the motor threshold. In parallel, the method of limits was used to devise a more rapid approach to determine motor threshold. 2) We observed significant differences between motor threshold based on therecruitment curve and perceptual thresholds (sensation/perception of movement). No significant difference was observed between the motor threshold based on the method of limits and perceptual thresholds . 3) Using orthogonal polynomial contrasts, we observed a linear progression between multiples of the objective motor threshold (0.5, 0.75, 1, 1.5x motor threshold) and the 95% confidence ellipse area, the first peak of center of pressure velocity, and the short and medium latency responses in the soleus. Hence, an objective motor threshold and a recruitment curve for GVS were determined based on head acceleration, which could increase understanding of the vestibular system.

scholarly journals Paving the Way Toward Distinguishing Fallers From Non-fallers in Bilateral Vestibulopathy: A Wide Pilot Observation

2021 ◽  
Vol 12 ◽  
Author(s):  
Nolan Herssens ◽  
Bieke Dobbels ◽  
Julie Moyaert ◽  
Raymond Van de Berg ◽  
Wim Saeys ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Fear Of Falling ◽  
Daily Life ◽  
Contextual Information ◽  
Vestibular Function ◽  
Future Research ◽  
Risk Of Falling ◽  
Bilateral Vestibulopathy ◽  
Activities Of Daily Life ◽  
Increased Risk

Patients with bilateral vestibulopathy (BVP) present with unsteadiness during standing and walking, limiting their activities of daily life and, more importantly, resulting in an increased risk of falling. In BVP patients, falls are considered as one of the major complications, with patients having a 31-fold increased risk of falling compared to healthy subjects. Thus, highlighting objective measures that can easily and accurately assess the risk of falling in BVP patients is an important step in reducing the incidence of falls and the accompanying burdens. Therefore, this study investigated the interrelations between demographic characteristics, vestibular function, questionnaires on self-perceived handicap and balance confidence, clinical balance measures, gait variables, and fall status in 27 BVP patients. Based on the history of falls in the preceding 12 months, the patients were subdivided in a “faller” or “non-faller” group. Results on the different outcome measures were compared between the “faller” and “non-faller” subgroups using Pearson's chi-square test in the case of categorical data; for continuous data, Mann–Whitney U test was used. Performances on the clinical balance measures were comparable between fallers and non-fallers, indicating that, independent from fall status, the BVP patients present with an increased risk of falling. However, fallers tended to report a worse self-perceived handicap and confidence during performing activities of daily life. Spatiotemporal parameters of gait did not differ between fallers and non-fallers during walking at slow, preferred, or fast walking speed. These results may thus imply that, when aiming to distinguish fallers from non-fallers, the BVP patients' beliefs concerning their capabilities may be more important than the moderately or severely affected physical performance within a clinical setting. Outcome measures addressing the self-efficacy and fear of falling in BVP patients should therefore be incorporated in future research to investigate whether these are indeed able to distinguish fallers form non-fallers. Additionally, information regarding physical activity could provide valuable insights on the contextual information influencing behavior and falls in BVP.

scholarly journals Could Brain–Computer Interface Be a New Therapeutic Approach for Body Integrity Dysphoria?

2021 ◽  
Vol 15 ◽  
Author(s):  
Stuti Chakraborty ◽  
Gianluca Saetta ◽  
Colin Simon ◽  
Bigna Lenggenhager ◽  
Kathy Ruddy
Keyword(s):  
Brain Activity ◽  
Brain Computer Interface ◽  
Treatment Options ◽  
Body Representation ◽  
Vestibular Stimulation ◽  
Current Treatment ◽  
Substantial Improvement ◽  
Computer Interface ◽  
Effective Form ◽  
Brain Correlates

Patients suffering from body integrity dysphoria (BID) desire to become disabled, arising from a mismatch between the desired body and the physical body. We focus here on the most common variant, characterized by the desire for amputation of a healthy limb. In most reported cases, amputation of the rejected limb entirely alleviates the distress of the condition and engenders substantial improvement in quality of life. Since BID can lead to life-long suffering, it is essential to identify an effective form of treatment that causes the least amount of alteration to the person’s anatomical structure and functionality. Treatment methods involving medications, psychotherapy, and vestibular stimulation have proven largely ineffective. In this hypothesis article, we briefly discuss the characteristics, etiology, and current treatment options available for BID before highlighting the need for new, theory driven approaches. Drawing on recent findings relating to functional and structural brain correlates of BID, we introduce the idea of brain–computer interface (BCI)/neurofeedback approaches to target altered patterns of brain activity, promote re-ownership of the limb, and/or attenuate stress and negativity associated with the altered body representation.

scholarly journals Effects of Different Types of Exercise Training on Pulmonary Arterial Hypertension: A Systematic Review

2020 ◽  
Vol 9 (6) ◽  
pp. 1689 ◽  
Author(s):  
Lena Waller ◽  
Karsten Krüger ◽  
Kerstin Conrad ◽  
Astrid Weiss ◽  
Katharina Alack
Keyword(s):  
Physical Activity ◽  
Pulmonary Arterial Hypertension ◽  
Exercise Training ◽  
Arterial Hypertension ◽  
Treatment Options ◽  
Human Studies ◽  
Respiratory Muscle Training ◽  
Exercise Interventions ◽  
Different Types ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) represents a chronic progressive disease characterized by high blood pressure in the pulmonary arteries leading to right heart failure. The disease has been a focus of medical research for many years due to its worse prognosis and limited treatment options. The aim of this study was to systematically assess the effects of different types of exercise interventions on PAH. Electronic databases were searched until July 2019. MEDLINE database was used as the predominant source for this paper. Studies with regards to chronic physical activity in adult PAH patients are compared on retrieving evidence on cellular, physiological, and psychological alterations in the PAH setting. Twenty human studies and 12 rat trials were identified. Amongst all studies, a total of 628 human subjects and 614 rats were examined. Regular physical activity affects the production of nitric oxygen and attenuates right ventricular hypertrophy. A combination of aerobic, anaerobic, and respiratory muscle training induces the strongest improvement in functional capacity indicated by an increase of 6 MWD and VO2 peak. In human studies, an increase of quality of life was found. Exercise training has an overall positive effect on the physiological and psychological components of PAH. Consequently, PAH patients should be encouraged to take part in regular exercise training programs.

Vestibular habituation during repetitive complex stimulation: a study of transfer effects

1964 ◽  
Vol 19 (5) ◽  
pp. 1005-1015 ◽  
Author(s):  
Fred E. Guedry ◽  
William E. Collins ◽  
Ashton Graybiel
Keyword(s):  
Vestibular Function ◽  
Frontal Plane ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Residual Effects ◽  
Slow Rotation ◽  
Transfer Effects ◽  
Center Of Rotation ◽  
Static Tests ◽  
Rotation Direction

Thirty-two men were rotated at 7.5 rev/min while facing the center of the Pensacola slow rotation room for several hours. The men were seated 4 ft from the center of rotation; direction of rotation was toward the subject's left. During rotation, subjects were immobile except for series of measured head movements restricted to the frontal plane and to a particular quadrant of that plane for each subject. Nystagmus, illusory phenomena, and nausea were reduced by this procedure, but this habituation did not transfer to other forms of vestibular stimulation including that induced by head movements in an “unpracticed” quadrant of the same plane. Residual effects exhibited in “static tests” after the habituation program were primarily restricted to the practiced quadrant. habituation; nystagmus; vestibular function Submitted on January 15, 1964

scholarly journals Finding a Balance: A Systematic Review of the Biomechanical Effects of Vestibular Prostheses on Stability in Humans

2020 ◽  
Vol 5 (2) ◽  
pp. 23
Author(s):  
Felix Haxby ◽  
Mohammad Akrami ◽  
Reza Zamani
Keyword(s):  
Vestibular System ◽  
Postural Sway ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Significant Heterogeneity ◽  
Vestibular Loss ◽  
Ocular Reflex ◽  
Gait Characteristics ◽  
Vestibulo Ocular Reflex ◽  
Meta Analyses

The vestibular system is located in the inner ear and is responsible for maintaining balance in humans. Bilateral vestibular dysfunction (BVD) is a disorder that adversely affects vestibular function. This results in symptoms such as postural imbalance and vertigo, increasing the incidence of falls and worsening quality of life. Current therapeutic options are often ineffective, with a focus on symptom management. Artificial stimulation of the vestibular system, via a vestibular prosthesis, is a technique being explored to restore vestibular function. This review systematically searched for literature that reported the effect of artificial vestibular stimulation on human behaviours related to balance, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) technique. A total of 21 papers matched the inclusion criteria of the literature search conducted using the PubMed and Web of Science databases (February 2019). The populations for these studies included both healthy adults and patients with BVD. In every paper, artificial vestibular stimulation caused an improvement in certain behaviours related to balance, although the extent of the effect varied greatly. Various behaviours were measured such as the vestibulo-ocular reflex, postural sway and certain gait characteristics. Two classes of prosthesis were evaluated and both showed a significant improvement in at least one aspect of balance-related behaviour in every paper included. No adverse effects were reported for prostheses using noisy galvanic vestibular stimulation, however, prosthetic implantation sometimes caused hearing or vestibular loss. Significant heterogeneity in methodology, study population and disease aetiology were observed. The present study confirms the feasibility of vestibular implants in humans for restoring balance in controlled conditions, but more research needs to be conducted to determine their effects on balance in non-clinical settings.

scholarly journals Dimensions of Design Space: A Decision-Theoretic Approach to Optimal Research Design

2009 ◽  
Vol 29 (6) ◽  
pp. 643-660 ◽  
Author(s):  
Stefano Conti ◽  
Karl Claxton
Keyword(s):  
Design Space ◽  
Treatment Options ◽  
Simultaneous Estimation ◽  
Theoretic Approach ◽  
Bayesian Decision ◽  
Sample Sizes ◽  
Net Benefit ◽  
Clinical Endpoints ◽  
Optimal Sample ◽  
Different Types

Bayesian decision theory can be used not only to establish the optimal sample size and its allocation in a single clinical study but also to identify an optimal portfolio of research combining different types of study design. Within a single study, the highest societal payoff to proposed research is achieved when its sample sizes and allocation between available treatment options are chosen to maximize the expected net benefit of sampling (ENBS). Where a number of different types of study informing different parameters in the decision problem could be conducted, the simultaneous estimation of ENBS across all dimensions of the design space is required to identify the optimal sample sizes and allocations within such a research portfolio. This is illustrated through a simple example of a decision model of zanamivir for the treatment of influenza. The possible study designs include: 1) a single trial of all the parameters, 2) a clinical trial providing evidence only on clinical endpoints, 3) an epidemiological study of natural history of disease, and 4) a survey of quality of life. The possible combinations, samples sizes, and allocation between trial arms are evaluated over a range of cost-effectiveness thresholds. The computational challenges are addressed by implementing optimization algorithms to search the ENBS surface more efficiently over such large dimensions.

Pigmentation disorders: types, aetiology and treatment options

2019 ◽  
Vol 8 (5) ◽  
pp. 235-239
Author(s):  
Rekha Tailor
Keyword(s):  
Skin Disorder ◽  
Detrimental Effect ◽  
Treatment Options ◽  
Skin Pigmentation ◽  
Different Types ◽  
Aesthetic Practice ◽  
Chronic Skin ◽  
Darker Skin Types ◽  
Pigmentation Disorders

Hyperpigmentation is a chronic skin disorder that can be very difficult to treat. Skin pigmentation disorders are commonly seen in women than in men, due to hormonal factors, and in those with darker skin types. Pigmentation disorders can cause significant stress for patients and can have a detrimental effect on their quality of life; it is therefore important that aesthetic practitioners have a sound understanding of the different types of hyperpigmentation and appropriate treatments. This article will explore pigmentation disorders and how they can be treated in aesthetic practice.

Vestibular function modulates the impact of nGVS on postural control in older adults

2020 ◽  
Author(s):  
Mujda Nooristani ◽  
Charlotte Bigras ◽  
Louise Lafontaine ◽  
Benoit-Antoine Bacon ◽  
Maxime Maheu ◽  
...  
Keyword(s):  
Older Adults ◽  
Postural Control ◽  
Path Length ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Sham Stimulation ◽  
Important Relationship ◽  
Increased Risk ◽  
Risk Of Falls ◽  
The Impact

Previous studies have reported an important relationship between increasing age, vestibular impairment and increased risk of falls. Recently, noisy galvanic vestibular stimulation (nGVS) has been shown to improve postural control in older adults. However, this effect of nGVS in older adults has not been examined in interaction with the integrity of the vestibular function. We aimed at determining the effect of nGVS on postural control in older adults with and without vestibular impairment and ii) at examining the sustained effect of nGVS as compared to a sham stimulation. 36 older adults were randomly assigned to the nGVS group [n=24] or the sham group [n=12]. In the nGVS group, 12 participants had normal vestibular function and 12 had vestibular impairment. Static postural control was assessed prior to stimulation, during stimulation and immediately following 30 minutes of nGVS. Results showed that nGVS induced a significant improvement in sway velocity (p<0.001) and path length (p<0.001) compared to sham stimulation. In the nGVS group, participants with vestibular impairment showed a significant decrease of sway velocity (p<0.05) and path length (p<0.05) as compared to those with normal vestibular function. Improvements in sway velocity (p<0.001) and path length (p<0.001) induced by nGVS were sustained immediately following stimulation. These findings suggest that nGVS improves postural control in older adults, and that the effect of nGVS varies depending on the integrity of the vestibular function. Results also show that nGVS effect on postural control, compared to a sham stimulation, can be sustained after the end of stimulation.

Sign in / Sign up

Export Citation Format

Share Document