A Randomized, Double Blind, Sham-Controlled Clinical Trial to Evaluate the Efficacy of Electrical Vestibular Nerve Stimulation (VeNS), Compared to a Sham Control for Generalized Anxiety Disorder

Aims and Objectives: It has been hypothesised that vestibular stimulation may have a modulatory effect on anxiety. The aim of this randomised, double blind, sham-controlled trial was to determine the efficacy and safety of a non-invasive electrical vestibular nerve stimulation (VeNS) device as a treatment for anxiety compared to a sham stimulation device. Materials and methods: A total of 60 participants (mean age [SD]: 35.6 [8.1]) with a generalized anxiety disorder assessment (GAD-7) score of ≥10 were randomised to receive either an active VeNS device (n = 34) or a sham control device (n = 26). Both groups were asked to complete 20 stimulation sessions (30 min duration) at a rate of 3-5 sessions per week at a research clinic. The primary outcome was change in GAD-7 score from baseline to the end of study (when each participant finished their 20 stimulation sessions). Secondary outcomes were change in Insomnia Severity Index (ISI), and the Short Form 36 Health Survey (SF-36) scores (8 domains). Results: One participant allocated to the sham group withdrew from the study. The mean (SD) number of weeks it took to complete the 20 stimulation sessions was 5.8. The active group had a statistically greater reduction in GAD-7 score compared to the sham group (-7.4 versus -2.2, P < .001; respectively). A total of 97% (n = 33) of the active group achieved a clinically meaningful reduction (defined as ≥4-point reduction) in GAD-7 from baseline to the follow up visit compared to 24% (n = 6) of the sham group (P < .001). Additionally, the active group showed a significant improvement in ISI (-4.9 versus 2.2, P < .001) and greater improvements on all eight SF36 domains (P < .001) compared with the sham group. There was no device related reported adverse events. Conclusion: Regular non-invasive electrical vestibular nerve stimulation appears to have a clinically meaningful benefit when used as an intervention for Generalized Anxiety Disorder.

Non-invasive vestibular nerve stimulation (VeNS) reduces visceral adipose tissue: results of a randomised controlled trial

Across multiple species, chronic vestibular stimulation activates hypothalamic regions involved in energy homeostasis and reduces body fat. This first-in-human randomised controlled trial evaluated the efficacy and safety of electrical vestibular nerve stimulation (VeNS) as a means of reducing excess body weight and fat. Overweight and obese adults were randomised 1:1 to receive 60 min of daily VeNS (n = 117) or sham stimulation (n = 124) for 6 months, together with a hypocaloric diet. The primary endpoints were weight loss based. Secondary endpoints included reduction in visceral adipose tissue (VAT). It is VAT, more than subcutaneous fat depots, which is particularly associated with the risks associated with obesity. The weight loss based primary endpoints were not met. However, mean change in VAT was significantly greater in the active (- 12.6%) versus the sham (- 4.7%) group (p = 0.03). This suggests that regular VeNS may cause a clinically meaningful reduction in VAT.

Anxiolytic effects of vestibular stimulation: an update

The vestibular system inhibits both HPA and SAM axis and contributes to the management of anxiety. Both direct and indirect pathways exist in the inhibition of the HPA and SAM axis. In this review article, the authors describe various pathways through which the vestibular system can regulate the HPA and SAM axis activity. Lastly, the authors highlight the need of starting translational research work in this field. Rocking is soothing and this is a universal fact that babies in the swing will calm down and sleep. These soothing effects of vestibular stimulation may be due to the inhibition of cortical and subcortical structures. Vestibular stimulation may be able to manage anxiety through its connections with multiple brain areas. There is a need to undertake translational research in this area to establish strong scientific evidence and recommend implementation of the vestibular stimulation in the management of anxiety.

Effects of vestibular rehabilitation on body composition and daily-living physical activity in chronic unilateral vestibular hypofunction

BACKGROUND

Unilateral vestibular hypofunction (UVH) may lead to modifications on metabolism and body composition. Vestibular rehabilitation (VR) demonstrated its effectiveness in ameliorating balance function and several other daily-living aspects.

OBJECTIVES

The aim of this study was to evaluate metabolic composition, by means of bioelectrical impedance analysis (BIA) and daily activity, with the use of a wrist-worn movement tracker, in UVH participants before and after VR, and to compare data with a healthy control group (CG) of adults.

METHODS

46 UVH and 60 CG participants underwent otoneurological testing, self-report and performance questionnaires, BIA, and wore a device tracking daily movement and energy expenditure for one full day; this was performed before and after VR.

RESULTS

UVH participants demonstrated a significant (p = 0.008) increase in muscle mass after VR, and, when compared to CG, no differences were present with respect to visceral fat and muscle mass. UVH adults reported a significant increase in energy expenditure spent in movement (p = 0.008) and during the day (p = 0.009), daily number of strides (p = 0.009) and calories spent in sweeping (p = 0.009) and stairing (p = 0.008).

CONCLUSIONS

Results from this study show that VR provided an improvement of metabolic function and body composition of people with UVH, possibly by contrasting structural modifications in neural pathways stemming from the vestibular nuclei and connected to autonomous function.

Changes in daily energy expenditure and movement behavior in unilateral vestibular hypofunction: Relationships with neuro-otological parameters

The vestibular system has been found to affect energy homeostasis and body composition, due to its extensive connections to the brainstem and melanocortin nuclei involved in regulating the metabolism and feeding behavior. The aim of this study was to evaluate - by means of a wrist-worn physical activity tracker and bioelectrical impedance analysis (BIA) - the energy expenditure (EE) in resting (REE) and free-living conditions and movement behavior in a group of chronic unilateral vestibular hypofunction (UVH) patients when compared with a control group (CG) of healthy participants. Forty-six chronic UVH and 60 CG participants underwent otoneurological (including video-Head Impulse Test [vHIT] for studying vestibulo-ocular reflex [VOR] and static posturography testing [SPT]), and EE and movement measurements and self-report (SRM) andperformance measures (PM). As well as significant (p < 0.001) changes in SPT variables (area and path length) and SRM/PM, UVH participants also demonstrated significantly (p < 0.001) lower values in REE, movement EE, hours/day spent upright, number of strides and distance covered and total daily EE (p = 0.007) compared to the CG. UVH patients consumed significantly lower Kcal/min in sweeping (p = 0.001) and walking upstairs and downstairs (p < 0.001) compared to the CG. Multiple correlations were found between free-living and resting EE and neuro-otological parameters in UVH participants. Since the melanocortin system could be affected along the central vestibular pathways as a consequence of chronic vestibular deafferentation, data collected by reliable wearables could reflect the phenomena that constitute an increased risk of falls and sedentary lifestyle for patients affected by UVH, and could improve rehabilitation stages.

Changes in body composition in unilateral vestibular hypofunction: relationships between bioelectrical impedance analysis and neuro-otological parameters

PURPOSE

Experimental works have indicated the potential of the vestibular system to affect body composition to be mediated by its extensive connections to brainstem nuclei involved in regulating metabolism and feeding behavior. The aim of this study was to evaluate-by means of bioelectrical impedance analysis (BIA)-the body composition in a group of chronic UVH normal-weighted patients when compared with an equally balanced group of healthy participants, serving as a control group (CG).

METHODS

Forty-six chronic UVH and 60 CG participants underwent otoneurological (including video Head Impulse Test [vHIT] and static posturography testing [SPT]), BIA measurements and self-report (SRM) and performance measures (PM).

RESULTS

Beyond significant (p < 0.001) changes in SPT variables (surface and length) and SRM/PM (including Dizziness Handicap Inventory, Dynamic Gait Index and Activity Balance Confidence scales), UVH participants demonstrated significant (p < 0.001) higher values of fat mass and visceral fat and lower values of muscle mass (p = 0.004), when compared to CG. Significant correlations were found in UVH participants between otoneurological and BIA measurements.

CONCLUSION

These study findings represent the first clinical in-field attempt at depicting, with the use of BIA parameters, changes in body composition related to chronic UVH. Since such alterations in metabolic parameters could be considered both the consequences and/or the cause of vestibular-related quality of life deficit, BIA parameters could be considered as cheap, easy to use, noninvasive assessments in case of chronic UVH.

Anti-diabetic effect of vestibular stimulation is mediated via AMP-activated protein kinase

There is abundant animal evidence that vestibular stimulation, particularly of the otolith organs, can trigger a shift in body mass composition towards a leaner physique. One way of non-invasively stimulating the otolith organs is via a small electrical current applied to the skin behind the ears. This technique is called vestibular nerve stimulation, or VeNS, and is believed to have a good safety profile. Thus, it has previously been argued that VeNS could be used in human health as a means of treating the complications of metabolic syndrome, such as obesity and type 2 diabetes mellitus. Weight loss itself is known to improve diabetic control, however, tantalizing evidence is now emerging that the improvements seen in the glycemic control of type 2 diabetics who undergo repeated vestibular stimulation are significantly better than would be expected on the basis of weight loss alone. As vestibular stimulation has been shown to increase levels of an anti-inflammatory protein, called sirtuin 1, we hypothesize here that VeNS will increase levels of an associated enzyme called AMP-activated protein kinase (AMPK). AMPK plays an important role in glucose and fat metabolism and is activated by exercise, as well as being a known target for certain anti-diabetic drugs. This hypothesis is readily amenable to clinical testing as specific assays for testing human AMPK are available. If substantiated, then this hypothesis could prove an important clinical insight and potentially offer a new treatment avenue for patients with type 2 diabetes; a condition which remains a major cause of morbidity and premature mortality worldwide.

Roles of the vestibular system in obesity and impaired glucose metabolism in high-fat diet-fed mice

The vestibular system controls balance, posture, blood pressure, and gaze. However, the roles of the vestibular system in energy and glucose metabolism remain unknown. We herein examined the roles of the vestibular system in obesity and impaired glucose metabolism using mice with vestibular lesions (VL) fed a high-sucrose/high-fat diet (HSHFD). VL was induced by surgery or arsenic. VL significantly suppressed body fat enhanced by HSHFD in mice. Glucose intolerance was improved by VL in mice fed HSHFD. VL blunted the levels of adipogenic factors and pro-inflammatory adipokines elevated by HSHFD in the epididymal white adipose tissue of mice. A β-blocker antagonized body fat and glucose intolerance enhanced by HSHFD in mice. The results of an RNA sequencing analysis showed that HSHFD induced alterations in genes, such as insulin-like growth factor-2 and glial fibrillary acidic protein, in the vestibular nuclei of mice through the vestibular system. In conclusion, we herein demonstrated that the dysregulation of the vestibular system influences an obese state and impaired glucose metabolism induced by HSHFD in mice. The vestibular system may contribute to the regulation of set points under excess energy conditions.