Bilateral vestibulopathy: the causes, diagnosis, and treatments

Nationwide Prevalence of Video Head Impulse Test Abnormality and its Risk Factors in South Korea

OBJECTIVE

To identify the prevalence of and relevant information for video head impulse test (vHIT) abnormality in a large population.

STUDY DESIGN

A cross-sectional design.

SETTING

Korean National Health and Nutrition Examination Survey, 2021.

METHODS

The sample was representative of the Korean population, with 2237 participants aged ≥40 years. A vHIT was performed to evaluate vestibular function. The vestibulo-ocular reflex (VOR) gain and the presence of reproducible catch-up saccades was assessed in a vHIT. Participants also completed questionnaires for demographics, socioeconomic status, and basic information regarding systemic diseases and dizziness and underwent hearing tests with automated pure-tone audiometry.

RESULTS

The prevalence of vHIT abnormality was 22.5%, with unilateral (14.3%) being more common than bilateral (8.2%). The prevalence of vHIT abnormality increased significantly with age, with the highest rate observed in individuals aged >70 years (42.5%). Both hearing and VOR gain deteriorated with age, but the patterns of age-related progression were different. While hearing loss (HL) deteriorated gradually and progressively throughout adulthood, VOR gain deterioration was markedly evident after 70 years of age.

CONCLUSION

Considering the high prevalence of vHIT abnormality, appropriate social and medical policies are needed to prevent associated injuries and improve patients' quality of life. The distinct age-related changes in HL and objective findings of vestibular dysfunction indicate the need for different approaches to address these social problems in aging countries.

Bilateral vestibulopathy as the initial presentation of CANVAS

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a slowly progressing autosomal recessive ataxic disorder linked to an abnormal biallelic intronic (most commonly) AAGGG repeat expansion in the replication factor complex subunit 1 (RFC1). While the clinical diagnosis is relatively straightforward when the three components of the disorder are present, it becomes challenging when only one of the triad (cerebellar ataxia, neuropathy or vestibular areflexia) manifests. Isolated cases of Bilateral Vestibulopathy (BVP) or vestibular areflexia that later developed the other components of CANVAS have not been documented. We report four cases of patients with chronic imbalance and BVP that, after several years, developed cerebellar and neuropathic deficits with positive genetic testing for RFC1. Our report supports the concept that CANVAS should be considered in every patient with BVP of unknown etiology, even without the presence of the other triad components. This is especially important given that about 50% of cases in many BVP series are diagnosed as idiopathic, some of which may be undiagnosed CANVAS.

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

[The six most frequent peripheral vestibular syndromes]

Three forms of peripheral vestibular disorders, each with its typical symptoms and clinical signs, can be differentiated functionally, anatomically and pathophysiologically: 1. inadequate unilateral paroxysmal stimulation or rarely inhibition of the peripheral vestibular system, e. g., BPPV, Menière's disease, vestibular paroxysmia or syndrome of the third mobile windows; 2. acute unilateral vestibulopathy leading to an acute vestibular tone imbalance manifesting as an acute peripheral vestibular syndrome; and 3. loss or impairment of function of the vestibular nerve and/or labyrinth: bilateral vestibulopathy. For all of these diseases, current diagnostic criteria by the Bárány-Society are available with a high clinical and scientific impact, also for clinical trials. The treatment depends on the underlying disease. It basically consists of 5 principles: 1. Explaining the symptoms and signs, pathophysiology, aetiology and treatment options to the patient; this is important for compliance, adherence and persistence. 2. Physical therapy: A) For BPPV specific liberatory maneuvers, depending on canal involved. Posterior canal: The new SémontPLUS maneuver is superior to the regular Sémont and Epley maneuvers; horizontal canal: the modified roll-maneuver; anterior canal the modified Yacovino-maneuver; 3. Symptomatic or causative drug therapy. There is still a deficit of placebo-controlled clinical trials so that the level of evidence for pharmacotherapy is most often low. 4. Surgery, mainly for the syndrome of the third mobile windows. 5. Psychotherapeutic measures for secondary functional dizziness.

[Vestibular rehabilitation for peripheral vestibular hypofunction: an interdisciplinary consensus]

The literature review presents approaches to the management of patients with vestibular disorders. The principles of organization of vestibular rehabilitation in peripheral vestibular hypofunction, indications for appointment, factors influencing its implementation, technique, methods of evaluating effectiveness are considered in detail. Attention is drawn to the fact that the selection of exercises and the duration of vestibular rehabilitation is carried out individually and depends on many factors, including the nature of vestibular deficiency and the specific characteristics of the patient. The possibilities of using additional pharmacological therapy with histamine preparations, which can accelerate the onset of vestibular compensation, are shown. It is noted that vestibular rehabilitation is a safe and effective method of treating peripheral vestibular hypofunction and should be recommended to patients of all ages with vestibular disorders leading to limited social and physical activity.

Neurological update: neuro-otology 2023

Much has changed since our last review of recent advances in neuro-otology 7 years ago. Unfortunately there are still not many practising neuro-otologists, so that most patients with vestibular problems need, in the first instance, to be evaluated and treated by neurologists whose special expertise is not neuro-otology. The areas we consider here are mostly those that almost any neurologist should be able to start managing: acute spontaneous vertigo in the Emergency Room-is it vestibular neuritis or posterior circulation stroke; recurrent spontaneous vertigo in the office-is it vestibular migraine or Meniere's disease and the most common vestibular problem of all-benign positional vertigo. Finally we consider the future: long-term vestibular monitoring and the impact of machine learning on vestibular diagnosis.

Altered gait parameters in distracted walking: a bio-evolutionary and prognostic health perspective on passive listening and active responding during cell phone use

The underpinnings of bipedal gait are reviewed from an evolutionary biology and prognostic health perspective to better understand issues and concerns related to cell phone use during ambulation and under conditions of distraction and interference. We also consider gait-related health issues associated with the fear of or risk of falling and include prognostic dimensions associated with cognitive decline, dementia, and mortality. Data were acquired on 21 healthy young adults without hearing loss, vestibular, balance, otological or neurological dysfunction using a computerized walkway (GAITRite® Walkway System) combined with specialized software algorithms to extract gait parameters. Four experimental conditions and seven temporo-spatial gait parameters were studied: gait velocity, cadence, stride length, ambulatory time, single-support time, double-support time, and step count. Significant main effects were observed for ambulation time, velocity, stride velocity, and double-support time. The greatest impact of distraction and interference occurred during the texting condition, although other significant effects occurred when participants were verbally responding to queries and passively listening to a story. These experimental observations show that relatively simple distraction and interference tasks implemented through the auditory sensory modality can induce significant perturbations in gait while individuals were ambulating and using a cell phone. Herein, emphasis is placed on the use of quantifiable gait parameters in medical, psychological, and audiological examinations to serve as a foundation for identifying and potentially averting gait-related disturbances.

Individualized Vibrotactile Neurofeedback Training in Patients with Chronic Bilateral Vestibulopathy

Patients with bilateral vestibulopathy (BVP) suffer from postural imbalance during daily life conditions, which in turn leads to a high frequency of falls. Unfortunately, vestibular rehabilitation has only modest and somewhat inconsistent effects in this patient group. Approximately 50% of BVP patients show an improved postural control after conventional vestibular rehabilitation training. New and more promising approaches are required. The individualized vibrotactile neurofeedback training (IVNT) in stance and gait conditions has already been described as highly effective in patients with various vestibular disorders. The purpose of the present multicenter study was to determine the efficacy of the IVNT in improving balance, reducing self-perceived disability, and improving gait in patients with confirmed BVP. In total, 22 patients performed the IVNT with the Vertiguard® system for 10 daily sessions. The dizziness handicap inventory (DHI), the stance stability score of the sensory organization test (SOT) and the score for everyday life mobility in stance and gait tasks (SBDT) were obtained immediately before and after the rehabilitation training period, as well as 3 and 12 months later. All measures improved significantly after the IVNT. Between 77.3% and 94.4% of patients showed an individual benefit (depending on outcome measure). The effect was not significantly reduced within the follow-up period of 12 months. The results demonstrate a high efficacy of the IVNT for vestibular rehabilitation in BVP patients.

Vibrations on mastoid process alter the gait characteristics during walking on different inclines

Background

Eighty-eight percent of the persons with bilateral vestibular dysfunction have reported at least one fall within the past 5 years. The apparent alternations due to the bilateral vestibular dysfunctions (BVD) are the gait characteristics, such as slower walking speed, prolonged stance phase, and shorter step length. Unexpectedly, due to the prevalence of this BVD being relatively low, attention is not obtained as same as in other vestibular disorders. Moreover, how does walking on different inclines, part of daily activities, alter the gait characteristics under the unreliable bilateral vestibular systems? Previous studies used vibration-based stimulations (VS) as a perturbation to understand the postural control during walking while the bilateral vestibular systems were perturbed. Therefore, this study attempted to extend the knowledge to understand the alternations in spatial-temporal gait characteristics under perturbed bilateral vestibular systems while walking on different inclines.

Methods

Nineteen healthy young adults participated in this study. Eight walking conditions were randomly assigned to each participant: 0%, 3%, 6%, and 9% grade of inclines with/without VS. The preferred walking speed was used for gait analysis. The dependent variables were stance time, double support time, step length, step time, step width, foot clearance, and respective variabilities. All dependent variables were defined by two critical gait events: heel-strike and toe-off. Pre-Hoc paired comparisons with Bonferroni corrections were used to prioritize the dependent variables. A two-way repeated measure was used to investigate the effect of VS and the effect of inclines on the selected dependent variables from Pre-Hoc analysis. Post-Hoc comparisons were also corrected by the Bonferroni method.

Results

The step length, step time, foot clearance, and foot clearance variability were selected by the Pre-Hoc analysis because the corrected paired t-test demonstrated a significant VS effect (p < 0.05) on these gait parameters at least one of four inclines. The significant interaction between the effect of VS and the effect of inclines was found in step length (p = 0.005), step time (p = 0.028), and foot clearance variability (p = 0.003). The results revealed that implementing a VS increased step length and step time when walking on 0%, 3%, and 9% of grade inclines. In particular, the foot clearance variability was found when walking on 9% of grade inclines.

Conclusion

The observations in the current study suggested that VS increased the step length, step time, foot clearance, and foot clearance variability while walking on inclines. These results suggested that these gait parameters might be promising targets for future clinical investigations in patients with BVD while walking on different inclines. Importantly, the increases in spatial-temporal gait performance under bilateral VS might be an indicator of gait improvement while walking on different inclines.

Efficacy of nGVS to improve postural stability in people with bilateral vestibulopathy: A systematic review and meta-analysis

Objective

Noisy galvanic vestibular stimulation (nGVS) has been used to boost vestibular afferent information to the central nervous system. This has the potential to improve postural control for people for whom vestibular signals are weak, such as in bilateral vestibulopathy (BVP). The aim of this systematic review and meta-analysis is to investigate the evidence for nGVS as a modality to improve postural control in people with BVP.

Methods

A comprehensive systematic search was conducted of five databases up to July 2022 to find studies applying nGVS to people with BVP, with the aim of improving postural control. Two independent reviewers screened and identified eligible studies, completed a risk of bias evaluation (Cochrane) and extracted relevant data. The standardized mean difference (SMD) based on Hedges' g was calculated as a measure of effect size for the primary outcome measure that best identified postural control, and a forest plot generated.

Results

Seven studies met the eligibility criteria, with five being suitable for meta-analysis. Meta-analysis revealed a moderate effect in favor of nGVS improving postural control during standing and walking [pooled SMD = 0.47 95% CI (0.25, 0.7)]. nGVS-mediated improvements in postural control were most evident in observations of reduced sway velocity when standing on a firm surface with eyes closed, and in the reduced variability of gait parameters, particularly those measuring lateral stability.

Conclusions

Coincident nGVS in people with BVP improves postural control during standing and walking. This improvement appears to be context specific, in that vestibular augmentation is most effective in situations where visual inputs are limited, and where reliable context specific proprioceptive cues are available. Further research is warranted investigating additional circumstances in which nGVS improves postural control, including investigating the residual, and sustained effects of nGVS.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=342147, identifier: 342147.