Bilateral Vestibular Hypofunction Research Articles

Vestibular Implantation

Abstract Purpose of Review This review aims to introduce vestibular implants as investigational devices with the potential to provide a novel rehabilitative treatment for patients with vestibular dysfunction. Recent Findings Vestibular implants are being investigated in clinical trials in the USA and Europe as a treatment option for patients with bilateral vestibular hypofunction (also called bilateral vestibulopathy). Analogous to cochlear implants, vestibular implants aim to encode head motion information and provide electric stimulation targeting the vestibular nerve of the inner ear. Published clinical trial results suggest vestibular implants can electrically drive vestibular mediated reflexes, including the vestibulo-ocular reflex and vestibulo-cervical reflex, as well as decreasing dizziness-specific symptoms and improving measures of quality of life. Summary Vestibular implants are an investigational technology with the potential to provide treatment options for patients with chronic bilateral vestibulopathy.

Vestibular Hypofunction Screening in Older Cochlear Implant Candidates.

Vestibular loss is associated with increasing age and hearing loss. Cochlear implantation (CI) may be performed in these patients; however, CI can induce vestibular hypofunction (VH) postoperatively. If CI is performed in the "better balancing ear," patients may experience vestibulopathy from new bilateral VH. The objective of this study was to evaluate the rates of VH in older CI candidates, thereby helping to identify patients at increased risk for bilateral VH after CI. Retrospective cohort study from 2019 to 2022 of patients age 60 to 80 years old who underwent videonystagmography (VNG). Tertiary care neurotology practice. VNG, including spontaneous nystagmus, cervical vestibular evoked myogenic potential (cVEMP), caloric stimulation, and rotary chair, was reviewed and stratified by CI candidacy. Patients with prior CI or known vestibular diagnosis were excluded. Thirty-three patients were CI candidates and 184 patients were controls. cVEMP demonstrated a significantly greater rate of unilateral VH in CI candidates (P = .018). Caloric stimulation demonstrated an elevated rate of bilateral VH and presbyvestibulopathy in CI candidates (P = .057 and P = .036, respectively). Rotary chair demonstrated a significantly higher rate of bilateral VH and incomplete vestibular compensation based on reduced gain and gain asymmetry, respectively, in CI candidates (P < .001 and P = .043, respectively). Mean bithermal slow phase velocity sum and rotary chair gain were significantly lower in the CI candidate group (P = .002 and P < .001, respectively). Preoperative identification of VH determined the side of implantation in 4 patients (15%). VH and incomplete vestibular compensation are common and more frequently seen in CI candidates compared to age-matched controls. Vestibular screening can play a role in surgical counseling and planning, and should be considered in older patients undergoing CI.

Vestibular Hypofunction Secondary to Topical Use of Aminoglycosides in Ears with Perforated Tympanic Membrane

Introduction: The objective of this study was to identify and clinically characterize patients treated in an Otoneurology Unit who experienced vestibular ototoxicity as a result of using aminoglycoside ear drops during outbreaks of superinfection in chronic otitis media. Material and Methods: An observational retrospective study was conducted, including patients with perforated eardrums who developed vestibular ototoxicity within the past 10 years following the application of topical ear aminoglycosides in a tertiary referral center. The study encompassed the assessment of the clinical presentation, treatment, quality of life, and evolution after treatment of the identified individuals. Results: During the study period, 6 patients, aged between 33 and 71 years, developed vestibular ototoxicity following the use of topical aminoglycoside drops due to infection flares in chronic otitis media. All cases involved the use of gentamicin. Two cases were unilateral, and 4 were unilateral. The onset of symptoms occurred within one to four weeks of using the drops, resulting in all patients experiencing instability without vertigo attacks. After discontinuing the drops and undergoing vestibular rehabilitation, 4 patients experienced sequelae, with 2 patients (both with bilateral vestibular hypofunction) suffering significant impairment in their quality of life. Conclusions: Vestibular ototoxicity due to the topical application of aminoglycosides during acute exacerbations of chronic otitis media is a rare occurrence. However, given its potential for severe consequences and the fact that we are still encountering patients with this condition, healthcare professionals should explore alternative antibacterial agents that offer similar efficacy.

Effects of structured exercise program on severity of dizziness, kinesiophobia, balance, quality of sleep, activities of daily living and quality of life in bilateral vestibular hypofunction: case study

Background and Purpose. The vestibular rehabilitation is an exercise-based method, aiming to maximize central nervous system(CNS) compensation at vestibular nuclear and other CNS levels for vestibular pathology. A minimal number of studies have documented the impact of Vestibular rehabilitation on the recovery rate of patients with Bilateral Vestibular Hypofunction(BVH). The purpose of this study was to investigate the effectiveness of structured vestibular rehabilitation (VR) programs on severity of dizziness, kinesiophobia, balance, quality of sleep, activities of daily living(ADL) and quality of life(QoL) in subjects with chronic BVH. Case Description. Three participants diagnosed with BVH who suffered from severity of dizziness, kinesiophobia, balance, quality of sleep, ADL and QoL were included in the study. Intervention. A structured VR program was applied in 50-minute sessions once a week and as a home exercise program 3 days a week over 8 weeks. Outcomes. Participants were evaluated for severity of dizziness with the Visual Analog Scale (VAS), for kinesiophobia with the Tampa Scale of Kinesiophobia (TSK), for balance with the Semitandem, tandem, and standing tests, for quality of sleep with the Pittsburgh Sleep Quality Index (PSQI), for ADL with the Vestibular Disorders Activities of Daily Life (VADL) and for QoL with Dizziness Handicap Inventory (DHI) at the baseline (T0), at 4th week (T1), 8th week (T2), and 20th week (T3) after study started. Conclusion. In conclusion, a twelve-week structured VR program may enhance severity of dizziness, kinesiophobia, balance, quality of sleep, ADL and QoL in participants with chronic BVH.

Patient-Reported Outcomes After Vestibular Implantation for Bilateral Vestibular Hypofunction

Standard-of-care treatment proves inadequate for many patients with bilateral vestibular hypofunction (BVH). Vestibular implantation is an emerging alternative. To examine patient-reported outcomes from prosthetic vestibular stimulation. The Multichannel Vestibular Implant (MVI) Early Feasibility Study is an ongoing prospective, nonrandomized, single-group, single-center cohort study conducted at Johns Hopkins Hospital that has been active since 2016 in which participants serve as their own controls. The study includes adults with severe or profound adult-onset BVH for at least 1 year and inadequate compensation despite standard-of-care treatment. As of March 2023, 12 candidates completed the eligibility screening process. The MVI system electrically stimulates semicircular canal branches of the vestibular nerve to convey head rotation. Patient-reported outcome instruments assessing dizziness (Dizziness Handicap Inventory [DHI]) and vestibular-related disability (Vestibular Disorders-Activities of Daily Living [VADL]). Health-related quality of life (HRQOL) assessed using the Short Form-36 Utility (SF36U) and Health Utilities Index Mark 3 (HUI3), from which quality-adjusted life-years were computed. Ten individuals (5 female [50%]; mean [SD] age, 58.5 [5.0] years; range, 51-66 years) underwent unilateral implantation. A control group of 10 trial applicants (5 female [50%]; mean [SD] age, 55.1 [8.5] years; range, 42-73 years) completed 6-month follow-up surveys after the initial application. After 0.5 years of continuous MVI use, a pooled mean (95% CI) of within-participant changes showed improvements in dizziness (DHI, -36; 95% CI, -55 to -18), vestibular disability (VADL, -1.7; 95% CI, -2.6 to -0.7), and HRQOL by SF36U (0.12; 95% CI, 0.07-0.17) but not HUI3 (0.02; 95% CI, -0.22 to 0.27). Improvements exceeded minimally important differences in the direction of benefit (exceeding 18, 0.65, and 0.03, respectively, for DHI, VADL, and SF36U). The control group reported no mean change in dizziness (DHI, -4; 95% CI, -10 to 2), vestibular disability (VADL, 0.1; 95% CI, -0.9 to 1.1) or HRQOL per SF36U (0; 95% CI, -0.06 to 0.05) but an increase in HRQOL per HUI3 (0.10; 95% CI, 0.04-0.16). Lifetime HRQOL gain for MVI users was estimated to be 1.7 quality-adjusted life-years (95% CI, 0.6-2.8) using SF36U and 1.4 (95% CI, -1.2 to 4.0) using HUI3. This cohort study found that vestibular implant recipients report vestibular symptom improvements not reported by a control group. These patient-reported benefits support the use of vestibular implantation as a treatment for bilateral vestibular hypofunction.

Inertial Measurement Unit-Based Romberg Test for Assessing Adults With Vestibular Hypofunction.

This work aims to explore the utility of wearable inertial measurement units (IMUs) for quantifying movement in Romberg tests and investigate the extent of movement in adults with vestibular hypofunction (VH). A cross-sectional study was conducted at an academic tertiary medical center between March 2021 and April 2022. Adults diagnosed with unilateral vestibular hypofunction (UVH) or bilateral vestibular hypofunction (BVH) were enrolled in the VH group. Healthy controls (HCs) were recruited from community or outpatient clinics. The IMU-based instrumented Romberg and tandem Romberg tests on the floor were applied to both groups. The primary outcomes were kinematic body metrics (maximum acceleration [ACC], mean ACC, root mean square [RMS] of ACC, and mean sway velocity [MV]) along the medio-lateral (ML), cranio-caudal (CC), and antero-posterior (AP) axes. A total of 31 VH participants (mean age, 33.48 [SD 7.68] years; 19 [61%] female) and 31 HCs (mean age, 30.65 [SD 5.89] years; 18 [58%] female) were recruited. During the eyes-closed portion of the Romberg test, VH participants demonstrated significantly higher maximum ACC and increased RMS of ACC in head movement, as well as higher maximum ACC in pelvic movement along the ML axis. In the same test condition, individuals with BVH exhibited notably higher maximum ACC and RMS of ACC along the ML axis in head and pelvic movements compared with HCs. Additionally, BVH participants exhibited markedly increased maximum ACC along the ML axis in head movement during the eyes-open portion of the tandem Romberg test. Conversely, no significant differences were found between UVH participants and HCs in the assessed parameters. The instrumented Romberg and tandem Romberg tests characterized the kinematic differences in head, pelvis, and ankle movement between VH and healthy adults. The findings suggest that these kinematic body metrics can be useful for screening BVH and can provide goals for vestibular rehabilitation.

Supervised multicomponent exercise as an adjuvant program for people with unilateral and/or bilateral chronic vestibular hypofunction: EXERVEST study protocol

BackgroundUnilateral and bilateral peripheral vestibular hypofunction (UVH and BVH) often complains of dizziness, gaze, and balance disturbances. There is a lack of evidence on exercise intervention in UVH and BVH patients. To investigate the effect of an eight-week supervised multicomponent exercise program in people suffering from UVH or BVH in comparison with a control group doing conventional vestibular rehabilitation at home. MethodsThis longitudinal, controlled, randomized, prospective, single-blinded, two-arm, parallel intervention study will include 66 adults (≥18 years old) with chronic UVH or BVH. Participants will be randomly assigned to an exercise intervention group or an attention control group. Participants will be assessed at baseline, after a two-month intervention period, and after a six-month follow-up. The primary variable will be the balance, measured by the dynamic posturography sensory organization test and the Modified Dynamic Gait Index test. Secondary outcome variables will include cardiorespiratory fitness (peak cardiopulmonary exercise test), body composition (bioimpedance and anthropometric variables), physical activity level and sleep quality (accelerometry), health-related quality of life (Dizziness Handicap Inventory questionnaire), emotional state (Beck Depression and Anxiety Inventory questionnaires), and blood pressure monitoring. DiscussionThis study will try to answer whether in people with UVH/BVH, an adjuvant program of multicomponent exercise will help the prognosis of this population. Trial registrationClinicalTrials.gov, identifier [NCT05192564]. Verification date: April 2023.

Prosthetic Stimulation of the Vestibular Nerve Can Evoke Robust Eye and Head Movements Despite Prior Labyrinthectomy.

Prosthetic electrical stimulation can evoke compensatory eye and head movement despite vestibular implant electrode insertion occurring years after prior labyrinthectomy. Vestibular implants sense head rotation and directly stimulate the vestibular nerve, bypassing damaged end organs. Animal research and current clinical trials have demonstrated the efficacy of this approach. However, candidacy criteria for vestibular implants currently require presence of a patent labyrinth in the candidate ear and at least aidable hearing in the opposite ear, thus excluding patients who have undergone prior labyrinthectomy for unilateral Menière's disease that later progressed to bilateral vestibular hypofunction. Eight years after right unilateral labyrinthectomy, we implanted stimulating electrodes in the previously exenterated right ear ampullae of a rhesus macaque monkey. The left labyrinth had long-standing hypofunction due to intratympanic gentamicin injection and surgical disruption. We used three-dimensional video-oculography to measure eye movement responses to prosthetic electrical stimulation. We also measured head-movement responses to prosthetic stimulation with the head unrestrained. Bilateral vestibular hypofunction was confirmed by absence of vestibuloocular reflex responses to whole-body rotation without prosthetic stimulation. For a subset of the implanted electrodes, prosthetic vestibular stimulation evoked robust compensatory eye and head movements. One electrode reliably elicited responses aligned with the implanted ear's anterior canal nerve regardless of the return electrode used. Similarly, a second electrode also elicited responses consistent with excitation of the horizontal canal nerve. Responses grew quasilinearly with stimulation rate and current amplitude. Prosthetic electrical stimulation targeting the vestibular nerve can be effective years after labyrinthectomy, if at least some parts of the vestibular nerve's ampullary branches remain despite destruction or removal of the membranous labyrinth.

Effects of structured exercise program on severity of dizziness, kinesiophobia, balance, fatigue, quality of sleep, activities of daily living, and quality of life in bilateral vestibular hypofunction.

A minimal number of studies have documented the impact of Vestibular rehabilitation (VR) on the recovery rate of patients with bilateral vestibular hypofunction (BVH). The purpose of this study was to investigate the effectiveness of structured VR programs on severity of dizziness, kinesiophobia, balance, fatigue, quality of sleep, activities of daily living (ADL) and quality of life (QoL) in subjects with chronic BVH. Twenty-five participants diagnosed with BVH were included in the study. A structured VR program was applied in 50-minute sessions once a week and as a home exercise program 3 times a day over 8 weeks. Participants were evaluated for severity of dizziness with the visual analog scale, for kinesiophobia with the tampa scale of kinesiophobia, for balance with the Semitandem, tandem, and standing tests, for quality of sleep with the Pittsburgh sleep quality index, for ADL with the vestibular disorders activities of daily life, for QoL with dizziness handicap inventory and for fatigue with the fatigue severity scale at the baseline (T1), at 4th week (T2), 8th week (T3), and 20th week (T4) after study started. Significant difference in terms of Tandem Test and 1 Leg Stand Test was found in favor of T3-T4 Period (P < .05). There were significant improvements in terms of vestibular disorders activities of daily life, tampa scale of kinesiophobia, Pittsburgh sleep quality index and dizziness handicap inventory in favor of the T3 to T4 Period (P < .05). Significant difference in terms of visual analog scale was found in favor of T2 Period (P < .05). A twelve-week structured VR program may enhance severity of dizziness, kinesiophobia, balance, quality of sleep, ADL and QoL in participants with chronic BVH.

Retracted: IGST Combined with Conventional Drug Therapy and TCM Therapy for Treatment of Bilateral Vestibular Hypofunction.

[This retracts the article DOI: 10.1155/2022/5689454.].

The overarching effects of vestibular deficit: Imbalance, anxiety, and spatial disorientation

BackgroundComorbid Balance, Anxiety, and Spatial symptoms are observed in neurodevelopmental disorders and aging. Each of these symptoms was studied separately in association with vestibular hypofunction. We aimed to investigate whether such a diffuse range of symptoms has common vestibular pathophysiology. Specifically, we tested whether this Triad of dysfunctions is associated with central or peripheral vestibular hypofunction. We also assessed the possible contribution of semicircular canals (SCCs) vs. saccular function. MethodsWe tested patients with Peripheral bilateral and unilateral Vestibular Hypofunction (PVH), Machado Joseph Disease (MJD) with cerebellar and central bilateral vestibular hypofunction, and healthy controls. SCCs and sacculi functioning were evaluated by the video Head Impulse Test (vHIT) and cervical Vestibular Evoked Myogenic Potentials (cVEMP), respectively. Balance was assessed by the Activities-specific Balance Confidence scale (ABC), anxiety by the Hamilton Anxiety Rating Scale (HAM-A), and spatial orientation by the Object Perspective Taking test (OPT-t). ResultsPVH patients with vestibular SCCs and saccular hypofunction presented the Triad of symptoms, imbalance, anxiety, and spatial disorientation. MJD patients with SCCs-related vestibular hypofunction but preserved saccular-related vestibular function presented with a partial profile of imbalance and spatial disorientation. ConclusionsThe present study provides evidence that peripheral vestibular hypofunction is associated with the Triad of dysfunctions, i.e., imbalance, anxiety, and spatial disorientation. The combination of SCCs and saccular hypofunction seems to contribute to the emergence of the Triad of symptoms.

Cortical facilitation of somatosensory inputs using gravity-related tactile information in humans with vestibular hypofunction.

A few years after their bilateral vestibular loss, patients usually show a motor repertoire that is almost back to normal. This recovery is thought to involve an upregulation of the visual and proprioceptive information that compensates for the lack of vestibular information. Here, we investigated whether plantar tactile inputs, which provide body information relative to the ground and to the Earth vertical, contribute to this compensation. More specifically, we tested the hypothesis that somatosensory cortex response to electric stimulation of the plantar sole in standing adults will be greater in humans (n = 10) with bilateral vestibular hypofunction (VH) than in an age-matched healthy group (n = 10). Showing significantly greater somatosensory evoked potentials (i.e., P1N1) in VH than in control subjects, the electroencephalographic recordings supported this hypothesis. Furthermore, we found evidence that increasing the differential pressure between both feet, by adding a 1-kg mass at each pendant wrist, enhanced the internal representation of body orientation and motion relative to a gravitational reference frame. The large decrease in alpha power in the right posterior parietal cortex (and not in the left) is in line with this assumption. Finally, behavioral analyses showed that trunk oscillations were smaller than head oscillations in VH and showed a reverse pattern for healthy participants. These findings are consistent with a tactile-based postural control strategy in the absence of vestibular input and a vestibular-based control strategy in healthy participants where the head serves as a reference for balance control.NEW & NOTEWORTHY Somatosensory cortex excitability is greater in participants with bilateral vestibular hypofunction than in age-matched healthy humans. To control balance, healthy humans "locked" the head whereas participants with vestibular hypofunction "locked" their pelvis. For participants with vestibular hypofunction, increasing loading/unloading of the feet enhances the internal representation of body state in the posterior parietal cortex.

Quantitative vestibular assessment: The development and validation of a novel, remote video head impulse test against in-clinic measurements.

To develop a novel remote head impulse test (rHIT), and to provide preliminary data validating the rHIT vestibular-ocular reflex (VOR) gains against the in-clinic vHIT. A convenience sample of 10 patients referred for vestibular assessment at our institution was recruited. In-clinic vHIT was used to quantify lateral VOR gains. Patients subsequently underwent an rHIT protocol, whereby patients performed active, lateral head rotations while their eyes and heads were recorded using a laptop camera and video-conferencing software. The vHIT and rHIT VOR gains were compared using paired t-tests, and a Pearson correlation coefficient between the gains was calculated. Absolute accuracy, sensitivity, and specificity of the rHIT were additionally calculated. Of the 10 patients recruited, 4 were male, and the average ± standard deviation (SD) age was 61.4 ± 15.3 years. As determined by the vHIT, 2 patients had normal bilateral VOR gains, 6 with unilateral vestibular hypofunction, and 2 with bilateral vestibular hypofunction. The correlation between the rHIT and vHIT gains was 0.73 (p < .001). The rHIT exhibited an absolute accuracy of 75.0%, sensitivity of 70.0%, and specificity of 80.0%. When ears had a vHIT VOR gain less than 0.40, the rHIT exhibited 100.0% accuracy. Conversely, 60.0% of deficient ears with vHIT VOR gains greater than 0.40 were incorrectly categorized by the rHIT. The rHIT may be better suited for detecting more severe vestibular deficiencies. Future iterations of the rHIT should aim to increase the video frame-rate capabilities to detect subtler VOR impairments. 4.

The Effect of Vestibular Rehabilitation on Balance and Quality of Life in Patients with Bilateral Vestibular Hypofunction.

This study aims to investigate the effectiveness of vestibular rehabilitation on balance, dynamic visual acuity, and quality of life in patients with bilateral vestibular hypofunction (BVH). 20 patients diagnosed by videonystagmography were included in the study. Balance tests, Visual Analogue Scale (VAS), testing of Dynamic Visual Acuity (DVA), Dizziness Handicap Inventory (DHI), Computer-modified Clinical Test of Sensory Interaction in Balance (m-CTSIB), and Limits of Stability Test were applied before and 3 and 6months after the treatment. Physiotherapy sessions were given at two-week intervals. According to the development of the patients, they were asked to perform a home exercise program with 10 repetitions 3 times a day. After 6months of vestibular rehabilitation, improvements in balance and quality of life parameters were observed in the patients. VAS, DVA, DHI, all static balance parameters except Romberg, Semi-tandem eyes open were significant (p < 0.005). In computerized M-CTSIB, while no significant results were obtained on the hard surface with the eyes open (p = 0.126), statistically significant improvement was observed on the hard surface with the eyes closed and on a foam surface with eyes open and close. LOS results showed significant improvement in velocity, reaching the endpoint, and maximal deviation in all directions except the right posterior. While significant results were found in the right, posterior, left anterior, and left posterior directions in the reaction time section, there was no statistical significance in any of the direct control sections (p < 0.005). Trial registration number:NCT05231109, Date of registration:27/01/2022 (Retrospectively registered).

Binocular 3-D otolith-ocular reflexes: responses of chinchillas to natural and prosthetic stimulation after ototoxic injury and vestibular implantation.

The otolith end organs inform the brain about gravitational and linear accelerations, driving the otolith-ocular reflex (OOR) to stabilize the eyes during translational motion (e.g., moving forward without rotating) and head tilt with respect to gravity. We previously characterized OOR responses of normal chinchillas to whole body tilt and translation and to prosthetic electrical stimulation targeting the utricle and saccule via electrodes implanted in otherwise normal ears. Here we extend that work to examine OOR responses to tilt and translation stimuli after unilateral intratympanic gentamicin injection and to natural/mechanical and prosthetic/electrical stimulation delivered separately or in combination to animals with bilateral vestibular hypofunction after right ear intratympanic gentamicin injection followed by surgical disruption of the left labyrinth at the time of electrode implantation. Unilateral intratympanic gentamicin injection decreased natural OOR response magnitude to about half of normal, without markedly changing OOR response direction or symmetry. Subsequent surgical disruption of the contralateral labyrinth at the time of electrode implantation surgery further decreased OOR magnitude during natural stimulation, consistent with bimodal-bilateral otolith end organ hypofunction (ototoxic on the right ear, surgical on the left ear). Delivery of pulse frequency- or pulse amplitude-modulated prosthetic/electrical stimulation targeting the left utricle and saccule in phase with whole body tilt and translation motion stimuli yielded responses closer to normal than the deficient OOR responses of those same animals in response to head tilt and translation alone.NEW & NOTEWORTHY Previous studies to expand the scope of prosthetic stimulation of the otolith end organs showed that selective stimulation of the utricle and saccule is possible. This article further defines those possibilities by characterizing a diseased animal model and subsequently studying its responses to electrical stimulation alone and in combination with mechanical motion. We show that we can partially restore responses to tilt and translation in animals with unilateral gentamicin ototoxic injury and contralateral surgical disruption.

Catch-Up Saccades in Vestibular Hypofunction: A Contribution of the Cerebellum?

Long-term deficits of the vestibulo-ocular reflex (VOR) elicited by head rotation can be partially compensated by catch-up saccades (CuS). These saccades are initially visually guided, but their latency can greatly decrease resulting in short latency CuS (SL-CuS). It is still unclear what triggers these CuS and what are the underlying neural circuits. In this study, we aimed at evaluating the impact of cerebellar pathology on CuS by comparing their characteristics between two groups of patients with bilateral vestibular hypofunction, with or without additional cerebellar dysfunction. We recruited 12 patients with both bilateral vestibular hypofunction and cerebellar dysfunction (BVH-CD group) and 12 patients with isolated bilateral vestibular hypofunction (BVH group). Both groups were matched for age and residual VOR gain. Subjects underwent video head impulse test recording of the horizontal semicircular canals responses as well as recording of visually guided saccades in the step, gap, and overlap paradigms. Latency and gain of the different saccades were calculated. The mean age for BVH-CD and BVH was, respectively, 67.8 and 67.2 years, and the mean residual VOR gain was, respectively, 0.24 and 0.26. The mean latency of the first catch-up saccade was significantly longer for the BVH-CD group than that for the BVH group (204 ms vs 145 ms, p < 0.05). There was no significant difference in the latency of visually guided saccades between the two groups, for none of the three paradigms. The gain of covert saccades tended to be lower in the BVH-CD group than in BVH group (t test; p = 0.06). The mean gain of the 12° or 20° visually guided saccades were not different in both groups. Our results suggest that the cerebellum plays a role in the generation of compensatory SL-CuS observed in BVH patients.

The Effects of Vestibular Implants and Other Existing Treatment Options of Individuals with Bilateral Vestibular Hypofunction: A Review

Vestibular dysfunction (VD) is an experience that is shared by nearly 35&amp;#37; of Americans above the age of 40 (nearly 69 million). This percentage increases to 80&amp;#37; when looking at the population of individuals over the age of 80. VD can have tremendously negative health outcomes for patients. Improper vestibular function can result in a loss of balance and patients often cite vertigo as a common symptom, which is often associated with dramatically reduced quality of life. Falls are another common clinically significant outcome of VD and place a huge social and financial burden on the patient and healthcare system. Although the pathophysiology and treatment options for certain vestibular disorders have been well researched, disorders such as bilateral vestibular dysfunction (BVD), have had traditionally ineffective treatment options. That said, novel therapeutics such as vestibular implants (VIs) have been recently tested and showed positive health outcomes for patients with BVD. This review aims to investigate the health outcomes of patients who have received VIs, as well as discuss the limitations and existing treatment options.

How vestibular dysfunction transforms into symptoms of depersonalization and derealization?

BackgroundPsychiatric Depersonalization/Derealization (DPDR) symptoms were demonstrated in patients with peripheral vestibular disorders. However, only semicircular canals (SCCs) dysfunction was evaluated, therefore, otoliths' contribution to DPDR is unknown. Also, DPDR symptoms in patients with central vestibular dysfunction are presently unknown. DPDR was also studied in the context of spatial disorientation and anxiety, but the relation of these cognitive and emotional functions to vestibular dysfunction requires clarification. MethodsWe tested patients with peripheral Bilateral Vestibular Hypofunction (pBVH), Machado Joseph Disease (MJD) with cerebellar and central bilateral vestibular hypofunction, and healthy controls. Participants completed the video Head Impulse Test (vHIT) for SCCs function, cervical Vestibular Evoked Myogenic Potentials test (cVEMPt) for sacculi function, Body Sensation Questionnaire (BSQ) for panic anxiety, Object Perspective-Taking test (OPTt) for spatial orientation and Cox & Swinson DPDR inventory for DPDR symptoms. ResultspBVH patients showed significant SCCs and sacculi dysfunction, spatial disorientation, elevated panic anxiety, and DPDR symptoms. MJD patients showed significant SCCs hypofunction but preserved sacculi function, spatial disorientation but normal levels of panic anxiety and DPDR symptoms. Only pBVH patients demonstrated a positive correlation between the severity of the DPDR and spatial disorientation and panic anxiety. ConclusionsDPDR develops in association with sacculi dysfunction, either with or without SSCs dysfunction. Spatial disorientation and anxiety seem to mediate the transformation of vestibular dysfunction into DPDR symptoms. DPDR does not develop in MJD with central vestibular hypofunction but a normal saccular response. We propose a three-step model that describes the development of DPDR symptoms in vestibular patients.

Bilateral Vestibular Hypofunction in a Tertiary Dizziness Center: Occurrence and Etiology.

Background:The primary goal of this study was to determine the occurrence of bilateral vestibular hypofunction in a specialized dizziness clinic and to assess the etiology in patients diagnosed with bilateral vestibular hypofunction. Secondary goal was to find out if the diagnosis was already made before the patient was seen at our clinic.Methods:A retrospective cohort study, including patients who visited our specialized dizziness center between January 1, 2008, and December 31, 2018, fulfilling the criteria for bilateral vestibular hypofunction according to the Classification Committee of the Bárány Society (2017). Data were collected regarding symptoms, causes, and vestibular function.Results:In total, 126 patients met our initial inclusion criteria, of which 103 patients met the Classification Committee of the Bárány Society criteria for bilateral vestibular hypofunction, so patients with bilateral vestibular hypofunction comprised 0.9% of the total population seen at our clinic. Mean age was 65.2 years and 49.5% were female. In only 29.1% of patients, the diagnosis was already made elsewhere. A definite cause was identified in 39.8%, the most common cause being ototoxicity.Conclusion:About 1% of the patients visiting our dizziness clinic has bilateral vestibular hypofunction. In our patient population, ototoxicity was the most common cause of bilateral vestibular hypofunction, and in more than 40%, the cause remains unknown. In the majority of the cases, the diagnosis of bilateral vestibular hypofunction was first made at our clinic and not by the referring general practitioner or specialist. When using the Classification Committee of the Bárány Society criteria for bilateral vestibular hypofunction and presbyvestibulopathy, some patients with bilateral vestibular weakness and complaints cannot be categorized in either group.

IGST Combined with Conventional Drug Therapy and TCM Therapy for Treatment of Bilateral Vestibular Hypofunction.

Objective To investigate the effects of intensive gaze stability training (IGST) combined with conventional drug therapy and traditional Chinese medicine (TCM) therapy on hearing recovery and quality of life (QOL) in patients with bilateral vestibular dysfunction. Materials and Methods A total of 120 patients with bilateral vestibular dysfunction admitted to our hospital from January 2019 to January 2020 were recruited and assigned to group A (n = 60) and group B (n = 60) based on the order of admission. Group B received conventional medication and TCM therapy, and group A received IGST plus conventional medication and TCM therapy. The serum biochemical indexes, blood rheology indexes, symptoms disappearance time, hearing recovery time, pure-tone hearing threshold, vestibular symptom index (VSI), and QOL of the two groups were compared. Results The serum biochemical indexes and blood rheology indexes in group A were lower than those in group B after treatment (P < 0.001). Patients in group A had a shorter time lapse before symptoms disappearance and hearing recovery than those in group B (P < 0.001). Group A had lower results of the pure-tone hearing threshold (P < 0.001) and of VSI (P < 0.05) than group B. Patients in group A had higher QOL scores than those in group B after treatment (P < 0.001). Conclusion IGST plus conventional drug therapy effectively improves the serum biochemical indexes and blood rheological indexes of patients with bilateral vestibular hypofunction, accelerates their hearing recovery process, and alleviates their clinical symptoms, thereby improving their QOL, which shows good potential in clinical application.