Bilateral Vestibular Dysfunction Research Articles

Evaluation of Semicircular Canal Function Using Video Head Impulse Test in Patients With Peripheral Vestibular Disorders Without Nystagmus.

Objectives This study aims to evaluate semicircular canal function using video head impulse test (vHIT) in patients with peripheral vestibular disorders without nystagmus. Methods Patients who underwent vHIT were enrolled in this study, and the proportion of abnormal findings on vHIT in patients without nystagmus was investigated. In addition, the results of vestibular testing were investigated in cases in which both vHIT and caloric testing were performed in patients without nystagmus. Results Forty-six patients (23.4%) of 197 patients who had no abnormal findings on the nystagmus tests, including the gaze nystagmus test, positional nystagmus test, and positioning nystagmus test, showed dysfunction in at least one semicircular canal on vHIT. The most frequent diagnosis was vestibular schwannoma (14/46, 30.4%), and cases with bilateral vestibular dysfunction were also included (12/46, 26.1%). A disorganized pattern of catch-up saccade was observed more frequently in patients with subjective symptoms of dizziness/vertigo compared to those without subjective symptoms. Although the sensitivity of vHIT was low compared to caloric testing, vHIT could detect isolated vertical canal dysfunction not detected by caloric testing. Conclusions vHIT is considered to be a useful test for patients without nystagmus, as vHIT could detect abnormalities in approximately one-quarter of patients without nystagmus. vHIT is considered to be one of the first tests to be performed following nystagmus testing, including the gaze nystagmus test, the positional nystagmus test, and the positioning nystagmus test. On the other hand, there are some cases in which vHIT shows no abnormality while caloric testing shows canal paresis. It is necessary to perform vHIT, bearing in mind that there are abnormalities that cannot be detected by vHIT alone.

Executive functions in patients with bilateral and unilateral peripheral vestibular dysfunction.

Previous research suggests that patients with peripheral vestibular dysfunction (PVD) suffer from nonspatial cognitive problems, including executive impairments. However, previous studies that assessed executive functions are conflicting, limited to single executive components, and assessments are confounded by other cognitive functions. We compared performance in a comprehensive executive test battery in a large sample of 83 patients with several conditions of PVD (34 bilateral, 29 chronic unilateral, 20 acute unilateral) to healthy controls who were pairwise matched to patients regarding age, sex, and education. We assessed basic and complex executive functions with validated neuropsychological tests. Patients with bilateral PVD performed worse than controls in verbal initiation and working memory span, while other executive functions were preserved. Patients with chronic unilateral PVD had equal executive performance as controls. Patients with acute unilateral PVD performed worse than controls in the exact same tests as patients with bilateral PVD (verbal initiation, working memory span); however, this effect in patients with acute PVD diminished after correcting for multiple comparisons. Hearing loss and affective disorders did not influence our results. Vestibular related variables (disease duration, symptoms, dizziness handicap, deafferentation degree, and compensation) did not predict verbal initiation or working memory span in patients with bilateral PVD. The results suggest that bilateral PVD not only manifests in difficulties when solving spatial tasks but leads to more general neurocognitive deficits. This understanding is important for multidisciplinary workgroups (e.g., neurotologists, neurologists, audiologists) that are involved in diagnosing and treating patients with PVD. We recommend screening patients with PVD for executive impairments and if indicated providing them with cognitive training or psychoeducational support.

Dynamic visual acuity screening test results analysis of 25 patients with peripheral vertigo

Objective:To observe the results of dynamic visual acuity screening tests in patients with peripheral vertigo and explore its clinical significance. Methods:The number of 48 healthy volunteers were enrolled as control group and 25 peripheral vertigo patients as experimental group. In the experimental group, there are 12 patients with vestibular neuritis, 1 patient with Hunt syndrome, 5 patients with sudden deafness with vertigo and 7 patients with bilateral vestibular dysfunction. Horizontal and vertical dynamic visual acuity screening tests were performed on them. The number of lost rows of horizontal and vertical dynamic visual acuity was compared between the control group and the experimental group to figure out if there is a statistical difference. The number of lost rows of horizontal and vertical dynamic visual acuity was compared within the experimental group to figure out if there is a statistical difference. The two groups of 18 cases of unilateral vestibular function decline and 7 cases of bilateral vestibular function decline in the experimental group were compared with the control group, and figure out if there is a statistical difference. Results:The median number of lost rows of horizontal dynamic visual acuity in 48 healthy volunteers was 1.5 and median number of lost rows of vertical dynamic visual acuity was 1.0 in the control group. The median number of lost rows of horizontal dynamic visual acuity of 26 healthy volunteers was 6 and median number of lost rows of vertical dynamic visual acuity was 5 in the experimental group. Compared to the experimental group, the number of lost rows both have statistical significance in horizontal and vertical dynamic visual acuity（P<0.01）. The comparison of horizontal and vertical lost rows within the test group also have statistical significance（P<0.01）. Twenty five patients with exceptional vestibular disease in the experimental group were divided into unilateral vestibular function reduction group（n=18） and bilateral vestibular function reduction group（n=7）. Compared with the control group, there was significant differences in the number of horizontal and vertical lost rows（P<0.01） within the three groups. After pairwise comparison, the number of lost rows of horizontal and vertical in the control group was significantly lower than that in the unilateral vestibular function reduction group and the bilateral vestibular function reduction group（P<0.01）. There was a highly significant correlation between the number of horizontally lost rows of DVA and the mean vHIT values of bilateral horizontal semicircular canals in 25 patients（P<0.01）; and a highly significant correlation between the number of vertically lost rows of DVA and the mean vHIT values of vertical semicircular canals in 4 groups bilaterally（P<0.01）. Conclusion:The Dynamic Visual Acuity Screening Test is a useful addition to existing tests of peripheral vestibular function, particularly the vHIT test, and provides a rapid assessment of the extent of 2 Hz VOR impairment in patients with reduced vestibular function.

Characteristics of vestibular-evoked myogenic potentials in children with vestibular malformation and severe sensorineural hearing loss

BackgroundWith the increasing clinical focus on the safety of bilateral cochlear implantation (CI) and the potential risk of bilateral vestibular dysfunction, evaluating vestibular end-organ function in patients with vestibular malformations with accompanying abnormalities has been strongly recommended. ObjectivesTo identify the vestibular-evoked myogenic potential (VEMP) values among children with sensorineural hearing loss (SNHL) with vestibular malformation and assess the effectiveness of VEMP testing for inner ear malformations (IEM) diagnosis. MethodsThis study included 96 children (192 ears), including those with vestibular malformations (48 ears), large vestibular aqueduct syndrome (LVAS) (50 ears), and SNHL without IEM (94 ears; control group). All groups underwent ocular and cervical VEMP (oVEMP and cVEMP, respectively) testing. The response rates, VEMP parameters, and wave characteristics were compared. ResultsThe cVEMP response rates were 37.5 %, 64 %, and 58.51 % and the oVEMP response rates were 42.86 %, 78.95 %, and 77.27 % in the vestibular malformation, LVAS, and control groups, respectively, and significantly differed between groups (cVEMP: X2 = 18.228, P<0.001) (oVEMP: X2 = 7.528, P = 0.023). Significant inter-group differences were observed for the cVEMP and oVEMP latency and amplitude (P < 0.05). The LVAS group's waveform exhibited a prolonged latency and increased amplitude compared with that of the other groups. ConclusionPatients with SNHL were highly susceptible to otolith dysfunction, regardless of comorbid vestibular malformation presence. Measuring VEMPs is an effective and rapid evaluation technique for vestibular function and could provide a basis for vestibular rehabilitation training.

Vestibular function after simultaneous bilateral cochlear implantation in adults.

Binaural hearing enhances speech intelligibility, source localization, and speech comprehension in noisy environments. Although bilateral cochlear implantation (CI) offers several benefits, concerns arise regarding the risk of bilateral postoperative vestibular dysfunction with simultaneous CI. This study aimed to longitudinally evaluate changes in vestibular function in adult patients who underwent simultaneous bilateral CI using minimally invasive electrodes and surgical techniques. A retrospective review was conducted on 10 patients who underwent simultaneous bilateral CI at our hospital. Vertigo symptoms and vestibular function test results were examined preoperatively, 1-6 months postoperatively, and 1 year postoperatively. Nystagmus tests, caloric reflex tests, vestibular evoked myogenic potentials (VEMP) measurements, and static stabilometry were performed as vestibular function tests. Although an initial transient decline in vestibular function was observed, no significant long-term decline was observed in the caloric reflex test, ocular VEMP (oVEMP), or cervical VEMP (cVEMP). Moreover, regardless of the presence or absence of abnormalities in caloric reflex, oVEMP, or cVEMP, no significant deterioration was detected in the static stabilometer test. While two patients reported preoperative dizziness, all patients were symptom-free 1 year postoperatively. The findings suggest that using current minimally invasive electrodes and surgical techniques in simultaneous bilateral CI leads to temporary vestibular function decline postoperatively. However, most patients experience a recovery in function over time, highlighting the potential safety and efficacy of the procedure. Simultaneous bilateral CI surgery is viable, depending on the patient's auditory needs and burden.

The effects of vestibular dysfunction on balance and self-concept in children with cochlear implants.

Children with cochlear implants (CCI) have an increased rate of vestibular dysfunction. Vestibular dysfunction is associated with decreased balance and dynamic visual acuity ability. Hearing loss alone is associated with reduced speech perception and vocabulary in children. In adults, vestibular dysfunction is associated with reduced quality of life; however, similar relationships have not been studied in children with vestibular dysfunction. Therefore, the objective of the present study was to evaluate the effect of hearing loss and vestibular dysfunction on self-concept in CCI (n=33) compared to children with normal hearing (CNH, n=38). It was hypothesized that children with vestibular dysfunction would have reduced self-concept beyond that from hearing loss, secondary to the presence of balance and visual acuity deficits. The Piers-Harris Children's Self-Concept Scale - 2, speech perception, vocabulary, video head impulse test (vHIT), rotary chair, balance using the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2), and dynamic visual acuity (DVA) testing were completed on all participants. In the 34 CCI, 24 had normal vestibular function, 6 had unilateral vestibular dysfunction, and 4 had bilateral vestibular dysfunction. There were no significant mean differences in the Piers-Harris Children's Self-Concept Scale - 2 between groups. A Principal Component Analysis (PCA) was conducted on the predictor variables (average horizontal canal vHIT gain, BOT-2 score, DVA, speech perception, and vocabulary) resulting in two factors; factor 1 represented "vestibular" components (vHIT, BOT-2, and DVA) and factor 2 represented "auditory-language" components (speech perception and vocabulary). In addition to age and gender, the 2 PCA factors were analyzed using multivariate regression with stepwise selection to determine which factors best predicted self-concept. The PCA auditory-language factor was the only significant predictor of self-concept. Auditory-language, not vestibular related factors, contribute to the self-concept of CCI. While adults with vestibular dysfunction have reduced quality of life, it could be that children with vestibular dysfunction have some psychosocial resilience.

Age-Related Peripheral Vestibular Dysfunction: A Review

Age-related peripheral vestibular dysfunction is usually associated with an imbalance that has a major impact on morbidity, mortality, and health-care resources. Age-related vestibular hypofunction has been shown to correlate with the age-related reduction in the number of vestibular hair cells and neurons. Progressive disequilibrium of aging is a complex and multifactorial condition leading to dizziness and a higher chance of risk of falls. The stability of the posture and gaze during standing and walking is maintained by the processing of vestibular, visual, and somatosensory inputs in the central nervous systems, followed by outputs to the musculoskeletal and visual systems. Every component in this stem deteriorates as the age increases or in the aging process. Vestibular rehabilitation is an effective treatment option for both unilateral and bilateral vestibular dysfunction in the elderly age group. There are different prosthetic devices developed to enhance the postural balance in the older person. Although there is no definitive medical treatment available for age-related peripheral vestibular dysfunction, new medical treatments such as mitochondrial antioxidants or caloric restriction which have been useful for preventing age-related hearing impairment should be investigated in the future for treating age-related peripheral vestibular dysfunction.

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

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. 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. 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. 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.

Long-term outcome of vestibular function and hearing in children with congenital cytomegalovirus infection: a prospective cohort study

PurposeCongenital cytomegalovirus infection (cCMV) is the most frequent nonhereditary cause for sensorineural hearing loss (SNHL) in children. Data on vestibular function in children with cCMV are, however, scarce, although some evidence for cCMV-associated vestibular dysfunction exists. In this prospective cohort study, we evaluated long-term vestibular function and hearing outcomes in a cohort of children with cCMV.MethodsParticipants were 6–7-year-old children with cCMV from a large population-based screening study. Controls were age and gender matched healthy children, who were CMV-negative at birth. Hearing was examined with pure tone audiometry. Definition of hearing loss was pure-tone average > 20 dB. Vestibular function was assessed using the video head impulse test that provides a measure of semicircular canal function. Definition of vestibular dysfunction was lateral semicircular canal gain < 0.75.ResultsVestibular dysfunction occurred in 7/36 (19.4%) of children with cCMV and in 1/31 (3.2%) of controls (p = 0.060). SNHL was recorded in 4/38 (10.5%) of children with cCMV and in 0/33 of controls (p = 0.118). Hearing loss was unilateral in all cases. In cCMV group, the two children with bilateral vestibular dysfunction also had SNHL, whereas those with unilateral vestibular dysfunction (n = 5) had normal hearing.ConclusionsIn this cohort of children with cCMV identified using newborn screening, vestibular dysfunction was more common than SNHL at 6 years of age. Vestibular dysfunction occurred both in children with and without SNHL. Based on these data, inclusion of vestibular tests in follow-up protocol of cCMV should be considered.

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.

Vestibular Dysfunction in Replication Factor C Subunit 1 (RFC1) Spectrum Disorder

More than 90% of replication factor c subunit 1 (RFC1) gene-related spectrum disorders such as cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) have bilateral vestibular dysfunction. A case with CANVAS presented in this paper showed repeat extension of AAGGG in the intron region of the RFC1 gene, and showed bilateral vestibular dysfunction in caloric test, vestibular evoked myogenic potential, video Head Impulse Test and rotary chair test. Visual enhanced vestibulo-ocular reflex tests also revealed abnormalities, suggesting the presence of combined lesions of the cerebellum and brainstem including vestibular nuclei.

Dynamic Visual Acuity Results in Otolith Electrical Stimulation in Bilateral Vestibular Dysfunction.

(1) Background. Patients with bilateral vestibular disease (BVD) experience oscillopsia with a detriment to visual acuity (VA). This VA is driven mainly by the VOR that has two components: rotational and translational. VA can be tested by using dynamic visual acuity (DVA) on a treadmill because both systems are activated. The aim of this study is to compare VA before and after chronic electrical stimulation of the otolith organ. (2) Materials and Method. Five patients suffering from bilateral vestibular dysfunction (BVD), previously implanted with a new vestibular implant prototype, were included in this study with the aim to check VA with and without vestibular implant use (W and W/O) in static, 2 km/h and 4 km/h walking situations. DVAtreadmill was measured on a treadmill with a dynamic illegible E (DIE) test in static and dynamic conditions (while walking on the treadmill at 2 and 4 km/h). The DVA score was registered in a logarithm of the minimum angle of resolution (LogMAR) for each speed. In addition, every patient completed the oscillopsia severity questionnaire (OSQ) and video head impulse test (vHIT) before and after activation of the vestibular implant. (3) Results. The analysis shows a significant difference in OSQ scores and DVA with an improvement in dynamic conditions. Organized corrective saccades during the use of a vestibular implant with no changes in gain were also detected in the video head impulse tests (vHIT). (4) Conclusion. The vestibular implant with otolithic stimulation offers changes in the response of DVA, which makes this paper one of the first to address the possible restoration of it. It is not possible to rule out other contributing factors (presence of covert saccades, somatosensory system, …). More work seems necessary to understand the neurophysiological basis of these findings, but this implant is added as a therapeutic alternative for the improvement of oscillopsia.

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.

The Role of Neck Input in Producing Corrective Saccades in the Head Impulse Test.

BackgroundThe head impulse test is a valuable clinical test that can help identify peripheral vestibular dysfunction by observing corrective saccades that return the eyes to the target of interest. Corrective saccades have been classified as covert if the onset occurs before the end of the head impulse and as overt if they occur afterwards. However, the mechanism that trigger these saccades remain unclear.ObjectiveThe objective of this study was to examine the role of neck input in generating overt as well as covert saccades.MethodsSixteen patients (9 males and 7 females: age 35-80 years, average 62.7 years old) who showed corrective saccades during the head impulse test were included. Twelve patients had unilateral vestibular dysfunction, and 4 patients had bilateral vestibular dysfunction. Patients underwent both the head impulse test (HIT) and the body impulse test (BIT) in a randomized order. While the head is rotated horizontally in HIT, the body is rotated horizontally in BIT. During BIT, the neck is fixed by a cervical collar (neck lock extrication collar) to reduce somatosensory input from the neck. The head movements and eye movements were recorded and analyzed by the video HIT recording system.ResultsIn all 16 patients, corrective saccades were observed in HIT as well as in BIT. While there were no significant differences in peak head velocities between HIT and BIT (p = 0.33, paired t-test), the VOR gain in BIT was significantly smaller than that in HIT (p = 0.011, paired t-test). The number of overt saccades per trial in BIT was significantly decreased compared to that in HIT (p < 0.001, paired t-test) whereas there were no significant differences in the number of covert saccades between the two tests. The proportion of overt saccades among all corrective saccades in BIT was significantly lower than the proportion in HIT (p < 0.001, paired t-test).ConclusionsSomatosensory input from the neck contributes to the generation of overt saccades and reinforces the vestibulo-ocular reflex complementing the retinal slip during high frequency head movements.

Is the clinical head impulse test helpful in cochlear implantation candidacy evaluation?

Vestibular dysfunction is a known risk of cochlear implantation (CI). However, the utility of the physical exam to screen CI candidates for vestibular dysfunction is not well-studied. The objective of this study is to evaluate the preoperative role of the clinical head impulse test (cHIT) in subjects undergoing CI surgery evaluation. We conducted a retrospective review of 64 adult CI candidacy cases between 2017 and 2020 at a tertiary health care center. All patients underwent audiometric testing and evaluation by the senior author. Patients with an abnormal catch-up saccade contralateral to their worse hearing ear during cHIT were referred for formal vestibular testing. Outcomes included clinical and formal vestibular results, operated ear with regard to audiometric and vestibular results, and postoperative vertigo. Among all CI candidates, 44% (n = 28) reported preoperative disequilibrium symptoms. Overall, 62% (n = 40) of the cHITs were normal, 33% (n = 21) were abnormal, and 5% (n = 3) were inconclusive. There was one patient who presented with a false positive cHIT. Among the patients who endorsed disequilibrium, 43% had a positive preoperative cHIT. Fourteen percent of the subjects (n = 9) without disequilibrium had an abnormal cHIT. In this cohort, bilateral vestibular impairment (71%) was more common than unilateral vestibular impairment (29%). In 3% of the cases (n = 2), surgical management was revisited or altered due to cHIT findings. There is a high prevalence of vestibular hypofunction in the CI candidate population. Self-reported assessments of vestibular function are often not congruent with cHIT results. Clinicians should consider incorporating cHITs as part of the preoperative physical exam to potentially avoid bilateral vestibular dysfunction in a minority of patients.

The clinical application of mobile internet remote guidance platform for vestibular rehabilitation

Objective: To guide the patients with vertigo who are suitable for vestibular rehabilitation therapy (VRT), and to evaluate the curative effect through a remote guidance platform based on mobile internet. Methods: Adult outpatients, who were diagnosed as vestibular disorders and required VRT, were selected and conducted baseline evaluation and formulated vestibular rehabilitation plan according to their symptoms, diagnosis and vestibular function examination results. These patients downloaded and installed the mobile internet remote guidance platform app for VRT, and then registered and uploaded medical records. According to the VRT plan formulated by clinicians for patients, the platform launched corresponding exercise guidance videos to guide them to complete 4-week VRT exercise at home. Before and after VRT, the patients were scored with Visual Analogue Scale (VAS), Activities-specific Balance Confidence (ABC), Dizziness Handicap Inventory (DHI) and Self-rating Anxiety Scale (SAS). The rehabilitation effects were statistically analyzed by SigmaStat 4.0 software. Results: From October 2019 to October 2021, 233 patients with vertigo completed the registration of vestibular rehabilitation guidance platform, of whom 187 patients insisted on 4-week rehabilitation training and completed the scale evaluation. Among 187 patients, 65 were male and 122 were female; Age was (49.8±16.0) years; The medical history ranged from one to 192 months, with a median of eight months. Compared with that before rehabilitation exercise, the subjective feeling of vertigo in 170 patients was improved, and the overall effective rate was 90.9% (170/187). The subjective symptoms of vertigo were basically improved after rehabilitation training in patients with unilateral vestibular dysfunction, vestibular neuritis, sudden deafness with vertigo, Hunt syndrome and acoustic neuroma. There were significant differences in ABC, DHI and SAS scores before and after VRT (P<0.05). Of those patients with Meniere's disease in the intermittent period and the patients with Meniere's disease who underwent surgical treatment, more than 90% of their subjective symptoms of vertigo or dizziness improved after VRT, and there were significant differences in the scores of ABC, DHI and SAS before and after VRT exercise (P<0.05). In patients with vestibular migraine, 36.7% (11/30) had no improvement or even aggravation of subjective symptoms of vertigo after VRT, however, the DHI score after rehabilitation exercise was lower than that before exercise, and the difference was statistically significant (P<0.05). In patients with bilateral vestibular dysfunction, although most (6/8) subjective symptom scores were improved compared with those before exercise, there was no significant difference in ABC, DHI and SAS scores before and after rehabilitation (P>0.05). Conclusion: VRT with the help of vestibular rehabilitation mobile internet remote guidance platform can effectively improve the subjective symptoms of vertigo, balance ability and anxiety in patients with unilateral vestibular lesions.

Why Should Constant Stimulation of Saccular Afferents Modify the Posture and Gait of Patients with Bilateral Vestibular Dysfunction? The Saccular Substitution Hypothesis.

An ongoing EU Horizon 2020 Project called BionicVEST is investigating the effect of constant electrical stimulation (ES) of the inferior vestibular nerve in patients with bilateral vestibular dysfunction (BVD). The evidence is that constant ES results in improved postural stability and gait performance, and so the question of central importance concerns how constant ES of mainly saccular afferents in these BVD patients could cause this improved performance. We suggest that the constant ES substitutes for the absent saccular neural input to the vestibular nuclei and the cerebellum in these BVD patients and indirectly via these structures to other structures, which have been of great recent interest in motor control. One target area, the anterior midline cerebellum (the uvula), has recently been targeted as a location for deep-brain stimulation in human patients to improve postural stability and gait. There are projections from midline cerebellum to basal ganglia, including the striatum, which are structures involved in the initiation of gait. It may be that the effect of this activation of peripheral saccular afferent neurons is analogous to the effect of deep-brain stimulation (DBS) by electrodes in basal ganglia acting to help alleviate the symptoms of patients with Parkinson’s disease.

Hippocampal volume in patients with bilateral and unilateral peripheral vestibular dysfunction

Previous studies have found that peripheral vestibular dysfunction is associated with altered volumes in different brain structures, especially in the hippocampus. However, published evidence is conflicting. Based on previous findings, we compared hippocampal volume, as well as supramarginal, superior temporal, and postcentral gyrus in a sample of 55 patients with different conditions of peripheral vestibular dysfunction (bilateral, chronic unilateral, acute unilateral) to 39 age- and sex-matched healthy controls. In addition, we explored deviations in gray-matter volumes in hippocampal subfields. We also analysed correlations between morphometric data and visuo-spatial performance. Patients with vestibular dysfunction did not differ in total hippocampal volume from healthy controls. However, a reduced volume in the right presubiculum of the hippocampus and the left supramarginal gyrus was observed in patients with chronic and acute unilateral vestibular dysfunction, but not in patients with bilateral vestibular dysfunction. No association of altered volumes with visuo-spatial performance was found. An asymmetric vestibular input due to unilateral vestibular dysfunction might lead to reduced central brain volumes that are involved in vestibular processing.

Association between vestibular function and rotational spatial orientation perception in older adults.

Spatial orientation is a complex process involving vestibular sensory input and possibly cognitive ability. Previous research demonstrated that rotational spatial orientation was worse for individuals with profound bilateral vestibular dysfunction. Determine whether rotational and linear vestibular function were independently associated with large amplitude rotational spatial orientation perception in healthy aging. Tests of rotational spatial orientation accuracy and vestibular function [vestibulo-ocular reflex (VOR), ocular and cervical vestibular evoked myogenic potentials (VEMP)] were administered to 272 healthy community-dwelling adults participating in the Baltimore Longitudinal Study of Aging. Using a mixed model multiple linear regression we regressed spatial orientation errors on lateral semicircular canal function, utricular function (ocular VEMP), and saccular function (cervical VEMP) in a single model controlling for rotation size, age, and sex. After adjusting for age, and sex, individuals with bilaterally low VOR gain (β= 20.9, p = 0.014) and those with bilaterally absent utricular function (β= 9.32, p = 0.017) made significantly larger spatial orientation errors relative to individuals with normal vestibular function. The current results demonstrate for the first time that either bilateral lateral semicircular canal dysfunction or bilateral utricular dysfunction are associated with worse rotational spatial orientation. We also demonstrated in a healthy aging cohort that increased age also contributes to spatial orientation ability.

Differences in Vestibular-Evoked Myogenic Potential Responses by Using Cochlear Implant and Otolith Organ Direct Stimulation.

Objective: Several studies have demonstrated the possibility to obtain vestibular potentials elicited with electrical stimulation from cochlear and vestibular implants. The objective of this study is to analyze the vestibular-evoked myogenic potentials (VEMPs) obtained from patients implanted with cochlear and vestibulo-cochlear implant.Material and Methods: We compared two groups: in the first group, four cochlear implant (CI) recipients with present acoustic cVEMPs before CI surgery were included. In the second group, three patients with bilaterally absent cVEMPs and bilateral vestibular dysfunction were selected. The latter group received a unilateral cochleo-vestibular implant. We analyze the electrically elicited cVEMPs in all patients after stimulation with cochlear and vestibular electrode array stimulation.Results: We present the results obtained post-operatively in both groups. All patients (100%) with direct electrical vestibular stimulation via the vestibular electrode array had present cVEMPs. The P1 and N1 latencies were 11.33–13.6 ms and 18.3–21 ms, respectively. In CI patients, electrical cVEMPs were present only in one of the four subjects (25%) with cochlear implant (“cross”) stimulation, and P1 and N1 latencies were 9.67 and 16.33, respectively. In these patients, the responses present shorter latencies than those observed acoustically.Conclusions: Electrically evoked cVEMPs can be present after cochlear and vestibular stimulation and suggest stimulation of vestibular elements, although clinical effect must be further studied.