Aging and the peripheral vestibular system

Vestibular perceptual learning improves self-motion perception, posture, and gait in older adults

Vestibular motion perception declines with age, increasing the risk of falling substantially. We performed a two-week perceptual learning intervention using a self-motion direction discrimination task (2800 training trials per person) on a 6 degrees of freedom motion platform in healthy older adults (n = 40, aged 70-88 yr). Linear inter-aural and angular roll tilt vestibular thresholds improved with training (95% credible interval for pre/post difference), suggesting altered sensitivity post-training. Moreover, improved perceptual abilities transfer to actual posture (reduced sway) and gait parameters. Passive self-motion discrimination training provides a new and promising way to counteract age-related sensory decline. It can reduce the risk of falling, and thereby maintain individual autonomy and quality of life.

Effects of monaural sound stimulation on subjective visual vertical

BACKGROUND

Sound stimulation can influence electrophysiological vestibular reflexes. However, the effects of sound stimulation on space perception remain unknown.

OBJECTIVE

To know the effects of monaural sound stimulation on subjective visual vertical (SVV).

METHODS

We measured SVV with and without monaural sound stimulation (105 dB, 500 Hz short tone burst presented at 4.7 Hz) in 50 healthy volunteers (aged 20-77 [mean = 42.7] years).

RESULTS

The mean SVV was deviated 0.139° to the left by right monaural sound stimulation and 0.123° to the right by left monaural sound stimulation. SVV changes due to right and left ear stimulations were significantly different (p = 0.019). Sound stimulation resulted in a significant change in SVV on the left side (p = 0.014) in participants aged 50 or younger (mean = 35.6 years) (n = 37).

CONCLUSIONS

This study is the first to show the possibility that the monaural sound input deviates the SVV toward the opposite side and is more pronounced for left-ear input. The vestibular-evoked myogenic potential responses may be involved in the mechanism of the contralateral SVV deviation due to sound input.

The rationale and recommendations for inclusion of screening for benign paroxysmal positional vertigo in falls clinics

BACKGROUND

There have been many studies linking falls and benign paroxysmal positional vertigo. This article collates those studies, and demonstrates how a community falls service fast-tracked patients with benign paroxysmal positional vertigo by implementing validated screening tools and recognised guidance.

OBJECTIVE

This study aimed to explore whether routine screening of referrals to a community falls service can identify those with benign paroxysmal positional vertigo, for fast-tracked management.

METHODS

Patients referred to a community falls service were screened for possible benign paroxysmal positional vertigo using the Dizziness Handicap Inventory, and triaged to a physiotherapy-led falls and benign paroxysmal positional vertigo assessment service.

RESULTS

Twenty-five per cent of patients were fast-tracked to a falls and benign paroxysmal positional vertigo assessment service for management. The community falls service waiting list reduced by 25 per cent.

CONCLUSION

The data support incorporating assessment and treatment of benign paroxysmal positional vertigo into routine practice within all falls services.

Residual dizziness after BPPV management: exploring pathophysiology and treatment beyond canalith repositioning maneuvers

Despite the high success rate of canalith repositioning maneuvers (CRMs) in the treatment of benign paroxysmal positional vertigo (BPPV), a growing number of patients report residual dizziness symptoms that may last for a significant time. Although the majority of BPPV cases can be explained by canalolithiasis, the etiology is complex. Consideration of the individual patient's history and underlying pathophysiology of BPPV may offer the potential for treatment approaches supplementary to CRMs, as well as a promising alternative for patients in whom CRMs are contraindicated. This article provides a summary of the possible underlying causes of BPPV and residual dizziness, along with suggestions for potential management options that may be considered to relieve the burden of residual symptoms.

Assessing the Effects of Mild Traumatic Brain Injury on Vestibular Home Exercise Performance with Wearable Sensors

After a mild traumatic brain injury (mTBI), dizziness and balance problems are frequently reported, affecting individuals' daily lives and functioning. Vestibular rehabilitation is a standard treatment approach for addressing these issues, but its efficacy in this population remains inconclusive. A potential reason for suboptimal outcomes is the lack of objective monitoring of exercise performance, which is crucial for therapeutic success. This study utilized wearable inertial measurement units (IMUs) to quantify exercise performance in individuals with mTBI during home-based vestibular rehabilitation exercises. Seventy-three people with mTBI and fifty healthy controls were enrolled. Vestibular exercises were performed, and IMUs measured forehead and sternum velocities and range of motions. The mTBI group demonstrated a slower forehead peak angular velocity in all exercises, which may be a compensatory strategy to manage balance issues or symptom exacerbation. Additionally, the mTBI group exhibited a larger forehead range of motion during specific exercises, potentially linked to proprioceptive deficits. These findings emphasize the usefulness of utilizing IMUs to monitor the quality of home-based vestibular exercises for individuals with mTBI and the potential for IMUs improving rehabilitation outcomes.

Genome-Wide Association Study of Chronic Dizziness in the Elderly Identifies Loci Implicating MLLT10, BPTF, LINC01224, and ROS1

PURPOSE

Chronic age-related imbalance is a common cause of falls and subsequent death in the elderly and can arise from dysfunction of the vestibular system, an elegant neuroanatomical group of pathways that mediates human perception of acceleration, gravity, and angular head motion. Studies indicate that 27-46% of the risk of age-related chronic imbalance is genetic; nevertheless, the underlying genes remain unknown.

METHODS

The cohort consisted of 50,339 cases and 366,900 controls in the Million Veteran Program. The phenotype comprised cases with two ICD diagnoses of vertigo or dizziness at least 6 months apart, excluding acute or recurrent vertiginous syndromes and other non-vestibular disorders. Genome-wide association studies were performed as individual logistic regressions on European, African American, and Hispanic ancestries followed by trans-ancestry meta-analysis. Downstream analysis included case-case-GWAS, fine mapping, probabilistic colocalization of significant variants and genes with eQTLs, and functional analysis of significant hits.

RESULTS

Two significant loci were identified in Europeans, another in the Hispanic population, and two additional in trans-ancestry meta-analysis, including three novel loci. Fine mapping revealed credible sets of intronic single nucleotide polymorphisms (SNPs) in MLLT10 - a histone methyl transferase cofactor, BPTF - a subunit of a nucleosome remodeling complex implicated in neurodevelopment, and LINC01224 - a proto-oncogene receptor tyrosine kinase.

CONCLUSION

Despite the difficulties of phenotyping the nature of chronic imbalance, we replicated two loci from previous vertigo GWAS studies and identified three novel loci. Findings suggest candidates for further study and ultimate treatment of this common elderly disorder.

Aged mice are less susceptible to motion sickness and show decreased efferent vestibular activity compared to young adults

INTRODUCTION

The efferent vestibular system (EVS) is a feedback circuit thought to modulate vestibular afferent activity by inhibiting type II hair cells and exciting calyx-bearing afferents in the peripheral vestibular organs. In a previous study, we suggested EVS activity may contribute to the effects of motion sickness. To determine an association between motion sickness and EVS activity, we examined the effects of provocative motion (PM) on c-Fos expression in brainstem efferent vestibular nucleus (EVN) neurons that are the source of efferent innervation in the peripheral vestibular organs.

METHODS

c-Fos is an immediate early gene product expressed in stimulated neurons and is a well-established marker of neuronal activation. To study the effects of PM, young adult C57/BL6 wild-type (WT), aged WT, and young adult transgenic Chat-gCaMP6f mice were exposed to PM, and tail temperature (Ttail ) was monitored using infrared imaging. After PM, we used immunohistochemistry to label EVN neurons to determine any changes in c-Fos expression. All tissue was imaged using laser scanning confocal microscopy.

RESULTS

Infrared recording of Ttail during PM indicated that young adult WT and transgenic mice displayed a typical motion sickness response (tail warming), but not in aged WT mice. Similarly, brainstem EVN neurons showed increased expression of c-Fos protein after PM in young adult WT and transgenic mice but not in aged cohorts.

CONCLUSION

We present evidence that motion sickness symptoms and increased activation of EVN neurons occur in young adult WT and transgenic mice in response to PM. In contrast, aged WT mice showed no signs of motion sickness and no change in c-Fos expression when exposed to the same provocative stimulus.

The reliability of a subtype-determining questionnaire in efficient benign paroxysmal positional vertigo diagnosis in geriatrics

Introduction

Benign paroxysmal positional vertigo (BPPV), the most common cause of dizziness, especially for older adults, exposes patients to the lethal risk of falling. However, the diagnosis of BPPV in this population can be more elusive as they present few characteristic symptoms. Therefore, we explored the application of a subtype-determining questionnaire in BPPV diagnosis among the geriatric population.

Methods

Patients were assigned to the aware and unaware groups. In the aware group, the technician would directly test the suspected canal indicated by the questionnaire, whereas, in the unaware group, the technician performed the regular positional test. The diagnostic parameters of the questionnaire were examined.

Results

The accuracy, sensitivity, and specificity of questions 1-3 for diagnosing BPPV were 75.8, 77.6, and 74.7%, respectively. Question 4 demonstrated an accuracy of 75.6% in ascertaining the BPPV subtype, question 5 showed an accuracy of 75.6% in determining the affected side, and question 6 yielded an accuracy of 87.5% in distinguishing canalithiasis or cupulolithiasis. Examination time was shorter in the aware group than that in the unaware group (P < 0.05). No difference was found between the two groups for treatment time (P = 0.153).

Conclusion

This subtype-determining questionnaire is practical in daily use and capable of providing instructive information for an efficient diagnosis in geriatric patients with BPPV.

Spatial orientation, postural control and the vestibular system in healthy elderly and Alzheimer's dementia

Background

While extensive research has been advancing our understanding of the spatial and postural decline in healthy elderly (HE) and Alzheimer's disease (AD), much less is known about how the vestibular system contributes to the spatial and postural processing in these two populations. This is especially relevant during turning movements in the dark, such as while walking in our garden or at home at night, where the vestibular signal becomes central. As the prevention of falls and disorientation are of serious concern for the medical service, more vestibular-driven knowledge is necessary to decrease the burden for HE and AD patients with vestibular disabilities.

Overview of the article

The review briefly presents the current "non-vestibular based" knowledge (i.e. knowledge based on research that does not mention the "vestibular system" as a contributor or does not investigate its effects) about spatial navigation and postural control during normal healthy ageing and AD pathology. Then, it concentrates on the critical sense of the vestibular system and explores the current expertise about the aspects of spatial orientation and postural control from a vestibular system point of view. The norm is set by first looking at how healthy elderly change with age with respect to their vestibular-guided navigation and balance, followed by the AD patients and the difficulties they experience in maintaining their balance or during navigation.

Conclusion

Vestibular spatial and vestibular postural deficits present a considerable disadvantage and are felt not only on a physical but also on a psychological level by all those affected. Still, there is a clear need for more (central) vestibular-driven spatial and postural knowledge in healthy and pathological ageing, which can better facilitate our understanding of the aetiology of these dysfunctions. A possible change can start with the more frequent implementation of the "vestibular system examination/rehabilitation/therapy" in the clinic, which can then lead to an improvement of future prognostication and disease outcome for the patients.

Dynamic changes of otolith organ function before and after repositioning in patients with benign paroxysmal positional vertigo detected by virtual reality auxiliary technology: A cohort study

Objectives

To dynamically investigate otolith function in patients with benign paroxysmal positional vertigo (BPPV) before, after, and 1 month after repositioning, and explore the possible compensation mechanisms.

Methods

Thirty-six patients confirmed with BPPV (canal lithiasis) treated in our hospital between August 2020 and March 2021, as well as 36 health controls matched for age and gender (normal control group, NC group) were enrolled. For NC group, the virtual reality (VR) auxiliary static subjective visual vertical (SVV), subjective visual horizontal (SVH), and SVV of dynamic unilateral centrifugation (DUC), were measured at inclusion. For the BPPV group, visual analog scale (VAS) was used to assess the vertigo degree, while static SVV, SVH, and DUC were performed before, after, and 1 month after repositioning. First, we compare the deviations of SVV0/SVH0° when the subject's head is in the positive position, and SVV of DUC between BPPV and NC groups before repositioning, after which we compared the deviations in SVV45, SVV90, SVH45, SVH90°, and SVV of DUC between the affected and unaffected sides before repositioning. Finally, paired t-test was used to compare the VAS score, deviations in static SVV0, SVV45, SVV90, SVH0, SVH45, and SVH90°, and deviations in SVV of DUC before, after, and 1 month after repositioning. (Here, 0, 45, and 90° refer to the angle which the center axis of head deviates from the gravity line.)

Results

SVV0 SVH0°, and SVV of DUC at 120 and 180°/s 0 significantly differed between BPPV and NC group before repositioning. The deviations in SVV45, SVV90, SVH45, SVH90°, and SVV of DUC at 120°/s-2 and 180°/s-4.5 did not significantly differ between bilateral sides in BPPV patients before repositioning. The deviation in SVH90° was significantly lower after repositioning than before. The deviation in SVH45° was significantly higher 1 month after repositioning than before. The deviation angle of SVV of DUC at 180°/s-0 was significantly lower after repositioning than before. The vertigo VAS score of patient with BPPV continued to decrease after repositioning.

Conclusion

Before repositioning, the otolithic organ function of BPPV patients was obviously impaired, with no significant difference between the healthy and affected ear. After repositioning, there was a transient recovery of otolithic organ dysfunction followed by a sustained decline to similar levels to before repositioning.

[The changes in subjective visual vertical after otolith reduction in patients with BPPV]

Objective:To observe and analyze the changes in subjective visual vertical（SVV） after otolith reduction in patients with BPPV. Methods:46 patients with confirmed BPPV recieving successful otolith reduction were selected as the test group. 31 cases of posterior canal stones and 15 cases of horizontal semicircular canal stones, 29 cases of right ear and 17 cases of left ear. Fifty cases of healthy young volunteers were in the control group. Using the virtual reality SVV examination system, 0° SVV in the positive head were tested in the test group patients before and after the reduction of SVV , and were tested in the control group .The deviation angle of the SVV before and after the otolith reduction in the test group were analyzed. Results:Before otoliths reduction, the SVV was （0.08±3.83）° of right BPPV and was （-1.69±2.23）° of left BPPV. After otoliths reduction, the SVV was （-1.52±3.74）° of right BPPV and was （-1.04±2.50）° of left BPPV. In the control group, the SVV was（-1.57±2.28）° . The changes of SVV deflection angle between the control group and the right BPPV before the otolith reduction, and before and after the otolith reduction in the right BPPV were analyzed, and the differences were all statistically significant. There was no significant difference in SVV deflection angle between the left BPPV（before and after reduction） and the control group. In the test group, after the otolith reduction, 18 cases had larger bias angles, 28 cases had smaller bias angle among which 13 cases the deviation angle even turned to the contralateral side. Conclusion:Utriculare dysfunction in patients with BPPV leads to the judgment error of SVV. Reduction of otolithoid can cause new stimulation to the eutricule and affect its functional status. SVV detection can provide help for the evaluation of utricular function in patients with BPPV.

Age-related High-frequency Hearing Loss Is Not Associated With Horizontal Semicircular Canal Function

OBJECTIVE

Investigate the association between age-related hearing loss and reduced peripheral vestibular function using paired assessments of high-frequency hearing and horizontal semicircular canal (HSC) function. We hypothesized that age-related high-frequency hearing loss would be correlated with reduced HSC function and, therefore, useful to predict age-related vestibular hypofunction.

DESIGN

We conducted a single center, retrospective cross-sectional study in a tertiary/academic referral hospital. This study included 185 patients who were diagnosed with a cerebellopontine angle (CPA) tumor and referred to the academic hospital to evaluate treatment options. Data collected included pure-tone audiometry, caloric reflex test, video head-impulse test (vHIT), and medical history. High-frequency hearing loss was quantified by the high Fletcher index (hFI), and horizontal semicircular canal (HSC) function were quantified by the caloric reflex test and vHIT.

RESULTS

We observed a significant association between age and high-frequency hearing loss that was significantly worse in men compared with women. In contrast, we observed no significant association between age and HSC function assessed by either the caloric reflex test or vHIT. We observed associations between HSC function and sex, with male sex predicting reduced HSC function by caloric reflex testing but enhanced HSC function by vHIT. High-frequency hearing loss did not predict HSC hypofunction.

CONCLUSIONS

We found no evidence indicating age-related decline in HSC function or an association between age-related high-frequency hearing loss and age-related decline in HSC function. We did observe sex-specific differences in HSC function. Our study highlights the need for sex-specific normative values for identifying age-related reduced peripheral vestibular function and for future work linking comprehensive assessments of inner ear function with tests of balance and stability to understand the complex interactions underlying hearing loss and imbalance, especially in the elderly.

Static posturography as a novel measure of the effects of aging on postural control in dogs

Aging is associated with impairment in postural control in humans. While dogs are a powerful model for the study of aging, the associations between age and postural control in this species have not yet been elucidated. The aims of this work were to establish a reliable protocol to measure center of pressure excursions in standing dogs and to determine age-related changes in postural sway. Data were obtained from 40 healthy adult dogs (Group A) and 28 senior dogs (Group B) during seven trials (within one session of data collection) of quiet standing on a pressure sensitive walkway system. Velocity, acceleration, root mean square, 95% ellipse area, range and frequency revolve were recorded as measures of postural sway. In Group A, reliability was assessed with intraclass correlation, and the effect of morphometric variables was evaluated using linear regression. By means of stepwise linear regression we determined that root mean square overall and acceleration in the craniocaudal direction were the best variables able to discriminate between Group A and Group B. The relationship between these two center-of-pressure (COP) measures and the dogs’ fractional lifespan was examined in both groups and the role of pain and proprioceptive deficits was evaluated in Group B. All measures except for frequency revolve showed good to excellent reliability. Weight, height and length were correlated with most of the measures. Fractional lifespan impacted postural control in Group B but not Group A. Joint pain and its interaction with proprioceptive deficits influence postural sway especially in the acceleration in the craniocaudal direction, while fractional lifespan was most important in the overall COP displacement. In conclusion, our study found that pressure sensitive walkway systems are a reliable tool to evaluate postural sway in dogs; and that postural sway is affected by morphometric parameters and increases with age and joint pain.

[Effects of cochlear implantation on vestibular function]

The literature review is devoted to the effects arising from the effect of a cochlear implant on the vestibular system. Due to the pronounced anatomical proximity and physiological interaction of vestibular receptors with the cochlea, the installation of a cochlear implant and its electrical activity are associated with an effect on the vestibular system. The analysis of the works of foreign and domestic researchers who carried out monitoring of vestibular function in patients after cochlear implantation using modern objective methods was carried out.

Age-Related Changes in the Cochlea and Vestibule: Shared Patterns and Processes

Both age-related hearing loss (ARHL) and age-related loss in vestibular function (ARVL) are prevalent conditions with deleterious consequences on the health and quality of life. Age-related changes in the inner ear are key contributors to both conditions. The auditory and vestibular systems rely on a shared sensory organ - the inner ear - and, like other sensory organs, the inner ear is susceptible to the effects of aging. Despite involvement of the same sensory structure, ARHL and ARVL are often considered separately. Insight essential for the development of improved diagnostics and treatments for both ARHL and ARVL can be gained by careful examination of their shared and unique pathophysiology in the auditory and vestibular end organs of the inner ear. To this end, this review begins by comparing the prevalence patterns of ARHL and ARVL. Next, the normal and age-related changes in the structure and function of the auditory and vestibular end organs are compared. Then, the contributions of various molecular mechanisms, notably inflammaging, oxidative stress, and genetic factors, are evaluated as possible common culprits that interrelate pathophysiology in the cochlea and vestibular end organs as part of ARHL and ARVL. A careful comparison of these changes reveals that the patterns of pathophysiology show similarities but also differences both between the cochlea and vestibular end organs and among the vestibular end organs. Future progress will depend on the development and application of new research strategies and the integrated investigation of ARHL and ARVL using both clinical and animal models.

Progress in protecting vestibular hair cells

Vestibular hair cells are mechanosensory receptors that are capable of detecting changes in head position and thereby allow animals to maintain their posture and coordinate their movement. Vestibular hair cells are susceptible to ototoxic drugs, aging, and genetic factors that can lead to permanent vestibular dysfunction. Vestibular dysfunction mainly results from the injury of hair cells, which are located in the vestibular sensory epithelium. This review summarizes the mechanisms of different factors causing vestibular hair cell damage and therapeutic strategies to protect vestibular hair cells.

Measuring threshold and latency of motion perception on a swinging bed

INTRODUCTION

Our objective was to develop and to evaluate a system to measure latency and threshold of pendular motion perception based on a swinging bed.

MATERIALS AND METHODS

This prospective study included 30 healthy adults (age: 32 ± 12 years). All subjects were tested twice with a 10 min. interval. A second trial was conducted 2 to 15 days after. A rehabilitation swinging bed was connected to an electronic device emitting a beep at the beginning of each oscillation phase with an adjustable time lag. Subjects were blindfolded and auditory cues other than the beep were minimized. The acceleration threshold was measured by letting the bed oscillate freely until a natural break and asking the patient when he did not perceive any motion. The perception latency was determined by asking the patient to indicate whether the beep and the peak of each oscillation were synchronous. The time lag between sound and peak of the head position was swept from -750 to +750 ms by 50 ms increments.

RESULTS

The mean acceleration threshold was 9.2±4.60 cm/s2. The range width of the synchronous perception interval was estimated as 535±190 ms. The point of subjective synchronicity defined as the center of this interval was -195±106 ms (n = 30). The test-retest evaluation in the same trial showed an acceptable reproducibility for the acceleration threshold and good to excellent for all parameters related to sound-movement latency.

CONCLUSION

Swinging bed combined to sound stimulation can provide reproducible information on movement perception in a simple and non-invasive manner with highly reproducible results.

Benign paroxysmal positional vertigo and vestibular impairment among older adults with dizziness

OBJECTIVE

This article aimed to investigate older adults visiting a geriatric institution for a bone density measurement who reported dizziness on a daily or weekly basis (but who are not seeking care for dizziness), according to BPPV, vestibular function, walking abilities, and frequency of falls.

METHODS

Patients coming for a bone density measurement answered questions regarding occurrence of dizziness. Patients having dizziness on a daily or weekly basis were considered eligible for the study and invited for investigation at the Ear, Nose, and Throat clinic at Södra Älvsborg Hospital, Sweden. The patients answered questions about history of dizziness, medications, and comorbidities. They were also investigated for BPPV, vestibular deficits using the video head impulse test (vHIT), walking speed, Timed Up and Go test (TUG), and for perception of verticality and horizontality and Romberg test.

RESULTS

A total of 55 patients with dizziness were included. Fifteen (27%) were diagnosed with BPPV. Forty (73%) patients reported falling during the previous year, including 11 with BPPV. Dizziness when turning in bed was more common among patients with BPPV and increased the risk of BPPV 8-fold.

CONCLUSION

BPPV is common among older adults with dizziness, including among those not seeking medical care. It is important to identify older adults with BPPV and treat the condition since BPPV may contribute to falls. Asking about dizziness when turning in bed can help to distinguish patients with increased risk for BPPV and older adults with dizziness should be investigated for BPPV even when typical history is lacking. Level of evidence: 4.

Visual-vestibular integration is preserved with healthy aging in a simple acceleration detection task

Aging is associated with a gradual decline in the sensory systems and noisier sensory information. Some research has found that older adults compensate for this with enhanced multisensory integration. However, less is known about how aging influences visual-vestibular integration, an ability that underlies self-motion perception. We examined how visual-vestibular integration changes in participants from across the lifespan (18-79 years old) with a simple reaction time task. Participants were instructed to respond to visual (optic flow) and vestibular (inertial motion) acceleration cues, presented either alone or at a stimulus onset asynchrony. We measured reaction times and computed the violation area relative to the race model inequality as a measure of visual-vestibular integration. Across all ages, the greatest visual-vestibular integration occurred when the vestibular cue was presented first. Age was associated with longer reaction times and a significantly lower detection rate in the vestibular-only condition, a finding that is consistent with an age-related increase in vestibular noise. Although the relationship between age and visual-vestibular integration was positive, the effect size was very small and did not reach statistical significance. Our results suggest that although age is associated with a significant increase in vestibular perceptual threshold, the relative amount of visual-vestibular integration remains largely intact.

[Screening for bilateral vestibulopathy in outpatients with unsteadiness]

Objective:This study aimed to find bilateral vestibulopathy（BVP） patients in outpatients with unsteadiness and investigate their clinical characteristics. Methods:According to the common manifestation and etiologies of BVP, 2075 outpatients who were diagnosed as imbalance, follow up on chemotherapy, bilateral Menière's disease, systemic lupus erythematosus（SLE） and vasculitis from January 2018 to October 2019 were searched based on the hospital information system. After completing a telephone screening interview, eligible individuals whose symptoms were in consistent with the diagnostic criteria of BVP were scheduled for questionnaires and video head impulse test（vHIT）. Results:A total of 131 patients replied and complained chronic unsteadiness. The response rates of patients with bilateral Menière's disease, chemotherapy, SLE and vasculitis were 10.0%, 0%, 0.3% and 1.2%, respectively. Unsteadiness is uncommon or mild in outpatients with vasculitis, SLE and chemotherapy. Twenty-nine patients presented with typical symptoms of BVP and only 3 were diagnosed as BVP after vHIT. The horizontal vHIT gain was significantly lower among patients who reported very severe life impact than those reported mild to severe impact in older patients, as well as in male patients（both P<0.01）. However, no significant differences were noted in younger and female patients（P=0.396, 0.180, respectively）. Conclusion:BVP accounts for 2.3% in outpatients with unsteadiness, and only 10.3% of patients who presents with typical symptoms meet the diagnostic criteria, suggesting vestibular function test is of great significance in making diagnosis.

Vestibular Dysfunction and Gross Motor Milestone Acquisition in Children With Hearing Loss: A Systematic Review

OBJECTIVE

To describe the impact of vestibular dysfunction on gross motor development in children with hearing loss.

DATA SOURCES

MEDLINE (PubMed), Embase (Elsevier), Web of Science (Clarivate), and the Cumulative Index of Nursing and Allied Health Literature (EBSCO).

REVIEW METHODS

A systematic review was reported in concordance with the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses). Articles on children with hearing loss who underwent at least 1 instrumented measure of vestibular function and had gross motor milestones assessed were included. The Downs and Black checklist was used to assess risk of bias and methodological quality.

RESULTS

Eleven articles were included in the systematic review. Three articles stratified quantitative results of gross motor milestone acquisition by severity of vestibular impairment. Over half of studies were case series published within the last 5 years. This systematic review showed that children with hearing loss and severe, bilateral vestibular dysfunction demonstrate delayed gross motor milestones. However, it was difficult to draw conclusions on whether milder forms of vestibular dysfunction significantly affect gross motor milestone acquisition in children with hearing loss. The reason is that most studies were of low to moderate quality, used different assessment methods, and contained results that were descriptive in nature.

CONCLUSIONS

This emerging area would benefit from future research, such as higher-quality studies to assess vestibular function and gross motor milestones. This would allow for better characterization of the impacts of vestibular impairment, especially milder forms, in children with hearing loss.

Joint Assessment of Equilibrium and Neuromotor Function: A Validation Study in Patients with Fibromyalgia

OBJECTIVE

To develop and validate a tool for evaluating balance and neuromotor function in patients with fibromyalgia (FMS).

METHODS

Brainstorming, the nominal group technique, and pilot-testing were used to select a battery of 20 functional balance tests that were included in a screening tool. A total of 108 subjects (62 with fibromyalgia syndrome, 22 aged over 65 years, and 24 healthy subjects) participated in this validation study. Factor validity, internal consistency, the ability to discriminate between patients and healthy subjects, and concurrent validity with the Fibromyalgia Impact Questionnaire (FIQ), the Central Sensitization Inventory (CSI), the 12-Item Short-Form Health Survey (SF-12), and other tools for measuring balance, such as the Dizziness Handicap Inventory (DHI), the Activities-Specific Balance Confidence Scale (ABC-16), the Falls Efficacy Scale-International (FES-I), and posturographic parameters, were evaluated.

RESULTS

The factorial analysis extracted four factors that explained 70% of the variance. The Alpha Cronbach value was 0.928. Concurrent validity of the screening tool with respect to other tools was high, and the receiver operating characteristic (ROC) curve analysis showed an AUC value of 0.932 for discriminating between healthy and FMS subjects. Severe balance disorder related to head movements in FMS patients was found.

CONCLUSION

The 20-item JAEN (Joint Assessment of Equilibrium and Neuro-motor Function) screening tool is a valid and reliable tool for assessing balance in patients with FMS.

Effect of head roll-tilt on the subjective visual vertical in healthy participants: Towards better clinical measurement of gravity perception

OBJECTIVE

Gravity perception is an essential function for spatial orientation and postural stability; however, its assessment is not easy. We evaluated the head-tilt perception gain (HTPG, that is, mean perceptual gain [perceived/actual tilt angle] during left or right head roll-tilt conditions) and head-upright subjective visual vertical (SVV) using a simple method developed by us to investigate the characteristics of gravity perception in healthy participants.

METHODS

We measured the SVV and head roll-tilt angle during head roll-tilt within ±30° of vertical in the sitting and standing positions while the participant maintained an upright trunk (sitting, 434 participants; standing, 263 participants). We evaluated the head-upright SVV, HTPG, and laterality of the HTPG.

RESULTS

We determined the reference ranges of the absolute head-upright SVV (<2.5°), HTPG (0.80-1.25), and HTPG laterality (<10%) for the sitting position. The head-upright SVV and HTPG laterality were not influenced by sex or age. However, the HTPG was significantly greater in women than in men and in middle-aged (30-64 years) and elderly (65-88 years) participants than in young participants (18-29 years). The HTPG, but not the head-upright SVV or HTPG laterality, was significantly higher in the standing vs sitting position.

CONCLUSION

The HTPG is a novel parameter of gravity perception involving functions of the peripheral otolith and neck somatosensory systems to the central nervous system. The HTPG in healthy participants is influenced by age and sex in the sitting position and immediately increases after standing to reinforce the righting reflex for unstable posture, which was not seen in the head-upright SVV, previously considered the only parameter.

LEVEL OF EVIDENCE

4.

Worldwide survey on laboratory testing of vestibular function

Background

The function of the peripheral vestibular system can nowadays be quantified. The video head impulse test (vHIT) and caloric irrigation are used for the semicircular canals, cervical vestibular evoked myogenic potentials (cVEMP) for the sacculus, and ocular vestibular evoked myogenic potentials (oVEMP) for the utriculus. Because there is no agreement on normal and pathologic values, we performed a worldwide survey.

Methods

A web-based standardized survey questionnaire was used to collect data on "reference values" and "cutoff" values. Thirty-eight centers from all continents (except Africa) replied.

Results

"Reference values": vHIT: mean for the vestibulo-ocular reflex gain of the left horizontal canal 0.91 (range: 0.7-1.01) and of the left horizontal canal 0.92 (0.7-1.05); side difference 0.15 (0.25-0.3). Caloric irrigation: mean peak slow phase velocity of caloric-induced nystagmus for warm (44°C) water 18.65°/s (12-30°/s); cold (30°C) water 18.21°/s (10-25°/s). cVEMP: P13-N23 amplitude mean for the lower limit 28.67 μV (16-50 μV); upper limit 200 μV (50-350 μV). "Cutoff values": vHIT: side difference 0.26 (0.1-0.4), bilateral vestibulopathy <0.61 (0.3-0.8); unilateral vestibulopathy (UVP) <0.68 (0.4-0.8). Caloric irrigation pathologic side difference mean 25.93% (17.7%-40%) or 12°/sec (5-30°/s); side difference UVP 26.73% (20%-40%) or 29.8°/s (5-100°/s). cVEMP: P13/N23 amplitude mean lower cutoff 32.5 μV (15-50 μV), mean upper cutoff 125 μV (50-200 μV), asymmetry 36.08 μV (20-50 μV).

Conclusion

This worldwide survey showed a large variability in terms of reference and pathologic cutoff values in the 38 centers included. Therefore, standardization of how to achieve these values and agreement on which values should be used is highly warranted to guarantee a high quality of vestibular testing and interpretation of clinical and scientific results.

Antisense Oligonucleotides for the Treatment of Inner Ear Dysfunction

Antisense oligonucleotides (ASOs) have shown potential as therapeutic molecules for the treatment of inner ear dysfunction. The peripheral sensory organs responsible for both hearing and equilibrium are housed within the inner ear. Hearing loss and vestibular balance problems affect a large portion of the population and limited treatment options exist. Targeting ASOs to the inner ear as a therapeutic strategy has unique pharmacokinetic and drug delivery opportunities and challenges. Here, we review ASO technology, delivery, disease targets, and other key considerations for development of this therapeutic approach.