Age-related changes on the morphology of the otoconia

Assessment of vitamin D deficiency in recurrent BPPV patients: A cross-sectional study

PURPOSE

This study aimed to investigate the vitamin D deficiency of patients with BPPV recurrence and to evaluate the differences of 25-hydroxy vitamin D (25(OH)D) and serum calcium levels among gender and age categories.

METHODS

This cross-sectional study enrolled patients with BPPV. The diagnosis of BPPV was based on positional nystagmus and vertigo induced by certain head positions (The Dix-Hallpike maneuver and head roll tests). All patients' age, serum 25(OH)D, calcium measurements and recurrence data were collected and analyzed.

RESULTS

The median of 25(OH)D was 15.32 (IQR 10.61, 20.90) ng/ml. The recurrent group showed lower 25(OH)D levels than that of non-recurrent group [13.28 (IQR 9.47, 17.57) ng/ml vs 16.21 (IQR 11.49, 21.13) ng/ml]. There were significant differences of 25(OH)D levels among age categories. The proportion of vitamin D deficiency in patients ≥60 years old was lower than that in the other two groups.

CONCLUSION

Our study suggested that BPPV patients had a decreased 25(OH)D level and a high incidence of vitamin D deficiency. The 25(OH)D level of recurrent BPPV patients was lower than that in non-recurrent ones. Among them, the elderly group (≥60 years) took the preponderance, which had the lowest incidence of vitamin D deficiency and the highest incidence of vitamin D sufficiency.

Pediatric Benign Paroxysmal Positional Vertigo: Degree of Nystagmus and Concurrent Dizziness Differs from Adult BPPV

Background: Benign paroxysmal positional vertigo (BPPV) is characterized by brief, intense episodes of vertigo triggered by abrupt changes in head position. It is generally accepted as being most common in adults, while it is regarded as rare in children. It is necessary to compare the disease between pediatric and adult patients for a better understanding of the disease's characteristics and its natural history. This study aimed to identify the clinical characteristics of BPPV in children and compare them with those of adult BPPV patients. Methods: All children ≤ 18 years old who were diagnosed with BPPV were selected by searching the electronic database of our hospital. Clinical features were identified by medical record review. For adult patients, we collected data from patients > 19 years of age. Results: A total of 30 pediatric (13.65 ± 4.15 years old) and 264 adult patients (60.86 ± 13.74 years old) were included in the study. Among pediatric patients, the lateral canals were involved in 80% and the posterior canals in 16.67%. In adult patients, the lateral and posterior canals were involved similarly (p = 0.007). The degree of nystagmus in pediatric patients was 6.82 ± 12.09, while in adults it was 15.58 ± 20.90 (p < 0.001). The concurrent dizziness disorder was higher in the pediatric group and recurrence was higher in the adult group. In the regression analysis, it was found that adult patients had a stronger nystagmus with a value of 6.206 deg/sec, and the risk of concurrent dizziness disorder was found to be 5.413 times higher in the pediatric group (p < 0.05). Conclusions: BPPV occurs in pediatric patients with lower prevalence, but it cannot be overlooked. In the pediatric group, a relatively high proportion of patients demonstrated lateral canal involvement, weaker nystagmus, and additional dizziness disorder.

Numerical Simulations of the Epley Maneuver With Clinical Implications

OBJECTIVES

Canalith repositioning procedures to treat benign paroxysmal positional vertigo are often applied following standardized criteria, without considering the possible anatomical singularities of the membranous labyrinth for each individual. As a result, certain patients may become refractory to the treatment due to significant deviations from the ideal membranous labyrinth, that was considered when the maneuvers were designed. This study aims to understand the dynamics of the endolymphatic fluid and otoconia, within the membranous labyrinth geometry, which may contribute to the ineffectiveness of the Epley maneuver. Simultaneously, the study seeks to explore methods to avoid or reduce treatment failure.

DESIGN

We conducted a study on the Epley maneuver using numerical simulations based on a three-dimensional medical image reconstruction of the human left membranous labyrinth. A high-quality micro-computed tomography of a human temporal bone specimen was utilized for the image reconstruction, and a mathematical model for the endolymphatic fluid was developed and coupled with a spherical particle model representing otoconia inside the fluid. This allowed us to measure the position and time of each particle throughout all the steps of the maneuver, using equations that describe the physics behind benign paroxysmal positional vertigo.

RESULTS

Numerical simulations of the standard Epley maneuver applied to this membranous labyrinth model yielded unsatisfactory results, as otoconia do not reach the frontside of the utricle, which in this study is used as the measure of success. The resting times between subsequent steps indicated that longer intervals are required for smaller otoconia. Using different angles of rotation can prevent otoconia from entering the superior semicircular canal or the posterior ampulla. Steps 3, 4, and 5 exhibited a heightened susceptibility to failure, as otoconia could be accidentally displaced into these regions.

CONCLUSIONS

We demonstrate that modifying the Epley maneuver based on the numerical results obtained in the membranous labyrinth of the human specimen under study can have a significant effect on the success or failure of the treatment. The use of numerical simulations appears to be a useful tool for future canalith repositioning procedures that aim to personalize the treatment by modifying the rotation planes currently defined as the standard criteria.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Seasonality of benign paroxysmal positional vertigo : A retrospective study from Central Europe

BACKGROUND

Although benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo in clinical practice, factors influencing the pathophysiology remain not fully understood.

OBJECTIVE

Here we aim to investigate possible seasonal influences on the occurrence of BPPV in Vienna, a city located in a Central European country with pronounced seasonal fluctuations.

METHODS

We retrospectively investigated data from 503 patients presenting with BPPV to the outpatient clinics of the Medical University of Vienna between 2007 and 2012. Analyses included age, gender, type of BPPV, seasonal assignment, as well as daylight hours and the temperature in Vienna at symptom onset.

RESULTS

Out of 503 patients (159 male, 344 female, ratio 1:2.2; mean age 60 ± 15.80 years), most patients presented with posterior (89.7%) and left-sided (43.1%) BPPV. There was a significant seasonal difference (χ2 p = 0.036) with the majority of symptoms occurring in winter seasons (n = 142), followed by springtime (n = 139). Symptom onset did not correlate with the average temperature (p = 0.24) but on the other hand very well with daylight hours (p < 0.05), which ranged from 8.4 h per day in December, to an average of 15.6 h in July.

CONCLUSION

Our results show a seasonal accumulation of BPPV during winter and springtime, which is in line with previous studies from other climatic zones, suggesting an association of this seasonality with varying vitamin D levels.

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.

Low vitamin D and uric acid status in patients with benign paroxysmal positional vertigo

PURPOSE

Growing evidence reported that vitamin D and uric acid metabolism played roles in the occurrence of benign paroxysmal positional vertigo, an otoconia-related vestibular disorder. We aimed to investigate the serum 25-hydroxy vitamin D (25(OH)D) and uric acid in patients with benign paroxysmal positional vertigo and to determine the risk factor for benign paroxysmal positional vertigo.

METHODS

This case-control study comprised 182 patients with benign paroxysmal positional vertigo and 182 age- and gender-matched controls. All subjects' age, body mass index, systolic blood pressure, diastolic blood pressure, 25-hydroxyvitamin D (25(OH)D), uric acid and serum calcium measurements were analyzed.

RESULTS

We found a female preponderance of benign paroxysmal positional vertigo patients, with a median of 60 (52-66) years old. The results showed low vitamin D status both in benign paroxysmal positional vertigo and controls, with no significant difference of 25(OH)D levels between benign paroxysmal positional vertigo patients and controls (P > 0.05). Compared with the control group, patients with benign paroxysmal positional vertigo had a higher prevalence of vitamin D deficiency and a lower prevalence of vitamin D sufficiency (P < 0.05). Uric acid was significantly lower in the benign paroxysmal positional vertigo groups (P < 0.05). Logistic regression analysis revealed that age and uric acid were considered higher risk predictors for benign paroxysmal positional vertigo.

CONCLUSION

Our study observed low vitamin D status in patients with benign paroxysmal positional vertigo, with no significant differences of the 25(OH)D level in patients with benign paroxysmal positional vertigo and controls. Elderly, vitamin D deficiency and low uric acid levels may be risk factors for benign paroxysmal positional vertigo occurrence.

Otoconial Degeneration After Transient Ischemia Induced by Four-Vessel Occlusion in Rats

BACKGROUND AND PURPOSE

Ischemia of the inner ear may damage the otoconia. However, no study has explored any changes in the configuration of otoconia after transient ischemia of the labyrinth.

METHODS

Nineteen 7-week-old Sprague-Dawley rats were randomly assigned to either the sham (n=5) or the experimental group (n=14). The rats in the experimental group were subjected to global ischemia for 20 minutes using a four-vessel occlusion model, and were sacrificed seven days after the procedure. The rats in the sham group were sacrificed without any procedure. The otolithic organs (utricle and saccule) were dissected out for scanning electron microscope.

RESULTS

The otolithic organs in the sham group showed their normal gross configuration with a dense clumping of otoconia with a normal hexagonal morphology and a smooth surface. The otolithic organs in the experimental group also maintained a grossly normal configuration, but each otoconia showed irregular surfaces with numerous cracks or furrows, especially in the periphery of the otoconial bed.

CONCLUSIONS

The current study showed that otoconial degeneration may occur even after transient ischemia of the labyrinth. This finding supports an association between cerebral ischemia and benign paroxysmal positional vertigo.

Cellular and Molecular Mechanisms of Vestibular Ageing

While age-related auditory deficits and cochlear alterations are well described, those affecting the vestibular sensory organs and more broadly the central vestibular pathways are much less documented. Although there is inter-individual heterogeneity in the phenomenon of vestibular ageing, common tissue alterations, such as losses of sensory hair cells or primary and secondary neurons during the ageing process, can be noted. In this review, we document the cellular and molecular processes that occur during ageing in the peripheral and central vestibular system and relate them to the impact of age-related vestibular deficits based on current knowledge.

Aging effect and test-retest reliability of the sinusoidal harmonic acceleration test and velocity step test using nanotorque rotatory chair

Introduction

Rotatory chair testing has been used to evaluate horizontal canal function. Frequently used tests include sinusoidal harmonic acceleration test (SHAT) and velocity step test (VST).

Objectives

Assessment of age effect on the SHAT and VST and assessment of test-retest reliability of the parameters of those two tests.

Methods

A prospective study was performed on 100 subjects with no ear or vestibular complaints and normal vestibular evaluation. They were divided into two groups; Group A: below 50 years of age and Group B: 50 years of age or above. SHAT was presented at frequencies 0.02, 0.04, 0.08, 0.16, 0.32, 0.64 Hz with a peak velocity of 60°/s. VST was performed using a maximum velocity of 100°/s with acceleration and deceleration of 200°/s^2. Thirty subjects were tested twice to assess reliability.

Results

Study participants ranged in age from 20 to 67 years. Regarding group A, the mean age was 30.92 ± 7.31 and 55.36 ± 4.61 for group B. No significant differences were found in SHAT parameters between the two groups. As well, there was no significant difference in VST per-rotatory time constant, however, post-rotatory time constant was significantly longer for Group B (P value < 0.05). Intraclass correlation coefficient (ICC) values showed moderate to good reliability (ICC 0.580-0.818) for SHAT parameters for the lower frequencies and indicated moderate reliability for VST time constant (ICC 0.509-0.652).

Conclusions

Age has no significant effect on the parameters of SHAT and VST. Test-retest reliability is generally good for both tests.

Geriatric benign paroxysmal positional vertigo: a single-center study

OBJECTIVE

To compare the clinical features, risk factors, distribution of Benign Paroxysmal Positional Vertigo (BPPV) subtypes, and effectiveness of canalith repositioning between geriatric and non-geriatric patients with BPPV.

METHODS

A total of 400 patients with BPPV were enrolled. Canalith repositioning was performed according to the semicircular canals involved. Patients were divided by age into a geriatric group (≥60 years) and a non-geriatric group (20-59 years). Clinical characteristics, potential age-related risk factors, distribution of subtypes, and effectiveness of canalith repositioning were compared between the groups.

RESULTS

Female sex was significantly more common in all age groups, with a peak female-to-male ratio of 5.1:1 in the group aged 50-59 years. There was a higher proportion of men in the geriatric group. A history of disease associated with atherosclerosis was significantly more common in the geriatric group (p < 0.05). Migraine was significantly more common in the non-geriatric group (p = 0.018), as was posterior canal BPPV. The horizontal canal BPPV (especially horizontal canal BPPV-cupulolithiasis), and multicanal BPPV subtypes were more common in the geriatric group, whereas anterior canal BPPV was more common in the non-geriatric group. Two canalith repositioning sessions were effective in 58.0% of the geriatric cases and in 72.6% of the non-geriatric cases (p = 0.002). There was a tendency for the effectiveness of canalith repositioning to decrease with increasing age.

CONCLUSION

BPPV was more common in women. However, the proportion of men with BPPV increased with age. Elderly patients often had a history of diseases associated with atherosclerosis (i.e., hypertension, diabetes, and hyperlipidemia). The horizontal canal BPPV (particularly horizontal canal BPPV-cupulolithiasis) and multicanal BPPV subtypes were more common and the anterior canal BPPV subtype was less common in elderly patients. The effectiveness of canalith repositioning may decrease with age. Therefore, older patients should receive more comprehensive medical treatment.

LEVEL OF EVIDENCE: 4

Relationship of vitamin D levels with clinical presentation and recurrence of BPPV in a Southeastern United States institution

OBJECTIVE

To examine the relationship of 25hydroxyvitamin D serum levels with BPPV incidence and recurrence rates.

METHODS

A retrospective cross-sectional, case-controlled study with follow-up phone survey was performed on patients diagnosed with BPPV between 05/2017-05/2020, who had available 25hydroxyvitamin D serology. Patients were seen at a multidisciplinary, vestibular-focused, neurotology clinic at a tertiary referral center. Controls consisted of subjects from the National Health and Nutrition Examination Survey (NHANES), and a locoregional age, sex, and race-matched group of patients from our institution.

RESULTS

Our BPPV cohort consisted of 173 patients (mean age 66.2 ± 11.8 years), who were predominately female (75.7%) and Caucasian (76.3%). Almost all age subgroups (BPPV, NHANES, and locoregional groups) ≤60 years old had insufficient levels of vitamin D. However, the overall BPPV cohort had a significantly higher vitamin D level than the NHANES control (31.4 ± 16.5 v. 26.0 ± 11.2 ng/mL, d=0.474 [0.323, 0.626]). There was no significant difference when compared to the overall locoregional control (31.4 ± 20.5 ng/mL). Migraines were significantly correlated to increased BPPV recurrence rates on univariate (beta=0.927, p=0.037, 95% CI: [0.057, 1.798]) and multiple regression analyses (beta=0.231, 95% CI: [0.024, 2.029], p=0.045). Furthermore, patients with BPPV recurrences had significantly lower levels of vitamin D at initial presentation when compared to patients with no recurrences (29.0 ± 12.0 v. 37.6 ± 18.3 ng/mL, d=0.571[0.139,1.001]).

CONCLUSION

Many BPPV patients in our cohort had insufficient vitamin D levels, and patients with BPPV recurrences had insufficient and significantly lower vitamin D levels than those without. As a readily available and affordable supplement, vitamin D may be used as an adjunct treatment but prospective studies should be done to confirm if it can prevent or reduce recurrence.

Association between otolin-1 and benign paroxysmal positional vertigo: A meta-analysis

Background

There is increasing research on the potential of inner ear proteins as serum biomarkers for the diagnosis and prognosis of various inner ear diseases. Among them, benign paroxysmal positional vertigo (BPPV) is the most common vestibular disease. Notably, otolin-1, an inner ear-specific protein, is detectable in the serum of most patients with BPPV patients. Therefore, we found a need to conduct this meta-analysis to determine the relationship between otolin-1 in serum and BPPV.

Methods

This meta-analysis was conducted by searching PubMed, EMBASE, Cochrane Library, Google Scholar, and China Network Knowledge Infrastructure databases for the eligible original studies in Chinese or English published between January 2010 and February 2022. Data were collected and pooled by using the mean differences (MDs) corresponding to 95% confidence intervals (CIs). Heterogeneity among these studies was assessed by using I² statistics and the adopted fixed or random-effect mode thereafter. Egger's and Begg's tests were also used to assess the publication bias.

Results

This meta-analysis included six articles with a total of 585 participants. Serum otolin-1 levels were remarkably increased in patients with BPPV as compared to that in healthy controls (MD: 165.38, 95% CI: 110.13-220.64, p < 0.00001). However, Egger's and Begg's tests have indicated no publication bias, and the results were reliable based on the sensitivity analysis.

Conclusion

This meta-analysis indicated that there is a higher serum level of otolin-1 in patients with BPPV than in healthy controls. Therefore, otolin-1 may serve as a biomarker for the onset of BPPV.

Bilateral Dysfunction of Otolith Pathway in Patients With Unilateral Idiopathic BPPV Detected by ACS-VEMPs

Objective

To observe the functional status of the otolith pathway in patients with unilateral idiopathic benign paroxysmal positional vertigo (BPPV) by combining air-conducted sound elicited cervical vestibular-evoked myogenic potential (ACS-cVEMP) and ocular vestibular-evoked myogenic potential (ACS-oVEMP).

Methods

One hundred and eighty patients with BPPV were recruited for conventional cVEMP and oVEMP tests. The abnormal rates of VEMPs were compared between BPPV patients and control participants.

Results

The abnormal rates of cVEMP and oVEMP in BPPV patients were 46.7% (84/180) and 57.2% (103/180) in affected ears, respectively, and 45.0% (81/180) and 56.7% (102/180) in unaffected ears, respectively; both were significantly higher than the abnormal rates of cVEMP and oVEMP in normal control ears. Compared with normal subjects, the cVEMP response rate was lower in affected and unaffected ears in BPPV patients. The abnormal rates of cVEMP and oVEMP were 48.1% (76/158) and 57.6% (91/158) in patients with posterior semicircular canal BPPV, and 36.4% (8/22) and 54.5% (12/22) in lateral semicircular canal BPPV. There was no significant difference in VEMP abnormalities between posterior semicircular canal BPPV and lateral semicircular canal BPPV.

Conclusion

The prevalence of abnormal cVEMPs and oVEMPs in both affected and unaffected ears of patients with BPPV was significantly higher than that observed in the control group. The pathological mechanism of unilateral idiopathic BPPV may be associated with bilateral degeneration of otolith pathways.

Second harmonic generation microscopy of otoconia

The origin of second harmonic generation (SHG) signal in otoconia was investigated. SHG signal intensity from otoconia was compared to pure calcite crystals, given calcite is the primary component of otoconia and is known to emit surface SHG. The SHG intensity from calcite was found to be ∼41× weaker than the SHG intensity from otoconia signifying that the SHG signal from otoconia is likely generated from the organic matrix. Furthermore, the SHG intensity from otoconia increased when treated with a chelating agent known to dissolve calcite which confirms that calcite is not the source of SHG. Additionally, polarization-resolved SHG microscopy imaging revealed that the arrangement of the SHG emitters is radial and can form highly ordered domains.

Effects of Age and Middle Ear on the Frequency Tuning of the cVEMP and oVEMP

BACKGROUND

Upward shift in the air conducted (AC) frequency tuning of vestibular evoked myogenic potentials (VEMPs) as an effect of aging is hypothesized to be due to the microstructural stiffening changes in the inner ear. However, with an AC stimulus, it may be possible that the shift in the frequency tuning of VEMPs as an effect of aging may also be due to contributions from the middle ear.

PURPOSE

The main aim of this study was to examine the effects of age on the frequency tuning of the cervical VEMP (cVEMP) and ocular VEMP (oVEMP) and determine the role of middle ear transmission characteristics in shaping these effects.

RESEARCH DESIGN

Standard group comparison.

STUDY SAMPLE

One-hundred seven participants divided in three groups: young adult, middle-age, and older adults with "normal" middle ear and negative history of neurological or vestibular complaints.

DATA COLLECTION AND ANALYSES

Middle ear measures included static admittance and middle ear resonant frequency. cVEMP and oVEMPs were elicited with AC tone bursts at 500, 750, and 1,000 Hz.

RESULTS

No significant effect of age was observed on any of the middle ear measures. There was a significant effect of age on the amplitude of the cVEMP, but this effect was frequency specific. The age-related reduction in cVEMP corrected amplitude was only observed when the eliciting stimulus was 500 or 750 Hz, with no significant effect observed with a 1,000 Hz stimulus. For the oVEMP, the effects of age were apparent at all stimulus frequencies. We also observed a general upward shift in the frequency tuning of both the cVEMP and oVEMP for middle-age and older adults, with 750 and 1,000 Hz yielding higher response rates and larger amplitudes among middle-aged and older adults. Measurements of middle ear did not significantly contribute to the observed findings.

CONCLUSIONS

The upward shift in frequency tuning of VEMPs among middle age and older adults could be due to the changes in the vestibular system and not from the middle ear. These results support the use of different frequency stimuli (i.e., 750 or 1,000 Hz) to elicit a VEMP if a response is absent using a 500 Hz stimulus, especially in patients over the age of 40.

High Serum Levels of Otolin-1 in Patients With Benign Paroxysmal Positional Vertigo Predict Recurrence

Background

Otolin-1 is an inner ear-specific protein that is exclusively expressed in otoconia and vestibule and cochlea cells. Recent investigations reported that otolin-1 can cross the blood-labyrinthine barrier and that the levels in serum well-reflected otolith status. Serum otolin-1 levels in patients with benign paroxysmal positional vertigo (BPPV) are significantly elevated compared with healthy controls. We aimed to explore whether otolin-1 can also serve as a biomarker for predicting BPPV recurrence.

Method

Patients at our institution with new-onset of idiopathic BPPV between May, 2017 and May, 2018 were recruited and followed up for 2 years. All demographic data of the patients were collected, and serum levels of otolin-1 and other laboratory indicators were measured and compared according to the recurrence status.

Results

A total of 74 patients, who met the inclusion criteria were enrolled in this study, of which 27 (36.5%) patients had suffered one or more episodes of recurrence after undergoing canal repositioning treatments during the study. The serum levels of otolin-1 in patients with recurrent BPPV were significantly higher than those in patients without recurrent BPPV (363.9 vs. 309.8 pg/ml, p = 0.001). In multivariate analysis comparing the second to fourth quartiles (Q2–Q4) against the first quartile (Q1) of otolin-1, the level of otolin-1 in Q4 could significantly predict BPPV recurrence, and the odds ratio (OR) was elevated by approximately 812% (OR = 9.12; 95% confidence interval [CI]: 1.44–57.9; p = 0.019).

Conclusion

High serum levels of otolin-1 were associated with an increased risk of BPPV recurrence, and further investigation is required to confirm this association and clarify the exact mechanism.

Risk factors for residual dizziness in patients with benign paroxysmal positional vertigo after successful repositioning: a systematic review and meta-analysis

PURPOSE

To investigate the risk factors for residual dizziness (RD) in patients with benign paroxysmal positional vertigo (BPPV) after successful repositioning.

METHODS

Searches were performed in PubMed, Embase, Cochrane library, Web of Science, Chinese National Knowledge Infrastructure, and Sino Med up to March 7, 2021 and references of relevant articles were screened. Data from eligible studies were meta-analyzed using Stata version 16.0 and Review Manager 5.4.

RESULTS

In this systematic review and meta-analysis of 4487 patients from 31 studies, the prevalence of RD was 43.0% (95% CI 39.0-48.0%). Age (MD 4.17; 95% CI 2.13-6.21, P = 0.000), female gender (OR = 1.28, 95% CI 1.11-1.47, P = 0.001), secondary BPPV (OR 1.88; 95% CI 1.27-2.77, P = 0.001), a longer duration of BPPV before treatment (MD 3.45; 95% CI 1.87-5.02, P = 0.000), abnormal ocular vestibular evoked myogenic potential (OVEMP, OR 4.34; 95% CI 2.78-6.78, P = 0.000), abnormal cervical vestibular evoked myogenic potential (CVEMP, OR 2.48; 95% CI 1.54-3.99, P = 0.000), higher Dizziness Handicap Index (DHI) score before treatment (MD 10.88; 95% CI 5.96-15.80, P = 0.000), anxiety (OR 9.58; 95% CI 6.32-14.52, P = 0.000), osteopenia (OR = 4.40, 95% CI 2.17-8.96, P = 0.000), onset in winter (OR 7.27; 95% CI 2.38-22.24, P = 0.001) and with a history of BPPV (OR 1.79; 95% CI 1.06-3.04, P = 0.03) are the risk factors for RD in patients with BPPV after successful repositioning. The affected side, location or type of semicircular involvement, hyperlipidemia, diabetes, hypertension, heart disease, migraine, sleep disorders, canalolithiasis/cupulolithiasis, the number of times the canalith repositioning procedures (CRPs) were performed and number of vertigo attacks did not correlate with the occurrence of RD.

CONCLUSIONS

Despite successful treatment, nearly half of the BPPV patients developed RD. RD seems to be a syndrome caused by multiple factors. The pathogenesis of most factors can be explained by psychological and/or physical disorders. Early recognition of these risk factors contributes to the prevention and treatment of RD.

Study on the Bone Metabolism Indices and Otoconin-90 in Benign Paroxysmal Positional Vertigo

OBJECTIVE

To investigate the correlation between benign paroxysmal positional vertigo (BPPV) and abnormal bone metabolism and to evaluate the value of otoconial protein otoconin-90 in the pathogenesis research and clinical treatment of BPPV.

STUDY DESIGN

Prospective pilot clinical trial (Level of Evidence: 2b).

SETTING

Outpatient otolaryngologic department.

PATIENTS

Twenty seven patients with a diagnosis of BPPV referred to the otolaryngologic department and 25 controls with no history of dizziness from 2018.4 to 2018.9 were reviewed.

INTERVENTIONS

No.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry scanning (DEXA), bone mineral density (BMD) measurement, and assessment of serum levels of otoconin-90 and bone metabolism indices (osteocalcin, OC; 25-OH Vitamin D; total procollagen type 1 N-peptide, TP1NP; β-C-terminal telopeptide of type 1 collagen, β-CTX).

RESULTS

1) The average serum level of otoconin-90 in the BPPV group was significantly higher than that in the control group (p < 0.05), whereas both the BMD T scores and serum 25-OH Vitamin D levels of the BPPV group were significantly lower than those of the control group (p < 0.05). 2) There was a strong positive correlation between serum otoconin-90 and age (r = 0.44, p < 0.05) and a moderate negative correlation between otoconin-90 and the bone metabolism indices OC (r = -0.33, p > 0.05), 25-OH Vitamin D (r = -0.35, p > 0.05), and TP1NP (r = -0.30, p > 0.05). 3) Logistic regression analysis showed that serum otoconin-90 level was an independent risk factor for BPPV (odd ratio = 0.998, 95% confidence interval 0.997-0.999, p < 0.01).

CONCLUSION

A correlation between BPPV and abnormal bone metabolism was found. Moreover, otoconin-90 could serve as a research tool for BPPV.

Downregulation of VDR in benign paroxysmal positional vertigo patients inhibits otolith‑associated protein expression levels

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vertigo‑associated disease. Vitamin D (VD) helps maintain normal otolith function and may be associated with BPPV. VD exerts its biological functions primarily via the VD receptor (VDR). The present study demonstrated that serum VD levels were significantly decreased in patients with BPPV compared with in controls. VDR, otolith‑associated protein otoconin‑90 (OC90) and NADPH oxidase 3 (NOX3) expression levels were also significantly decreased in patients with BPPV compared with in controls. Furthermore, a positive correlation was observed between VD levels and VDR expression. Receiver operating characteristic curve analysis identified VDR expression levels as a potential diagnostic marker for BPPV. OC90 and NOX3 expression levels were notably lower in the inner ear tissue of VDR knockout mice compared with in those of wild‑type mice. In mice overexpressing VDR, OC90 and NOX3 were also overexpressed. Following intravenous injection of VD in VDR knockout mice, expression levels of OC90 and NOX3 were not significantly different from those in VDR knockout mice injected with saline. This indicated that VDR may be underexpressed in patients with BPPV and was associated with the expression levels of otolith‑associated proteins. Moreover, VDR mediated VD activation, leading to otolith protein formation. The present study provided a novel theoretical basis for BPPV onset that may facilitate the development of more effective diagnostic and treatment options.

Two Symptoms Strongly Suggest Benign Paroxysmal Positional Vertigo in a Dizzy Patient

Introduction: This prospective cohort study determined which questions in patient history are most likely to identify symptoms that are independently associated with a diagnosis of benign paroxysmal positional dizziness (BPPV) in patients presenting with dizziness, and to evaluate whether the patient's age and type of BPPV are of influence. Methods: We included adult patients with dizziness referred to our dizziness center, Apeldoorn, the Netherlands, from December 2018 to November 2019. All patients completed a questionnaire, underwent vestibular testing and received a diagnosis. Symptoms strongly suggesting BPPV were tested with multivariable analysis to determine their independent associations with BPPV. Subgroup analysis was performed for patient age, and the type of BPPV. Results: We included a total of 885 patients, 113 of whom (13%) were diagnosed with BPPV. The duration of dizziness spells <1 min (Q2) and dizziness provoked by rolling over in bed (Q4) were independently associated with the diagnosis BPPV. Q2 showed a sensitivity of 43%, and a specificity of 75%; Q4 scored 81% and 68%, respectively. Overall, the way patients perceived their dizziness (vertigo, light-headedness or instability) was not independently associated with the diagnosis BPPV. In younger patients, light-headedness and instability decreased the likelihood of BPPV compared to vertigo. Conclusion: The most reliable predictors for BPPV in patient history are a short duration of the dizziness spell and provocation of dizziness by rolling over in bed. Unlike younger patients, elderly patients with BPPV do not only perceive the dizziness as vertigo, but also as a feeling of instability.

Impaired Calcium Metabolism in Benign Paroxysmal Positional Vertigo: A Topical Review

BACKGROUND AND PURPOSE

Although acute attacks of benign paroxysmal positional vertigo (BPPV) may be treated with canalith repositioning maneuvers, there have been no well-designed prospective trials to prevent this highly prevalent and recurrent disorder. This topical review explores the evidence related to the association between deficient calcium metabolism and BPPV. We also describe the development of therapeutic options to prevent recurrences of BPPV and introduce results from a recent randomized controlled trial on the effect of vitamin D and calcium supplementation in preventing BPPV recurrences.

SUMMARY OF KEY POINTS

The literature describes 3 lines of evidence on association of impaired calcium metabolism and development of BPPV: (1) decreased bone mineral density was more frequently observed in persons with BPPV than in healthy controls; (2) estrogen plays a vital role in maintenance of otoconia, and estrogen deficiency appears to precipitate degeneration of otoconia and development of BPPV; and (3) lower serum vitamin D level is associated with development of BPPV, and supplementation of vitamin D and calcium carbonate may reduce further attacks of BPPV in persons with BPPV and subnormal serum vitamin D level.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Restoration of impaired calcium metabolism with supplementation of vitamin D or estrogen should be considered in the treatment of individuals with frequent recurrences of BPPV. Future randomized controlled trials are mandatory to validate these supplementation therapies in individuals with recurrent BPPV.

Causes and treatment of idiopathic benign paroxysmal positional vertigo based on endocrinological and other metabolic factors

The genesis of the Benign Paroxysmal Positional Vertigo (BPPV) seems to be related to some metabolic factors. These factors, such as vitamin D, glucocorticoids, and even thyroid and growth hormones, can affect bone metabolism and the mineralization of otoconia. It also seems to link to factors related to aging or nutritional habits. Besides, since the incidence of BPPV is quantitatively higher in women than in men, female sex steroids could be associated with this process. It could be useful to understand how these factors act in otoconial mineralization if we want to develop treatments aimed at preventing or delaying BPPV recurrences. In this review, we will analyze the role of these metabolic and hormonal factors in otoconial mineralization and in the treatment of BPPV.

Combination of head-up sleep and vertical recognition training may cure intractable motion-evoked dizziness with unknown origin

Background: It has been reported that head-up sleep (HUS) prevents free-floating otoliths from entering canals and that vertical recognition training (VRT) promotes vestibular compensation.Aims/objectives: We would like to assess HUS and VRT for intractable motion-evoked dizziness, including possible benign paroxysmal positional vertigo (BPPV).Materials and methods: 162 patients diagnosed with intractable motion-evoked dizziness of unknown origin were enrolled and randomly divided into the following four groups: HUS-/VRT-, HUS+/VRT-, HUS-/VRT+, and HUS+/VRT+. The at-home interventions comprised HUS with an upper head position of 45° when lying down and VRT with a right down-left down 30° head inclination while watching the vertical index.Results: At the post-treatment 6th month, visual analogue scale (VAS) scores for vertiginous sensation were significantly lower in the HUS+/VRT + group than in the HUS+/VRT - and HUS-/VRT + groups, which were in turn significantly lower than those in the HUS-/VRT - group. VAS scores in the HUS-/VRT + group of patients with abnormal subjective visual vertical (SVV) were significantly lower than those in the HUS+/VRT - group, while those in the HUS+/VRT - group of patients with normal SVV were significantly lower than those in the HUS-/VRT + group.Conclusions: HUS and/or VRT is a good initial treatment for patients with intractable undiagnosed motion-evoked dizziness, including possible BPPV.

The Price of Immune Responses and the Role of Vitamin D in the Inner Ear

OBJECTIVE

In this review the authors discuss evidence from the literature concerning vitamin D and temporal bone diseases (benign paroxysmal positional vertigo [BPPV], Menière's disease [MD], vestibular neuritis, idiopathic facial paralysis, idiopathic acute hearing loss). Common features shared by Menière's disease, glaucoma, and the possible influence by vitamin D are briefly discussed.

DATA SOURCES, STUDY SELECTION

Publications from 1970 until recent times have been reviewed according to a keyword search (see above) in PubMed.

CONCLUSIONS

MD, BPPV, vestibular neuritis, idiopathic facial paralysis, idiopathic acute hearing loss may all have several etiological factors, but a common feature of the current theories is that an initial viral infection and a subsequent autoimmune/autoinflammatory reaction might be involved. Additionally, in some of these entities varying degrees of demyelination have been documented. Given the immunomodulatory effect of vitamin D, we postulate that it may play a role in suppressing an eventual postviral autoimmune reaction. This beneficial effect may be enhanced by the antioxidative activity of vitamin D and its potential in stabilizing endothelial cells. The association of vitamin D deficiency with demyelination has already been established in other entities such as multiple sclerosis and experimental autoimmune encephalitis. Mice without vitamin D receptor show degenerative features in inner ear ganglia, hair cells, as well as otoconia. The authors suggest further studies concerning the role of vitamin D deficiency in diseases of the temporal bone. Additionally, the possible presence and degree of demyelination in these entities will have to be elucidated more systematically in the future.

Increased Otolin-1 in Serum as a Potential Biomarker for Idiopathic Benign Paroxysmal Positional Vertigo Episodes

Objective: Otolin-1, a main specific otoconia matrix protein, passes through the labyrinth-blood barrier and is detectable in peripheral blood. Serum otolin-1 levels differ between patients with benign paroxysmal positional vertigo (BPPV) and healthy controls and are significantly age-related, increasing in healthy controls with age, suggesting that serum otolin-1 levels reflect otolith status. The aim of this study was to determine whether otolin-1 levels change during vertigo episodes in patients with BPPV and whether any change is specific and sensitive enough for BPPV episodes.

Method: Patients diagnosed with de novo idiopathic BPPV during an acute episode were included in the study from May 2017 to May 2018. Blood samples were drawn before patients were treated with canalith-repositioning maneuvers. Serum otolin-1 levels were compared between 78 patients and 121 age- and sex-matched healthy individuals.

Results: There were no significant differences between the groups in the age distribution, sex ratio, body mass index, clinical history, routine blood parameters, or total protein, albumin, uric acid, creatinine, blood urea nitrogen and lipid profiles (P > 0.05). Serum levels of otolin-1 were significantly higher in BPPV patients than in healthy controls (P < 0.001). Receiver operating characteristic analysis revealed that a serum otolin-1 value of 299.45 pg/ml was the optimal cut-off value to discriminate patients with BPPV from healthy controls (area under the curve 0.757, 95% CI 0.687~0.826) with a sensitivity of 67.9% and a specificity of 72.7%.

Conclusion: Serum levels of otolin-1 may be a potential biomarker for BPPV episodes.

Observational study on risk factors determining residual dizziness after successful benign paroxysmal positional vertigo treatment: the role of subclinical BPPV

After successful treatment for benign paroxysmal positional vertigo, many patients may complain of residual dizziness. Possible explanations may be the persistence of otolith into canal insufficient to provoke noticeable nystagmus, utricular dysfunction and undiagnosed coexisting vestibular disorder. We conducted a prospective observational case-control study, focusing on the role of risk factors in determining residual dizziness after BPPV treatment. In the present study, 148 patients were recruited and residual dizziness was documented in the 57.5% of the cohort. Among patients with residual dizziness 36 had subclinical BPPV and after retreatment, although nystagmus was not clinically evident, there was resolution of dizziness. We conclude that residual otoliths may play a role in determining post-maneuver residual dizziness that is often linked to subclinical BPPV; this conclusion is also supported by the high prevalence of BPPV recurrence in patients with residual dizziness, as confirmed by our analysis. The main cause appears to be linked with dispersed otolith in semicircular canals.

[The impairment of bone-mineral metabolism in the development of benign paroxysmal positional vertigo]

Benign paroxysmal positional vertigo (BPPV) is one of the most common causes of systemic vertigo in clinical practice. The results of recent research demonstrated the decrease of bone mineral density, level of vitamin D and estrogen in blood serum in patients with BPPV. In summary these data points at the relationship between osteoporosis/osteopenia and BPPV. This association is most obvious in menopausal women and in those with recurrent BPPV. Patients with recurrent BPPV should undergo investigation for osteoporosis/osteopenia. Treatment of bone-mineral metabolism allows decreasing the frequency of BPPV recurrence, however more research is needed in this area.

A mouse model for benign paroxysmal positional vertigo with genetic predisposition for displaced otoconia

Abnormal formation of otoconia, the biominerals of the inner ear, results in balance disorders. The inertial mass of otoconia activates the underlying mechanosensory hair cells in response to change in head position primarily during linear and rotational acceleration. Otoconia associate exclusively with the two gravity receptors, the utricle and saccule. The cristae sensory epithelium is associated with an extracellular gelatinous matrix known as cupula, equivalent to otoconia. During head rotation, the inertia of endolymphatic fluids within the semicircular canals deflects the cupula of the corresponding crista and activates the underlying mechanosensory hair cells. It is believed that detached free-floating otoconia particles travel ectopically to the semicircular canal and cristae and are the culprit for benign paroxysmal positional vertigo (BPPV). The Slc26a4 mouse mutant harbors a missense mutation in pendrin. This mutation leads to impaired transport activity of pendrin and to defects in otoconia composition and distribution. All Slc26a4 ^loop/loop homozygous mutant mice are profoundly deaf but show inconsistent vestibular deficiency. A panel of behavioral tests was utilized in order to generate a scoring method for vestibular function. A pathological finding of displaced otoconia was identified consistently in the inner ears of mutant mice with severe vestibular dysfunction. In this work, we present a mouse model with a genetic predisposition for ectopic otoconia with a clinical correlation to BPPV. This unique mouse model can serve as a platform for further investigation of BPPV pathophysiology, and for developing novel treatment approaches in a live animal model.

[Repositioning maneuver for self-performing by patients in cupulolithiasis of horizontal canal BPPV]

OBJECTIVE

The aim of the study is to evaluate the efficiency of the new repositioning maneuver for patients with horizontal canal cupulolithiasis benign paroxysmal positional vertigo (BPPV) to perform independently at home between doctor's sessions.

MATERIALS AND METHODS

28 patients with isolated horizontal canal cupulolithiasis BPPV were enrolled. In all of them treatment with Gufoni maneuver was not successful after first session. They were divided in M«-» group (17 patients), M«-» group (11 patients). M«-» group performed forced prolong prositionig on the side with less dizziness between sessions. M«-» group performed forced prolong prositionig on the side with less dizziness and 3-5 repetitions of new repositioning maneuver 2-3 times a day between sessions. Repositioning maneuver consists of head shaking, then moving to one side-lying position with maintaining it until dizziness stops and resuming the upright sitting position, then without a pause performing head shaking and moving to the other side-lying position with maintaining it until dizziness stops and resuming the upright sitting position. The patients visited doctor once a week. Before treatment and 1 week after treatment dizziness handicap inventory (DHI) was administrated.

RESULTS

After 2 and 3 weeks of treatment more patients in M«-» group than in M«-» group were cured (p<0.05). After 4 weeks of treatment the number of recovered patients did not significantly differ in both groups. After 1 week of treatment according to DHI scores in M«-» group there were less patients with mild dizziness and more patients with moderate dizziness than in M«-» group (p<0.05).

CONCLUSION

Recovery from horizontal canal cupulolithisis BPPV could be achieved at an early date with self-performing of new repositioning maneuver. Patient-perceived disability in persisting horizontal canal cupulolithiasis could be less if the new repositioning maneuver is performed.

Review of the pathology underlying benign paroxysmal positional vertigo

The pathophysiological mechanism underlying benign paroxysmal positional vertigo (BPPV) is related to free-floating debris/otoliths in the semicircular canal (canalolithiasis) or debris/otoliths attached to the cupula (cupulolithiasis). These debris/otoliths are considered to originally accumulate after detachment from the neuroepithelium of the utricular macula secondary to a type of degeneration. An idiopathic form, which is assumed to occur spontaneously, is diagnosed when the causative pathology is obscure. However, an association between various other systemic or inner ear conditions and BPPV has been reported, indicating the existence of secondary BPPV. This study was performed to present the first review of the pathology underlying BPPV following a complete PubMed/Medline search. In total, 1932 articles published from 1975 to 2018 were reviewed. The articles were classified according to 17 potentially causative factors (aging; migraine; Meniere's disease; infection; trauma; idiopathic sudden sensorineural hearing loss; sleeping habits; osteoporosis and vitamin D insufficiency; hyperglycemia and diabetes mellitus; chronic head and neck pain; vestibule or semicircular canal pathology; pigmentation disorders; estrogen deficiency; neurological disorders; autoimmune, inflammatory, or rheumatologic disorders; familial or genetic predisposition; and allergy). A discussion of the underlying cause of BPPV for each factor is presented.

Cervical Vestibular Evoked Myogenic Potentials in Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis

Objective: The objective of our study was to investigate the potential association between the occurrence of benign paroxysmal positional vertigo (BPPV) and saccular dysfunction using cervical vestibular evoked myogenic potentials (cVEMP) testing. Methods: The databases including Pubmed, Embase, and CENTRAL were systemically searched for case-control literatures investigating saccular dysfunction using cVEMP testing in BPPV patients compared with healthy controls. The literatures were published up to 16 April 2019 and were limited to the English language. All statistical processes were carried out using software Review Manager, version 5.3. Subgroup analysis and sensitive analysis were performed simultaneously. Results: Of the 12 case-control studies confirmed for meta-analysis, p13 latency of cVEMP was assessed in 8 studies, n23 latency in 6 studies, amplitude in 5 studies, asymmetry ratio (AR) in 3 studies, proportion of absent response in 9 studies, and abnormal cVEMP in 8 studies. Compared with healthy controls, the p13 mean latency of cVEMP was longer (MD = 0.88, 95% CI = 0.64-1.12, p < 0.00001), the mean amplitude was lower (SMD = -0.60, 95% CI = -0.80 to -0.41, p < 0.00001), and the proportions of absent response (OR = 8.76, 95% CI = 2.28-33.61, p = 0.002), and abnormal cVEMP (OR = 7.47, 95% CI = 4.65-12.01, p < 0.00001) were higher in BPPV patients. But there was no significant difference in the n23 mean latency (MD = 0.37, 95% CI = -0.23-0.98, p = 0.22) and the AR of cVEMP (MD = 3.95, 95% CI = -4.75-12.65, p = 0.37) between BPPV patients and healthy controls. In the sub-group analysis based on age, only the result of the proportion of absent response of cVEMP indicated a significant difference existed (p = 0.002) between the studies with age-matched controls (OR = 2.78, 95% CI = 1.09-7.10, p = 0.03) and the studies without age-matched controls (OR = 53.85, 95% CI = 10.09-287.13, p < 0.00001). In the sub-group analysis of the proportion of abnormal cVEMP according to the diagnostic criteria of abnormal cVEMP, the result indicated no significant difference existed between the four groups (p = 0.61, I ² = 0%). In the sensitivity analysis, we obtained the consistent results after removing each study sequentially. Conclusion: The meta-analysis reveals that saccular dysfunction may be associated with BPPV occurrence, and neural degeneration in the saccular macula may be a potential pathogenesis for BPPV.

Caloric tests in clinical practice in benign paroxysmal positional vertigo

Background: The value of caloric tests in benign paroxysmal positional vertigo (BPPV) patients is unclear. Objectives: To analyze the features and clinical significance of caloric tests in BPPV patients. Materials and methods: About 2192 patients (256 BPPV and 1936 non-BPPV) who complained of dizziness triggered by movement, accompanied by the symptom of hearing loss or a history of vertigo, participated in this prospective clinical study. All subjects received a caloric test, 213 BPPV patients underwent follow-up for at least 6 months after canalith repositioning procedures (CRPs). Results: (1) The abnormal canal paresis (CP) prevalence of BPPV was 57%. (2) The curative rate of single CRP decreased during follow-up from 90.1% after 7 days to 61% after 6 months and was significantly lower in patients with (54.1%) than in those without (70.1%) an abnormal CP at 6 months post-treatment (p = .01). (3) The recurrent rate was significantly higher in BPPV patients with abnormal CP (25.2%) than with normal CP (12.5%; p = .017). Conclusions and significance: Patients with abnormal CP needed more CRPs and were more prone to relapse. The value of the caloric test in treatment planning and predicting recurrence in BPPV patients should be emphasized.

Otopetrin-2 Immunolocalization in the Human Macula Utricle

BACKGROUND

In the present study, we investigated the localization of otopetrin-2-a member of the otopetrin family that encodes proton-selective ion channels-in the human macula utricle using immunohistochemistry.

METHODS

Macula utricle were acquired at surgery from patients who required transmastoid labyrinthectomy for intractable vertigo due to Meniere's disease (MD; n = 3) and/or vestibular drops attacks (VDA; n = 2) and from temporal bones (n = 2) acquired at autopsy from individuals with no balance disorders. Immunofluorescence staining with otopetrin-2 (rabbit affinity purified polyclonal antibody) and GFAP (mouse monoclonal antibody) to identify vestibular supporting cells was made in formalin fixed cryostat sections or whole microdissected utricle (for flat mount preparations). Secondary antibodies against rabbit and mouse were used for the identification of both proteins. Digital fluorescent images were obtained using a high-resolution laser confocal microscope.

RESULTS

Using cryostat sections and flat mount preparations otopetrin-2 immunofluorescence was seen as punctated signal throughout the supporting cells cytoplasm. GFAP immunofluorescence was present in the supporting cell cytoplasm. The distribution of otopetrin-2 was similar in the macula utricle obtained from MD, VDA, or autopsy normative patients.

CONCLUSIONS

Otopetrin-2 was localized in supporting cells in a similar fashion that otopetrin-1 previously reported in the mouse macula utricle. The differential expression of otopetrin-2 in the supporting cells of the human macula utricle suggest an important role in the vestibular sensory periphery homeostasis and otolith maintenance.

Generation of Vestibular Tissue-Like Organoids From Human Pluripotent Stem Cells Using the Rotary Cell Culture System

Hair cells are specialized mechanosensitive cells responsible for mediating balance and hearing within the inner ear. In mammals, hair cells are limited in number and do not regenerate. Human pluripotent stem cells (hPSCs) provide a valuable source for deriving human hair cells to study their development and design therapies to treat and/or prevent their degeneration. In this study we used a dynamic 3D Rotary Cell Culture System (RCCS) for deriving inner ear organoids from hPSCs. We show RCCS-derived organoids recapitulate stages of inner ear development and give rise to an enriched population of hair cells displaying vestibular-like morphological and physiological phenotypes, which resemble developing human fetal inner ear hair cells as well as the presence of accessory otoconia-like structures. These results show that hPSC-derived organoids can generate complex inner ear structural features and be a resource to study inner ear development.

The Vestibular System and Ageing

The world's population is ageing due to increased hygiene and improved medical care. Dizziness and imbalance frequently affect the elderly and is most common among individuals over the age of 60. In this age group approximately 30% of the population experience these debilitating symptoms at some point. They contribute to falls and frailty, which often result in hospitalization causing tremendous cost for the health care systems, and increased mortality. To make the matters worse balance disorders are often complex. Physicians face the difficulty of diagnosing the patient with the exact disorder especially since each disorder may manifest differently in each patient. In addition, several treatment options exist, however, with a low level of evidence. This chapter summarizes the underlying degenerative processes of the peripheral as well as the central vestibular system, diagnostic tools, the most common balance disorders in the elderly, and possible treatment options of these disorders.

Aging Is a Risk Factor for Utricular Dysfunction in Idiopathic Benign Paroxysmal Positional Vertigo

Benign paroxysmal positional vertigo (BPPV) is the most common cause of balance disorders in the elderly. Dislodgement of the otoconia in BPPV might have an association with damage to the otolith organs. The aim of this study was to investigate whether aging is a risk factor for otolith organ dysfunction in idiopathic BPPV. We retrospectively reviewed the medical records of 112 consecutive idiopathic BPPV patients who underwent cervical VEMP testing to air-conducted sound (ACS cVEMP), ocular VEMP testing to bone-conducted vibration (BCV oVEMP), and caloric testing. We performed binomial logistic regression analyses to see whether age, the side affected by BPPV or the canal affected by BPPV have an association with the presence of peripheral vestibular dysfunction in idiopathic BPPV patients. The elderly group (aged ≥65 years) had a significantly positive association with abnormalities in BCV oVEMPs (p = 0.0109), while the side affected by BPPV (p = 0.598) and the canal affected by BPPV (p = 0.576) did not. The odds ratio of the abnormal BCV oVEMPs for the elderly group compared with the non-elderly group (aged < 65 years) was 2.676 (95% confidence interval, 1.254–5.079). The elderly group had no significant association with the abnormalities in ACS cVEMPs (p = 0.0955) or caloric testing (p = 0.488). Dysfunction of the utricle, where the dislodgement of the otoconia mainly occurs, is affected by aging in idiopathic BPPV.

Traumatic versus Idiopathic Benign Positional Vertigo: Analysis of Disease, Treatment, and Outcome Characteristics

Objective

To compare characteristics between traumatic and idiopathic benign paroxysmal positional vertigo (BPPV) focusing on outcomes.

Study Design

Retrospective chart review.

Setting

High-volume tertiary otology center.

Subjects and Methods

Records of patients with BPPV treated at a single institution from 2007 to 2017 were analyzed. Traumatic BPPV was defined as BPPV symptoms beginning within 30 days following head trauma. Patient, disease, treatment, and outcome characteristics were compared between traumatic and idiopathic BPPV groups.

Results

A total of 1378 patients with BPPV were identified, 110 (8%) of which had traumatic BPPV. The overall resolution rate was 76%, and the recurrence rate was 38%. Patients with traumatic BPPV were younger (mean age: 61 vs 65 years, P = .007) and more likely to be male (40% vs 27%, P = .004) than patients with idiopathic BPPV. Traumatic BPPV was more likely to affect both ears (32% vs 19%, P = .009). No significant association was detected between trauma history and resolution rate, recurrence rate, number of treatment visits, or affected semicircular canals.

Conclusion

Patients with traumatic BPPV are more likely to be young and male than those with idiopathic disease. Although traumatic BPPV is often bilateral, outcomes for traumatic BPPV may be similar to those for idiopathic BPPV, contrary to prior reports.

Generating inner ear organoids containing putative cochlear hair cells from human pluripotent stem cells

In view of the prevalence of sensorineural hearing defects in an ageing population, the development of protocols to generate cochlear hair cells and their associated sensory neurons as tools to further our understanding of inner ear development are highly desirable. We report herein a robust protocol for the generation of both vestibular and cochlear hair cells from human pluripotent stem cells which represents an advance over currently available methods that have been reported to generate vestibular hair cells only. Generating otic organoids from human pluripotent stem cells using a three-dimensional culture system, we show formation of both types of sensory hair cells bearing stereociliary bundles with active mechano-sensory ion channels. These cells share many morphological characteristics with their in vivo counterparts during embryonic development of the cochlear and vestibular organs and moreover demonstrate electrophysiological activity detected through single-cell patch clamping. Collectively these data represent an advance in our ability to generate cells of an otic lineage and will be useful for building models of the sensory regions of the cochlea and vestibule.

Assessment of Bone Metabolism in Male Patients With Benign Paroxysmal Positional Vertigo

Objective: Several studies have suggested a probable association between benign paroxysmal positional vertigo (BPPV) and both reduction of bone mineral density (BMD) and serum vitamin D levels, but none of these studies have explored their findings by examining bone turnover markers (BTM) in male idiopathic BPPV patients. This study aimed to evaluate the relationship between BMD and serum 25-hydroxyvitamin D (25(OH) D), with the occurrence of BPPV along with the characteristics of bone metabolism in male idiopathic BPPV patients. Methods: This retrospective study comprised 60 male idiopathic BPPV patients and 92 age-matched healthy controls referred to Ningbo No.2 Hospital during the period of February 2016 to February 2018. All subjects' serum levels of 25(OH) D, bone formation marker amino-terminal propeptide of type I procollagen (PINP), and bone resorption marker β-isomerized carboxy-terminal telopeptide of type I collagen (β-CTX) were measured. BMD was determined by dual energy X-ray absorption at the lumbar spine and hip. Results: Among male patients with BPPV, the prevalence of BMD reduction was 35.0%, which was similar to that of 27.2% in healthy controls. There were significant differences in the mean serum 25(OH) D level and prevalence of vitamin D deficiency between the two groups, with p-values of 0.049 and 0.009, respectively. The bone turnover markers of PINP and β-CTX in BPPV patients were lower than those in healthy controls. Logistic regression showed that vitamin D deficiency were associated with BPPV with an odds ratio of 3.8 (95% confidence interval = 1.25-11.73). Conclusion: Our study found that decreased serum vitamin D may be a risk factor for BPPV in male patients. The level of bone turnover among male patients with BPPV was lower than that among healthy controls.

Mechanism Underlying the Effects of Estrogen Deficiency on Otoconia

Otoconia-related vertigo and balance deficits, particularly benign paroxysmal positional vertigo (BPPV), are common. Our recent studies in humans show that, while BPPV prevalence greatly increases with age in both genders, peri-menopausal women are especially susceptible. In the present study, we show that bilateral ovariectomized (OVX) mice have significant balance behavioral deficits, and that estrogen deficiency compromises otoconia maintenance and anchoring by reducing the expression of otoconial component and anchoring proteins. There is ectopic debris formation in the ampulla under estrogen deficiency due to aberrant matrix protein expression. Furthermore, phytoestrogen is effective in rescuing the otoconia abnormalities. By comparing the expression levels of known estrogen receptor (Esr) subtypes, and by examining the otoconia phenotypes of null mice for selected receptors, we postulate that Esr2 may be critical in mediating the effects of estrogen in otoconia maintenance.

Age-Related Increase in Blood Levels of Otolin-1 in Humans

OBJECTIVE

To test the hypothesis that age-related demineralization of otoconia will result in an age-related increase in blood levels of otoconia matrix protein, otolin-1.

STUDY DESIGN

Cross-sectional observational clinical trial.

SETTING

Clinical research center.

PATIENTS

Seventy nine men and women ranging in age from 22 to 95 years old.

INTERVENTIONS

Diagnostic.

MAIN OUTCOME MEASURES

Blood levels of otolin-1 in relation to age.

RESULTS

Levels of otolin-1 of subjects divided into four age groups (1: 20-30 [n = 20], 2: 50-65 [n = 20], 3: 66-80 [n = 20], 4: 81-95 [n = 19] years old) demonstrated an increasing trend with age. The difference between otolin levels of groups 2 and 3, as well as, (p = 0.04) and 2 and 4 (p = 0.031) were statistically significant, but there was no significant difference between the two oldest groups.

CONCLUSIONS

Otolin-1 blood levels are significantly higher in patients older than 65 years of age. This is consistent with previous scanning electron microscopy findings of age-related otoconia degeneration and increased prevalence of benign paroxysmal positional vertigo (BPPV) with age. Normative data provided here can serve as important reference values against which levels from BPPV patients can be compared with further evaluate otolin-1 as a circulatory biomarker for otoconia degeneration.

Reduction of bone mineral density in native Chinese female idiopathic benign paroxysmal positional vertigo patients

OBJECTIVE

This study aimed to investigate the clinical association between idiopathic benign paroxysmal positional vertigo (BPPV) and reduction of bone mineral density (BMD).

METHODS

BMD was measured in 78 native Chinese female de novo idiopathic BPPV patients and 126 healthy controls using dual-energy X-ray absorptiometry. We compared the mean T-scores and abnormal BMD prevalence between the two groups.

RESULTS

The mean T-scores were significantly lower in idiopathic BPPV patients than in healthy controls. The prevalence of osteopenia and osteoporosis were significantly higher in idiopathic BPPV patients than in healthy controls (65.4% vs 48.4%, p=0.013).

CONCLUSION

BMD reduction may be associated with idiopathic BPPV occurrence.

Characteristics and Treatment Outcomes of Benign Paroxysmal Positional Vertigo in a Cohort of Veterans

BACKGROUND

The Mountain Home Veterans Affairs (VA) Medical Center has been diagnosing and treating veterans with benign paroxysmal positional vertigo (BPPV) for almost 2 decades. The clinic protocol includes a 2-week follow-up visit to determine the treatment outcome of the canalith repositioning treatment (CRT). To date, the characteristics of BPPV and treatment efficacy have not been reported in a cohort of veterans with BPPV.

PURPOSE

To determine the prevalence and characteristics of veterans diagnosed with BPPV in a Veterans Affairs Medical Center Audiology Clinic and to examine treatment outcomes.

RESEARCH DESIGN

Retrospective chart review.

STUDY SAMPLE

A total of 102 veterans who tested positive for BPPV in the Vestibular Clinic at the Mountain Home VA Medical Center from March 2010 to August 2011.

RESULTS

In 102 veterans who were diagnosed with BPPV, the posterior semicircular canal was most often involved (75%), motion-provoked vertigo was the most common symptom (84%), and the majority (43%) were diagnosed with BPPV in their sixth decade. The prevalence of BPPV in the Audiology Vestibular Clinic was 15.6%. Forty-one percent of veterans reported a symptom onset within 12 months of treatment for BPPV; however, 36% reported their symptoms began > 36 months prior to treatment. CRT was effective (negative Dix-Hallpike/roll test) in most veterans (86%) following 1 treatment appointment (M = 1.6), but more than half reported incomplete symptom resolution (residual dizziness) at the follow-up appointment. Eighteen percent of veterans experienced a recurrence (M = 1.8 years; SD = 1.7 years).

CONCLUSIONS

The characteristics and treatment outcomes of BPPV in our veteran cohort was similar to what has been reported in the general population. Future work should focus on improving the timeliness of evaluation and treatment of BPPV and examining the time course and management of residual dizziness.

Structural properties of the intrinsically disordered, multiple calcium ion-binding otolith matrix macromolecule-64 (OMM-64)

Fish otoliths are calcium carbonate biominerals that are involved in hearing and balance sensing. An organic matrix plays a crucial role in their formation. Otolith matrix macromolecule-64 (OMM-64) is a highly acidic, calcium-binding protein (CBP) found in rainbow trout otoliths. It is a component of high-molecular-weight aggregates, which influence the size, shape and polymorph of calcium carbonate in vitro. In this study, a protocol for the efficient expression and purification of OMM-64 was developed. For the first time, the complete structural characteristics of OMM-64 were described. Various biophysical methods were combined to show that OMM-64 occurs as an intrinsically disordered monomer. Under denaturing conditions (pH, temperature) OMM-64 exhibits folding propensity. It was determined that OMM-64 binds approximately 61 calcium ions with millimolar affinity. The folding-unfolding experiments showed that calcium ions induced the collapse of OMM-64. The effect of other counter ions present in trout endolymph on OMM-64 conformational changes was studied. The significance of disordered properties of OMM-64 and the possible function of this protein is discussed.