Journal of Vestibular Research-Equilibrium & Orientation最新文献

The vestibular disorders, which generally manifest themselves as nausea, vomiting, and dizziness or vertigo, have troubled many people. Increasing evidence suggests that certain vestibular disorders are hereditary, and gene variants contribute to the onset and susceptibility of these disorders. This review summarizes the latest research progress, especially the molecular and genetic aspects of several common vestibular disorders, including Meniere's disease, vestibular migraine, benign paroxysmal positional vertigo, and motion sickness, with the aim of encouraging more fundamental research and enhancing our understanding of the molecular and genetic mechanisms underlying vestibular disorders.

BackgroundThe ocular vestibular evoked myogenic potential (oVEMP) n1 peak is the first of many that form part of the oscillating waveform. Previous work showed that up to 5 peaks can be elicited when an intact labyrinth is stimulated, with larger peaks contralaterally.ObjectiveWe investigated what happens to these later peaks when the n1 amplitude is enlarged, which is typically seen in superior canal dehiscence (SCD) and sometimes vestibular migraine (VM).MethodsWe measured oVEMPs elicited to air- (AC) and bone-conducted (BC) stimuli in 14 patients with SCD, 20 with SCD and classical migraine, 26 with clinically definite VM, and 20 with clinically definite VM and enlarged n1 peaks. We compared these results to 49 healthy volunteers.ResultsBoth groups of SCD patients had the largest peaks, but the same number of peaks as healthy volunteers (maximum 4 for AC; 5 for BC). In contrast, patients with VM had more later peaks than other groups (maximum 6 for both stimuli).ConclusionsAs the patients with the largest amplitudes did not have prolonged oscillation in their waveforms, our results suggest that the oscillation may be enhanced by central processes, such as lack of habituation that is reported in patients with VM.

BackgroundEmerging evidence indicates an association between vestibular dysfunction and Depersonalization/Derealization (DD) symptoms. However, substantial heterogeneity in the studied populations, experimental paradigms, and assessment methodologies limits clear conclusions regarding the involvement of the vestibular system in the onset of DD symptoms.ObjectiveTo clarify the contribution of the vestibular system to DD symptoms in vestibular patients and healthy individuals undergoing vestibular stimulation.MethodsFollowing PRISMA guidelines, we reviewed studies examining: (1) DD symptoms in vestibular patients, and (2) DD symptoms in healthy individuals during vestibular stimulation.ResultsTwenty-three studies met the inclusion criteria. Among these, 86.9% reported DD symptoms either in patients with vestibular disorders (14/15) or in healthy individuals during vestibular stimulations (6/8). Additionally, 82.61% of the studies identified an association between DD symptoms and anxiety or spatial disorientation.ConclusionsTogether, these findings indicate that vestibular alterations may contribute to the emergence of DD symptoms. Anxiety and spatial disorientation were found to frequently co-occur suggesting an interaction between vestibular processing, affective regulation, and spatial cognition. This association can be interpreted within a neurofunctional framework, which posits that vestibular alterations disrupt multisensory integration in parietotemporal, insular, and hippocampal regions, contributing to the core phenomenology of DD.

Caloric and video head impulse tests (vHITs) are essential for vestibular diagnostics, both employing Jongkees' formula (JF) to quantify asymmetry. JF calculates unilateral weakness (UW) by subtracting the weaker ear (WE) response from the stronger ear (SE) and using the sum of both responses as a reference. However, the result is unwieldy and may mislead clinicians if interpreted as an indication of how much weaker the response of the WE is compared to the contralateral SE as a percentage. Through mathematical analysis, we examined what question JF answers and explored, for each vestibular test, alternative asymmetry equations for a more meaningful assessment of vestibular asymmetry. JF has three key limitations. First, its nonlinear nature leads to an underestimation of paresis, particularly when the WE response is near 41% of SE, where the calculated UW is capped at 18%. Second, JF derives the asymmetry from a "symmetry point", splitting the difference between both sides, with the average response in the middle, rather than directly quantifying UW as clinicians understand it. Instead, JF answers two separate questions: "How much is the WE response below the average" and "How much is the SE response above the average." To address these issues, a linear paresis calculation using only the SE response as a reference was later introduced. However, this approach did not resolve JF's third limitation: artificially inflated values and sensitivity to small variations in WE when both ears are affected. Unlike the caloric test, the vHIT already relies on head velocity as an absolute reference for gain calculation, eliminating the need for SE in asymmetry calculation. Employing an ideal gain of 1, asymmetry can be expressed as a simple side-to-side gain difference, preventing inflated results in bilateral deficits and easing clinical calculation.

BackgroundThe pathophysiology of Meniere's disease (MD) is complex and intertwined with endolymphatic hydrops. Available experimental models have limitations.ObjectiveThis study aimed to analyze the impact of endolymphatic hydrops on cochleovestibular hydrodynamics through numerical simulations.MethodsA comprehensive literature review was conducted following PRISMA guidelines for Scoping Reviews. Articles were sourced in June 2024 from PubMed and Google Scholar using a combination of MESH terms related to hydrodynamics, numerical simulation, and MD. Studies involving numerical simulations of hydrops in the vestibule, cochlea, or both were included.ResultsEight studies on hydrodynamics in hydrops using numerical simulations were included. In cochlear models, hydrops affect basilar membrane mechanics, causing low-frequency hearing loss, auditory distortions, and frequency shifts. Vestibular models revealed increased static pressure in the horizontal semicircular canal, explaining abnormal vHIT findings in hydrops patients. Models also suggested chaotic fluid dynamics in dilated labyrinthine structures during caloric tests. The reviewed studies underscore the utility of numerical models in understanding the mechanics of MD; however, significant limitations were identified.ConclusionsNumerical modeling offers valuable insights into the hydrodynamic changes caused by endolymphatic hydrops in MD, but future work should address the current limitations by incorporating more accurate anatomical features and chronic progression in simulations.

BackgroundVestibular disorders significantly impact daily activities and participation, leading to reduced quality of life. The Shortened Vestibular Activities and Participation Measure (VAP) is a 12-item tool designed to assess activity limitations and participation restrictions in individuals with vestibular disorders.ObjectiveIn this study, the Turkish Shortened VAP was translated and culturally adapted. Its validity and reliability were also assessed.MethodsA total of 123 participants with vestibular disorders were included. The translation and cultural adaptation followed standard guidelines. Structural validity was assessed through exploratory and confirmatory factor analyses, and convergent validity was evaluated using correlations with the Dizziness Handicap Inventory (DHI). Reliability was examined using internal consistency (Cronbach's alpha and McDonald's omega) and item analysis.ResultsFactor analyses confirmed the two-factor structure with good fit indices (GFI = 0.938). Significant correlations with the DHI supported convergent validity (r = 0.65). Internal consistency was strong for the total scale (Cronbach's α = 0.85; McDonald's ω = 0.91) and acceptable for subscales. All items demonstrated acceptable corrected item-total correlations.ConclusionsThe Turkish Shortened VAP is a valid and reliable tool for assessing activity limitations and participation restrictions in vestibular disorders, suitable for clinical and research use in Turkey.

ObjectivesWe aimed to investigate the prevalence and age-related changes in vestibular function within the general population using survey data from the Korean National Health and Nutrition Examination Survey (KNHANES) and examine the potential factors influencing it.MethodsWe analyzed retrospective data from 1270 participants from the 2021 KNHANES who completed both the video head impulse test and audiometric evaluations. Participants with vestibulo-ocular reflex (VOR) gains <0.8 and >1.2 were excluded to minimize the impact of possible testing errors and prior impaired vestibular function. We assessed the prevalence and age-related changes in vestibular function and analyzed potential influencing factors using logistic regression analysis.ResultsThe VOR gain decreased with age; however, statistical significance was not achieved (coefficient -0.0003, p = 0.281). The presence of corrective saccades significantly increased with age (p < 0.001), with those in their 70s being 3.98 times more likely to exhibit corrective saccades than those in their 40s. The overall prevalence was 17.08%. Subjects with corrective saccades exhibit lower VOR gain than those without it (p < 0.001). Age, sex, hypertriglyceridemia, and hearing levels at 4000 Hz were significantly associated with the presence of corrective saccades.ConclusionVestibular function declined with age, influenced significantly by sex, hypertriglyceridemia, and hearing level at 4000 Hz. The increased prevalence of corrective saccades among older adults underscores the importance of early detection and intervention. Understanding age-related changes in vestibular function can facilitate appropriate management strategies and countermeasures at the personal and societal healthcare level.

BackgroundMilitary duty may place Service members and Veterans at an increased risk of experiencing dizziness. Individuals with dizziness report poor sleep quality as well as abnormal sleep duration, which is associated with increased risk of falling and worse quality of life. The overall pooled prevalence of poor sleep quality in Service members and Veterans was 69%, but it is not known if Service members and Veterans with self-reported dizziness report poorer sleep quality than their counterparts without dizziness.ObjectiveThe purpose of this research study was to evaluate the sleep quality of Service members and Veterans with and without reports of dizziness.MethodsDescriptive statistics were used to explore the prevalence of self-reported dizziness among Service members and Veterans by demographic characteristics. Descriptive statistics were also used to describe the prevalence of participants' dizziness symptoms and the mean age participants first noticed dizziness. Models (unadjusted and adjusted) were created by regressing sleep disorders and daytime sleepiness on dizziness frequency. Potential confounders were chosen a priori through a theoretical framework. Military status (Service member vs Veteran) was explored as an interaction term. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, with statistical significance determined by the 95% CI.ResultsDizziness was reported by 22.4% of Service members (n = 171 of 763) and 31.7% of Veterans (n = 241 of 761). Service members and Veterans with dizziness were 1.7 times more likely to have a sleep disorder than Service members and Veterans without dizziness.ConclusionsService members and Veterans with dizziness were more likely to have poor sleep quality than those without dizziness. Medical providers should screen for sleep disturbances, evaluate for obstructive sleep apnea, treat chronic insomnia disorder, and consider referral for vestibular rehabilitation in Service members and Veterans presenting with dizziness.

Background and PurposePrevious studies on benign paroxysmal positional vertigo (BPPV) have primarily been performed in referral-based clinics. This study aimed to explore the clinical characteristics of BPPV and its variant (light cupula) in a primary care setting.MethodsWe retrospectively analyzed the clinical data of 1126 patients who visited a primary care neurology clinic due to dizziness or vertigo between March 2023 and February 2024. We collected information on age, sex, affected ear, symptom duration at the first evaluation, BPPV subtypes (including the variant), duration of positional nystagmus (transient: <1 min vs persistent: ≥1 min), and the number of canalith repositioning procedures (CRPs) required for treatment.ResultsA total of 308 patients (27.4%) were diagnosed with BPPV or its variant. Subtypes included posterior canal (PC) type in 183 (59.4%), geotropic horizontal canal (HC) type in 73 (23.7%), apogeotropic HC type in 43 (14.0%), anterior canal type in 4 (1.3%), and mixed type in 5 (1.6%). The proportion of PC type increased with a longer duration of symptoms (p = 0.012). In multinomial regression, only the duration of positional nystagmus was significantly associated with the number of CRPs (p < 0.001), as patients with persistent nystagmus required more CRPs than those with transient nystagmus.ConclusionsIn primary care, the proportion of each subtype of BPPV and its variant differs according to symptom duration. Furthermore, patients with positional nystagmus lasting more than 1 minute tend to be more refractory to CRPs.

ObjectivesBenign paroxysmal positional vertigo (BPPV) is a prevalent triggers of persistent postural-perceptual dizziness (PPPD). The maladaptation of brain function may be one of the pathophysiology in PPPD. This study aims to identify brain functional neuroimaging features and establish prediction models to predict PPPD after BPPV.MethodsThe diagnosis of BPPV and PPPD was based on the criteria established by the Bárány Society. Patients with posterior semicircular canal BPPV were treated using the Epley maneuver. Patients with geotropic lateral canal BPPV were treated with the barbecue rotation maneuver, while those with apogeotropic lateral canal BPPV were treated using the Gufoni maneuver. After successful canalith repositioning maneuver treatment, the patient underwent resting-state functional magnetic resonance imaging (fMRI) scan. Using feature selection and extraction techniques, six machine learning algorithms were implemented to predict PPPD. The models were trained with 5-fold cross-validation, and performance was evaluated using the receiver operating characteristic curve (AUC), accuracy, precision, recall, and F1 score (F1).ResultsA total of 101 patients were included in the final analysis, comprising 64 patients without PPPD (non-PPPD) and 37 patients with PPPD (PPPD). A total of 22 functional neuroimaging features were identified to be closely associated with PPPD after BPPV. Among the six machine learning algorithms, the Multilayer Perceptron model exhibited superior performance, with an AUC of 0.93, a recall of 0.82, a precision of 0.83, an accuracy of 0.82, and an F1 score of 0.82. SHAP analysis identified the most influential resting-state fMRI features in this model. For the top 10 important resting-state fMRI features, 3 features overlapped in all six machine learning algorithms. These features include FC between the vermis 3 and the superior frontal gyrus, orbital part, DC in the cerebellum 7b, left, and FC between the Heschl gyrus, left, and the caudate, right.ConclusionsThese findings provide brain functional neuroimaging features which may be closely associated with the transition from BPPV to PPPD, thereby offering a valuable tool for the early detection of PPPD.