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This case report presents bilateral hearing loss after vestibular‐evoked myogenic potential (VEMP) testing. The loud acoustic stimulus used in VEMP testing can cause noise‐induced hearing loss in some cases with high sensitivity to noise exposure or by exceeding individual cochlear safety thresholds.

It remains unclear whether the dominance of 1000 Hz responses over responses at 500 Hz in cervical vestibular evoked myogenic potentials (cVEMPs) are characteristic of endolymphatic hydrops (EH), due to the presence of patients with absent responses at both frequencies. The purpose of the present study is to examine whether the dominant cVEMP responses at 1000 Hz over 500 Hz are characteristic findings of EH-related diseases among patients who show various cVEMP findings.We retrospectively reviewed the medical records of 470 consecutive patients who underwent cVEMP testing with short-tone bursts at both 500 Hz and 1000 Hz. We categorized the cVEMP responses of these 470 patients into the following five groups: (group 1) present responses at both frequencies bilaterally, (group 2) present responses at 500 Hz but absent at 1000 Hz on at least one side, (group 3) absent responses at 500 Hz but present at 1000 Hz on at least one side, (group 4) absent responses at both frequencies on one side and present at both frequencies on the other side, and (group 5) absent responses at both frequencies bilaterally. We compared the proportion of EH-related diseases between each group and the other four groups and then investigated any increased or decreased disease incidence in each group.In group 3, the proportion of EH-related disease was significantly higher (p0.01), and the incidence of an EH-related disease was greatly increased (standard residual value3).cVEMPs that are absent at 500 Hz and present at 1000 Hz may be characteristic of EH-related disease.

Background:Vestibular dysfunction is a complication of cochlear implantation (CI). Reports on the evaluation of vestibular function before and after CI are limited, especially in children. We investigated the effect of CI on vestibular function in pediatric patients.Patients and Methods:We routinely evaluated vestibular function before but not immediately after CI. Therefore, patients who underwent sequential bilateral CI were enrolled in this study. Seventy-three children who underwent sequential CI from 2003 to 2020 at our hospital were included. Since the vestibular function of the first implanted ear was evaluated before the second surgery for the contralateral ear, post-CI evaluation timing differed among the cases. The evaluation included a caloric test, a cervical vestibular-evoked myogenic potential (cVEMP) test, and a damped rotation test. The objective variables included the results of these tests, and the explanatory variables included the age at surgery, cause of hearing loss, electrode type, and surgical approach used. The associations of these tests were analyzed.Results:cVEMP was the most affected after CI (36.1%), followed by the caloric test (23.6%), and damped rotation test (7.8%). Cochleostomy was significantly more harmful than a round window (RW) approach or an extended RW approach based on the results of the caloric test (p= 0.035) and damped rotation test (p= 0.029). Perimodiolar electrodes affected the caloric test results greater than straight electrodes (p= 0.041). There were no significant associations among these tests' results.Conclusions:Minimally invasive surgery in children using a round window approach or an extended round window approach with straight electrodes is desirable to preserve vestibular function after CI.

Objective: To evaluate various machine learning algorithms in predicting peripheral vestibular dysfunction using the dataset of the center of pressure (COP) sway during foam posturography measured from patients with dizziness. Study Design: Retrospective study. Setting: Tertiary referral center. Patients: Seventy-five patients with vestibular dysfunction and 163 healthy controls were retrospectively recruited. The dataset included the velocity, the envelopment area, the power spectrum of the COP for three frequency ranges and the presence of peripheral vestibular dysfunction evaluated by caloric testing in 75 patients with vestibular dysfunction and 163 healthy controls. Main Outcome Measures: Various forms of machine learning algorithms including the Gradient Boosting Decision Tree, Bagging Classifier, and Logistic Regression were trained. Validation and comparison were performed using the area under the curve (AUC) of the receiver operating characteristic curve (ROC) and the recall of each algorithm using K-fold cross-validation. Results: The AUC (0.90 ± 0.06) and the recall (0.84 ± 0.07) of the Gradient Boosting Decision Tree were the highest among the algorithms tested, and both of them were significantly higher than those of the logistic regression (AUC: 0.85 ± 0.08, recall: 0.78 ± 0.07). The recall of the Bagging Classifier (0.82 ± 0.07) was also significantly higher than that of logistic regression. Conclusion: Machine learning algorithms can be successfully used to predict vestibular dysfunction as identified using caloric testing with the dataset of the COP sway during posturography. The multiple algorithms should be evaluated in each clinical dataset since specific algorithm does not always fit to any dataset. Optimization of the hyperparameters in each algorithm are necessary to obtain the highest accuracy.

A 39-year-old man presented with chief complaints of epistaxis and pain on the right cheek that lasted for approximately 2 months. A very hard calcified black mass with a foreign body was found in the right inferior nasal meatus. The patient underwent endoscopic endonasal surgery and antimicrobial therapy, which included intravenous injection of Penicillin G 4 million units 6 times/day for 1 week and oral amoxicillin 1500 mg/day for 6 months. Actinomyces species was identified from the calcified foreign body that measured 5 mm in size. There was no recurrence for 1 year after the surgery. Surgical removal and long-term high-dose penicillin for 6 months or longer are necessary because death caused by poor compliance with antibiotics have been reported in previous studies. Keywords: Rhinolithiasis, Actinomyces

Ameliorating effect of noisy galvanic vestibular stimulation (nGVS) on posture varies among subjects. In this feasibility study, we investigated the association between original postural instability and the ameliorating effect of nGVS on posture. Data were collected in a previously published study. Thirty healthy elderly were recruited. Two nGVS sessions (30 min or 3 h) were performed in a randomised order. The optimal intensity of nGVS, the most effective intensity for improving posture, was determined before each session. Posture was measured for 30 s during and after nGVS in the eyes-closed/foam rubber condition. The velocity, envelopment area, and root mean square of the centre of pressure movement without nGVS were significantly larger in the group with an optimal intensity than those in the group without an optimal intensity. There was a significant positive correlation between these values and the long-term ameliorating effects. The ratio of the values in the eyes-closed/foam rubber condition to those in the eyes-open condition was significantly larger in the group with an optimal intensity, and had a significant correlation with the long-term ameliorating effects. The ameliorating effects are greater in subjects who were originally unstable and in those whose postural stability was relatively independent of vestibular input.

OBJECTIVE To determine parameters in computed tomography (CT) of the temporal bone that would be useful for prediction of cerebrospinal fluid (CSF) gusher during cochlear implantation (CI) surgery and postoperative facial nerve stimulation (FNS) in patients with inner ear malformations. STUDY DESIGN Retrospective study. SETTING Tertiary referral center. PATIENTS Three hundred seventy-five cases who had undergone CI surgery including 54 inner ear malformation cases were analyzed. MAIN OUTCOME MEASURES The diameters of the cochlea modiolar base and porus of the internal auditory canal (IAC), length of IAC, diameter of the vestibular aqueduct (VA) at the operculum, and presence or absence of the modiolus of the cochlea were evaluated by using CT. RESULTS CSF gusher occurred in 12 (22%) cases, in whom the diameters of the cochlea modiolar base (2.7 ± 0.6 mm, p

Objective:To investigate the influence of vestibular function on dynamic postural stability assessed by the functional reach test (FRT) and the timed up and go test (TUG).Study design:Retrospective study.Setting:Tertiary referral center.Subjects and Methods:The FRT and TUG were performed in 399 patients with dizziness. The effects of peripheral vestibular dysfunction assessed by the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs) to air-conducted sound (500 Hz, tone burst) on the results of FRT and TUG were analyzed.Results:Neither FRT nor TUG scores showed significant differences in relation to the results of the caloric test ( P > .3). The FRT scores in patients who showed abnormal cVEMP responses on both sides were significantly smaller than those in patients who showed normal cVEMP responses ( P < .01). The TUG scores in patients who showed abnormal cVEMP responses on both sides were significantly greater than those in patients who showed normal cVEMP responses ( P < .05).Conclusion:The vestibulo-spinal reflex mediated by the saccule and its afferents is one of the factors that influence the maintenance of dynamic postural stability as measured by FRT and TUG.

Exercise (Ex) and caloric restriction (CR) reduce oxidative stress and improve organ function. For instance, voluntary Ex or CR is known to reduce age-related cochlear damage in male C57BL/6J mice. However, the effect of Ex and CR on the olfactory system is unknown. In this study, we confirmed the positive effect of Ex and CR on age-related cochlear damage, but found that Ex and CR affected negatively cell dynamics in the olfactory epithelium (OE) by reducing the number of mature olfactory sensory neurons (OSNs) and increasing the number of proliferative basal cells and apoptotic OSNs in the dorsal zone of the olfactory epithelium (OE), which contains neurons expressing NADPH quinone oxido-reductase 1 (NQO1). In addition, these interventions resulted in lower odor-induced c-fos expression in areas of the olfactory bulb receiving projections from dorsal-zone OSNs than in areas receiving ventral-zone projections. Further, we observed substantial oxidative stress in NQO1-positive cells and apoptotic OSNs in the dorsal zone in Ex and CR animals. These results suggest that, in contrast to their positive effects in other organs, Ex and CR facilitate oxidative stress and negatively impact structure and function in dorsal-zone OSNs, probably in association with NQO1 bioactivation.

Objective To determine minimally important differences (MIDs) for subjective improvement in postural stability after a therapeutic intervention in patients with bilateral vestibulopathy (BVP). Methods Thirteen BVP patients received noisy galvanic vestibular stimulation (nGVS) for 30 min and their static posture with eyes closed was monitored after the stimuli. The velocity of the center of pressure (COP) movement, the area enclosed by the COP movement, and the root mean square (RMS) of the displacement of the COP were measured for 30 s. Subjective evaluation of postural stability after nGVS was graded as worsened, slightly worsened, unchanged, slightly improved and improved in comparison with postural stability measured without nGVS. Anchor-based methods were used to estimate MIDs for subjective improvement. Velocity, area and RMS for each anchor-response group were averaged (2 sessions, each with 5 measurement periods during 3 h after the stimuli). The mean changes between the slightly improved group and unchanged group were used as estimates for MID for improvement. Results A total of 129 anchors were analyzed. Subjective evaluations numbered 83 (64%) for unchanged and 33 (26%) for slightly improved. Anchor-based methods yielded estimates for MIDs of -0.43 cm/s in velocity improvement (p Conclusion The present study provides the estimation of MIDs for improving postural stability in BVP patients and may be useful for interpreting whether the results from clinical trials are meaningful in future studies.

CI improves hearing thresholds and auditory skills in children with most types of inner ear malformations. However, the development of sound detection skills is not as good as it is in children without inner ear malformations.To investigate the influence of inner ear malformations on development of auditory skills after cochlear implantation (CI).Records of 20 children with inner ear malformations who underwent cochlear implantation before 4 years of age and followed up for more than 2 years were retrospectively reviewed. Hearing thresholds, the Meaningful Auditory Integration Scale (MAIS), and Meaningful Use of Speech Scale (MUSS) scores before and after CI were analyzed and compared with 20 age-matched deaf children who underwent CI.The children with inner ear malformations showed significant improvements in hearing thresholds and the MAIS and MUSS scores 1 year after CI (p 0.01). However, their development of the MAIS scores was significantly delayed compared to children without inner ear malformations (p 0.05), while there was no significant difference in development of the MUSS scores between them. Significant improvements in hearing thresholds and the MAIS and MUSS scores were observed in cochlear hypoplasia and incomplete partition (p 0.05).

Vertigo attacks in IBV patients involving both the superior and inferior vestibular nerve systems were significantly more severe than vertigo attacks in patients with selective involvement of the inferior vestibular nerve system alone.To investigate the relationship between the frequency and duration of vertigo and the affected vestibular nerve system in idiopathic bilateral vestibulopathy (IBV).This study categorized 44 IBV patients into the following three sub-groups according to the affected vestibular nerve system: superior, inferior, and mixed type. These patients were also categorized into the following three sub-groups according to their clinical time course: progressive type showing no episodes of vertigo, sequential type showing recurrent vertigo attacks and single-attack type showing a single episode of vertigo.Ten, 11 and 23 patients were classified as the superior, the inferior, and the mixed type, respectively. Seventeen, 23, and four patients were classified as the progressive, the sequential, and the single-attack type, respectively. For the patients having one or more vertigo attacks, the duration of the vertigo attack was longer than 24 h in 69% of the mixed type, and the duration of vertigo in the mixed type was significantly longer than that in the inferior type (p 0.05).

Objective Galvanic vestibular stimulation (GVS) delivered as zero-mean current noise (noisy GVS) has been shown to improve static and dynamic postural stability probably by enhancing vestibular information. The purpose of this study was to examine the effect of an imperceptible level noisy GVS on ocular vestibular-evoked myogenic potentials (oVEMPs) in response to bone-conducted vibration (BCV). Materials and methods oVEMPs to BCV were measured during the application of white noise GVS with an amplitude ranging from 0 to 300 µA [in root mean square (RMS)] in 20 healthy subjects. Artifacts in the oVEMPs caused by GVS were reduced by inverting the waveforms of noisy GVS in the later half of the stimulus from the one in the early half. We examined the amplitudes of N1 and N1–P1 and their latencies. Results Noisy GVS significantly increased the N1 and N1–P1 amplitudes (p 0.05). Noisy GVS had facilitatory effects in 79% of ears. The amplitude of the optimal stimulus was 127 ± 14 µA, and it increased the N1 and N1–P1 amplitude by 75.9 ± 15% and 47.7 ± 9.1%, respectively, as compared with 0 µA session (p

We aimed at determining the mitochondrial function in premature senescence model of auditory cells. Short exposure to H2O2 (1 h, 0.1 mM) induced premature cellular senescence in House Ear Institute-Organ of Corti 1 auditory cells. The transmission electron microscopy analysis revealed that damaged mitochondria and autophagosomes containing dense organelles appeared in the auditory cells after short exposure to H2O2. The branch and junction parameters of the skeletonized image of the mitochondria were found to decrease significantly in H2O2-treated cells. A branched reticulum of tubules was poorly formed, featuring coexistence of numerous tiny clusters along with few relatively large entities in the H2O2-treated cells. In terms of bioenergetics, H2O2-treatment led to the dose-dependent decrease in mitochondrial membrane potential in the auditory cells. The fragmented mitochondria (fusion fission) was slightly lower than the control cells. The short-time exposure of live auditory cells to H2O2 damaged the mitochondrial respiratory capacity without any effect on the baseline ATP production rates. The vulnerability of the mitochondrial membrane potential to the uncoupling reagent was increased after H2O2 treatment. Our findings indicated that the mitochondrial dysfunction due to the decline in the O2 consumption rate should be the first event of premature senescence process in the auditory cells, resulting in the imbalance of mitochondrial fusion/fission and the collapse of the mitochondrial network., Auditory system senescence: Mitochondrial dynamics and respiration The mitochondrial morphology and physiology could influence the process of age-related hearing loss. Prof. Tatsuya Yamasoba’s research group at the University of Tokyo has examined the functional changes of mitochondria in terms of its respiratory function, membrane potential and morphology under premature senescence induced by oxidative stress in an auditory cell line. The morphological and functional mitochondrial damage were observed as the respiratory capacity deficiency and the fluctuation of the fusion/fission balance. Their results provide evidence of the fundamental interdependence between mitochondrial metabolic activity and its network structure in premature senescence process of auditory cells. This is a pioneer study to indicate the influence of mitochondrial dynamics and respiratory system on the premature senescence process of auditory cells. Further studies into inter cellular communication including cytoskeleton and nucleus can help us understand the etiology underlying age-related hearing loss.

Vestibular dysfunction causes postural instability, which is prevalent in the elderly. We previously showed that an imperceptible level of noisy galvanic vestibular stimulation (nGVS) can improve postural stability in patients with bilateral vestibulopathy during the stimulus, presumably by enhancing vestibular information processing. In this study, we investigated the after-effects of an imperceptible long-duration nGVS on body balance in elderly adults. Thirty elderly participants underwent two nGVS sessions in a randomised order. In Session 1, participants received nGVS for 30 min twice with a 4-h interval. In Session 2, participants received nGVS for 3 h. Two-legged stance tasks were performed with eyes closed while participants stood on a foam rubber surface, with and without nGVS, and parameters related to postural stability were measured using posturography. In both sessions, the postural stability was markedly improved for more than 2 h after the cessation of the stimulus and tended to decrease thereafter. The second stimulation in Session 1 caused a moderate additional improvement in body balance and promoted the sustainability of the improvement. These results suggest that nGVS can lead to a postural stability improvement in elderly adults that lasts for several hours after the cessation of the stimulus, probably via vestibular neuroplasticity.

Reactive oxygen species (ROS) generation is one of the mechanisms underlying noise-induced hearing loss (NIHL). Manganese superoxide dismutase (Mn-SOD), an antioxidant enzyme acting within the mitochondria, converts toxic superoxide to hydrogen peroxide. We investigated the role of Mn-SOD in NIHL by examining the extent of hearing loss and hair cell damage after noise exposure in C57BL/6 wild-type (WT) mice and Mn-SOD heterozygous knockout (HET) mice (n = 6 each). Both HET and WT mice were exposed to 120 dB sound pressure level at 4 kHz octave band noise for 4 h. Auditory brainstem responses (ABRs) were used to evaluate hearing thresholds before noise exposure, and at 1 h, and 1, 3, 7, and 14 days after exposure. The mice were euthanized 14 days after noise exposure for examination of the cochlear pathology. Mean ABR thresholds were similarly elevated at all frequencies in both groups 1 h after noise exposure, but were significantly worse, particularly at 4 kHz, on post-noise exposure days 7 and 14 in HET mice compared with WT mice. Outer hair cell damage was significantly greater in all cochlear turns in HET mice compared with WT mice. Collectively, these findings suggest that Mn-SOD plays an important role in protecting the cochlea from noise-induced damage.

Reactive oxygen species (ROS) production is involved in several apoptotic and necrotic cell death pathways in auditory tissues. These pathways are the major causes of most types of sensorineural hearing loss, including age-related hearing loss, hereditary hearing loss, ototoxic drug-induced hearing loss, and noise-induced hearing loss. ROS production can be triggered by dysfunctional mitochondrial oxidative phosphorylation and increases or decreases in ROS-related enzymes. Although apoptotic cell death pathways are mostly activated by ROS production, there are other pathways involved in hearing loss that do not depend on ROS production. Further studies of other pathways, such as endoplasmic reticulum stress and necrotic cell death, are required.

Objective:To investigate the clinical features and vestibular symptoms of patients with abnormal ocular vestibular evoked myogenic potentials (oVEMPs) and/or cervical VEMPs (cVEMPs) in the presence of normal caloric responses.Study Design:Retrospective chart review.Setting:Tertiary referral center.Methods:One thousand five hundred twenty-one consecutive patients with balance problems who underwent the caloric, cVEMP, and oVEMP tests were included, and patients who showed abnormal oVEMPs and/or cVEMPs in the presence of normal caloric responses were selected. Clinical characteristics, diagnoses, and vestibular symptoms of the patients were analyzed.Results:Of the 1521 patients, 227 (15%) were found to have abnormal oVEMPs and/or cVEMP responses with normal caloric responses. Benign paroxysmal positional vertigo (BBPV), Meniere’s disease, and vestibular migraine were the common diagnoses of these patients. Eighty-one patients (36%) could not be diagnosed with a recognizable disease. Multiple episodes of spinning vertigo with a duration of seconds to hours were their most common vestibular symptoms.Conclusion:BPPV, Meniere’s disease, and vestibular migraine are the most frequent diagnoses showing abnormal oVEMP and/or cVEMPs without canal paresis. Apart from these clinical entities, a portion of undiagnosed patients with multiple episodes of vertigo might have a disease that involves the otolith organs only.

OBJECTIVE To assess the frequency-domain characteristics of postural instability caused by peripheral vestibular dysfunction by performing a power spectral analysis of the center of pressure (COP) sway during foam posturography. METHODS Data were obtained from 78 patients and 163 controls. Two-legged stance tasks were performed in 4 conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. We estimated the power spectrum of the acceleration signal using the maximum entropy method. The areas under the curve (AUCs) of power spectral density of the COP were calculated across low-frequency (0.02 to 0.1 Hz, LF-AUC), middle-frequency (0.1 to 1Hz, MF-AUC), and high-frequency (1 to 10 Hz, HF-AUC) ranges. We performed binomial logistic regression analyses to see whether the AUCs of selected bandwidths of COP have a stronger association with the presence of peripheral vestibular dysfunction in comparison with the velocity and area in the eyes closed/foam rubber condition. RESULTS In both the controls and patients, the MF-AUC was significantly larger than the LF-AUC or HF-AUC in the eyes closed/foam rubber condition. In this condition, the presence of peripheral vestibular dysfunction had a significantly positive relationship with MF-AUC and HF-AUC (p < 0.05) and the MF-AUC of the anterior-posterior axis showed a stronger association with the presence of peripheral vestibular dysfunction than area. CONCLUSION An increase in activity at middle frequency movements could be characteristic of peripheral vestibular dysfunction when standing on foam rubber with the eyes closed.