Difference in the immediate effect on positional nystagmus for head positions with interval time during Epley maneuver: a randomized trial.

OBJECTIVES: The Epley maneuver (EM) shows immediate effect, wherein disappearance of positional nystagmus occurs soon after the EM. Our previous study showed that setting interval times during the EM reduced the immediate effect. The purpose of this study is to identify the head position for which interval time reduces the immediate effect. METHODS: Fifty-one patients with posterior canal type of benign paroxysmal positional vertigo (BPPV) were randomly assigned to the following three groups: 10 min interval time set at the first head position of the EM in group A, at the third head position in group B, and at the fourth head position in group C. The primary outcome measure (POï¼­) was the ratio of maximum slow-phase eye velocity of positional nystagmus soon after the EM, compared with that measured before the EM. A large ratio value indicates a poor immediate effect of the EM. RESULTS: The POï¼­ in group A (0.07) was smallest (B: 0.36, C: 0.49) (p < 0.001). DISCUSSION: The interval times at the third and fourth head positions reduced the immediate effect of the EM. Our previous study showed that the effect of BPPV fatigue is continued by maintaining the first head position of the EM. BPPV fatigue constitutes fatigability of positional nystagmus with repeated performance of the Dix-Hallpike test. Our findings may be interpreted in accordance with the theory that the immediate effect of the EM is BPPV fatigue itself, because we observed that the effect of BPPV fatigue is strongest in group A.

Stratification of patients with Menière's disease based on eye movement videos recorded from the beginning of vertigo attacks and contrast-enhanced MRI findings.

Purpose: Diagnosis of Menière's disease (MD) relies on subjective factors and the patients diagnosed with MD may have heterogeneous pathophysiologies. This study aims to stratify MD patients using two objective data, nystagmus videos and contrast-enhanced magnetic resonance imaging (CE-MRI). Methods: This is a retrospective cross-sectional study. According to the Japan Society for Equilibrium Research criteria (c-JSER), adults diagnosed with definite MD and who obtained videos recorded by portable nystagmus recorder immediately following vertigo attacks and underwent CE-MRI of the inner ear were included (ss = 91). Patients who obtained no nystagmus videos, who had undergone sac surgery, and those with long examination intervals were excluded (n = 40). Results: The gender of the subjects was 22 males and 29 females. The age range was 20-82 y, with a median of 54 y. Endolymphatic hydrops (EH) were observed on CE-MRI in 84% (43 patients). Thirty-one patients had unilateral EH. All of them demonstrated EH on the side of the presence of cochlear symptoms. The number of patients who had both nystagmus and EH was 38. Five patients only showed EH and 5 patients only exhibited nystagmus, while 3 patients did not have either. Of the 43 nystagmus records, 32 showed irritative nystagmus immediately after the vertigo episode. The direction of nystagmus later reversed in 44% of cases over 24 h. Conclusion: Patients were stratified into subgroups based on the presence or absence of EH and nystagmus. The side with cochlear symptoms was consistent with EH. The c-JSER allows for the diagnosis of early-stage MD patients, and it can be used to treat early MD and preserve hearing; however, this approach may also include patients with different pathologies.

The effect of cochlear implants on cognitive function in older adults: A prospective, longitudinal 2-year follow-up study.

OBJECTIVES: It is shown that eliminating hearing loss in mid-life may reduce the risk for deterioration in cognitive function. Cochlear implantation (CI) is the only available therapy that can eliminate hearing loss in patients who suffer from profound sensorineural hearing loss. This suggests there may be positive effects of hearing level on cognition in older adults following CI. Therefore, the purpose of this study is to clarify whether cognitive function can be improved or maintained using cochlear implants in older adult patients with hearing impairments. METHODS: Data for patients that underwent CI surgery for profound bilateral sensorineural hearing loss were collected prospectively. Patients aged 65 years and older were recruited at our university hospital from 2013 to 2017. Twenty-one patients (age range: 65-80 years) were included in this study. The primary outcome measurement was the change in cognitive function three points assessed by Mini-Mental State Examination (MMSE): preoperatively, and at 1 and 2 years after surgery. The secondary outcome measurements were the followings; the Nijmegen Cochlear Implant Questionnaire (NCIQ), the Self-Rating Depression Scale (SDS), and hearing and speech recognition threshold assessment before CI, and 1 and 2 years after CI. Differences in MMSE scores were compared for statistical significance using the Friedman test. The Wilcoxon signed-rank test was used as a post hoc test. Possible correlations between MMSE scores and NCIQ subdomain scores 2 years after surgery were evaluated with Spearman's tests. Statistical significance was defined as a p-value <0.05. RESULTS: CI recipients showed significant improvement in MMSE scores. This improvement peaked 1 year after CI surgery. The postoperative MMSE score was correlated with the NCIQ speech production score but not with the other five NCIQ subdomains. There was no correlation between MMSE score and speech recognition. CONCLUSION: Speech production is important to improve cognitive function after CI, and this improvement peaked 1 year after CI. Although severe or profound hearing loss in older adults worsens the natural course of cognitive function decline, CI has positive impacts on cognitive function even if MMSE scores decrease 1 year after the peak (i.e., 2 years after CI). Talking with others based on hearing is crucial to improve cognitive function. We should encourage older adult patients to take many opportunities to talk with others after CI surgery.

Vestibular Compensation after Vestibular Dysfunction Induced by Arsanilic Acid in Mice.

When vestibular function is lost, vestibular compensation works for the reacquisition of body balance. For the study of vestibular dysfunction and vestibular compensation, surgical or chemical labyrinthectomy has been performed in various animal species. In the present study, we performed chemical labyrinthectomy using arsanilic acid in mice and investigated the time course of vestibular compensation through behavioral observations and histological studies. The surgical procedures required only paracentesis and storage of 50 µL of p-arsanilic acid sodium salt solution in the tympanic cavity for 5 min. From behavioral observations, vestibular functions were worst at 2 days and recovered by 7 days after surgery. Spontaneous nystagmus appeared at 1 day after surgery with arsanilic acid and disappeared by 2 days. Histological studies revealed specific damage to the vestibular endorgans. In the ipsilateral spinal vestibular nucleus, the medial vestibular nucleus, and the contralateral prepositus hypoglossal nucleus, a substantial number of c-Fos-immunoreactive cells appeared by 1 day after surgery with arsanilic acid, with a maximum increase in number by 2 days and complete disappearance by 7 days. Taken together, these findings indicate that chemical labyrinthectomy with arsanilic acid and the subsequent observation of vestibular compensation is a useful strategy for elucidation of the molecular mechanisms underlying vestibular pathophysiologies.

Clinical significance of cervical and ocular vestibular evoked myogenic potentials in benign paroxysmal positional vertigo: a meta-analysis.

PURPOSE: As the pathological cause of benign paroxysmal positional vertigo (BPPV), the dislocation or degeneration of otoconia in the utricle and saccule is suggested. Vestibular evoked myogenic potential (VEMP) could reflect otolithic dysfunction due to these etiologies of BPPV. The aim of this study was to validate the clinical significance of cervical (c) and ocular (o) VEMP in BPPV by a meta-analysis of previous articles. METHODS: Articles related to BPPV with data on cVEMP and oVEMP were collected. The following keywords were used to search PubMed and Scopus for English language articles: benign paroxysmal positional vertigo or BPPV and vestibular evoked myogenic potential or VEMP. RESULTS: The p13 latency in cVEMP and n1 latency in oVEMP were slightly but significantly prolonged in BPPV patients compared to control patients. AR in oVEMP of BPPV patients also showed higher value than that of control patients. However, the n23 latency and AR in cVEMP and p1 latency in oVEMP showed no significant difference between BPPV and control patients. Furthermore, latencies in VEMPs also showed no significant difference between an affected and a non-affected ear in BPPV patients. CONCLUSIONS: Our results indicated that otolith dysfunction of BPPVs was detected by latencies in VEMPs, and AR in oVEMP more sensitively reflects the difference between affected and non-affected ears in BPPV patients. The otolith dysfunction of BPPV might be induced by the systemic condition. However, the differences of latencies between BPPV patients and control patients were too small to use VEMPs as a prognostic predictor.

Osteoclasts Modulate Bone Erosion in Cholesteatoma via RANKL Signaling.

Cholesteatoma starts as a retraction of the tympanic membrane and expands into the middle ear, eroding the surrounding bone and causing hearing loss and other serious complications such as brain abscess and meningitis. Currently, the only effective treatment is complete surgical removal, but the recurrence rate is relatively high. In rheumatoid arthritis (RA), osteoclasts are known to be responsible for bone erosion and undergo differentiation and activation by receptor activator of NF-κB ligand (RANKL), which is secreted by synovial fibroblasts, T cells, and B cells. On the other hand, the mechanism of bone erosion in cholesteatoma is still controversial. In this study, we found that a significantly larger number of osteoclasts were observed on the eroded bone adjacent to cholesteatomas than in unaffected areas, and that fibroblasts in the cholesteatoma perimatrix expressed RANKL. We also investigated upstream transcription factors of RANKL using RNA sequencing results obtained via Ingenuity Pathways Analysis, a tool that identifies relevant targets in molecular biology systems. The concentrations of four candidate factors, namely interleukin-1ß, interleukin-6, tumor necrosis factor α, and prostaglandin E2, were increased in cholesteatomas compared with normal skin. Furthermore, interleukin-1ß was expressed in infiltrating inflammatory cells in the cholesteatoma perimatrix. This is the first report demonstrating that a larger-than-normal number of osteoclasts are present in cholesteatoma, and that the disease involves upregulation of factors related to osteoclast activation. Our study elucidates the molecular basis underlying bone erosion in cholesteatoma.

Effects of cochlear implants on otolith function as evaluated by vestibulo-ocular reflex and vestibular evoked myogenic potentials.

OBJECTIVE: The aim of this study was to investigate whether the insertion of an implant into the cochlea is accompanied by a deterioration in otolith function. Cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) and linear vestibulo-ocular reflex (lVOR) during eccentric rotation were assessed before and after cochlear implantation (CI) to evaluate otolith function. METHODS: Twelve patients with bilateral severe sensorineural hearing loss who had undergone CI surgery in our hospital between May 2016 and November 2017 were included in this study. cVEMP and oVEMP were assessed using the asymmetry ratio (AR), calculated with the following formula: [(peak-to-peak amplitude calculated as the sum of the p13 and n23 amplitudes in the non-operated side) - (that in the operated side)]/[(that in the non-operated side) + (that in the operated side)]. The ratio of VOR gain during eccentric rotation against VOR gain during center rotation was used to assess lVOR. For eccentric rotation, patients were rotated while displaced from the axis of rotation. At the same time, linear acceleration stimulated the utricle and induced lVOR. All patients underwent cVEMP and oVEMP tests and center and eccentric rotation tests before and about 30days after CI surgery. RESULTS: Three patients with absent cVEMP responses before surgery were excluded, leaving pre-surgery cVEMP results for 9/12 patients. In five of these patients, the AR of cVEMP increased after CI, indicating that saccular function, as evaluated by cVEMP, did not deteriorate significantly postoperatively. One patient with an absent oVEMP response before CI was excluded, leaving pre-surgery oVEMP results for 11/12 patients. In 10 of these patients, the AR of oVEMP increased after CI surgery, indicating that utricular function, as evaluated by oVEMP, deteriorated significantly postoperatively. However, because the ratio of VOR gain during eccentric rotation against VOR gain during center rotation did not become worse after CI, utricular function, as evaluated by lVOR, did not deteriorate significantly postoperatively. Symptoms of vertigo became worse after CI in two of the 12 patients. CONCLUSION: CI does not cause a deterioration in saccular function, as evaluated by cVEMP. Although CI does cause a deterioration in utricular function in oVEMP tests, this is not consistent in lVOR tests. These results indicate that CI causes a slight deterioration in utricular function that is insufficient to cause vertigo or deterioration of lVOR.

Change in endolymphatic hydrops 2 years after endolymphatic sac surgery evaluated by MRI.

OBJECTIVE: This study was performed to determine whether endolymphatic sac surgery improves vestibular and cochlear endolymphatic hydrops 2 years after sac surgery and to elucidate the relationship between the degree of improvement of endolymphatic hydrops and the changes in vertigo symptoms, the hearing level, and the summating potential/action potential ratio (-SP/AP ratio) by electrocochleography (ECochG) in patients with Ménière's disease (MD). METHODS: Twenty-one patients with unilateral MD who underwent sac surgery were included in this study. All patients underwent gadolinium-enhanced magnetic resonance imaging (Gd-MRI) before and 2 years after sac surgery. We evaluated the difference in vestibular and cochlear endolymphatic hydrops between before and after surgery in both ears and compared these findings with the frequency of vertigo attacks, hearing level, and ECochG findings. RESULTS: In affected ears, the presence of vestibular endolymphatic hydrops and the frequency of vertigo attacks significantly decreased after surgery. However, affected ears showed no significant improvement in the presence of cochlear endolymphatic hydrops or the -SP/AP ratio by ECochG; there was also no significant improvement or deterioration in the hearing level. CONCLUSION: The present findings suggest that sac surgery reduces vestibular endolymphatic hydrops and prevents aggravation of cochlear endolymphatic hydrops, and these changes lead to a reduction of vertigo attacks and suppress the progression of hearing impairment associated with vertigo attacks.

Recovery of positional nystagmus after benign paroxysmal positional vertigo fatigue.

PURPOSE: In benign paroxysmal positional vertigo (BPPV), positional nystagmus is generally weaker when the Dix-Hallpike test is repeated. This phenomenon is known as BPPV fatigue. The positional nystagmus induced by the Dix-Hallpike test can be observed again when time has passed. There has been no study regarding the length of time required to recover the positional nystagmus. The purpose of this study was to examine whether positional nystagmus recovers within 30 min after the disappearance of the nystagmus by BPPV fatigue. METHODS: This was a prospective observational study. Twenty patients with posterior canal type of BPPV (canalolithiasis of the posterior canal) were included. Dix-Hallpike tests were performed three times for each patient. A second Dix-Hallpike test was performed immediately after the first Dix-Hallpike test. A third Dix-Hallpike test was performed 30 min after the second Dix-Hallpike test. We recorded positional nystagmus induced by the Dix-Hallpike tests and analyzed maximum slow-phase eye velocity (SPEV) of the positional nystagmus. RESULTS: The average maximum SPEV of positional nystagmus induced by the second Dix-Hallpike test (4.8°/s) was statistically lower than that induced by the first Dix-Hallpike test (48.0°/s); this decrease was caused by BPPV fatigue. There was no statistical difference between average maximum SPEV of positional nystagmus induced by the first Dix-Hallpike test and that induced by the third Dix-Hallpike test (41.6°/s); this indicates that the effect of BPPV fatigue disappeared. The effect of BPPV fatigue disappears within 30 min. CONCLUSIONS: A second Dix-Hallpike test should be performed at least 30 min after the first.

A high jugular bulb and poor development of perivestibular aqueductal air cells are not the cause of endolymphatic hydrops in patients with Ménière's disease.

OBJECTIVE: The presence of endolymphatic hydrops in the inner ear, which can be detected with gadolinium-enhanced magnetic resonance imaging (Gd-MRI), is widely recognized as the main pathological cause of Ménière's disease (MD). However, the precise mechanisms underlying the development of endolymphatic hydrops remains unclear. One hypothesis proposes a relationship between the presence of a high jugular bulb (HJB) and MD, which disrupts the vestibular aqueduct leading to the development of endolymphatic hydrops. This study sought to identify anatomical features in MD patients using computed tomography (CT) images of the temporal bone. METHODS: Fifty-nine MD patients meeting the AAO-HNS diagnostic criteria and exhibiting endolymphatic hydrops in Gd-MRI were enrolled between July 2009 and December 2015. We only included MD patients who showed unilateral endolymphatic hydrops in Gd-MRI. Sixty-six patients with otosclerosis or facial palsy were also enrolled as control participants. In both groups, patients with other pathologies (e.g., chronic otitis media or cholesteatoma) and patients <16years old were excluded. HJB was defined as a JB that was observable in the axial CT image at the level where the round window could be visualized. JB surface area was measured on the axial image at the level where the foramen spinosum could be visualized. Finally, to investigate the relationship between the pneumatization of perivestibular aqueductal air cells and the existence of endolymphatic hydrops, the development of the air cells was rated using a three-grade evaluation system and the distance between the posterior semicircular canal (PSCC) and the posterior fossa dura was measured. RESULTS: The presence of HJB was observed in 22 of 59 affected sides of MD patients and in 17 healthy sides. The likelihood that HJB was detected on an affected side (22/39) was not significantly above chance (50%). The HJB detection rate did not significantly differ between the three groups (MD affected side, MD healthy side, and control patients). Furthermore, there were no significant group differences in JB surface area, distance between the PSCC and posterior fossa dura, or the development of perivestibular aqueductal air cells. CONCLUSION: We did not find any relationship between the anatomy of the temporal bones and the existence of endolymphatic hydrops. Moreover, we found no evidence suggesting that HJB or poor development of perivestibular aqueductal air cells were the cause of endolymphatic hydrops in MD patients.