Relationship between vestibular schwannoma and endolymphatic hydrops.

BACKGROUND: Both vestibular schwannoma (VS) and Meniere's disease (MD) patients underwent hydrops MRI to clarify the relationship between VS and endolymphatic hydrops (EH). METHODS: Eighty patients with VS or MD underwent an inner ear test battery followed by hydrops MRI, and were then divided into 3 groups. Group A comprised 58 MD patients (62 ears) with positive EH but negative VS. Group B included 18 VS patients (18 ears) with negative EH, while Group C consisted of 4 patients (4 ears) who had VS concomitant with EH. Another 14 MD patients who tested negative for EH on hydrops MRI were initially excluded from this cohort, but were later included for comparison. RESULTS: The decreasing prevalence of EH at the cochlea, saccule and utricle in Group A was identified in 59 (95%), 42 (68%) and 40 (65%) ears, respectively, mimicking a declining sequence of abnormality rates running from audiometry (86%), cervical vestibular-evoked myogenic potential (cVEMP) test (55%) to the ocular (oVEMP) test (53%). However, such decreasing trend was not identified in Groups B and C. In Groups C and A combined, 4 (6%) of 62 EH patients had concomitant VS. Conversely, 4 (18%) of 22 VS patients in Groups C and B combined had concurrent EH. CONCLUSION: A very low (6%) rate of VS in EH patients indicates that VS in EH patients may be coincidental. In contrast, EH was identified in 18% prevalence of VS patients, mirroring the 22% prevalence of cochlear EH demonstrated in VS donors through histopathological studies.

Role of conventional MD staging in modern era of hydrops MR imaging.

Objective/Hypothesis: This study correlated stage of Meniere's disease (MD) with MR imaging of endolymphatic hydrops (EH) to assess the role of MD staging in modern era. Study Design: Retrospective study. Methods: Fifty-four MD patients (60 ears) underwent an inner ear test battery and were further confirmed by MR imaging. Sixty MD ears were divided into stages I-IV, and hydrops MR images at each stage were compared. Results: Hydrops MRI demonstrated that EH at the cochlea with respective Grades 0/I/II were 3/7/1 ears for stage I, 0/5/3 ears for stage II, 1/6/26 ears for stage III and 0/2/6 ears for stage IV. Significant relationship was not identified between MD stage and grades of cochlear hydrops. Similarly, no significant relationship was shown between MD stage and grades of vestibular (saccular/utricular) hydrops. The optimal cutoff value of four-tone average for predicting severe type (Grade II-III) cochlear/vestibular EH was 48 dB, which was within the stage III. Hence, prevalence of severe type (Grade II) cochlear EH in stages III (79%) and IV (75%) was significantly higher than stages I (9%) and II (38%). Similarly, severe type saccular/utricular EH in stages III (64%) and IV (75%) also showed significantly higher than stages I (18%) and II (25%). Conclusion: Although conventional MD staging fails to correlate with the grades of EH on hydrops MRI, late-stage MD may indicate heightened EH severity in the cochlea and vestibule. Level of Evidence: 4.

Potential Application of Hydrops MR Imaging: A Systematic Review.

BACKGROUND: Diagnostic dilemma between clinical Meniere's disease and radiological endolymphatic hydrops (EH) has emerged since the introduction of hydrops magnetic resonance imaging (MRI). The aim of this study is to explore the potential application of hydrops MRI on diagnosing the EH. METHODS: This review was developed from peer-reviewed articles published in those journals listed on journal of citation reports. The MEDLINE database of the US National Library of Medicine, Scopus, and Google Scholar were used to collect articles based on the guidelines (PRISMA 2020 statement) for reporting reviews. RESULTS: Initially, 470 articles were retrieved from 1983 to 2023, and 80 relevant articles were ultimately selected. The sensitivity (69%-92%) and specificity (78%-96%) values varied from each laboratory for detecting EH via hydrops MRI, probably due to candidate selection and the grading system employed. CONCLUSION: The application of hydrops MRI allows (1) differentiation between EH and sudden sensorineural hearing loss; (2) determination of the affected side of EH; and (3) confirmation of the diagnosis of EH concomitant with other disorders. Notably, not all differentials for EH can be visualized on MR images. One of the existing gaps to be filled is that updated hydrops MRI fails to identify distortion, that is, rupture, collapse, fistula, or fibrosis of the inner ear compartments, akin to what histopathological evidence can demonstrate. Hence, enhanced ultrahigh resolution of hydrops MRI is required for demonstrating fine structures of the inner ear compartments in the future.

Red flags alerting a posterior cranial fossa tumor from audiovestibular perspectives - a review.

BACKGROUND: There is no comprehensive and up-to-date overview of audiovestibular approach to the posterior fossa tumors in the literature. OBJECTIVE: This paper reviewed the literature relating to tumors at the posterior cranial fossa to find red flags alerting a posterior fossa lesion from audiovestibular perspectives. METHODS: This review was developed from articles published in those journals listed on the journal citation reports. Through the PubMed database, Embase, Google Scholar, and Cochrane library, 60 articles were finally obtained based on the PRISMA guidelines for reporting reviews. RESULTS: The presence of one red flag indicates a positive predictive value of 33% for detecting a posterior fossa lesion. Clinical features, namely, 1) mid-frequency sudden sensorineural hearing loss (SNHL), 2) bilateral sudden SNHL, and 3) rebound nystagmus may indicate a posterior fossa lesion, representing one, two, and three red flags, respectively. CONCLUSION: Those with 1) mid-frequency sudden SNHL, 2) bilateral sudden SNHL, and 3) rebound nystagmus trigger one, two, and three red flags, respectively, alerting clinicians the possibility of a posterior fossa lesion, which warrant MR imaging to exclude life-threatening or treatable conditions. SIGNIFICANCE: Patients with posterior fossa tumors may have potential life-threatening outcome.

Effect of long-term betahistine treatment on the clinical outcomes of patients with cochlear Meniere's disease.

BACKGROUND: Many studies have discussed the betahistine treatment for Meniere's disease (MD). However, regarding cochlear MD, there is no consensus on the long-term betahistine treatment. AIMS/OBJECTIVES: This study aims to investigate the relationship between the betahistine treatment duration in patients with cochlear MD and their clinical outcomes. MATERIAL AND METHODS: We enrolled 78 patients with 96 ears who were diagnosed with cochlear MD and received the treatment for more than 6 months. Outcomes included the hearing status, frequency of acute hearing loss attack, and whether the disease progressed to MD. Clinical characteristics including age, sex, side of affected ear, treatment duration of betahistine and trichlormethiazide, and pre-treatment hearing level was recorded from medical charts. RESULTS: Comparing the clinical characteristics by outcomes, the average betahistine treatment duration was the independent factor for hearing status of four-tone average (p = 0.01) and low-tone average (p = 0.03). Patients with average betahistine treatment duration of at least 277 days per year had higher odds ratio for improvement of the hearing status of four-tone and low-tone average. CONCLUSIONS: For patients with cochlear MD, regular and long-term betahistine treatment can benefit their hearing outcome in the low- and medium-frequency.