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.

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.

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.

Limitation of updated MR images on the vestibular hydrops in Meniere's disease.

PURPOSE: This study adopted the cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) tests in Meniere's disease (MD) patients to correlate them with vestibular endolymphatic hydrops (EH) on MR images. METHODS: A total of 25 patients with unilateral definite MD identified by positive cochlear hydrops on MR images were enrolled. All patients underwent audiometry, cVEMP test and oVEMP test, followed by MR imaging for confirmation. RESULTS: A significantly declining sequence of abnormality rates in MD patients was identified from the audiometry (92%), cVEMP test (52%) to the oVEMP test (40%), which was consistent with a significantly decreasing order of prevalence of EH on MR images running from the cochlea (100%), saccule (56%) to the utricle (52%). The cVEMP test for detecting the saccular hydrops revealed a sensitivity of 62%, while the oVEMP test for assessing the utricular hydrops showed a sensitivity of 70%. However, correlating VEMP results with vestibular hydrops did not show any significant relationship. In addition, mean hearing level (MHL) at four frequencies (500, 1000, 2000, and 3000 Hz) of Grade I cochlear hydrops (51 ± 19 dB) did not significantly differ from Grade II cochlear hydrops (53 ± 19 dB). CONCLUSION: Limitations of the updated MR imaging for visualizing the hydrops comprised: (1) failure to correlate vestibular hydrops with VEMP results, and (2) failure to correlate grade of cochlear hydrops with MHL. The reason is probably because updated MR imaging fails to identify distorted contour of the cochlea/utricle/saccule. Further advanced technique using ultrahigh resolution of fine structures in the inner ear compartments is essential to promote a wider use of MR imaging.

Post-irradiation endolymphatic hydrops vs. post-irradiation sudden deafness.

BACKGROUND: Increasing numbers of acute sensorineural hearing loss (SNHL) are recently experienced in irradiated nasopharyngeal carcinoma (NPC) survivors. AIM: This study adopted MR imaging to differentiate between post-irradiation sudden deafness (PISD) and post-irradiation endolymphatic hydrops (PIEH) in long-term NPC survivors with acute SNHL. METHODS: From 2012 to 2021, consecutive 10 irradiated NPC survivors with acute SNHL were enrolled. All patients underwent an inner ear test battery and MR imaging using HYDROPS-Mi2 technique. Six patients (11 ears) with positive cochlear hydrops on MR images were diagnosed as PIEH, while another 4 patients (4 ears) without cochlear hydrops on MR images were referred to PISD. RESULTS: The interval from the onset of NPC to acute SNHL did not significantly differ between the PIEH (10 ± 6 years) and PISD (8 ± 2 years). No significant difference was found between the two disorders from any of the symptomatic, radiotherapeutic, audiological, or vestibular perspective. Interestingly, most (5/6) patients with PIEH had bilateral involvement, while all (4/4) patients with PISD showed unilateral affliction. A significantly declining sequence of abnormality rates in the inner ear test battery was noted in the PIEH patients, running from the audiometry (100%), cervical vestibular-evoked myogenic potential (VEMP) test (100%), ocular VEMP test (73%), to the caloric test (36%). However, such declining trend was not observed in patients with PISD. CONCLUSION: When facing an NPC survivor who had acute SNHL over a prolonged period after irradiation, MR imaging using HYDROPS-Mi2 technique should be performed to differentiate the PIEH from the PISD, since both disorders have various treatment modalities and hearing outcome.

Evaluation of retrootolithic function using galvanic vestibular-evoked myogenic potentials in patients with benign paroxysmal positional vertigo.

PURPOSE: The purpose is to investigate possible vestibulopathy in patients with benign paroxysmal positional vertigo (BPPV), inner ear tests, including cervical and ocular vestibular-evoked myogenic potentials (cVEMPs and oVEMPs) via various stimulation modes, were adopted. METHODS: Fifty BPPV patients were enrolled in this study. All patients underwent pure tone audiometry, cVEMPs, oVEMPs, and caloric tests. The recurrence status, abnormal rates of inner ear tests, and the characteristic parameters of VEMPs, such as wave latencies and amplitudes, were analyzed. RESULTS: In affected ears, the abnormal rates of acoustic cVEMPs, vibratory oVEMPs, galvanic cVEMPs, and galvanic oVEMPs were 62%, 28%, 36%, and 14%, respectively. The abnormalities of acoustic cVEMPs were significantly larger than those of vibratory oVEMPs, and acoustic/vibratory VEMPs had significantly higher abnormal rates than the corresponding galvanic VEMPs. CONCLUSION: BPPV patients may have both otolithic and neural dysfunctions. Otolithic organ damage occurs more frequently than retrootolithic neural degeneration, and the saccular macula might have a greater extent of damage than the utricular macula.

Evolution of incidence of audiovestibular disorders during the pandemic COVID-19 period.

PURPOSE: Despite sporadic case reports describing hearing problems in patients with coronavirus disease 2019 (COVID-19), whether COVID-19 affects the audiovestibular system remains unclear. This study assessed the evolution of incidence of audiovestibular disorders during the pandemic COVID-19 period. METHOD: Three audiovestibular disorders namely, sudden sensorineural hearing loss (SSHL), autonomic dysfunction, and Meniere's disease (MD) were analyzed and compared from 2016 to 2020. RESULTS: The annual new cases at our clinic comprised overall 2107, 1997, 1984, 2068, and 1829 from 2016 to 2020, respectively, and the respectively annual cases of SSHL were 54, 46, 42, 45 and 38. Accordingly, annual incidences of SSHL in relation to overall cases of audiovestibular disorders were 2.6%, 2.3%, 2.1%, 2.2% and 2.1% from 2016 to 2020, respectively, exhibiting a non-significant difference (p > 0.05). In contrast, incidence of autonomic dysfunction in the year 2020 was 15.3%, which revealed significantly higher than 8.5-13.1% from 2016 to 2019 (p < 0.001). Restated, the incidence of autonomic dysfunction in 2020 displayed a significantly higher percentage than the other 4 years. Conversely, the incidence of MD in 2020 was 9.8%, showing a significant decline compared with the other 4 years (12.6-15.6% from 2016 to 2019, p < 0.001), CONCLUSION: Evolution of incidence of audiovestibular disorders during the pandemic COVID-19 period revealed increase in the incidence of autonomic dysfunction and decrease in that of MD, while incidence of SSHL remained unchanged from 2016 to 2020. Thus, the SARS-CoV-2 may less affect the audiovestibular system.

Geriatric sudden deafness.

PURPOSE: Sudden sensorineural hearing loss, briefly sudden deafness (SD), in the elderly remains less investigated despite rapidly aging population in most countries around the world. This study investigated whether aging process affects the treatment outcome of SD in the elderly. PATIENTS AND METHODS: Eighty patients with SD, comprising 40 geriatric patients aged >65 years and 40 non-geriatric patients aged 55-64 years, were enrolled in this study. All patients underwent an inner ear test battery including audiometry, and cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), and caloric tests. RESULTS: Pre-treatment mean hearing level in the geriatric group (94 ± 16 dB) did not significantly differ from non-geriatric group (89 ± 20 dB). After treatment for 3 months, mean hearing gain in the geriatric group (22 ± 18 dB) with an improvement rate of 65%, did not significantly differ from non-geriatric group (21 ± 28 dB) with 58% improvement rate. Both inter-subject and intra-subject analyses revealed that the aging process greatly influenced the cVEMP and oVEMP responses, while less influenced the caloric responses. CONCLUSION: The treatment outcome of SD in geriatric patients aged >65 years did not significantly differ from that in non-geriatric patients aged 55-64 years, indicating that aging process did not affect treatment outcome of SD. Unlike treatment outcome for the presbycusis is unsatisfactory, treatment outcome for the elderly with SD could be favorable.

Comorbidity of cerebellopontine angle meningioma with other primary neoplasms.

BACKGROUND: Meningioma is known to be accompanied by other primary neoplasms, yet has been evaluated less than these. OBJECTIVE: This study investigated comorbidity of cerebellopontine angle (CPA) meningioma with other primary neoplasms. METHODS: Overall 1,085 meningioma cases including 16 meningiomas at the CPA were enrolled for investigating the presence of other primary neoplasms. Another 16 age-, sex-, and size-matched CPA schwannoma were also included for comparison. RESULTS: Of a data-base cohort study of overall 1085 meningioma cases, 165 cases (15%) were associated with other primary neoplasms. In contrast, 8 (50%) of 16 CPA meningioma and one (8%) of 16 CPA schwannoma showed other primary neoplasms. Except for one patient who had oral cancer prior to the diagnosis of CPA meningioma by 4 years, the interval from diagnosis of CPA meningioma to that of other primary neoplasm ranged 0-6 (mean, 3.1 ± 2.5) years. CONCLUSION: Prevalence of comorbidity with other primary neoplasms is significantly higher in CPA meningioma (50%) than overall meningioma (15%) and CPA schwannoma (8%). In addition to follow-up MR imaging to visualize both residual tumor and regional brain environment after treatment of CPA meningioma, long-term systemic screening for other primary neoplasm is also mandatory.

Contemporary review of the causes and differential diagnosis of sudden sensorineural hearing loss.

Objectives: This article provides an overview of the causes and differential diagnosis of sudden deafness (SD) and sudden sensorineural hearing loss (SSHL).Design: Contemporary review.Study sample: This review is based on peer-reviewed articles published in those journals listed on journal of citation reports. Through the PubMed database of the US National Library of Medicine, Scopus, and Google Scholar using the keywords of "sudden deafness", "acute hearing loss", and "sudden sensorineural hearing loss", totally 1493 papers were considered and 166 relevant papers were selected.Results: Sensorineural hearing loss of sudden onset may be classified as primary SD and secondary SSHL. Proposed aetiologies of primary SD comprised viral infection, vascular insufficiency, autoimmune disorder and stress theory, while causes of secondary SSHL include neoplasm, stroke and irradiation.Conclusion: SD/SSHL is a syndrome that comprises various entities, and results from a variety of aetiologies. An inner ear test battery in SD/SSHL patients helps determine its aetiology, and provides comprehensive information on the affected territory. Identification of the cause and differential diagnosis of the different types of SD/SSHL may provide substantial benefits such as determining the prognosis, identifying associated risk factors and preventing further hearing loss.

Acute sensorineural hearing loss in patients with vestibular schwannoma early after cyberknife radiosurgery.

OBJECTIVE: This study reviewed our experience in treating patients with vestibular schwannoma (VS) who had acute sensorineural hearing loss (ASHL) early after radiosurgery. PATIENTS AND METHODS: Seventy VS patients underwent cyberknife radiosurgery. Of them, 6 patients had ASHL early (<6 m) after radiosurgery (Group A), accounting for 8.6% prevalence. The remaining 64 patients without ASHL were assigned to Group B. Another 10 VS patients with tiny tumor and serviceable hearing adopted observation policy (Group C). All patients underwent a test battery for inner ear function, and tumor size was measured via MR imaging. RESULTS: The mean hearing level of Group A was 39 ±â€¯16 dB before radiosurgery, which deteriorated to 67 ±â€¯14 dB at the onset of ASHL after radiosurgery. Three months after treatment for ASHL, hearing improvement was noted in only one patient (17%). Mean tumor volumes of Group A before and after ASHL were 1.54 ±â€¯1.48 cc and 1.33 ±â€¯1.04 cc, respectively, showing non-significant difference. Receiver operating characteristic curve analysis revealed that the optimal cutoff value for tumor size was 1.45 cm for predicting absence of ASHL, with a sensitivity of 96% and a specificity of 67%. In contrast, Group C with mean tumor size of 0.64 ±â€¯0.15 cm adopted observation policy, and none of them had ASHL two years after diagnosis. CONCLUSION: Prevalence of ASHL in VS patients early after radiosurgery is 8.6%, likely due to radiation injury to the cochlear nerve. Thus, when tumor size is <1.45 cm, serviceable hearing is the criteria for determining whether observation policy (with serviceable hearing) or radiosurgery (lack of serviceable hearing) is given. For those tumor sizes ranged 1.45-3.0 cm, radiosurgery is indicated regardless of hearing level.

Irradiated ears in nasopharyngeal carcinoma survivors: A review.

This article reviews the literature on otological complications in nasopharyngeal carcinoma (NPC) survivals after irradiation during the past three decades. Symptoms of the irradiated ears were assessed from the external ear canal, through the middle ear cavity including the Eustachian tube, and to the inner ear compartments. The development of radioimaging diagnostic techniques, the introduction from adjuvant chemotherapy to concurrent chemoradiotherapy, and the invention of radiotherapeutic equipment to intensity-modulated radiotherapy (IMRT) have increased the survival rate of NPC patients during the past 30 years. The prevalence of cochlear and vestibular deficits has decreased a lot, whereas middle ear complications (i.e., otitis media with effusion and radiation-induced otitis media) do not decline in NPC survivors even in the IMRT era, probably because the medial half of the Eustachian tube receives > 95% of the total dose despite 2DRT or IMRT. Laryngoscope, 129:637-642, 2019.

N-acetylcysteine as a single therapy for sudden deafness.

CONCLUSION: Like NAC ameliorates hearing loss from acoustic trauma in the inner ear, NAC may also rescue hearing loss from sudden deafness confined to the inner ear. OBJECTIVE: This study assesses the effect of N-acetyl-L-cysteine (NAC) as a single therapy for sudden deafness. METHODS: Thirty-five sudden deafness patients with neither systemic disorders nor central signs in electronystagmography were treated with NAC alone and assigned to Group A. For comparison, another 35 sudden deafness patients treated by corticosteroids and plasma expander were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and pre-treatment mean hearing level. All patients underwent an inner ear test battery comprising audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests. RESULTS: Groups A and B did not significantly differ in the pre-treatment mean hearing level, and percentages of abnormal oVEMP, cVEMP, and caloric tests, indicating that the involvement severity of sudden deafness between the two groups was similar. However, Group A (43 ± 27 dB) showed significantly greater mean hearing gain than Group B (21 ± 28 dB), and Group A (91%) revealed better improved rate of hearing than Group B (57%).

Assessing residual vestibular function in adults with congenital hearing loss.

This study adopted an inner ear test battery in adults with congenital hearing loss to assess residual vestibular function. Thirty patients with non-inherited non-syndromatic congenital hearing loss were assigned to two groups based on their pure tone average (PTA). Subjects in Group A (n = 10) had PTA >90 dB, and those with PTA ≤90 dB were assigned to Group B (n = 20). All patients underwent audiometry, and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP) and caloric tests. Percentages of abnormal PTA, and cVEMP, oVEMP, and caloric test results showed a significantly sequential decline in inner ear deficits from the cochlea to the saccule, utricle, and semicircular canals. Group A had significantly higher percentages of absent oVEMP and caloric areflexia than Group B. Via receiver operating characteristic curve analysis, the cutoff value of PTA was 65 dB for discriminating between present and absent oVEMP/caloric responses, with a sensitivity of 71 % and a specificity of 88 %. In conclusion, congenitally deaf patients with PTA ≥65 dB may retain less vestibular function than those with PTA <65 dB, as evidenced by higher percentages of absent oVEMP and caloric areflexia. Hence, comprehensive assessment of the residual vestibular function in congenitally deaf patients may help predict the occurrence of vertigo in the future.