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Objectives/hypothesis: To establish the prevalence of abnormal vestibular test findings in children with enlarged vestibular aqueduct (EVA) and determine if these findings correlate with clinical symptoms, radiographic findings (EVA size and laterality), audiometric findings, and genetic testing in these patients., Study Design: Prospective cohort., Methods: Patients 3 to 12 years of age with hearing loss and imaging findings consistent with EVA treated at our tertiary care institution were sequentially enrolled from 2009 to 2011. The following six outcome measurements were analyzed: audiometric findings, EVA laterality, temporal bone measurements, genetic testing, vestibular testing (cervical-evoked myogenic potentials, posturography, rotational chair, and calorics), and vestibular symptoms., Results: Twenty-seven patients with EVA (mean age 9.2 years, 48% female) were enrolled in and completed the study. Vertigo was reported in six patients. Twenty-four of 27 (89%) had at least one abnormal vestibular test result. Midpoint and operculum size correlated with directional preponderance (P = .042 and P = .032, respectively). Also, high-frequency pure tone average (HFPTA) correlated with unilateral weakness (P = .002). Walking at a later age correlated with abnormal posturography results. There was no correlation between EVA laterality and vestibular test findings., Conclusion: We found a high rate of vestibular pathology in children with EVA; however, the prevalence of abnormal vestibular test findings in this patient population was not correlated with vestibular symptoms. Enlarged vestibular aqueduct size, HFPTA, and walking at a later age were correlated with abnormal vestibular test findings. In view of these results, it may be prudent to consider vestibular testing in children with these clinical characteristics., Level of Evidence: 2b. Laryngoscope, 126:2344-2350, 2016., (© 2016 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: Pathologic third window lesions, such as superior semicircular canal dehiscence syndrome (SCDS) or large vestibular aqueduct syndrome (LVAS), cause several auditory and vestibular symptoms, which might affect perilymphatic pressure and induce endolymphatic hydrops (EH). In this study, the existence of EH in subjects with SCDS or LVAS was investigated using contrast-enhanced magnetic resonance imaging (MRI)., Study Design: Case series at university hospital., Methods: Seventeen ears from nine subjects who were diagnosed as having SCDS (five ears from three cases) or LVAS (12 ears from six cases) were studied. Ears were evaluated by 3-T MRI performed 4 hours after intravenous injection of gadodiamide hydrate. Imaging data concerning the degree of EH in the cochlea and the vestibule were compared with clinical symptoms and hearing levels for all ears., Results: All ears showed air-bone gaps at low frequencies on pure tone audiometry. None of the subjects with SCDS had episodes of acute sensorineural hearing loss (SNHL) or vestibular symptoms, except for one patient who complained of head vibration induced by loud noise. Conversely, five of six subjects with LVAS had episodes of acute SNHL or vestibular symptoms. Four of five ears with SCDS showed severe EH in the cochlea, and two ears showed mild EH in the vestibule. All ears with LVAS showed mild to severe EH in both the cochlea and vestibule., Conclusions: The present study demonstrated the existence of EH in ears with pathologic third window lesions, which might affect patients' auditory or vestibular symptoms., Level of Evidence: 4 Laryngoscope, 126:1446-1450, 2016., (© 2015 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: To describe the clinical experience and characterize the outcomes of cochlear implantation (CI) in children with isolated enlarged vestibular aqueduct (IEVA) as compared to children with enlarged vestibular aqueduct (EVA) associated with other bony labyrinth abnormalities., Study Design: Single, tertiary care, institutional retrospective review over 2 decades., Methods: The clinical course and outcomes of 55 children with EVA undergoing CI between 1991 and 2013 were reviewed. Test measures included open and closed set speech perception tests, and various speech and language measures., Results: In 18 children (32.7%), IEVA was the only defect present. In 33 children (60%), EVA occurred concomitantly with incomplete partition type 2 (IP 2) bilaterally, and three children with incomplete partition type 1 bilaterally. Ninety-two percent (51 of 55) occurred bilaterally and had matching bony defects. Mean age of CI was 73.4 months. A statistically significant defect-related and linguistic-status pattern was noted, impacting the timing of implantation: IEVA = 112.8 months, IP 2 = 58.4 months (P < .001), prelingual deafness = 53.8 months, postlingual deafness = 110.8 months (P < .001). Controlling for implant age and hearing loss severity, IEVA children demonstrated superior performance on speech perception tests (8.2 to 20.3 point differences), though statistical significance was inconsistent (P = .01-.40. Performance was also superior in speech and language tests, though statistical significance was never reached (2.9-13.9 point differences; P = .14-.69)., Conclusions: Children with hearing loss secondary to EVA respond meaningfully to cochlear implantation. However, the severity of temporal bone anomalies in these children has clinical relevance., Level of Evidence: 4., (© 2015 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives: To review the controversial aspects of the enlarged vestibular aqueduct syndrome., Study Design: Contemporary review., Methods: A literature search using the terms "enlarged vestibular aqueduct and large vestibular aqueduct" were used to generate the articles for review in this article., Results: The enlarged vestibular aqueduct is a condition causing variable auditory and vestibular dysfunction. Although it has been 32 years since Valvasorri and Clemis recognized the clinical importance of the enlarged vestibular aqueduct, many controversial aspects of the diagnosis remain. The topics reviewed in this discussion are as follows: size criteria for radiographic diagnosis, precipitating factors for hearing loss, corticosteroid treatment and sac surgery, conductive component to hearing loss, natural progression of hearing loss, correlations between aqueduct size and hearing loss, genetics, vestibular symptoms, and theories regarding mechanisms behind the symptoms., Conclusion: The enlarged vestibular aqueduct remains a controversial entity with variable presentation, progression, and prognosis., (Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.)

Objectives: : The objectives of this study were to identify SIX1 gene mutations in a patient with branchio-oto syndrome (BO) and to clarify the relationship between SIX1 mutation and enlargement of the vestibular aqueduct (EVA)., Methods: : A genetic study and retrospective chart review for a patient in whom EYA1 mutation had already been excluded was conducted. We studied a Japanese patient who had autosomal-dominant mixed hearing loss, a unilateral ear pit and unilateral EVA, and who was previously diagnosed as having BO. We searched for SIX1 and SLC26A4 mutations using polymerase chain reaction and direct gene sequencing., Results: : The patient carried a heterozygous A-->G mutation at nucleotide 386 within exon 1 of SIX1 that resulted in substitution of a cysteine for a tyrosine at codon 129 (Y129C) of the gene product. Y129C is a previously identified SIX1 mutation and was not detected in any of our 164 control chromosomes. No SLC26A4 mutations were identified., Conclusion: : Y129C mutation in SIX1 may cause EVA as well as BO.

Objectives: To describe the chronologic changes of hearing in patients with large vestibular aqueduct syndrome (LVAS) and identify the prognostic factors., Study Design: A retrospective chart-review study., Methods: Twelve consecutive patients with LVAS were recruited at Taipei Veterans General Hospital between July 1986 and July 2000. The records of serial pure-tone audiogram and high-resolution computer tomography were collected. The chronologic figures of pure-tone average (PTA) were sketched. The investigated variables included sex, laterality and type of hearing loss (HL), size of vestibular aqueduct, and the chronologic changes and configurations of hearing. Data were analyzed statistically., Results: The degree of HL in early childhood was from moderate to profound. The worst hearing could be estimated by the hearing level in early childhood. Sixteen of 24 ears were stable. Bilateral, chronologically stepwise-downhill hearing occurred in only one patient (1/12) during the follow-up period. Chronologically, high-tone hearings were worse than those of low-tone, but fluctuations of high-tone hearing were smaller than those of low-tone. The sizes of vestibular aqueduct were predictive of the density of major depression and its depth., Conclusions: LVAS, a congenital disease, is characterized by fluctuating sensorineural HL. Most hearing at PTA remained stable at least in one ear chronologically. The standard deviation of hearing at 500 Hz was the only prognostic factor for the progression of PTA. An enlarged vestibular aqueduct affects fluctuations of hearing, but the pathogenesis of HL still remains unclear and deserves further investigations.

Objectives: The purpose of this study was to study systematically some relationships between the resonance frequency of the middle-ear transmission system and the volume of the endolymphatic duct and sac in patients with an enlarged vestibular aqueduct (EVA)., Study Design: Prospective study., Methods: Thirteen patients (24 ears) with EVA, 17 subjects (29 ears) with normal hearing, and 17 patients (21 ears) with sensorineural hearing loss without EVA served as experimental subjects. Standard pure-tone audiometry, standard clinical tympanometry (using a 226-Hz probe tone), and multifrequency tympanometry were performed on each ear. Magnetic resonance imaging was used to determine the area of the cochlear modiolus and the volume of the endolymphatic duct and sac., Results: The audiometric configurations for most patients sloped downward from the low to the high frequencies. A significant air-bone gap was computed at each of these test frequencies. Multifrequency tympanometry yielded resonance frequencies for the patients with EVA that was significantly lower than those measured for the control subjects. In general, for patients with EVA, the resonance frequency of the middle ear system decreased as the volume of the endolymphatic duct and sac increased. This inverse relation was significant (correlation coefficient = -0.483, P =.0157). However, there was no correlation between resonance frequency and the degree of cochlea modiolar deficiency., Conclusions: Clinically, our findings suggest that EVA probably should be included in the differential diagnosis for a patient who presents with a moderate to severe mixed hearing loss, a normal tympanogram at 226 Hz, and a resonance frequency that is abnormally low.

Objectives: In this investigation, we report the outcomes of 14 adults (age >18 y) and 9 children (age <18 y) with radiographically proven large vestibular aqueduct syndrome (LVAS) who received cochlear implants at Indiana University School of Medicine., Study Design: This is a retrospective case-control study detailing the outcomes of 23 patients with LVAS and 46 control patients implanted with Nucleus (Cochlear Corp., Englewood, CO), Clarion (Advanced Bionics Corp., Sylmar, CA), or Med-El (MED-EL Corp., Innsbruck, Austria) cochlear implants., Methods: Performance data on pure-tone averages, speech detection thresholds, and a variety of auditory and speech recognition tasks from these patients with LVAS were compared with performance data obtained from a matched group of 46 cochlear implant users who did not have LVAS. Specific patient characteristics used in matching included the age of the patient, the age at implant of the patient, and whether the patient was pre- or postlingually deafened. Data for the adult group was analyzed using the Student t test, and data for the pediatric patient group was compared using a chi2 test., Results: The results indicated positive outcomes for both pediatric and adult groups. With both adult and pediatric groups, auditory and speech recognition performance did not differ significantly between those patients with LVAS and control subjects., Conclusions: This study adds further support for the use of cochlear implantation in patients with LVAS. Cochlear implantation is beneficial and can be offered as an eventual treatment of LVAS if hearing loss progresses to profound levels in these patients.

Objective: Etiopathogenesis of Ménière's disease has not been resolved. The principal histopathologic finding in this disease is endolymphatic hydrops. The majority of radiologic and histopathologic studies demonstrated a narrow vestibular aqueduct in Ménière's disease. There is no study in the literature investigating the relationship between inner ear pressure and vestibular aqueduct dimensions. Static acoustic compliance is a noninvasive procedure that is thought to measure perilymphatic pressure at the footplate. An increase in mechanical fluid pressure in the inner ear is transmitted to the footplate of the stapes. This causes a reduction in the compliance at the drum. The aim of this study is to investigate the relationship between vestibular aqueduct dimensions and static acoustic compliance in Ménière's disease and the normal population., Study Design: Prospective study., Methods: Forty patients with Ménière's disease and 40 healthy individuals with no otolaryngologic disorders were the subjects of this study. Each group was further divided into two according to static compliance value (normal and low static compliance). In these four groups dimensions of vestibular aqueduct were determined radiologically by high-resolution computerized tomography and correlated with normal and low static acoustic compliance values (normal and high perilymphatic pressure)., Results: The results demonstrated that vestibular aqueduct is narrower in patients with Ménière's disease than the normal population. However, there is no relationship between vestibular aqueduct dimensions and inner ear pressure obtained by static acoustic compliance measurements.