ORIGINAL ARTICLE Audiometric Findings in Children With a Large

Ellis M. Arjmand, MD, PhD; Audra Webber, BS

Objective: To characterize audiometric findings in chil- profound in 10 (38%). Thirteen (50%) of 26 ears had dren with a large vestibular aqueduct (LVA). a downsloping or high-frequency SNHI, and 8 (31%) of 26 ears had a midfrequency-peaked audiogram. Bilat- Design: Retrospective review. eral LVAs were seen in 7 children, 6 of whom had bilat- eral and asymmetrical SNHI. Of 12 patients with a uni- Methods: Audiometric records of children with an iso- lateral LVA, 5 had bilateral SNHI. lated LVA, diagnosed by computed tomography of the tem- poral bone, from 1995 through 1998 were reviewed. Conclusions: In this series, the children with LVAs typi- cally had moderate-severe or worse SNHI. An unusual Results: Nineteen children had an isolated LVA in one midfrequency-peaked audiogram was present in approxi- or both ears. In all, 26 ears with an isolated LVA were mately one third of the study patients. The majority of identified. An LVA was seen in association with another the patients had a unilateral LVA; however, nearly 50% inner anomaly in an additional 7 ears. The of the patients with a unilateral LVA had bilateral SNHI. impairment was sensorineural in 22 ears (85%) with an The patients with bilateral LVAs generally had asym- isolated LVA and mixed in 3 (12%). The hearing was nor- metrical SNHI. mal in 1 ear. The sensorineural hearing impairment (SNHI) was moderate-severe in 12 ears (46%) and severe- Arch Otolaryngol Head Neck Surg. 2004;130:1169-1174

HE LARGE VESTIBULAR AQUE- toms have also been reported by some duct (LVA) is reported to be patients.4,5 the most common The mechanism of hearing impair- anomaly identified on com- ment associated with an LVA is un- puted tomograms (CTs) in known, although many hypotheses have children with sensorineural hearing impair- been presented.3,4,15 Treatment of an LVA T 1 ment (SNHI). As such, hearing impair- remains controversial. The purpose of this ment is frequently attributed to the pres- study is to examine the audiometric find- ence of an LVA.2 The description of LVA ings in children with isolated enlarge- syndrome in 1978, which included associ- ment of the VA as identified on temporal ated inner ear anomalies,3 led to an inter- bone CTs. The characteristics of hearing est in the LVA as an isolated anomaly.4 How- impairment (eg, severity and audiomet- ever, associated cochlear anomalies are ric configuration) are described, as is the thought to be more difficult than LVAs to relationship between VA findings and hear- detect on CTs.5 ing status. Radiographic criteria for the diagno- sis of LVAs have yet to be standardized. METHODS From the Department of The definition of a normal vestibular aq- Pediatric Otolaryngology, ueduct (VA) diameter varies consider- We performed a retrospective review of the Children’s Hospital of ably in published reports, as do the place medical records of children with SNHI who un- Pittsburgh, Pittsburgh, Pa. of measurement and the plane of CT derwent CT scans from 1995 Dr Arjmand is now with the scans.2-4,6-11 The clinical presentation of the through 1998. All children in this study were Department of Pediatric seen in the pediatric otolaryngology depart- LVA is variable; both stable and progres- Otolaryngology, Cincinnati 4,9,11-14 ment at Children’s Hospital of Pittsburgh Children’s Hospital Medical sive SNHI have been described, and (CHP), Pittsburgh, Pa, a university-affiliated Center, Cincinnati, Ohio. the characteristics of hearing impair- tertiary care children’s hospital. The study was The authors have no relevant ment (severity, type, and audiometric con- approved by the institutional review board of financial interest in this article. figuration) vary as well. Vestibular symp- CHP.

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 fied in 7 ears. The following inner ear anomalies were Profound Normal 8% 12% diagnosed on CTs (n=33): Anomaly No. (%) of Ears Isolated enlarged VA 26 (79) Severe Enlarged VA with cochlear anomalies 1 (3) 15% Enlarged VA with SCC anomalies 2 (6) Enlarged VA with cochleovestibular anomalies 1 (3) Enlarged VA with SCC and vestibular anomalies 3 (9)

AUDIOMETRIC FINDINGS

Mild Severity 38% Of the 26 ears with isolated LVAs, 22 (85%) had SNHI, Moderate 27% 3 (12%) had mixed hearing impairment, and 1 (3%) had no hearing loss. The severity of hearing impairment as determined by pure-tone averages ranged from none (3 of 26 ears; 12%) to profound (2 of 26 ears; 8%), with 17 Figure 1. Severity of sensorineural hearing impairment in 26 children with ears (65%) demonstrating mild or moderate hearing loss isolated large vestibular aqueducts. The severity of hearing impairment is classified according to the pure-tone average in the affected ear. and 6 ears (23%) with severe or profound hearing loss (Figure 1). As the use of pure-tone averages to de- scribe severity of hearing impairment does not measure Patients were referred for temporal bone imaging at the hearing above 2000 Hz, the degree of hearing impair- request of the evaluating pediatric otolaryngologist. Not all chil- ment can be underestimated in patients who are more dren diagnosed as having SNHI were referred for imaging. For severely affected at higher frequencies. example, some children with a known cause for acquired SNHI were not referred for CT. The study included only children with Audiometric Configuration unilateral or bilateral SNHI; therefore, the incidence of LVAs in normal-hearing subjects cannot be determined. High-resolution coronal or axial and coronal temporal bone In 13 (50%) of 26 ears with an isolated LVA, the audio- CT scans were performed (at 1- or 1.5-mm intervals) in accor- gram was downsloping or showed a high-frequency SNHI. dance with the standard clinical imaging protocol at CHP. The Eight (31% of the total) of the remaining 13 ears had au- VA was classified as enlarged by the evaluating radiologist if diograms with a midfrequency peak at 1000 or 2000 Hz. its width at the proximal intraosseous portion exceeded that The midfrequency-peaked audiogram is defined by the pres- of the adjacent posterior semicircular canal (SCC).16 The CTs ence of thresholds at 1000 or 2000 Hz that are 15 dB or of patients diagnosed as having an LVA were subsequently re- better than the adjacent octaves (Figure 2). Other audio- viewed, and the diameter of the VA at its widest intraosseus metric configurations were seen in 5 ears, including a flat portion was measured. hearing loss in 1 ear. The following tabulation shows the The audiometric records for all patients identified as hav- audiometric configuration in 26 ears with isolated LVAs: ing an LVA were reviewed. Behavioral audiograms or auditory brainstem response test results for all patients were available Configuration No. (%) of Ears from the department of at CHP. The type of hearing Downsloping 11 (42) impairment, the severity of hearing impairment, and the High frequency 2 (8) audiometric configuration were characterized by an individual Midfrequency peak 8 (31) review of the audiograms for each patient found to have an Flat 1 (4) LVA. Other 3 (11) Normal 1 (4) RESULTS Laterality PATIENT POPULATION Seven patients had bilateral isolated LVAs, and 12 pa- We reviewed the records of 221 children. At the time of tients had unilateral isolated LVAs. Of the 7 patients with evaluation, the patients ranged in age from 1 month to bilateral LVAs, 6 had bilateral SNHI and 1 had unilat- 17.2 years (mean age, 5.5 years). The female-male ratio eral SNHI. All 6 patients with bilateral LVAs had asym- was 1.1:1.0. metrical audiometric thresholds. Of the 12 patients with unilateral LVAs, 7 had unilateral SNHI and 5 had bilat- RADIOGRAPHIC FINDINGS eral SNHI. (In 1 patient with a unilateral isolated LVA, the contralateral ear had an LVA with associated anoma- Nineteen children had an LVA diagnosed as an isolated lies, and the patient had bilateral SNHI.) anomaly in one or both ears. An isolated LVA was iden- Overall, 11 patients with LVAs had bilateral SNHI. Au- tified in a total of 26 ears. The incidence of isolated LVAs diometric thresholds were asymmetrical in 7 of these pa- in this group was 8.6% (19 of 221 subjects), with a mean tients, inlcuding 6 children with bilateral isolated LVAs VA diameter of 2.3 mm (range, 1.2-3.9 mm). Also, an (Figure 3). Asymmetry was defined as hearing thresholds LVA with an associated inner ear anomaly was identi- differing 15 dB or more at 2 or more frequencies between

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 ears. Therefore, all patients with both bilateral LVAs and Frequency, Hz bilateral SNHI had asymmetrical audiometric thresholds. 125 250 500 1000 2000 4000 8000 – 10

0 COMMENT

10

15 dB DIAGNOSTIC CRITERIA 20

Radiographic 30 50 dB 40 The diagnostic criteria for LVAs are controversial and not 3 standardized. Valvassori and Clemis defined VA en- 50 largement as a diameter exceeding 1.5 mm. Subse- 60 quently, other investigators have defined VA enlarge- Hearing Level, dB ment as a diameter greater than or equal to 1.4,9 1.5,11 2.0,1,2,4,9 or 4.0 mm.8 The place at which the VA is mea- 70 3-5-11 sured varies from midway between the common crus 80 and external aperture to the external pore. Also, some investigators have defined the LVA on the basis of com- 90 parison to the posterior SCC16 or the diameter of the fa- cial nerve.13 Interestingly, malformation of the posterior 100 limb of the lateral SCC has recently been described as 110 occurring in association with an LVA.17 The radiologists at our institution, during the years Frequency, Hz 125 250 500 1000 2000 4000 8000 when these patients were initially evaluated, used com- – 10 parison to the diameter of the SCC as the primary deter- 16 minant of VA enlargement. Subsequent review of the 0 images obtained revealed that some VAs as small as 1.1 mm had been diagnosed as enlarged. We chose to ac- 10 cept the original interpretation of the radiologist, rather than to recategorize the findings, because (1) there is not 20

a consensus on the radiographic criteria for LVAs; (2) 30

the original evaluations were made consistently, in ac- 15 dB cordance with a published criterion; and (3) it is diffi- 40 cult to make precise measurements to the 10th of a mil- limeter on conventional CTs. 50

Axial CTs are commonly used to evaluate the VA. 60 Dimopoulos et al18 concluded that the axial transverse Hearing Level, dB view provides sufficient information for visualization of 70 the VA. In contrast, Murray et al19 reported that coronal CTs permit better visualization and more consistent mea- 80 surement of the VA. 90

Developmental Effects 100

Nonlinear growth of the VA throughout gestation and 110 up to the age of 3 to 4 years has been described, indicat- ing that LVAs may result from abnormal postnatal and Figure 2. Midfrequency-peaked audiograms for 2 patients with isolated large vestibular aqueducts. preadolescent development.6 This theory is consistent with the findings of an earlier study20 that reported a signifi- cant difference in VA area in children younger than 12 CLINICAL PRESENTATION months compared with those aged 3 to 4 years. The VA size was more variable in the older children. Progression These reports suggest that radiologic findings in younger subjects should be interpreted carefully. Some Progressive hearing loss has been reported in patients with children are evaluated by CT during the time when the LVAs.4,9,11,12,14 Jackler and De La Cruz4 cited a stepwise VA may be enlarging: the average age at presentation for progression of approximately 3.5 dB/y in their patient the current study was 5.5 years, and other studies have population with progressive loss. Arcand et al2 indi- reported average ages from as young as 3.1 years.7,8,12 To cated an average progression of 30 dB over a follow-up our knowledge, age-based normative data for VA size have period of 5.5 years in LVA cases, and Govaerts et al12 found not been reported. a 4-dB/y decrement in their patients with LVAs. Bamiou

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 The cause of conductive hearing impairment in pa- Isolated LVAs Total tients with LVAs is unknown. fixation has been 14 Unilateral LVAs Bilateral LVAs suggested as a cause, and a case study of a patient with an LVA, mixed hearing loss, and stapes fixation has been reported.21 However, other investigators have suggested 7 1 8 that cochlear conductive hearing impairment (resulting from abnormal intracochlear fluid pressure), rather than Unilateral SNHI ossicular fixation, is the cause of conductive hearing im- pairment in patients with LVAs.12

Bilateral SNHI 5 6 11

Hearing Loss Configuration

A downsloping or high-frequency SNHI was seen most frequently in our patients with isolated LVAs (13 of 26 3,9,12 Total 12 7 19 ears). This finding is consistent with earlier reports. A midfrequency-peaked audiogram was the sec- ond most commonly seen audiometric configuration in Figure 3. Relationship between large vestibular aqueduct (LVA) laterality and sensorineural hearing impairment (SNHI) in 19 patients. Note that 5 patients our patients with isolated LVAs. To our knowledge, this with unilateral LVAs had bilateral SNHI, and 1 patient with bilateral LVAs had audiometric configuration, seen in approximately 30% unilateral SNHI. All patients with bilateral LVAs had asymmetrical thresholds. of the ears with isolated LVAs in our study, has not pre- viously been described in association with LVAs. Inter- et al10 reported a significant correlation between LVAs estingly, this peaked audiometric configuration has pre- and progressive hearing loss, and Antonelli et al5 found viously been reported in adult patients with Me´nie`re’s that most patients with LVAs had progressive or fluctu- disease22,23 as well as in animal models of endolym- ating SNHI. phatic hydrops.24 Because of the retrospective nature of our study The midfrequency-peaked audiogram is upsloping and the lack of serial audiometric data for many of the in the low frequencies, peaks at 1 or 2 kHz, and slopes patients, we could not systematically examine the pro- downward through 8 kHz. We defined the peak as being gression of SNHI. However, progressive SNHI was 15 dB greater than its neighboring octaves. This is a stricter clearly seen in 2 patients with an isolated LVA; these criteria than that used in studies of patients with Me´- patients had changes in audiometric thresholds at 2000 nie`re’s disease.22,23 Paparella et al23 described a peaked au- Hz or above. The finding of threshold changes that are diogram in 42% of 300 patients with hydrops. The peak limited to higher frequencies also illustrates a problem audiogram was defined as having air-conduction thresh- with defining progressive SNHI on the basis of changes olds for 1 test frequency 10 dB better than adjacent oc- in pure-tone averages.4,11,12 By this definition, our 2 taves. The peak was at 2000 Hz in 75% of their patients. patients would not have been identified as having a pro- Lee at al22 also examined peak audiometric configura- gressive hearing loss. tions in patients with Me´nie`re’s disease, using the same criteria. A peaked audiometric configuration was re- Degree of Hearing Impairment ported in approximately 50% of their patients; the peak was at 2000 Hz in the majority. Ries et al25 performed a The degree of SNHI in our patients with LVAs ranges from retrospective analysis of audiometric findings in pa- none to profound, with 65% of ears having mild or mod- tients with unilateral hydrops, reporting that 27% of the erate hearing impairment. One patient with bilateral LVAs patients had a peaked audiometric configuration. had normal hearing in 1 ear. As the severity of hearing loss will vary over time in patients with progressive SNHI, Incidence and Laterality demonstration of a clear relationship between VA size and severity of SNHI may not be seen consistently. While In the present group of 221 children with SNHI or mixed Antonelli et al5 reported significant correlation between hearing impairment, 19 (8.5%) were found to have iso- VA size and severity of hearing impairment in patients lated LVAs. Other studies of patients with SNHI have re- with LVAs and cochlear dysplasia, several other reports ported an incidence of LVA ranging from 3.7% to have failed to demonstrate a relationship between VA size 11.4%.8,10,11,13,14 The incidence of asymmetrical SNHI in and audiometric thresholds.7,8 our population is consistent with that in previous re- ports.4,12 However, the high incidence of unilateral LVAs Type of Hearing Loss in this group of patients is in contrast to results of past studies.4,6,7-9 All of our patients had SNHI, as only patients with SNHI A single subject with bilateral isolated LVAs and uni- as an indication for temporal bone imaging were iden- lateral hearing loss was identified in our study, and at tified for review. An additional conductive component, least 2 similar cases have been reported previously.10 This resulting in mixed hearing impairment, was seen in 3 finding illustrates the usefulness of CT in counseling pa- patients (11%) with isolated LVAs. Mixed hearing im- tients with hearing loss, owing to the risk of progressive pairment has been reported to be more common in SNHI and the association of decreased hearing thresh- other studies.3,12 olds with minor head trauma.4,8,9

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 Five cases of a unilateral isolated LVA in children with cluding a breach in homeostasis of inner ear electrolytes bilateral SNHI were also identified. In 1 of the 5 cases, the brought about by the accumulation of excess endo- contralateral ear had a combined inner ear anomaly. In the lymph, which is caused by a dysfunctional endolym- others, the contralateral (radiographically normal) ear may phatic sac. A minor head injury could cause a rupture of have had a membranous anomaly that was not visualized the intracochlear membrane, thereby combining endo- on CTs, or the diagnostic criteria used for determining lymph with and contributing to a stepwise pro- the presence of an LVA may not have allowed an accurate gression of hearing loss. Also, cerebrospinal fluid pres- diagnosis in some cases. These cases emphasize the point, sure fluctuations may be transmitted to the inner ear via raised in earlier reports, that the LVA may be a marker for the patent VA. membranous inner ear abnormalities. Thus, the VA may The concept of intracochlear pressure change as a not always be enlarged in cases of membranous inner ear mechanism for hearing loss in patients with LVAs was anomaly and, when it is enlarged, may not be clearly iden- also proposed by Levenson et al,9 who hypothesized that tified by current CT criteria. sudden fluctuation in cerebrospinal fluid pressure could force hyperosmotic fluid into the basal end of the coch- MRI and Visualization lear duct and produce a high-frequency hearing loss. This of the and Sac reflux is thought to be possible because of an enlarged endolymphatic duct. Because of the limitations of CT in temporal bone imag- Several authors8,12 agree that volume or pressure ef- ing, fast spin-echo magnetic resonance imaging (MRI) has fects precipitated by an enlarged endolymphatic duct ac- been proposed as the procedure of choice for the exami- count for the hearing loss found in patients with LVAs. nation of patients with LVAs.26 Advances in MRI technol- Hirsch et al15 suggest that abnormalities of the inner ear ogy allow imaging of the endolymphatic structures.27 membrane are a factor in LVA-associated hearing losses, Several recent publications suggest that enlarge- but they reach a different conclusion regarding the mecha- ment of the and duct is related to hear- nism at work. They suggest that there is a dilated com- ing impairment in cases of LVA.15,26-28 For example, munication between the cerebrospinal fluid and the ves- Hirsch et al15 described 2 patients with bilateral LVAs who tibule that forms a fistula, damaging the membranous were found to have bilateral enlargement of the endo- labyrinth. Further histopathologic studies of confirmed lymphatic sac on MRI examination. Other studies also cases are needed before definitive conclusions can be describe enlarged endolymphatic sacs coincident with drawn. LVAs.27,28 Although some reports indicate that not all pa- If, in fact, the mechanism behind hearing loss in pa- tients with an LVA diagnosed on CTs have an enlarged tients with an LVA is a result of pressure fluctuations, it endolymphatic sac on MRIs, some authors propose that may follow that greater dilation of the VA (and corre- MRI is the preferred imaging modality for patients with sponding sac) leads to greater susceptibility to progres- suspected inner ear anomalies of this type.26,28 sion of hearing loss. Evaluation of this theory would re- quire close serial audiometric assessment, which is not Me´nie`re’s Disease and MRI available in this retrospective review.

The peak audiogram has been observed in animal mod- CONCLUSIONS els of Me´nie`re’s disease. During induction of Me´nie`re’s disease in guinea pigs, a low-frequency hearing loss de- velops first, followed by the development of a high- 1. An LVA was the most common inner ear anomaly frequency hearing loss. Eventually, the midfrequency identified on CTs in this selected group of children with range (8 kHz in the guinea pig) is affected.24 SNHI. In another experimental model of endolymphatic hy- 2. The incidence of a midfrequency-peaked audio- drops, a high-frequency SNHI developed in guinea pigs gram in this group of patients with SNHI and isolated after the endolymphatic sac pressure was raised. A low- LVAs was approximately 30%. A similar audiometric con- frequency hearing loss followed, creating a peaked- figuration has previously been reported in patients with configuration audiogram. Eventually a flat-configuration Me´nie`re’s disease. audiogram developed.29 3. Among children with SNHI and bilateral LVAs, Despite the common audiometric configurations of the degree of hearing impairment is frequently asym- patients with LVAs and Me´nie`re’s disease, the appear- metrical. ance of the endolymphatic sac on MRIs in these 2 pa- 4. Bilateral SNHI is commonly seen in children with tient populations seems to differ. In contrast to reports a unilateral LVA, which may illustrate that the LVA is a of endolymphatic duct and sac enlargement in patients marker for membranous inner ear abnormalities not vi- with LVAs, the endolymphatic duct and sac are typi- sualized on CTs. cally poorly visualized on the MRIs of patients with Me´- 5. The radiographic criteria for identifying LVAs are nie`re’s disease.30 not standardized.

Mechanisms of SNHI Submitted for publication April 4, 2002; final revision re- ceived February 9, 2004; accepted May 20, 2004. Jackler and De La Cruz4 suggest several potential causes This study was supported in part by the Eberly Fam- of progressive SNHI in patients with an isolated LVA, in- ily Foundation Endowed Chair in Pediatric Otorhinolar-

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©2004 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 yngology, University of Pittsburgh School of Medicine, Pitts- 13. Antonelli PJ, Varela AE, Mancuso AA. Diagnostic yield of high-resolution com- burgh, Pa. puted tomography for pediatric sensorineural hearing loss. Laryngoscope. 1999; 109:1642-1647. This study was presented at the American Society for 14. Callison DM, Horn KL. Large vestibular aqueduct syndrome: an overlooked eti- Pediatric Otolaryngology Annual Meeting; May 13, 2002; ology for progressive childhood hearing loss. J Am Acad Audiol. 1998;9:285- Boca Raton, Fla. 291. Correspondence: Ellis M. Arjmand, MD, PhD, Depart- 15. Hirsch BE, Weissman JL, Curtin HD, Kamerer DB. Magnetic resonance imaging of the large vestibular aqueduct. Arch Otolaryngol Head Neck Surg. 1992;118: ment of Pediatric Otolaryngology, Cincinnati Children’s Hos- 1124-1127. pital Medical Center, 3333 Burnet Ave, Cincinnati, OH 16. Pollock AN, Curtin HD, Towbin RB. Methods of examination: radiologic aspects. 45229-3039 ([email protected]). In: Bluestone CD, Stool SE, Kenna MA, eds. Pediatric Otolaryngology. Vol 1. 4th ed. Philadelphia, Pa: WB Saunders Co; 2003:230-271. 17. Johnson J, Lalwani AK. Sensorineural and conductive hearing loss associated REFERENCES with lateral semicircular canal malformation. Laryngoscope. 2000;110:1673- 1679. 1. Benton C, Bellet PS. Imaging of congenital anomalies of the temporal bone. Neu- 18. Dimopoulos PA, Smedby O, Wilbrand HF. Anatomical variations of the human roimaging Clin N Am. 2000;10:35-53. vestibular aqueduct, II: a radioanatomical study. Acta Radiol Suppl. 1996;403: 2. Arcand P, Desrosiers M, Dube J, Abela A. The large vestibular aqueduct syn- 33-41. drome and sensorineural hearing loss in the pediatric population. J Otolaryngol. 19. Murray LN, Tanaka GJ, Cameron DS, Gianoli GJ. Coronal computed tomogra- 1991;20:247-250. phy of the normal vestibular aqueduct in children and young adults. Arch Oto- 3. Valvassori GE, Clemis JD. The large vestibular aqueduct syndrome. Laryngo- laryngol Head Neck Surg. 2000;126:1351-1357. scope. 1978;88:723-728. 20. Kodama A, Sando I. Postnatal development of the vestibular aqueduct and en- 4. Jackler RK, De La Cruz A. The large vestibular aqueduct syndrome. Laryngo- dolymphatic sac. Ann Otol Rhinol Laryngol Suppl. 1982;96:3-12. scope. 1989;99:1238-1243. 21. Shirazi A, Fenton JE, Fagan PA. Large vestibular aqueduct syndrome and stapes 5. Antonelli PJ, Nall AV, Lemmerling MM, Mancuso AA, Kublis PS. Hearing loss fixation. J Laryngol Otol. 1994;108:989-990. with cochlear modiolar defects and large vestibular aqueducts. Am J Otol. 1998; 22. Lee C-S, Paparella MM, Margolis RH, Le C. Audiological profiles and Meniere’s 19:306-312. disease. Ear Nose Throat J. 1995;74:527-532. 6. Pyle GM. Embryological development and large vestibular aqueduct syndrome. 23. Paparella MM, McDermott JC, de Sousa LCA. Meniere’s disease and the peak Laryngoscope. 2000;110:1837-1842. audiogram. Arch Otolaryngol. 1982;108:555-559. 7. Zalzal GH, Tomaski SM, Vezina LG, Bjornsti P, Grundfast KM. Enlarged vestibu- 24. Horner KC. Auditory and vestibular function in experimental hydrops. Otolaryn- lar aqueduct and sensorineural hearing loss in childhood. Arch Otolaryngol Head gol Head Neck Surg. 1995;112:84-89. Neck Surg. 1995;121:23-28. 25. Ries DT, Rickert M, Schlauch RS. The peaked audiometric configuration in Me- 8. Okumara T, Takahashi H, Honjo I, Takagi A, Mitamura K. Sensorineural hearing niere’s disease: disease related? J Speech Lang Hear Res. 1999;42:829-843. loss in patients with large vestibular aqueduct. Laryngoscope. 1995;105:289- 26. Harnsberger HR, Dahlen RT, Shelton C, Gray SD, Parkin JL. Advanced tech- 294. niques in magnetic resonance imaging in the LVAluation of the large endolym- 9. Levenson MJ, Parisier SC, Jacobs M, Edelstein DR. The large vestibular aque- phatic duct and sac syndrome. Laryngoscope. 1995;105:1037-1042. duct syndrome in children: a review of 12 cases and the description of a new 27. Dahlen RT, Harnsberger HR, Gray SD, et al. Overlapping thin-section fast spin- clinical entity. Arch Otolaryngol Head Neck Surg. 1989;115:54-58. echo MR of the large vestibular aqueduct syndrome. AJNR Am J Neuroradiol. 10. Bamiou DE, Savy L, O’Mahoney C, Phelps P, Sirimanna T. Unilateral sensori- 1997;18:67-75. neural hearing loss and its aetiology in childhood: the contribution of comput- 28. Okamato K, Ito J, Furusawa T, Sakai K, Horikawa S, Tokiguchi S. MRI of en- erised tomography in aetiological diagnosis and management. Int J Pediatr Oto- larged endolymphatic sacs in the large vestibular aqueduct syndrome. Neuro- rhinolaryngol. 1999;51:91-99. radiology. 1998;40:167-172. 11. Bamiou DE, Phelps P, Sirimanna T. Temporal bone computed tomography find- 29. Horner KC, Cazals Y. Contribution of increased endolymphatic pressure to hear- ings in bilateral sensorineural hearing loss. Arch Dis Child. 2000;82:257-260. ing loss in experimental hydrops. Ann Otol Rhinol Laryngol. 1991;100:496-502. 12. Govaerts PJ, Casselman J, Daemers K, De Ceular G, Somers T, Offeciers FE. Au- 30. Lorenzi MC, Bento RF, Daniel MM, Leite CC. Magnetic resonance imaging of the diological findings in large vestibular aqueduct syndrome. Int J Pediatr Otorhi- temporal bone in patients with Meniere’s disease. Acta Otolaryngol. 2000;120: nolaryngol. 1999;51:157-164. 615-619.

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