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The Laryngoscope
VC 2013 The American Laryngological,
Rhinological and Otological Society, Inc.
TRIOLOGICAL SOCIETY
CANDIDATE THESIS
Significance of Unilateral Enlarged Vestibular Aqueduct
John Greinwald, MD; Alessandro deAlarcon, MD; Aliza Cohen, MA; Trina Uwiera, MD;
Keijan Zhang, PhD; Corning Benton, MD; Mark Halstead, MD; Jareen Meinzen-Derr, PhD
Objectives/Hypothesis: To describe the clinical phenotype of pediatric patients with unilateral enlarged vestibular
aqueduct (EVA) and then to compare the findings to two clinically related phenotypes: bilateral EVA and unilateral hearing
loss without EVA. In view of clinical observations and previously published data, we hypothesized that patients with unilat-
eral EVA would have a much higher rate of contralateral hearing loss than patients with unilateral hearing loss without EVA.
Study Design: Retrospective cohort study.
Methods: Patients with unilateral or bilateral EVA were identified from a database of children with sensorineural hear-
ing loss who were seen at a tertiary care institution between 1998 and 2010. Those with imaging findings consistent with
well-established EVA criteria were identified. A comparative group of patients with unilateral hearing loss without EVA was
also identified. The following specific outcome measurements were analyzed: 1) hearing loss phenotype, 2) laterality of EVA
and hearing loss, 3) midpoint and operculum vestibular aqueduct measurements, and 4) genetic test results.
Results: Of the 144 patients who met our inclusion criteria, 74 (51.4%) had unilateral EVA. There was a strong correla-
tion between the presence of hearing loss and ears with EVA. Fifty-five percent of patients with unilateral EVA had hearing
loss in the contralateral ear; in most of these patients, the hearing loss was bilateral. Contralateral hearing loss occurred in
only 6% of patients with unilateral hearing loss without EVA. No significant differences were found in temporal bone meas-
urements between the ears of patients with unilateral EVA and ipsilateral hearing loss and all ears with EVA and normal
hearing ( P ¼ .4). There was no difference in the rate of hearing loss progression in patients with unilateral EVA between ears
with or without EVA (16 of 48 [33.3%] vs. 9 of 27 [33.3%], respectively; P ¼ 1.0). There was no difference in the rate of
hearing loss progression in patients with bilateral and unilateral EVA (41 of 89 ears [46.1%] vs. 25 of 75 ears [33.3%],
respectively; P ¼ .1); however, both EVA groups had higher rates of progression compared to patients with unilateral hearing
loss without EVA. There was a strong correlation between the presence of hearing loss at 250 Hz and the risk of more severe
hearing loss and progressive hearing loss. Patients with bilateral EVA and SLC26A4 mutations had a higher rate of progression
than patients who had no mutations (P ¼ .02). No patients with unilateral EVA had Pendred syndrome.
Conclusions: Children with unilateral EVA have a significant risk of hearing loss progression. Hearing loss in the ear
contralateral to the EVA is common, suggesting that unilateral EVA is a bilateral process despite an initial unilateral imaging
finding. In contrast to bilateral EVA, unilateral EVA is not associated with Pendred syndrome and may have a different
etiology. Temporal bone measurements, hearing loss severity, and hearing loss at 250 Hz were all correlated with the risk of
progressive hearing loss. Clinicians should become knowledgeable regarding the implications of this disease process so that
families can be counseled appropriately.
Key Words: Hearing loss, genetics, molecular biology.
Level of Evidence: 2b.
Laryngoscope, 123:1537–1546, 2013
INTRODUCTION
Over the past two decades, abnormalities of the tem-
poral bone have increasingly been recognized as an
important etiology of sensorineural hearing loss (SNHL).1–
4 Given that high-resolution computed tomography (CT)
and magnetic resonance imaging have identified these
abnormalities in up to 37% of children with previously
unexplained SNHL, imaging has become an integral com-
ponent of the standard evaluation of children with
SNHL.3,4 The most common finding revealed by imaging is
an enlarged vestibular aqueduct (EVA); this is followed by
abnormalities of the cochlea and the vestibular system.5
Valvassori and Clemis were the first to describe a
group of children with SNHL and concomitant EVA.6 In
a cohort of 3,700 patients who had undergone polytomo-
graphic studies, these authors identified 50 patients with
From the Ear and Hearing Center, Division of Pediatric
Otolaryngology, Cincinnati Children’s Hospital Medical Center (J.G .,
A.D., A.C., T.U., J.M.-D.); Department of Otolaryngology–Head and Neck
Surgery, University of Cincinnati College of Medicine (J.G ., A. D., J.M.-D .);
Division of Human Genetics, Cincinnati Children’s Hospital Medical
Center (J.G., K. Z.); Department of Radiology, Cincinnati Children’s
Hospital Medical Center (C. B., M.H.); and Division of Biostatistics and
Epidemiology, Cincinnati Children’s Hospital Medical Center (J.M.-D .),
Cincinnati, Ohio, U.S.A.
Editor’s Note: This Manuscript was accepted for publication
October 22, 2012.
This project was funded in part by a State of Ohio Biotechnology
Research Technology Transfer grant.
The authors have no other funding, financial relationships, or con-
flicts of interest to disclose.
Send correspondence to John Greinwald, MD, FAAP, Ear and
Hearing Center, Division of Pediatric Otolaryngology–Head and Neck
Surgery, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Av-
enue, Cincinnati, OH 45229. E-mail:
DOI: 10.1002/lary.23889
Laryngoscope 123: June 2013 Greinwald et al.: Unilateral Enlarged Vestibular Aqueduct
Reprinted by permission of Laryngoscope. 2013; 123(6):1537-1546.
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