large vestibular aqueduct syndrome

Pathogenic
substitution of IVS15 + 5G > A in SLC26A4 in patients of Okinawa Islands with enlarged vestibular aqueduct syndrome or Pendred syndrome. Computed tomography of the temporal bone showing an enlarged vestibular aqueduct. Circles show the vestibular aqueduct. The vestibular aqueduct is not identified in control subject (A). The enlarged vestibular aqueduct is identified in a patient with EVA (B).
bmcmedgenet.biomedcentral.com • CC-by-2.0
Large
vestibular aqueduct syndrome (ECR 2016 Case of the Day). Bilateral dilated endolymphatic ducts and sacs
www.eurorad.org • CC by-nc-sa-4.0
Large
vestibular aqueduct syndrome (ECR 2016 Case of the Day). Bilateral dilated endolymphatic ducts and sacs on dedicated IAM imaging.
www.eurorad.org • CC by-nc-sa-4.0
Extremely
discrepant mutation spectrum of SLC26A4 between Chinese patients with isolated Mondini deformity and enlarged vestibular aqueduct. Typical CT scan images of MD, EVA with MD, EVA, and other inner ear malformations. a. MD; b. EVA with MD; c. EVA; d. common cavity (a cystic cavity representing the cochlea and vestibule without showing any differentiation into cochlea and vestibule); e. narrow internal auditory canal; f. internal auditory canal enlarged; g. inner ear ossification; h. cochlear, vestibular, and semicircular canal hypoplasia.
translational-medicine.biomedcentral.com • CC-by-2.0
Semicircular
canal dysplasia • Enlarged vestibular aqueduct syndrome - Ganzer Fall bei Radiopaedia
Bayat M, Enlarged vestibular aqueduct syndrome. Case study, Radiopaedia.org (Accessed on 21 Jul 2023) https://doi.org/10.53347/rID-76350 • CC by-nc-sa 3.0 (modified)
Pre- and
post-operative imaging of cochlear implants: a pictorial review. A 56-year-old male patient, with bilateral severe SNLH from birth. HRCT axial images show regular cochlea (open arrow), regular vestibulum and semicircular canals (not shown), and enlarged bony opening for the vestibular aqueduct (arrows), compatible with large vestibular aqueduct syndrome
insightsimaging.springeropen.com • CC-by-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Large vestibular aqueduct syndrome (LVAS), also known as enlarged vestibular aqueduct (EVA) or large endolymphatic sac anomaly (LESA), refers to the presence of congenital sensorineural hearing loss with an enlarged vestibular aqueduct due to enlargement of the endolymphatic duct. It is thought to be one of the most common congenital causes of sensorineural hearing loss.

Clinical presentation

Sensorineural hearing loss starts in childhood and is progressive . Hearing loss may be sudden onset and occurs after minor head trauma .

Pathology

Associations

Associated anomalies are the norm, occurring in ~85% of patients :

Radiographic features

CT/MRI

A measurement of the vestibular aqueduct of 1.5 mm is considered the upper limit of normal . This measurement is ideally made halfway between the crus and the aperture on an axial view (i.e. AP dimension). Some studies suggest consideration of upper limit measurements of the midpoint of the aqueduct and operculum being at 1 mm and 2 mm, respectively .

The bony modiolus is not visible in up to 90% of cases.

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