Enlarged Vestibular Aqueduct Syndrome (EVAS)

Enlarged Vestibular Aqueduct Syndrome (EVAS) is a congenital inner ear condition in which the vestibular aqueduct, a small bony canal connecting the inner ear to the skull, is larger than normal. This abnormal enlargement can affect the delicate structures responsible for hearing and balance. EVAS is one of the most common inner ear malformations associated with childhood hearing loss.

The condition may be present at birth, but hearing can initially appear normal and gradually worsen over time. Hearing loss in EVAS is often sensorineural, fluctuating, or progressive, and may affect one or both ears. Some individuals experience sudden declines in hearing following minor head injuries, rapid changes in air pressure, or intense physical activity.

In addition to hearing difficulties, people with EVAS may develop balance problems, dizziness, or unsteady movement. The severity of symptoms varies widely among individuals. Diagnosis typically involves hearing assessments and imaging studies such as CT scans or MRI, which help identify the enlarged vestibular aqueduct.

Although there is no cure for EVAS, management focuses on protecting hearing and improving communication. Hearing aids, educational support, and speech-language therapy are commonly recommended. In cases of severe hearing loss, cochlear implantation may be considered. Early diagnosis and regular monitoring can help individuals maintain better hearing outcomes and quality of life.