Expert: Harriet B Jacobster, Au.D. - 10/28/2008

Question
My son has mild/moderate sensorineural hearing loss in one ear only.  We have him scheduled for a CT scan.  The doctor suggested it COULD be EVA.  

Here's my question; if it is, is it possible that he really has it in both ears but only lost hearing "so far" in one?  Or, would we expect it to only be a defect in one ear?

Thanks.

Answer
Hi Chris,
Approximately 5-15% of children with sensorineural hearing loss have EVA. The loss is usually progressive.  Two tests that are often used to identify the cause of hearing loss are magnetic resonance imaging (MRI) and computed tomography (CT) imaging of a person's inner ear. One or both tests are often recommended to evaluate a child with sensorineural hearing loss. This is particularly true when a child's hearing loss occurs suddenly, is greater in one ear than the other, or varies or gets worse over time. Although most CT scans of children with hearing loss are normal, EVA is the most commonly observed abnormality. The presence of EVA can be a symptom of a genetic disorder called Pendred syndrome, a cause of childhood hearing loss. According to a study by the National Institute on Deafness and Other Communication Disorders (NIDCD), approximately one-third of individuals with EVA and hearing loss have Pendred syndrome. With Pendred syndrome, the hearing loss is progressive, which means that a child will have less hearing over time. Some children may become totally deaf.
For further information, see: http://www.nidcd.nih.gov/health/hearing/eva.htm
Hope this helps.
Harriet B. Jacobster, AuD
Board Certified in Audiology