The American Academy of Audiology (AAA) reports on research findings from the National Institute on Deafness and Other Communication Disorders showing that vestibular aqueducts are considered enlarged if greater than 1.5 millimeters in size.
If the vestibular aqueducts are enlarged, it is likely the endolymphatic duct and sac are enlarged, too, notes AAA. Generally, children with enlarged vestibular aqueducts (EVAs) will develop hearing loss ranging from mild to profound and may involve one or both ears. Some 15% of children with bilateral sensorineural hearing loss (SNHL) have EVAs and perhaps one-third of all children with unilateral SNHL have EVA (Dabrowski, Myers, and Daniliova, 2009).
EVAs may represent a symptom of Pendred Syndrome in one-third of the people diagnosed with EVAs, AAA notes. Pendred Syndrome is associated with progressive SNHL and may render the patient deaf (NIDCD, 2006). EVA patients may develop vestibular symptoms. EVA is the most commonly observed ear abnormality evidenced in children with SNHL via CT.
There is no medical or surgical treatment to reduce hearing loss or slow its progress in children with EVA. People with EVA are often advised to avoid activities such as contact sports that may lead to head injury (football, hockey, wrestling, bicycling, skiing, etc) and helmets should be worn to help avoid traumatic injury.
Dabrowski and colleagues report that 62% of all EVA cases (from a 1978 study by Valvassori and Clemens) have comorbid ear malformations, suggesting a propensity for EVA Syndrome.
For more information, references, and recommendations:
Dabrowski T, Myers B, Danilova R.(2009) Identifying Enlarged Vestibular Aqueduct Syndrome. Advance for Audiologists. November/December 2009:46-49.
Enlarged Vestibular Aqueducts and Childhood Hearing Loss National Institute on Deafness and Other Communication Disorders. NIH Pub. No. 06-6053. October 2006.