The Enlarged Vestibular Aqueduct Syndrome (EVA Syndrome)

The presentation to the Department of Pediatric Otolaryngology at the Children's Hospital of Michigan of a series of patients with sensorineural hearing loss and enlargement of the vestibular aqueduct prompted exploratory tympanotomy in three patients (two unilateral and one bilateral), for a total of four ears. These explorations were prompted by progression and/or fluctuation of hearing levels. The discovery of abnormal round windows in all four ears with a post-traumatic fistula present in one ear suggested the presence of a new association. A previously undescribed association of an enlarged vestibular aqueduct, sensorineural hearing loss and round window abnormality with potential fistula formation was identified. A review of the anatomy and physiology, literature review, and a prospective analysis with discussion of eight patients with enlarged vestibular aqueduct syndrome evaluated and treated at Children's Hospital of Michigan, is presented. We conclude that all children with sensorineural hearing loss should undergo extensive evaluation to determine etiology, including radiographic studies of the temporal bone. Further, the presence of an enlarged vestibular aqueduct should prompt the otolaryngologist to consider the presence of a round window abnormality and the potential for predisposition to perilymph fistula.