Abstract
Problem: Large vestibular aqueduct (LVA) syndrome is one of the most common anomalies in childhood hearing loss. Our purpose was to determine (1) whether there is any relationship between LVA and other systemic and/or otologic findings or syndromes and (2) characteristics of inner ear changes in these temporal bones.
Methods: To get the mean antero-posterior diameter of the vestibular aqueduct internal orifice, 40 normal bones (mean age, 35 years; range, 2–87 years) were selected. We defined the internal aperture diameter as the proximal opening of vestibular aqueduct into the medial wall of the vestibule. Values of its antero-posterior diameter were sorted from the smallest value to the biggest. Values above the 95th percentile (0.5 mm) of the normal group were accepted as LVA. From 1850 human temporal bones in our collection, 89 bones (59 cases) fit this criterion. We analyzed clinical histories for systemic or otologic anomalies and syndromes associated with them and noted histopathologic anomalies of the middle and inner ears.
Results: The age of patients ranged from stillborn to 91 years (mean, 22 years). A total of 119 external and middle ear anomalies were seen, the more frequent being dehiscent facial nerve, deformities of ossicles, and low-set auricles. A total of 110 inner ear anomalies were identified, with shortened cochlea, hair cell loss, decrease of spiral ganglion cells, and defects of interscalar septum most common. Conditions frequently associated with anomalies were congenital heart problems, Klippel-Feil syndrome, trisomies (10, 13, 18, 21), Hurler's syndrome, and Mondini's dysplasia. Only 1 of 89 bones did not have an anomaly of the inner ear.
Conclusion: We found LVA to be associated with other syndromes and systemic and/or otologic findings. Although the mechanism of hearing loss is unclear, it could be attributed to an accompanying cochlear anomaly.
Significance: The presence of LVA suggests that other syndromes and systemic and/or otologic findings are likely.
Support: The International Hearing Foundation and NIDCD P30 DC04660