Clinical significance of a hearing and imaging workup in a child with cochlear nerve aplasia and a normal internal auditory canal.

Modern magnetic resonance imaging has significantly improved the diagnosis of cochlear nerve deficiencies. A careful assessment of all clinical, imaging, and auditory data is of utmost importance in such cases in order to properly establish the site of the abnormality. We report the case of a 3-year-old girl with unilateral cochlear nerve aplasia, normal middle and inner ear anatomy, and an absence of otoacoustic emissions, all of which erroneously suggested cochlear damage. We also briefly review the embryogenesis of the inner ear and auditory pathway. A patient with similar findings in the setting of a bilateral hearing loss and insufficient imaging would be at risk of inappropriate cochlear implantation.