Congenital facial and cochlear nerve hypoplasia with cochlear dysplasia causing sensorineural hearing loss and facial palsy: A case report

Congenital cochlear nerve deficiency, facial nerve dysfunction, and inner ear malformations are all rare etiologies of sensorineural hearing loss and facial palsy. They become even rarer when occurring simultaneously in the same patient. The authors report a case of a 20-month-old male patient presenting with grade V House-Brackmann right facial palsy, associated with bilateral profound sensorineural hearing loss. Imaging revealed dysplastic cochlea on the right, left hypoplastic cochlear nerve within the internal auditory canal, bilateral absence of the semicircular canals, and bilateral hypoplasia of the facial nerves. The possible etiologies and embryological explanation of the pathogenesis behind these deformities are discussed.