Aberrant Course of the Intratemporal Facial Nerve in Children with Congenital Hearing Loss

Congenital facial nerve (FN) malformations are uncommon. Our aim is to determine the clinical and radiological features of FN malformations along with the associated cochlear and vestibular malformations. We conducted a retrospective study including children with a profound sensorineural hearing loss who were candidates for cochlear implantation. We evaluated the presence of FN malformations through temporal bone computed tomography scan and magnetic resonance imaging. We recorded an aberrant FN course in five out of 165 patients in a total of 9 ears. They consisted of a bifurcation of the mastoid segment, an anterior or posterior displacement of the labyrinthine segment and a hypoplasia of the geniculate ganglion. Associated inner ear malformations included vestibular aqueduct dilation, cochlear hypoplasia and total labyrinthine aplasia. We noted a bilateral agenesis of the cochlear nerve in three patients. Facial nerve malformations should be suspected in patients presenting a congenital hearing loss especially in association with other temporal bone malformations. Their pre-operative discovery is helpful in planning the surgical procedure.