A Case of Congenital Bifurcation of the Labyrinthine Segment of Facial Nerve

Abstract

The most common anomaly of facial nerve is bony dehiscence of the fallopian canal, being present in approximately 55% of the population. Abnormal courses of facial nerve are reported commonly. Of the malformation of the facial nerve, bifurcation of its intratemporal portion has been rarely reported, in which one or more segments of the facial nerve splits. Nine years-old girl (right-handed) came to our outpatient clinic for left hearing loss, which was incidentally found by herself. Audiologic and radiologic work-up demonstrated unilateral sensorineural hearing loss, which was resulted from the narrow bony cochlear nerve canal, and incidentally found the bifurcation of the labyrinthine segment of ipsilateral facial nerve. We described characteristic findings on the computed tomogram of this anomaly and discussed it. It is important to identify the anomalous facial nerve in the patients undergoing evaluation for congenital hearing loss. (J Clinical Otolaryngol 2019;30:83-87)