Unilateral Duplication of the Internal Auditory Canal: Stenosis and Incomplete Transverse Megacrest in a Pediatric Patient

Based on the available literature, duplicated internal auditory canals (DIACs) represent an exceedingly rare temporal bone anomaly that can result in sensorineural hearing loss (SNHL) in the pediatric population. Often associated with a hypoplastic or aplastic cochlear nerve, DIAC poses limitations on treatment options, such as cochlear implants, for affected patients. Accurate diagnosis and optimal management necessitate a thorough assessment of inner ear structures and potential neural abnormalities with high-resolution computed tomography and magnetic resonance imaging of the temporal bones. However, diagnosis of DIACs poses a significant challenge and may be underrecognized during imaging procedures due to similarities with non-duplicated stenotic cochlear abnormalities and unfamiliar characteristics. This case report describes pertinent radiologic features of DIAC in the case of a pediatric patient who presented with SNHL during late childhood and was subsequently found to have an incomplete bony megacrest within the internal auditory canal, resulting in a unilateral DIAC.