Internal auditory canal duplication with facial and cochlear nerve dysfunction: A case report

Area of Science:

• Otolaryngology
• Radiology
• Anatomy

Background:

• Internal auditory canal (IAC) duplication is a rare congenital anomaly of the temporal bone.
• It involves a bony septum dividing the IAC into two compartments, potentially affecting cranial nerves.

Observation:

• A 26-year-old female presented with long-standing right-sided facial nerve palsy and sensorineural hearing loss.
• High-Resolution Computed Tomography revealed an incomplete bony septum in the right IAC.
• Magnetic Resonance Imaging confirmed normal caliber vestibulocochlear and facial nerves.

Findings:

• The patient exhibited moderate sensorineural hearing loss and Grade IV lower motor neuron facial nerve palsy.
• Imaging confirmed incomplete IAC duplication on the right side.
• The left IAC and other inner/middle ear structures were normal.

Implications:

• This case underscores the importance of advanced imaging in diagnosing rare IAC anomalies.
• Understanding IAC duplication is crucial for managing associated neurological deficits like facial palsy and hearing loss.
• Further research into the embryological basis and clinical spectrum of IAC duplication is warranted.