Isolated Internal Auditory Canal Diverticula: A Normal Anatomic Variant Not Associated with Sensorineural Hearing...

Area of Science:

• Radiology
• Otolaryngology
• Anatomy

Background:

• Bony internal auditory canal diverticula are common, found in ~5% of temporal bone CTs.
• Historically considered incidental, recent studies suggest a link to sensorineural hearing loss.
• This study aimed to investigate the association between internal auditory canal diverticula and hearing loss in a large patient cohort.

Purpose of the Study:

• To evaluate the association between internal auditory canal diverticula and sensorineural hearing loss.
• To characterize the relationship in a large patient cohort.
• To determine if internal auditory canal diverticula represent a normal anatomic variant.

Main Methods:

• Retrospective analysis of 1759 temporal bone CT scans.
• Audiometric data collected for patients with internal auditory canal diverticula.
• Comparison of hearing in affected ears versus contralateral ears, excluding cases with otosclerosis or bilateral diverticula.

Main Results:

• 82 patients (4.7%) had internal auditory canal diverticula (33 unilateral, 49 bilateral).
• Otosclerosis co-occurred in 34% of cases.
• No significant difference in sensorineural hearing loss or word recognition was found between ears with isolated unilateral diverticula and their contralateral controls.

Conclusions:

• No statistically significant association was found between internal auditory canal diverticula and sensorineural hearing loss.
• Internal auditory canal diverticula are likely a normal anatomic variant, particularly in the absence of otosclerosis.