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Updated: Jun 22, 2026
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Behavioral Assessment of Hearing in 2 to 4 Year-old Children: A Two-interval, Observer-based Procedure Using Conditioned Play-based Responses
Published on: January 23, 2017
Cochlear nerve aplasia detected through kindergarten hearing screening
J Paul Moxham1, J Matthew Dickson, Michael A Sargent
1Pediatric Otolaryngology-Head and Neck Surgery, British Columbia Children's Hospital, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada.
Summary
Cochlear nerve agenesis, a condition causing sensorineural hearing loss, may be more common than previously thought in healthy children. Imaging like MR scans is crucial for definitive diagnosis when hearing tests suggest this rare condition.
Area of Science:
- Otolaryngology
- Pediatric Radiology
- Neuroscience
Background:
- Sensorineural hearing loss (SNHL) in children requires thorough investigation.
- The cochlear nerve plays a vital role in auditory signal transmission.
- Imaging modalities like MRI and CT are essential for evaluating inner ear and neural structures.
Purpose of the Study:
- To highlight the importance of magnetic resonance (MR) and computed tomography (CT) imaging in diagnosing cochlear nerve status in pediatric SNHL.
- To determine the diagnostic pathway and associated factors for cochlear nerve agenesis.
Main Methods:
- Retrospective chart review of pediatric patients diagnosed with absent cochlear nerve.
- Analysis of audiologic data including audiometry, auditory brainstem response (ABR), and otoacoustic emissions (OAE).
- Review of radiologic imaging (CT and MR scans) to assess cochlear nerve and internal auditory canal morphology.
Main Results:
- Twelve cases of cochlear agenesis were identified; eight met inclusion criteria.
- All affected children failed initial audiologic screening, with subsequent evaluations showing profound loss, dead ear, or abnormal ABR with normal OAE.
- Radiologic findings included internal auditory canals <1.4 mm or other MR-compatible abnormalities.
Conclusions:
- Cochlear nerve agenesis might be more prevalent than previously assumed, particularly in healthy, non-syndromic school-aged children.
- While audiologic tests strongly suggest the diagnosis, MR imaging remains the gold standard for definitive confirmation.
- Early and accurate diagnosis through imaging is critical for appropriate management of pediatric hearing loss.
