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Published on: February 29, 2020
Unilateral cochlear nerve deficiency in children.
Clarice S Clemmens1, Jessica Guidi, Aviva Caroff
1Department of Otorhinolaryngology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Summary
Cochlear nerve deficiency (CND) is a common cause of unilateral sensorineural hearing loss (SNHL) in children. A narrow bony cochlear nerve canal effectively predicts CND, which is often associated with ophthalmologic abnormalities.
Area of Science:
- Pediatric Otolaryngology
- Neuroimaging
- Auditory Neuroscience
Background:
- Cochlear nerve deficiency (CND) is increasingly identified in pediatric sensorineural hearing loss (SNHL).
- Understanding CND prevalence and imaging features is crucial for diagnosis and management.
Purpose of the Study:
- To determine the prevalence of CND in children with unilateral SNHL.
- To characterize imaging findings of CND.
- To explore correlations between CND and audiologic phenotype.
Main Methods:
- Retrospective case series of 128 children with unilateral SNHL.
- High-resolution magnetic resonance imaging (MRI) was used to assess cochlear nerve (CN) size and signal intensity.
- Bony cochlear nerve canal (BCNC) width was measured and correlated with CN parameters and hearing loss characteristics.
Main Results:
- CND was present in 26% of children with unilateral SNHL, rising to 48% in severe-to-profound cases.
- A narrow BCNC (<1.7 mm) strongly predicted CND and correlated with CN size and area.
- Hearing loss severity showed a modest correlation with nerve size, and progression was rare without other inner ear malformations.
- Ophthalmologic abnormalities, particularly oculomotor disturbances, were common (67%) in children with CND.
Conclusions:
- CND is a frequent cause of unilateral SNHL, especially congenital deafness.
- BCNC width is a reliable predictor of CND, valuable even with CT imaging.
- Hearing in affected ears is expected to remain stable.
- CND diagnosis warrants ophthalmologic evaluation.
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