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Published on: February 29, 2020
Cochlear implantation in children with labyrinthine anomalies and cochlear nerve deficiency: implications for
Craig A Buchman1, Holly F B Teagle, Patricia A Roush
1Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. buchman@med.unc.edu
Insights
Children with inner ear malformations and cochlear nerve deficiency (CND) receiving cochlear implants (CI) show varied outcomes. While most respond to stimulation, those with CND or severe malformations have limited speech perception and may need alternative communication strategies.
Area of Science:
- Otolaryngology
- Pediatric audiology
- Neurosurgery
Background:
- Inner ear malformations and cochlear nerve deficiency (CND) present unique challenges for hearing restoration.
- Cochlear implantation (CI) is a common intervention, but outcomes vary based on the specific malformation.
Purpose of the Study:
- To compare the outcomes of cochlear implantation in children with different types of inner ear malformations and/or CND.
- To identify factors influencing speech perception and communication abilities post-CI.
Main Methods:
- Retrospective cohort study of 76 children who received cochlear implants between 1993 and 2010.
- Assessment of imaging, surgical findings, complications, device programming, and audiological/speech performance.
- Comparison of outcomes across groups with varying inner ear malformations and CND.
Main Results:
- Most children responded to CI stimulation, regardless of malformation type or CND.
- Children with CND showed higher pure tone averages and required more charge for stimulation.
- Open-set speech perception success rates varied: 100% for incomplete partition-enlarged vestibular aqueduct (IP-EVA), 50% for hypoplastic malformations, and 19% for CND.
- Eighth nerve compound action potential (ECAP) responses correlated with speech perception; manual communication strategies were more common in hypoplastic and CND groups.
Conclusions:
- Children with IP-EVA malformations have a favorable prognosis for speech perception and oral communication after CI.
- Severe malformations or CND may lead to higher stimulation needs and limited potential for open-set speech understanding and mainstream education.
- Alternative interventions like auditory brainstem implantation or visual communication strategies should be considered for children with poorer prognoses.
Objectives/Hypothesis:
Compare outcomes among children with inner ear malformations and/or cochlear nerve deficiency (CND) who have received a cochlear implant (CI).
Study Design:
Individual retrospective cohort study from 1993 to 2010.
Methods:
A select cohort of 76 children was identified. Imaging characteristics, operative findings, complications, mapping parameters, and performance were assessed. Comparisons among the different groups were undertaken.
Results:
Surgery was mostly uncomplicated. Nearly all children demonstrated behavioral responses to CI stimulation irrespective of inner ear morphology or the presence of CND. Children with CND had higher pure tone averages (PTAs) and required greater charge for stimulation than other malformation types. Open-set speech perception was achieved in 100% of children with incomplete partition-enlarged vestibular aqueduct (IP-EVA), 50% of those with hypoplastic malformations, and 19% of CND cases. Robust responses on eighth nerve compound action potential (ECAP) testing through the implant was associated with higher levels of speech perception. Manually supplemented communication strategies were more common among children with hypoplastic malformations (69%) and CND (95%) than those with IP-EVA (18%).
Conclusions:
Children with IP-EVA malformations have an excellent prognosis for developing open-set speech perception and using oral communication modes following CI. On the contrary, children with severe malformations or CND may have elevated charge requirements for attaining sound detection alone. These children's prognosis for obtaining open-set speech understanding, using exclusive oral communication, and participating in mainstream education is more limited. These findings have important implications for considering alternative forms of intervention such as auditory brainstem implantation and/or supplementation with visually based communication strategies.