Cochlear implants in aplasia and hypoplasia of the cochleovestibular nerve.
OBJECTIVE
To report on the outcome of four patients with aplasia or hypoplasia of the cochleovestibular nerve who have received a cochlear implant.


METHODS
Retrospective case review.


METHODS
Tertiary referral center.


METHODS
Four patients with: 1) type I aplasia; 2) type IIa aplasia; 3) type IIa hypoplasia; and 4) type IIb aplasia received a cochlear implant. All patients had corner audiograms even with hearing aids.


METHODS
Three patients received a LAURA multichannel implant, and one patient received a Nucleus 24 implant.


METHODS
Auditory performance, educational setting.


RESULTS
The patients with type I and type IIb aplasia did not have auditive perception with their implant and became non-users. Both are now in a total communication educational setting. The patients with type IIa aplasia and hypoplasia had moderate audiological results with the implant with audiometrical thresholds of approximately 40-60 dB HL (pure tone average), moderate phoneme discrimination, and poor word discrimination. One child is in a total communication educational setting and the other in an oral educational setting, but the preferred mode of communication remains total communication for both. Both appear to benefit from the implant nonetheless.


CONCLUSIONS
Patients with aplasia/hypoplasia of the cochleovestibular nerve should be counseled with caution with respect to cochlear implantation, but particular circumstances may justify the intervention. At present these circumstances seem to be a type IIa aplasia or hypoplasia in which the end organ (cochlea or common cavity) still connects to a neural structure on MRI.
The Eargroup, Antwerp-Deurne, Belgium. dr.govaerts@eargroup.net
P J
PJ
Govaerts
J
J
Casselman
K
K
Daemers
C
C
De Beukelaer
M
M
Yperman
G
G
De Ceulaer
D001307:Auditory Perception; D001309:Auditory Threshold; D002675:Child, Preschool; D019929:Cochlear Implantation; D003145:Communication Methods, Total; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D000159:Vestibulocochlear Nerve / Q000002:abnormalities* / Q000000981:diagnostic imaging