Cochlear Implantation in Children With Cochlear Nerve Absence or Deficiency

Department of Otolaryngology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology (Impact Factor: 1.79). 06/2011; 32(6):956-61. DOI: 10.1097/MAO.0b013e31821f473b
Source: PubMed


To evaluate speech perception after cochlear implantation in children with cochlear nerve absence or deficiency.
A retrospective case review was performed to identify children who underwent cochlear implantation with cochlear nerve absence or deficiency. The cochlear nerve was evaluated by high-resolution three-dimensional T2-weighted fast spin echo MR in the oblique sagittal and axial planes. A deficient cochlear nerve was defined as a cochlear nerve that is smaller in diameter when compared with the adjacent facial nerve in the midportion of the internal auditory canal. The cochlear nerve was considered absent if there was no imaging evidence of a cochlear nerve. Speech awareness threshold and the speech perception category score were used to measure speech perception after cochlear implantation.
Seven children who underwent cochlear implantation in an ear without imaging evidence of a cochlear nerve were identified. One child developed early closed-set speech recognition. The other 6 children developed only speech detection or pattern perception. Two children underwent cochlear implantation with a deficient cochlear nerve. One developed consistent closed-set word recognition and the other developed early closed-set word recognition. The mean follow-up time for all patients was 3.8 years (range, 1.1-7.1 yr).
Cochlear nerve deficiency is not an uncommon cause for profound sensorineural hearing loss and presents a challenge in the decision-making process regarding whether to proceed with a cochlear implant. Children with a deficient but visible cochlear nerve on magnetic resonance image can expect to show some speech understanding after cochlear implantation; however, these children do not develop speech understanding to the level of implanted children with normal cochlear nerves. Children with an absent cochlear nerve determined by magnetic resonance imaging can be expected to have limited postimplantation sound and speech awareness.

Download full-text


Available from: Timothy N Booth, Mar 13, 2014
  • Source
    • "Historically, many possible prognostic factors have been identified, but as yet not validated. Examples include auditory neuropathy/auditory dysynchrony (Madden et al., 2002; Manchaiah et al., 2011; Schramm and Harrison, 2010); cochleovestibular nerve aplasia and hypoplasia (Bamiou et al., 2001; Govaerts et al., 2003; Kutz et al., 2011; Seymour et al., 2010); Waardenburg syndrome (Kaufmann et al., 2010; Kontorinis et al., 2011); CHARGE Association (Bauer et al., 2002; Dammeyer, 2012; Lanson et al., 2007; Lina-Granade et al., 2010; Pampal, 2010) and enlarged vestibular aqueduct (Chen et al., 2011; Lin et al., 2005). Multi-centre studies will be required to evaluate many of these satisfactorily. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Identification and evaluation of prognostic factors that are associated with paediatric cochlear implantation (PCI) outcomes was the aim of this study. A retrospective review of 174 charts was performed at the Royal Children's Hospital and the Hear and Say Centre, Brisbane. This examined the possible influence of a number of variables (including age at implant, family, additional disabilities, surgical complications, gender, GJB2 mutations, meningitis, inner ear malformations, and prematurity) on outcome measures: receptive, expressive, and total language, receptive and expressive vocabulary, speech articulation and categories of auditory performance at 18-24 months post-implant. Multiple regression analysis was used to identify variables related to language and vocabulary outcomes. The findings suggest that inner ear malformations and family concern are negatively associated with receptive and expressive language and receptive vocabulary scores. There was marginal evidence to suggest that increasing age at implantation was associated with lower receptive and expressive language scores. Prognostic factors that have been adequately validated statistically include inner ear malformations, the influence of family and late age at implantation. However, this study identified a need to define better the impact of the various degrees of inner ear malformations, to particularly emphasize the role of family as a strong predictor of PCI outcomes, and to confine the study of 'age at implantation' to pre-lingually deafened children. Evaluation of prognostic factors is a key element in PCI. This study confirmed several factors that are strongly associated with outcomes. For better research, there is a need for universal standardized outcome measures and development of a standardized framework for recording patient data.
    Full-text · Article · Aug 2013 · Cochlear implants international
  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess the normative size of the cochlear nerve (CN) and facial nerve (FN) in normal-hearing ears and to determine whether nerve size varies with age. Cross-sectional. We included 169 ears with normal hearing between 2005 and 2010. The height, width, and cross-sectional area (CSA) of the CN and FN in the middle of the internal auditory canal were measured on oblique sagittal images of 3.0-T magnetic resonance imaging. Results were compared by age. Young subjects were divided into three age groups, 0-5, 6-10, and 11-15 years. Subjects over age 40 years were divided into groups at 10-year intervals. Mean age was 32.6 years (range, 0.75-79 years). We found that the CN had significantly greater vertical (1.10 ± 0.21 mm vs. 0.95 ± 0.21 mm) and horizontal (1.11 ± 0.20 mm vs. 1.03 ± 0.22 mm) diameters than the FN. The CSA of the CN was larger than that of the FN (0.98 ± 0.33 mm(2) vs. 0.79 ± 0.31 mm(2) ). Except for the CN vertical diameter, there were no significant differences between right and left ears. Sex did not affect the nerve size. Although the CN was not affected by age, the FN vertical diameter and CSA of children <5 years were significantly smaller than those of children aged >5 years. The size of the two nerves did not differ among groups over age 40 years. The CN is not affected by age in normal-hearing ears. The FN vertical diameter and CSA of children <5 years are smaller than those of older children.
    No preview · Article · May 2012 · The Laryngoscope
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cochlear implantation for children with cochlear nerve deficiency remains controversial, as the presence of the cochlear nerve has been central to the success of cochlear implantation. This study sought to investigate whether there is any benefit from cochlear implantation for children with cochlear nerve deficiency. Nine children with cochlear nerve deficiency and bilateral prelingual profound sensorineural hearing loss were included in this study. Inner ear and internal auditory canal structures were evaluated using magnetic resonance imaging and temporal bone computed tomography scans. Meaningful auditory integration scales, categories of auditory performance scores, speech intelligibility ratings and pure tone average threshold with cochlear implantation were measured for evaluation of hearing and speech performance. Only four (44.4%) children had a significant improvement in pure tone average threshold with the cochlear implant device (77.5 dBHL, 45 dBHL, 51.3 dBHL and 68.8 dBHL). No child achieved sufficient speech intelligibility or perception ability during a follow-up of at least one year after surgery. The decision to perform cochlear implantation in children with cochlear nerve deficiency must be undertaken with caution as it has limited effectiveness and uncertain cost-benefit.
    No preview · Article · Jun 2012 · International journal of pediatric otorhinolaryngology
Show more