A New Classification of Cochleovestibular Malformations and Implications for Predicting Speech Perception Ability after Cochlear Implantation

Abstract

Objectives: The aims of this study were to introduce a new classification of cochleovestibular malformation (CVM) and to investigate how well this classification can predict speech perception ability after cochlear implantation in children with CVM. Methods: Fifty-nine children with CVM who had used a cochlear implant for more than 3 years were included. CVM was classified into 4 subtypes based on the morphology of the cochlea and the modiolus on temporal bone computed tomography (TBCT): normal cochlea and normal modiolus (type A, n = 16), malformed cochlea and partial modiolus (type B, n = 31), malformed cochlea and no modiolus (type C, n = 6), and no cochlea and no modiolus (type D, n = 6). Speech perception test scores were compared between the subtypes of CVM using analysis of covariance with post hoc Bonferroni test. Univariate and multivariate regression analyses were used to identify the significant predictors of the speech perception test scores. Results: The speech perception test scores after implantation were significantly better in children with CVM type A or type B than in children with CVM type C or type D. The test scores did not differ significantly between the implanted children with CVM type A or type B and those without CVM. In univariate regression analysis, the type of CVM was a significant predictor of the speech perception test scores in implanted children with CVM. Multivariate regression analysis revealed that the age at cochlear implantation, cochlear nerve size and preimplantation speech perception test scores were significant predictors of the postimplantation speech perception test scores. The chance of cochlear nerve deficiency increased progressively from CVM type A to type D. Conclusion: The new classification of CVM based on the morphology of the cochlea and the modiolus is simple and easy to use, and correlated well with postimplantation speech perception ability and cochlear nerve status. This simple classification of CVM using TBCT with cochlear nerve assessment by magnetic resonance imaging is helpful in the preoperative evaluation of children with CVM.

Cochlear Implantation in Inner Ear Malformations: Systematic Review of Speech Perception Outcomes and Intraoperative Findings

“…Fifty-nine articles (date range: 1993-2015) were included in this systematic review, of which 23 studies 11-33 had SP data and 57 studies 11-29,32…”

“…Only 1 study included in this systematic review had speech data from patients with IP-1 malformations. 30 It is reasonable to assume that previous studies with common cavities included patients with a cystic cochleovestibular malformation (IP-1). Furthermore, we were unable to observe differences in speech outcomes or intraoperative findings in the CC population when we directly compared the studies that used the Jackler and the Sennaroglu classification systems.…”

Assessing the Benefit-Risk Profile for Pediatric Implantable Auditory Prostheses

“…Auditory skill development of these children is variable, with some demonstrating open-set speech recognition. 44 Other children show more disappointing post-implant performance, which has led some to conclude that a CI may not be the optimal treatment. [45][46][47][48] The disappointing findings have also been used to support denial of third-party payer coverage (authors' experience) for children with abnormal anatomy.…”

Audiological and Radiological Characteristics in Incomplete Partition Malformations

“…Patients with IP-III malformations can be diagnosed with conductive hearing loss (CHL), mixed hearing loss (MHL), or, rarely, sensorineural hearing loss (SNHL). Audiological intervention is determined according to the type and degree of hearing loss [11] . While a literature review found papers related to the audiological findings of patients with IP-I, IP-II, large vestibular aqueduct (LVA), and IP-III malformations separately, no study was found investigating and comparing the audiological findings in IP-I, IP-II, and IP-III patients collectively.…”

“…The present study included 26 patients (41 ears) with IP-I, 54 patients (108 ears) with IP-II, and 4 patients (8 ears) with IP-III malformations. A total of 67 ears were excluded from the audiological evaluation for having a cochlear implant (53), an auditory brainstem implant (1), atresia of the outer ear (1), normal cochlear anatomy in the contralateral ear (1), or an- other type of IEM in the contralateral ear (11). Figure 3 indicates the types of IEMs of the contralateral ears of the patients with unilateral IP-I malformations.…”