Childhood Development after Cochlear Implantation (CDaCI) study: Design and baseline characteristics

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study. A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes. This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterise potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation. Copyright © 2007 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56091/1/333_ftp.pd

Surgical Factors in Pediatric Cochlear Implantation and Their Early Effects on Electrode Activation and Functional Outcomes

To assess the impact of surgical factors on electrode status and early communication outcomes in young children in the first 2 years of cochlear implantation

Language development after cochlear implantation: an epigenetic model

Growing evidence supports the notion that dynamic gene expression, subject to epigenetic control, organizes multiple influences to enable a child to learn to listen and to talk. Here, we review neurobiological and genetic influences on spoken language development in the context of results of a longitudinal trial of cochlear implantation of young children with severe to profound sensorineural hearing loss in the Childhood Development after Cochlear Implantation study. We specifically examine the results of cochlear implantation in participants who were congenitally deaf (N = 116). Prior to intervention, these participants were subject to naturally imposed constraints in sensory (acoustic–phonologic) inputs during critical phases of development when spoken language skills are typically achieved rapidly. Their candidacy for a cochlear implant was prompted by delays (n = 20) or an essential absence of spoken language acquisition (n = 96). Observations thus present an opportunity to evaluate the impact of factors that influence the emergence of spoken language, particularly in the context of hearing restoration in sensitive periods for language acquisition. Outcomes demonstrate considerable variation in spoken language learning, although significant advantages exist for the congenitally deaf children implanted prior to 18 months of age. While age at implantation carries high predictive value in forecasting performance on measures of spoken language, several factors show significant association, particularly those related to parent–child interactions. Importantly, the significance of environmental variables in their predictive value for language development varies with age at implantation. These observations are considered in the context of an epigenetic model in which dynamic genomic expression can modulate aspects of auditory learning, offering insights into factors that can influence a child’s acquisition of spoken language after cochlear implantation. Increased understanding of these interactions could lead to targeted interventions that interact with the epigenome to influence language outcomes with intervention, particularly in periods in which development is subject to time-sensitive experience

Benefits of Cochlear Implantation on the Whole Child: Longitudinal Changes in Cognition, Behavior, Parenting, and Health-Related Quality of Life

Early cochlear implantation has multiple benefits for children with hearing loss. Longitudinal studies have shown improvements in visual attention, behavioral regulation, and health-related quality of life. Although tremendous gains in oral language have been documented, significant deficits in behavioral and social–emotional functioning remain. Currently, pediatric cochlear implant teams focus on remediation of audiological and oral language skills, but often ignore the impact of deafness on broader areas of functioning and the family system. This chapter provides a review of outcomes across several domains, with recommendations for family-centered interventions that have shown promise

Development of Joint Engagement in Young Deaf and Hearing Children: Effects of Chronological Age and Language Skills

Purpose To evaluate joint engagement (JE) in age-matched children with and without hearing and its relationship to oral language skills. Method Participants were 180 children with severe-to-profound hearing loss prior to cochlear implant surgery, and 96 age-matched children with normal hearing; all parents were hearing. JE was evaluated in a 10-minute videotaped free play task with parents. Engagement states ranged from the lowest (unengaged) to the highest level (symbol-infused coordinated). Standardized language measures were administered. Results Multivariate analyses were conducted between the groups, stratified by chronological and language age. Children who were deaf (Deaf) spent less time in total symbol-infused JE than children with normal hearing (NH) across all ages. The majority of the Deaf group (83%) fell in the lowest language age group, in comparison to 35% of the NH group, and spent significantly less time in symbol-infused JE than hearing children. These delays were also observed in the Deaf group, who fell into the 18-36 month language age. No children in the Deaf group had achieved a language age of > 36 months. Conclusions Young children with and without hearing had different developmental trajectories of JE, which were related to oral language skills

Electric charge requirements of pediatric cochlear implant recipients enrolled in the Childhood Development After Cochlear Implantation study

To evaluate mapping characteristics of children with cochlear implants who are enrolled in the Childhood Development After Cochlear Implantation (CDACI) multicenter study. Longitudinal evaluation during 24 months of speech processor maps of children with cochlear implants prospectively enrolled in the study. Six tertiary referral centers. One hundred eighty-eight children enrolled in the CDACI study who were 5 years old or younger at the time of enrollment. Of these children, 184 received unilateral implants, and 4 received simultaneous bilateral implants. Children attended regular mapping sessions at their implant clinic as part of the study protocol. Maps were examined for each subject at 4 different time intervals: at device activation and 6, 12, and 24 months postactivation. Mean C/M levels (in charge per phase) were compared for 4 different time intervals, for 3 different devices, for 6 different implant centers, and for children with normal and abnormal cochleae. All 3 types of implant devices demonstrate significant increases in C/M levels between device activation and the 24-month appointment. Significant differences in mean C/M levels were noted between devices. Children with cochlear anomalies demonstrate significantly greater C/M levels than children with normal cochleae. The CDACI study has enabled us to evaluate the mapping characteristics of pediatric patients who use 3 different devices and were implanted at a variety of implant centers. Analysis of such data enables us to better understand the mapping characteristics of children with cochlear implants

Ultra-High-Field Magnetic Resonance Imaging of the Human Inner Ear at 11.7 Tesla

Objective: To evaluate the ability of ultra-high-field magnetic resonance imaging (UHF-MRI) at 11.7 T to visualize membranous structures of the human inner ear. Specimens: Three temporal bones were extracted from cadaveric human heads for use with small-bore UHF-MRI. Intervention: Ex vivo cadaveric temporal bone specimens were imaged using an 11.7 T magnetic resonance imaging (MRI) scanner via T1- and T2-weighted-imaging with and without contrast. Main Outcome Measure: Qualitative visualization of membranous components of the inner ear compared with reports of UHF-MRI at lower field strengths. Results: The membranous anatomy of the inner ear was superbly visualized at 11.7 T. In the cochlea, Reissner's membrane, the scala media, and the basilar membrane were clearly shown on the scan. In the vestibular labyrinth, the wedge-shaped crista ampullaris and the maculae of both the saccule and utricle were visible. Details of the endolymphatic sac and duct were also demonstrated. Conclusion: To our knowledge, this report presents the first images of the ex vivo human inner ear using 11.7 T UHF-MRI, offering near-histologic resolution. Increased field strength may be particularly useful when imaging the delicate membranous anatomy of the inner ear. Further research on the use of UHF-MRI in clinical and research settings could illuminate structural changes associated with inner ear disorders

Ultra-High-Field Magnetic Resonance Imaging of the Human Inner Ear at 11.7 Tesla

Objective: To evaluate the ability of ultra-high-field magnetic resonance imaging (UHF-MRI) at 11.7 T to visualize membranous structures of the human inner ear. Specimens: Three temporal bones were extracted from cadaveric human heads for use with small-bore UHF-MRI. Intervention: Ex vivo cadaveric temporal bone specimens were imaged using an 11.7 T magnetic resonance imaging (MRI) scanner via T1- and T2-weighted-imaging with and without contrast. Main Outcome Measure: Qualitative visualization of membranous components of the inner ear compared with reports of UHF-MRI at lower field strengths. Results: The membranous anatomy of the inner ear was superbly visualized at 11.7 T. In the cochlea, Reissner's membrane, the scala media, and the basilar membrane were clearly shown on the scan. In the vestibular labyrinth, the wedge-shaped crista ampullaris and the maculae of both the saccule and utricle were visible. Details of the endolymphatic sac and duct were also demonstrated. Conclusion: To our knowledge, this report presents the first images of the ex vivo human inner ear using 11.7 T UHF-MRI, offering near-histologic resolution. Increased field strength may be particularly useful when imaging the delicate membranous anatomy of the inner ear. Further research on the use of UHF-MRI in clinical and research settings could illuminate structural changes associated with inner ear disorders