Cochlear implants (CI) are now widely used in young deaf children and have shown tremendous promise in facilitating a variety of developmental outcomes. Specifically, improvements have been shown in oral language, speech perception and recognition, attention, and behavioral development [1
]. In the past two decades, behavioral, psychological, and cognitive disabilities were considered contraindications for pediatric cochlear implantation and CI Centers often refrained from implanting these children [6
]. More recently, as cochlear implantation has been extended to younger children, greater consideration has been given to implanting deaf children with other disabilities [9
]. However, little is currently known about the outcomes of cochlear implantation for these children. The purpose of this longitudinal study was to evaluate the language and behavioral outcomes of deaf children receiving CIs who had additional co-morbidities (e.g., autism/pervasive developmental disorder, learning disorders, cerebral palsy) in comparison to a large, national sample of deaf children with no other diagnoses.
Despite the fact that there are no guidelines for the use of CIs in children with disabilities, CI surgery for this population is steadily increasing and is estimated to be 30% to 40% of children using CIs [10
]. The most prevalent diagnoses reflect developmental disabilities, such as intellectual disabilities and learning disorders. One explanation for this increase is that hearing loss is being identified earlier, with the national uptake of newborn screening. In addition, the FDA has lowered the recommended age for implantation from 24 to 12 months of age, which has led to earlier cochlear implantation. Thus, a larger number of children may be implanted prior to the emergence or identification of certain disabilities (e.g., autism, attention-deficit hyperactivity disorder [ADHD] [11
To date, few studies have examined the outcomes of CI children with developmental disabilities and results across these studies have been mixed. Moreover, they have typically relied on retrospective reviews, individual case reports, anecdotal evidence, and studies with small samples [10
]. In general, improvements have been observed in auditory and speech perception and spoken communication. However, their performance at baseline has often been lower than deaf children without additional disabilities and their progress has often been slower [9
A recent, small study evaluated speech perception and intelligibility in 32 children implanted under the age of 3.5 years, with 11 evidencing developmental delays [16
]. Results showed that 8 of the delayed children made progress in speech perception and intelligibility, however, not to the same extent as the typically developing children, and 3 made almost no progress at all.
In a slightly larger study of 69 CI children, 19 children were identified as “cognitively delayed” using standardized IQ measures [17
]. The authors reported that, over two years, the CI children with cognitive delays achieved benefits similar to those of the typically developing CI children. Both groups of children made significant improvements in speech perception over time. However, children with additional disabilities continued to score lower on oral language than the children without additional disabilities.
More recently, Wiley, Meinzen-Derr and Choo completed a retrospective review of the acquisition of auditory skills in typical and developmentally delayed children one year post-implantation [18
]. Fourteen of the 36 children were identified with developmental delays. At the one-year follow-up, both groups evidenced improvements in auditory skills; however, children in the developmentally delayed group had lower scores at baseline and did not “catch up” to their typically developing peers.
A subsequent study by the same authors evaluated post-implant language skills in a sample of 20 deaf children with developmental disabilities compared to age- and cognition-matched controls [19
]. Results indicated that CI children with other disabilities scored significantly lower on oral language measures than matched controls. These results converge with a recent study of 66 children who received a cochlear implant and had at least one disability (e.g., developmental disability, CHARGE, cerebral palsy). Functional disability scores, derived from the Battelle developmental screen, were significant predictors of speech perception scores across a range of ages and duration of implant use [20
Although oral language has been the focus of CI research, other studies have also reported positive effects of cochlear implantation on behavioral, social, and emotional development [3
]. Research has consistently reported that deaf children and children with developmental disabilities have higher rates of behavior problems than children without disabilities [21
]. These higher rates of behavior problems may potentially increase parenting stress and family dysfunction [21
] and parents report that their children’s behavior problems are a greater stressor than the disability itself [27
Similarly, children with sensorineural hearing loss (SNHL) exhibit higher rates of externalizing behavior problems, such as inattention and aggression (30–38%; [24
]) than children with normal hearing (3–18%; [31
]). Parents of deaf children also report more internalizing problems (e.g., anxiety, sadness) compared to parents of hearing children (25–38% vs. 2–17%; [28
Recent studies showed that deaf children with worse language had higher rates of behavior problems [24
]. These studies suggest that language influences behavior problems by limiting the child’s ability to effectively communicate with others, or by affecting emotional and behavioral regulation [35
]. The current study expanded these results by examining behavior problems over three years post-implantation among typically developing children in a large cohort of young children who received CIs, and compared their performance to children with other comorbidities enrolled in the same cohort.
Participants for this report were drawn from the largest, youngest, nationally representative sample of children with CIs. Our main goal was to compare the oral language development of CI children with and without developmental disabilities over three years after implantation. Children with attention-deficit hyperactivity disorder (ADHD), learning disorders, autism/pervasive developmental disorders, and cerebral palsy were included in this study. Further, we evaluated rates of internalizing and externalizing behavior problems. We tested the following hypotheses: 1) children with developmental disabilities will have lower receptive and expressive language scores compared to typically developing children prior to cochlear implantation, 2) children with developmental disabilities were expected to have a slower rate of growth in oral language skills over three years, 3) children with developmental disabilities will have higher rates of internalizing and externalizing behavior problems at baseline than typically developing children using CIs, and 4) behavior problems were expected to decrease in both groups over time.