Cochlear Implantation in Infants: Why and How

Postural stability at activation and deactivation of the cochlear implant in adolescents with late lateral implantations: a quasi-experiment

BACKGROUND

Cochlear implantation (CI) surgery has become a prevalent method of hearing rehabilitation, since it has been acknowledged that it impacts effectively on the vestibular system. However, there is still no consensus among clinicians on the most appropriate age and area (lateral/bilateral) of CI surgery in terms of postural control. The present study aimed to assess the postural control in late lateral CI adolescents with different visual (eyes opened(EO)/eyes closed(EC)) and auditory (CI activated/deactivated) conditions and to build a theoretical model of postural control based on sensual compensatory mechanisms that are predominant in late CI individuals. It was hypothesized that kinesthetic sensation and exteroceptors of the superficial sensation are critical for neuromuscular control after late CI.

METHODS

A quasi-experimental study protocol was used in this study to assess the postural stability performance in the studied adolescents with different visual and auditory perceptions. 27 adolescent students with hearing loss participated in the study. A force plate (Accu Gait AMTI) with computer software (NetForce) was used in the study to assess the postural stability with four different conditions(EO)/EC), CI activated/deactivated).

RESULTS

vCOP was found to have a significant growing tendency within the conditions of CI activated/deactivated.No statistically significant relationships were noted between the range of the displacement of feet pressure (Area) and both the visual and auditory conditions. Hearing loss etiology was statistically significantly related to the values of vCOP, within the conditions of EO, CI activated/deactivated (p < 0.01), what did not occure with the condition of EC (p > 0.05). Neuromuscular control with the condition of EC x CI deactivated was found to be based on the kinesthetic-tactual compensatory model.

CONCLUSIONS

Kinesthetic sensation and exteroceptors of the superficial sensation seem to be the predominant source of information to maintain postural control in late CI adolescents, regardless of the visual and auditory conditions. The etiology of hearing loss (congenital/acquired) can be a predictor of the values of the vCOP. In order to improve neuromuscular control in this population, it is recommended that the patients perform physical activity tasks, especially to develop core muscles, based on direct stimulation and rotational stability.

Language, cognitive, and speech in noise perception abilities of children with cochlear ımplants: a comparative analysis by implantation period and bilateral versus unilateral cochlear implants

PURPOSE

The purpose of this study was to compare the language, cognitive, and speech in noise (SiN) perception abilities of children with cochlear implants (CIs) to those of their peers with NH by grouping them according to their implantation period (12-18 months/19-24 months) and unilateral/bilateral CI use.

METHODS

The sample comprised 50 children with cochlear implants (CIs) and 20 children with normal hearing (NH), ages 6-9 years. Children's language, cognitive, and speech in noise (SiN) perception skills were assessed.

RESULTS

Children with CIs between 12 and 18 months and 19 and 24 months performed more poorly than children with NH on language, verbal memory (VM), verbal-short-term memory (V-STM), verbal working memory (V-WM), rapid naming, and speech in noise (SiN) perception abilities measures (p < 0.001). In addition, children with CIs between 19 and 24 months performed worse on rapid naming and V-WM tasks than children with CIs between 12 and 18 months (p < 0.017). Children with unilateral and bilateral CI performed more poorly than children with NH on language, VM, V-STM, V-WM, rapid naming, and SiN perception abilities assessments (p < 0.001). Additionally children with unilateral CI users performed poorly than children with bilateral CI users on SiN perception (p < 0.017).

CONCLUSIONS

In children with congenital hearing loss (CHL), cochlear implantation between 12 and 18 months or sequential bilateral implantation is not sufficient for these children to perform like their NH peers in language, cognitive, and SiN perception abilities. In addition, intervention approaches should focus not only on increasing language skills, but also on cognitive abilities.

Vestibulo-ocular reflex dynamics with head-impulses discriminates Usher patients type 1 and 2

Usher Syndrome classification takes into account the absence of vestibular function but its correlation with genotype is not well characterized. We intend to investigate whether video Head Impulse Test (vHIT) is useful in screening and to differentiate Usher Syndrome types. 29 Usher patients (USH) with a genetically confirmed diagnosis and 30 healthy controls were studied with vHIT and dizziness handicap inventory questionnaire (DHI). Statistical significant differences between USH1, USH2 and controls were found in the vestibulo-ocular-reflex (VOR) gain of all SCCs, with USH1 patients consistently presenting smaller gains. VOR gain of the right lateral SCC could discriminate controls from USH1, and USH2 from USH1 with an overall diagnostic accuracy of 90%. USH1 DHI correlated with VOR (ρ = - 0,971, p = 0.001). Occurrence rate of covert and overt lateral semicircular canals refixation saccades (RS) was significantly different between groups, being higher in USH1 patients (p < 0.001). USH1 peak velocity of covert and overt saccades was higher for lateral semicircular canals (p < 0.05 and p = 0.001) compared with USH2 and controls. Covert saccades occurrence rate for horizontal SCCs could discriminate USH1 from USH2 patients and controls with a diagnostic accuracy of 85%. vHIT is a fast and non-invasive instrument which allowed us to screen and distinguish Usher patients from controls with a high precision. Importantly, its use allowed further discrimination between USH1 from USH2 groups. Moreover, VOR gain seems to correlate with vertigo-related quality of life in more severe phenotypes.

Safety and Early Outcomes of Cochlear Implantation of Nucleus Devices in Infants: A Multi-Centre Study

This multi-center study examined the safety and effectiveness of cochlear implantation of children between 9 and 11 months of age. The intended impact was to support practice regarding candidacy assessment and prognostic counseling of pediatric cochlear implant candidates. Data in the clinical chart of children implanted at 9-11 months of age with Cochlear Ltd devices at five cochlear implant centers in the United States and Canada were included in analyses. The study included data from two cohorts implanted with one or two Nucleus devices during the periods of January 1, 2012-December 31, 2017 (Cohort 1, n = 83) or between January 1, 2018 and May 15, 2020 (Cohort 2, n = 50). Major adverse events (requiring another procedure/hospitalization) and minor adverse events (managed with medication alone or underwent an expected course of treatment that did not require surgery or hospitalization) out to 2 years post-implant were monitored and outcomes measured by audiometric thresholds and parent-reports on the IT-MAIS and LittlEARS questionnaires were collected. Results revealed 60 adverse events in 41 children and 227 ears implanted (26%) of which 14 major events occurred in 11 children; all were transitory and resolved. Improved hearing with cochlear implant use was shown in all outcome measures. Findings reveal that the procedure is safe for infants and that they show clear benefits of cochlear implantation including increased audibility and hearing development.

Children then, adults now: long-term outcomes-performance at 15, 20, and 25 years of cochlear implant use

Motivation

Severe to profound sensorineural hearing loss interferes with a child's development at the cognitive, linguistic, academic, and social levels. Since the beginning of the pediatric auditory rehabilitation program through cochlear implantation in the Ear, Nose, and Throat (ENT) Service of the Coimbra Hospital and University Center (CHUC), Portugal, its mentors defended the early diagnosis of hearing loss followed by timely intervention, and this was considered the starting point to optimize (re)habilitation through this method. Three decades or so later, recently we conducted this study to evaluate the performance of patients implanted in the initial phase of the cochlear implantation program.

Objectives

The study aimed to evaluate the performance of individuals with severe to profound congenital hearing loss who underwent pediatric cochlear implantation and have used the cochlear implant for at least 25 years, to analyze the beneficial effect of early intervention in improving performance results.

Methods

The study sample is composed of 31 individuals with severe to profound congenital hearing loss and no other comorbidities, divided into two groups (Group 1: age at implantation was under 3 years; Group 2: age at implantation was over 3 years). All 31 subjects were evaluated at 15, 20, and 25 years of cochlear implant (CI) use with a comprehensive set of tests. In addition, data were collected regarding the academic level of each participant. The results of both groups were compared to find out if there is an effect of age at implantation on auditory performance, and if there is an improvement in the performance with CI over time (15, 20, and 25 years of use).

Results

The results show that there is a positive effect, with statistical significance, of early implantation on auditory performance, and telephone use. In both groups, there is an increase in performance over time, but it tends to stabilize after 20 years of CI use.

Discussion and conclusion

The results obtained in this work support the importance of early intervention in patients with severe to profound hearing loss who are cochlear implant users and show that CI is an effective and reliable method in the treatment of these patients, contributing to their improved socio-educational integration, and that the benefits last over time.

Cochlear implant-specific risks should be considered, when assessing the quality of life of children and adolescents with hearing loss and cochlear implants–not just cochlear implant-specific benefits–Perspective

Cochlear implants (CIs) are electronic medical devices that enable hearing in cases where traditional hearing aids are of minimal or no use. Quality of life (QoL) studies of children and adolescents with a CI have so far focused on the CI-specific benefits. However, the CI-specific risks listed by the U.S. Food and Drug Administration have not yet been considered. From this list, medical and device-related complications, lifelong dependency on the implanted device, and neurosecurity risks (CI technology is an interface technology) may be particularly relevant for young CI users. Medical and device-related complications can cause physical discomfort (e.g., fever, pain), as well as functioning problems (e.g., in speech discrimination, social behavior, and mood). In the worst case, reimplantation is required. Clinical experience shows that these complications are perceived as a burden for young CI users. Furthermore, many young patients are worried about possible complications. Additionally, CIs can be at least a temporary burden when children, typically at the age of 8–9 years, realize that they need the CI for life, or when they become peer victims because of their CI. Concerning neurosecurity risks, it is still unknown how young CI recipients perceive them. In summary, CI-specific risks can be perceived as a burden by young CI users that impairs their QoL. Therefore, they should not be ignored. There is an urgent need for studies on this topic, which would not only be important for professionals and parents, but also for the design of CI-specific QoL instruments.

Younger Age at Cochlear Implant Activation Results in Improved Auditory Skill Development for Children With Congenital Deafness

PURPOSE

The U.S. Food and Drug Administration indications for cochlear implantation in children is currently 9 months of age and older for children with bilateral profound sensorineural hearing loss (SNHL). Studies have shown that earlier activation of a cochlear implant (CI) can lead to better spoken language outcomes. As auditory skills are a precursor to the development of spoken language, this study was developed to investigate the influence of age at CI activation on auditory skill acquisition in young children. A secondary aim was to describe the auditory skills of children implanted prior to 9 months of age as compared to children with older ages of activation.

METHOD

Functional Listening Index (FLI) scores obtained during routine clinical visits were reviewed for 78 pediatric CI recipients with congenital bilateral profound hearing loss who were activated before 2 years of age. A linear mixed-effects model assessed the effect of age at CI activation on cumulative FLI scores over time.

RESULTS

There was a significant interaction between age at activation and chronological age at the time of evaluation, indicating that children with earlier access to sound achieved a greater number of auditory skills than those with later CI activations when measured at the same chronological age. Children activated before the age of 9 months approximated scores expected of children with typical hearing, whereas children activated between 9 and 24 months of age did not.

CONCLUSIONS

Younger age at CI activation is associated with increased auditory skills over time. Children who undergo cochlear implantation and CI activation before 9 months achieve more auditory skills by 4 years of age than children who are activated at later ages. These data suggest that reducing the approved age at cochlear implantation for children with congenital bilateral profound SNHL may support optimal auditory skill acquisition.

The Genomics of Auditory Function and Disease

Current estimates suggest that nearly half a billion people worldwide are affected by hearing loss. Because of the major psychological, social, economic, and health ramifications, considerable efforts have been invested in identifying the genes and molecular pathways involved in hearing loss, whether genetic or environmental, to promote prevention, improve rehabilitation, and develop therapeutics. Genomic sequencing technologies have led to the discovery of genes associated with hearing loss. Studies of the transcriptome and epigenome of the inner ear have characterized key regulators and pathways involved in the development of the inner ear and have paved the way for their use in regenerative medicine. In parallel, the immense preclinical success of using viral vectors for gene delivery in animal models of hearing loss has motivated the industry to work on translating such approaches into the clinic. Here, we review the recent advances in the genomics of auditory function and dysfunction, from patient diagnostics to epigenetics and gene therapy.

Long-Term Device Satisfaction and Safety after Cochlear Implantation in Children

(1) Objectives: For full benefit in children implanted with a cochlear implant (CI), wearing the device all waking hours is necessary. This study focuses on the relationship between daily use and audiological outcomes, with the hypothesis that frequent daily device use coincides with high device satisfaction resulting in better functional gain (FG). Confounding factors such as implantation age, device experience and type of device were considered. (2) Results: Thirty-eight CI children (65 ears) were investigated. In total, 76.92% of the children were using their device for >12 h per day (h/d), 18.46% for 9−12 h/d, the remaining for 6−9 h/d and one subject reported 3 h/d. The revision rate up to the 90-month follow-up (F/U) was 4.6%. The mean FG was 59.00 ± 7.67 dB. The Audio Processor Satisfaction Questionnaire (APSQ) separated for single unit (SU) versus behind the ear (BTE) devices showed significantly better results for the latter in terms of wearing comfort (WC) (p = 0.00062). A correlation between device use and FG was found with a device experience of <2 years (n = 29; r2 = 0.398), whereas no correlation was seen with ≥2 years of device experience (n = 36; r2 = 0.0038). (3) Conclusion: This study found significant relationships between daily device use and FG, wearing comfort and long-term safety (90 months).

Altered Functional Network in Infants With Profound Bilateral Congenital Sensorineural Hearing Loss: A Graph Theory Analysis

Functional magnetic resonance imaging (fMRI) studies have suggested that there is a functional reorganization of brain areas in patients with sensorineural hearing loss (SNHL). Recently, graph theory analysis has brought a new understanding of the functional connectome and topological features in central neural system diseases. However, little is known about the functional network topology changes in SNHL patients, especially in infants. In this study, 34 infants with profound bilateral congenital SNHL and 28 infants with normal hearing aged 11–36 months were recruited. No difference was found in small-world parameters and network efficiency parameters. Differences in global and nodal topologic organization, hub distribution, and whole-brain functional connectivity were explored using graph theory analysis. Both normal-hearing infants and SNHL infants exhibited small-world topology. Furthermore, the SNHL group showed a decreased nodal degree in the bilateral thalamus. Six hubs in the SNHL group and seven hubs in the normal-hearing group were identified. The left middle temporal gyrus was a hub only in the SNHL group, while the right parahippocampal gyrus and bilateral temporal pole were hubs only in the normal-hearing group. Functional connectivity between auditory regions and motor regions, between auditory regions and default-mode-network (DMN) regions, and within DMN regions was found to be decreased in the SNHL group. These results indicate a functional reorganization of brain functional networks as a result of hearing loss. This study provides evidence that functional reorganization occurs in the early stage of life in infants with profound bilateral congenital SNHL from the perspective of complex networks.