|Year : 2021 | Volume
| Issue : 3 | Page : 148-152
Pediatric cochlear implantation: Epidemiological characteristics and outcomes
Abdelaziz Raji, Houda Mounji, Mohammed Chehbouni, Youssef Rochdi, Hassan Nouri, Mehdi Elfakiri
Department of Otolaryngology-Head and Neck Surgery, University Hospital Mohammed VI, Marrakech, Morocco
|Date of Submission||22-Aug-2019|
|Date of Acceptance||13-Jan-2020|
|Date of Web Publication||16-Dec-2021|
Prof. Abdelaziz Raji
Department of Otolaryngology-Head and Neck Surgery, University Hospital Mohammed VI, Marrakech
Source of Support: None, Conflict of Interest: None
Background: Cochlear implants (CIs) are nowadays a widely accepted treatment for sensorineural hearing loss. Aim: This study aimed to describe the epidemiological characteristics and the surgical approach and to evaluate the outcomes of our experience in cochlear implantation in pediatric population at the Department of Otolaryngology–Head and Neck Surgery of Mohammed VI University Hospital, Marrakech, Morocco. Materials and Methods: A retrospective chart review was conducted on 113 children with severe-to-profound hearing loss who underwent a cochlear implantation between 2007 and 2018. Results: There were 65 females and 48 males with severe-to-profound bilateral deafness, of whom 103 had prelingual deafness. The mean age of pediatric cochlear implantation was 5.25 years. Implantation was unilateral in all patients. The procedure was followed by regular adjustments and speech therapy. The evaluation was carried out by the same team each month during the first 6 months and then every 6 months. The average duration of follow-up was 38.94 months. All patients benefited from their implants with interindividual variability. The good results were correlated with early implantation, significant parental investment, and a steady follow-up of speech therapy. Conclusion: Cochlear implantation has revolutionized the management of severe-to-profound deafness. It is a safe and effective technique when it is aimed at correctly selected populations.
Keywords: Children, cochlear implant, hearing loss, speech therapy
|How to cite this article:|
Raji A, Mounji H, Chehbouni M, Rochdi Y, Nouri H, Elfakiri M. Pediatric cochlear implantation: Epidemiological characteristics and outcomes. Indian J Otol 2021;27:148-52
|How to cite this URL:|
Raji A, Mounji H, Chehbouni M, Rochdi Y, Nouri H, Elfakiri M. Pediatric cochlear implantation: Epidemiological characteristics and outcomes. Indian J Otol [serial online] 2021 [cited 2022 Jan 18];27:148-52. Available from: https://www.indianjotol.org/text.asp?2021/27/3/148/332652
| Introduction|| |
A cochlear implant (CI) is a surgically implanted electronic device that transmits sounds directly to the auditory nerve through electrical stimulation of the cochlea. It has become the standard of care for severe or profound hearing loss and indeed has produced the first substantial restoration of a lost or absent human sense using a medical intervention. It has proven to be a useful treatment option for patients with severe-to-profound hearing loss by providing improved access to one's surrounding auditory environment. Both postlingually deafened adults and prelingually deafened children can benefit from a CI. The goal of the present study is to analyze the indications and the surgical aspects of cochlear implantation in children and the outcomes regarding the aural rehabilitation by cochlear implantation.
| Materials and Methods|| |
We completed a retrospective study on about 113 children with profound hearing loss implanted in our department between January 2007 and December 2018. All patients have benefited from a preimplant assessment based on clinical, audiological, and radiological with computed tomography (CT) scan and magnetic resonance imaging (MRI) and orthophonic, ophthalmologic, and psychological evaluation. The data were recorded from medical files as well as the database of CI settings and speech therapy evaluations. The patients were assessed regularly during the first 3 months and every 6 months after cochlear implantation. Communication abilities of the children are studied on base of the APCEI-score.
| Results|| |
A total of 113 children with profound bilateral hearing loss implanted from January 2007 to December 2018 were included in the study. One hundred and three children have had prelingual congenital deafness.
The average age of implantation was 5.25 years, with a minimum of 18 months and a maximum of 16 years. The majority (57.5%) of patients were female. In 89.5%, the CI was performed before 5 years old.
Multiple causes of deafness have been diagnosed [Table 1]. However, in the majority of cases, the etiology has been unknown.
Nonsyndromic deafness has been diagnosed in most of the cases (85.8%). Among the patients who had a syndromic deafness, we have noted: Waardenburg syndrom (5 cases) and Albinism-deafness syndrom (1case).
All children have had a bilateral profound hearing loss on BERA and behavioral audiometry with an absence of language. Ophthalmological examination has shown an iris heterochromia in six cases and unilateral blindness in one case. Psychological evaluation has not identified any contraindication for cochlear implantation.
Otitis media with effusion has been identified in eight patients, treated before surgery (medical treatment in four cases, adenoidectomy in one case, and adenoidectomy + tympanostomy tube ventilation in three cases). The associated comorbidities to deafness in our population were heart disease (2 cases), unilateral blindness (1 case), paresis of the left hemibody (1 case), and anemia (1 case). A unilateral complex inner ear malformation has been identified on CT scan and MRI in two cases. The trial of hearing aids has been used in 10 cases for 6 months with a poor speech result.
The indication of cochlear implantation has been decided in multidisciplinary staff including speech therapists, audiologists, psychologists, and surgeons. All children have been vaccinated against pneumococcus.
Cochlear implantation has been done on one side in all cases: 100 cases in the right ear and 13 cases in the left side. Reimplantation has been performed in three cases due to posttraumatic device failure.
The surgery has been done under general anesthesia with facial nerve monitoring.
A mastoidectomy with facial recess approach has been performed in all cases to access the round window [Figure 1].
The electrode holder has been fully inserted into the scala tympani, except for two cases (reimplantation and postmeningitis deafness).
Impedance testing and neural response telemetry have been performed to test the integrity of the CI. There has been no peroperative nor postcochlear implantation complication.
The duration of hospitalization has been 48 h in average. X-ray Stenvers view was performed systematically; it has shown the correct location of the CI in the cochlea.
The “initial stimulation” and device programming have been conducted after 4–5 weeks after surgery. Regular speech therapy has been conducted at an average of 2 sessions per week. The CI setting has been regular and modified afterward according to the evolution in speech therapy, schematically at 1, 2, 3, 6, 9, 12, 18, and 24 months and then yearly after cochlear implantation.
The speech–language assessment by the APCEI scale was conducted in preimplantation and during the follow-up. The evaluation has been done monthly during the first 6 months and every 6 months after [Figure 2].
|Figure 2: Average APCEI score of implanted patients according to the duration of the cochlear implant use|
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After an average follow-up of 38.94 months, the communications abilities improved during the period of use of the CI. The results have shown high interindividual variability regarding the age of implantation, the duration of implant use, parents motivation, and rhythm of speech therapy.
Good results in speech evaluation have been correlated with early cochlear implantation cases as this is shown in [Figure 3], which represents the average APCEI score of children with prelingual deafness according to the age of implantation.
Children with a significant parental investment and good follow-up of speech therapy had the best results compared to children with low or moderate follow-up [Figure 4].
|Figure 4: Average APCEI score in relation to parental investment and follow-up of speech therapy|
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The oral environment had a positive influence on the results unlike the signed communication [Figure 5].
Regarding our global results, all patients accepted the use of the CI with an acquisition of sound alertness from the 1st months. The words recognition started from 1 year of cochlear implantation use and the possibility to understand a conversation from the 3rd year. The CI has allowed a schooling rate of 80.95% in our study with a failure rate of 1.85%.
| Discussion|| |
Severe-to-profound hearing loss affects 1 of 1000 newborn each year. This incidence could reach 2–3 births on thousand. It is one of the major disabilities that adversely affect the development of speech and cognitive abilities in children.
CIs work by substituting the sensory hair cells within the cochlea with electrodes that stimulate electrically the auditory nerve fibers.
Pediatric CI candidates are in the majority of cases prelingual deafened children, who are born with sensorineural hearing loss (SNHL) due to genetic mutations, perinatal environmental exposures, or unidentified (idiopathic) causes. According to Tajudeen et al., these patients often obtain good speech outcomes after implantation, with the best results occurring when implanted within 1–2 years of age. [Table 2] provides a broad overview of conventional CI indications.
The Food and Drug Administration (FDA) requires children to be 12 months of age. However, several centers in the U. S. and Europe are implanting children as young as 6 months old. Colletti et al. reported on 12 children implanted at or before the age of 6 months; 4 years after implantation, these children had receptive and expressive language skills similar to normal-hearing peers. However, Tajudeen et al. did not confirm clear evidence of improved outcomes in children implanted in the 1st year of life compared with those implanted a year later.
There has been an expansion in CI candidacy criteria. For example, children with auditory neuropathy spectrum disorder have shown to achieve reliable open-set speech recognition, and the majority of patients with cochlear malformations (e.g. Mondini deformity) who were previously not implant candidates are now being implanted safely.
CI candidacy has been extended also to some children with significant residual hearing. An example is a bilateral and asymmetric SNHL, in which significant benefit can derive from cochlear implantation in the worse hearing ear in combination with a hearing aid in the better ear.
In addition, there is a growing interest in implanting patients with single-sided deafness (SSD). At present, implantation for SSD is not currently FDA approved, but increasing evidence suggests that this may be a viable option in the future.
Before implantation, several factors must be considered to establish whether a child is suitable or not; thus, for a successful cochlear implantation, the patient selection is of outstanding importance. A complete evaluation should comprise a series of tests, including audiological, medical, and imaging studies, as well as speech and language evaluation; furthermore, patient/family counseling is fundamental to explain them the potential benefits and to create realistic expectations.,
Contraindications to implantation, such as complete labyrinthine aplasia, cochlear aplasia, cochlear nerve aplasia, and complete cochlear ossification should be eliminated by radiographic assessment. According to Parry et al., 2005, MRI is the best modality for confirming a fluid-filled cochlear duct to receive the electrode, as well as the presence of a cochlear nerve to carry the signal to the brainstem and auditory cortex. Importantly, in older patients, obtaining an MRI before CI provides them with their last opportunity to obtain a high-quality brain image without artifact or the need to remove a magnet. High-resolution CT also has utility, particularly for surgical planning in cochlear malformations, and can also be done in a faster, more cost-effective manner compared with MRI.
Cochlear implantation is usually performed under general anesthesia without muscle relaxation to allow for facial nerve monitoring. Selected elderly patients have also been safely implanted under conscious sedation. Patients should be preoperatively vaccinated according to the Centers for Disease Control and Prevention guidelines for meningitis prophylaxis. CIs are placed through small skin incision in the retroauricular region; a surgical opening is made in the mastoid to provide access to the cochlea from behind. Once identified the round window, the latter is opened and the electrode array is inserted into the cochlea. After the implant has been secured in place and before closing the surgical access, intraoperative electrophysiological testing is performed to verify the correct functioning of the device and to record the neural responses to the electrical stimuli. In standard cases, the procedure takes about 2 h; children are generally discharged from hospital within 2–3 days.,
Cochlear implantation has a low rate (about 10%) of complications; major complications are rare, accounting for only 20%–30% of all complications on average, and include facial nerve injury (0.39%), perilymphatic gusher/cerebrospinal fluid fistula (0.25%), and meningitis (0.11%). The most frequent complications are temporary taste disturbance, wound infections, and device failure.,
The activation of the implant is usually done 2–4 weeks after surgery, when healing is complete, and consists in setting the sound levels presented to each electrode within the cochlea. During the 1st year after activation, the CI is periodically tuned according to the child responses to maintain optimal stimulation levels.
There are remarkable results regarding the acquisition of spoken language in implanted children with profound deafness. Prelingually deaf children develop significant speech perception and production abilities over time. According to O'Donoghue et al., 1998, these achievements may appear limited in the first 2 years, but show significant improvement after the 2nd year of implantation, and do not reach a plateau, even 5 years following implantation.
Prelingually deaf children also develop significant speech intelligibility, but a long period of CI use is needed before the emergence of intelligible speech.
Nevertheless, children with CI show an important variability. According to Gérard et al., 2010, and Clark et al., 2011,, several factors, such as the etiology of deafness, the age of the child at the time of the CI, the presence of residual hearing, the process of the auditory rehabilitation, and the family participation in the therapeutic process, all may influence the final performance.
The protocols of evaluation in postimplantation are multiple,, varying from one center and one country to another (TEEP, MUSS, APCEI, CAP, MAIS, and SIR.). There is no standardized protocol adapted to our culture. Despite being subjective, the APCEI scale was chosen in our evaluation, but it remains a simple test, is quick to perform, and explores the different areas of speech assessment.
| Conclusion|| |
Cochlear implantation is worldwide considered a safe and highly effective technique in rehabilitating children with severe-to-profound SNHL. Its effectiveness has already been demonstrated and our results are in agreement with those of the literature. Its benefits include not only better abilities to hear and to develop speech and language skills, but also improved academic attainment, improved quality of life, and better employment status.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2]