Langzeitergebnisse nach Kochleaimplantatversorgung bei Kindern

Hearing Loss: Genetic Testing, Current Advances and the Situation in Latin America

Congenital hearing loss is the most common birth defect, estimated to affect 2-3 in every 1000 births, with ~50-60% of those related to genetic causes. Technological advances enabled the identification of hundreds of genes related to hearing loss (HL), with important implications for patients, their families, and the community. Despite these advances, in Latin America, the population with hearing loss remains underdiagnosed, with most studies focusing on a single locus encompassing the GJB2/GJB6 genes. Here we discuss how current and emerging genetic knowledge has the potential to alter the approach to diagnosis and management of hearing loss, which is the current situation in Latin America, and the barriers that still need to be overcome.

Cochlear Implantation

BACKGROUND

Hearing impairment that is too severe to be adequately treated with conventional hearing aids can lead, in children, to severe developmental disturbances of hearing and language, and, in adults, to communicative and social deprivation. Recent advances in medical device technology and in microsurgical techniques have led to an expansion of the indications for cochlear implantation (CI) for adults with progressive hearing loss in older age, and to a restructuring of the process of care for these patients in Germany.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on the CI guidelines and CI "white book" of the German Society of Otolaryngology and Head and Neck Surgery.

RESULTS

Early and accurate diagnosis is crucial for the successful auditory rehabilitation of high-grade hearing impairment. In children, a key role is played by newborn auditory screening, which is mandatory in Germany and enables the provision of a CI in the first year of life when necessary. 86% of the children receiving a CI achieve linguistic comprehension of fluently spoken sentences. For adults, positive prognostic factors for hearing after the provision of a CI include a highly motivated patient, "postlingual" onset of the hearing impairment (i.e., after the acquisition of language), and a brief duration of deafness. Auditory rehabilitation is associated with significant improvement, not just of hearing and of the comprehension of spoken language, but also of quality of life, particularly in elderly patients. For patients of any age with bilateral hearing loss, CIs should be provided on both sides, if possible. The more common complications of the procedure, with a probability of 2-4% each, are technical implant defects, dizziness, and wound-healing disturbances.

CONCLUSION

Cochlear implantation, performed in specialized centers, is a safe and reliable technique and regularly enables the successful rehabilitation of hearing in both children and adults.

A Systematic Review to Define the Speech and Language Benefit of Early (<12 Months) Pediatric Cochlear Implantation

Objective: This review aimed to evaluate the additional benefit of pediatric cochlear implantation before 12 months of age considering improved speech and language development and auditory performance. Materials and Methods: We conducted a search in PubMed, EMBASE and CINAHL databases and included studies comparing groups with different ages at implantation and assessing speech perception and speech production, receptive language and/or auditory performance. We included studies with a high directness of evidence (DoE). Results: We retrieved 3,360 articles. Ten studies with a high DoE were included. Four articles with medium DoE were discussed in addition. Six studies compared infants implanted before 12 months with children implanted between 12 and 24 months. Follow-up ranged from 6 months to 9 years. Cochlear implantation before the age of 2 years is beneficial according to one speech perception score (phonetically balanced kindergarten combined with consonant-nucleus-consonant) but not on Glendonald auditory screening procedure scores. Implantation before 12 months resulted in better speech production (diagnostic evaluation of articulation and phonology and infant-toddler meaningful auditory integration scale), auditory performance (Categories of Auditory Performance-II score) and receptive language scores (2 out of 5; Preschool Language Scale combined with oral and written language skills and Peabody Picture Vocabulary Test). Conclusions: The current best evidence lacks level 1 evidence studies and consists mainly of cohort studies with a moderate to high risk of bias. Included studies showed consistent evidence that cochlear implantation should be performed early in life, but evidence is inconsistent on all speech and language outcome measures regarding the additional benefit of implantation before the age of 12 months. Long-term follow-up studies are necessary to provide insight on additional benefits of early pediatric cochlear implantation.

[Speech and general development in children receiving early cochlear implants]

BACKGROUND

After cochlear implantation, most parents expect a normal speech and general development of their child. However, it remains unclear how quickly after early cochlear implantation these children can compensate for their deficits compared to normal-hearing children.

METHODS

This study retrospectively analyzed ELFRA-1 questionnaire data from 40 children with borderline deafness or high-grade hearing loss (without other known impairments) who had undergone cochlear implantation at a university medical center before reaching 2 years of age. ELFRA-1 questionnaires were filled out parents assisted by specialists 12 months after implantation. Questions assessed the children's speech production and comprehension, as well as their use of gestures and fine motoric skills.

RESULTS

At an average hearing-age of 12 months, the children achieved normal values in all of the subgroups that were comparable to those of 12-month-old children without hearing impairments. A significant correlation (p = 0.01) between the individual subgroups of the ELFRA-1 (speech production, speech comprehension, gestures and fine motor skills) was observed. Unilingual educated children performed significantly better overall.

CONCLUSION

Within 12 months of receiving a cochlear implant, all children passed the four categories of the ELFRA-1. This demonstrates a rapid compensation of deficits in speech, motor skills and gesture development by children undergoing early cochlear implantation.

The differential diagnosis of hearing loss

BACKGROUND

According to the World Health Organization, hearing loss is one of the six leading contributors to the global burden of disease. It is becoming an ever more important problem in society at large, not just because the population is aging, but also because young people increasingly spend their leisure time in activities that expose them to excessive noise. On the other hand, the treatment of hearing loss is improving, as the result of technical developments in otological surgery, hearing aids, and cochlear implants. For nearly every type of hearing loss, there is now some type of rehabilitative treatment. The prerequisite to effective care is timely and accurate diagnosis.

METHOD

Review of the pertinent literature and national guidelines.

RESULTS AND CONCLUSION

The available epidemiological data on hearing loss in Germany are inadequate. It is roughly estimated that 13 to 14 million people in Germany are in need of treatment for hearing loss. The most common types of permanent hearing loss are those associated with old age, chronic otitis media, and acoustic trauma. Transient hearing loss is particularly common in childhood as a result of inadequate ventilation of the middle ear. The further technical development of cochlear implants has now widened their indications to include severe congenital deafness and presbycusis.

Measuring communicative performance with the German version of the FAPCI-instrument: normative data and longitudinal results

OBJECTIVE

The German version of the Functioning after Paediatric Cochlear Implantation (FAPCI) inventory was designed to capture the communicative performance of cochlear implanted children. In order to be able to compare cochlear-implanted children to their normal hearing peers, normative growth curves were designed. Furthermore it was of interest how the communicative performance develops over time and whether it is influenced by age at implantation.

METHOD

A polynomial regression curve was fit to the data of 133 normal hearing children. This normative curve was compared to individual growth curves of 90 cochlear implanted children. The cochlear-implanted study sample was split up into four groups depending on the age at implantation.

RESULTS

The normative growth curve increases from 1 year of age until saturation is reached with 3 years of age. The individual FAPCI trajectories of cochlear implanted children are heterogeneous, but in general they are delayed in comparison to the normative growth curve. "Early implanted children" follow the development of their normal hearing peers more closely than "later-implanted children".

CONCLUSION

The German version of the FAPCI parental questionnaire constitutes an additional instrument in monitoring the communicative performance development of cochlear implanted children and allows for comparison to normal hearing peers.

Spectrum of hearing disorders and their management in children with CHARGE syndrome

OBJECTIVE

The CHARGE syndrome is associated with ear anomalies and deafness in addition to other malformations. Deformations of the ossicles or aplasia of the semicircular canals, cochlear hypoplasia, hypoplasia or aplasia of the VIIIth cranial nerve and abnormal routing of the VIIth cranial nerve, sigmoid sinus, and emissaries are typical findings. The aim of this study is to explore the feasibility and procedure of cochlear implantation in patients with CHARGE syndrome and to assess the outcome.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center; cochlear implant program.

PATIENTS

Ten patients with CHARGE syndrome and 3 patients with CHARGE-like syndrome treated in our center due to hearing impairment. Eleven patients were congenitally deaf, 1 patient had progressive hearing loss, and 1 patient had mixed hearing loss.

INTERVENTION

Computed tomography of temporal bones and magnetic resonance imaging of the brain; bone-anchored hearing aid surgery, cochlear implantation, rehabilitation results.

MAIN OUTCOME MEASURES

Surgical suitability and hearing rehabilitation.

RESULTS

We illustrate the management of preoperative diagnostics, surgical planning, and hearing rehabilitation. One patient with mixed hearing loss underwent bilateral bone-anchored hearing aid surgery. Because 2 patients had bilateral aplasia of the auditory nerves, we recommended an auditory brainstem implant. The unilateral cochlear implantation was performed in 9 patients and bilateral in 1 patient. In selected cases, it was helpful to plan the operation using a simulator for temporal bone surgery. Complex malformations, such as in CHARGE syndrome, with an increased intraoperative risk for complications should be facilitated by using intraoperative digital volume tomography-assisted navigation and intraoperative digital volume tomography control of electrode position. The results after CI surgery vary due to the differing extent of additional disabilities such as developmental delay, intellectual delay, and visual impairment. Nine of our patients showed improved responsiveness with the cochlear implant. Open speech comprehension could not be observed in 8 patients, whereas the follow-up period was less than 1 year in 4 patients. The relatively high age of our patients at implantation might be an important factor.

CONCLUSION

Careful planning of the treatment of CHARGE syndrome patients with sensorineural hearing loss can, to a limited extent, lead to auditory benefit without increasing surgical complications. Cochlear implantation is therefore indicated after critical assessment.