Marjan Yperman

Outcome of cochlear implantation at different ages from 0 to 6 years.

Objective To evaluate the outcome of cochlear implantation in young children in relation to the age at implantation. Study Design A retrospective longitudinal and cross-sectional analysis of pediatric cochlear implant patients. Patients All children with congenital deafness who underwent implantation before the age of 6 years (n = 48 for the longitudinal analysis and n = 70 for the cross-sectional analysis) Interventions All children received a multichannel cochlear implant. Main Outcome Measures Categories of Auditory Performance (CAP) score and integration into the mainstream school system. Results For all children, the CAP score increased after implantation. Implantation beyond the age of 4 years hardly ever resulted in normal CAP scores or in integration into the mainstream primary school (20 to 30% of cases). Implantation between the age of 2 and 4 years always resulted in normal CAP scores after 3 years with a 66% probability of integration into the primary school. Implantation before the age of 2 years always resulted in immediate normalization of the CAP scores, with a 90% probability of integration into the mainstream kindergarten, well before entrance into the primary school. Conclusion All children with congenital deafness who underwent implantation before the age of 6 years appeared to benefit from the implant. However, these data add evidence to the importance of early implantation (before the age of 2 years). Intervention before the age of 4 years seemed to be critical to avoid irreversible auditory performance losses, and intervention before the age of 2 years seemed to be critical to achieve optimal results.

Cochlear implants in aplasia and hypoplasia of the cochleovestibular nerve

Objective To report on the outcome of four patients with aplasia or hypoplasia of the cochleovestibular nerve who have received a cochlear implant. Study Design Retrospective case review. Setting Tertiary referral center. Patients Four patients with: 1) type I aplasia; 2) type IIa aplasia; 3) type IIa hypoplasia; and 4) type IIb aplasia received a cochlear implant. All patients had corner audiograms even with hearing aids. Intervention Three patients received a LAURA multichannel implant, and one patient received a Nucleus 24 implant. Main Outcome Measure Auditory performance, educational setting. Results The patients with type I and type IIb aplasia did not have auditive perception with their implant and became non-users. Both are now in a total communication educational setting. The patients with type IIa aplasia and hypoplasia had moderate audiological results with the implant with audiometrical thresholds of approximately 40–60 dB HL (pure tone average), moderate phoneme discrimination, and poor word discrimination. One child is in a total communication educational setting and the other in an oral educational setting, but the preferred mode of communication remains total communication for both. Both appear to benefit from the implant nonetheless. Conclusion Patients with aplasia/hypoplasia of the cochleovestibular nerve should be counseled with caution with respect to cochlear implantation, but particular circumstances may justify the intervention. At present these circumstances seem to be a type IIa aplasia or hypoplasia in which the end organ (cochlea or common cavity) still connects to a neural structure on MRI.

Long-term evaluation of the effect of intracochlear steroid deposition on electrode impedance in cochlear implant patients.

Objective To evaluate the long-term effect of intracochlear steroid deposition on electrode impedance in patients with cochlear implants. Study Design A retrospective study was carried out comparing the impedances of cochlear implant electrodes with and without a single application of steroids in the cochlea. Patients Ninety two implanted children with an average age of 5 years (range, 0.7 to 16 years) were divided in four groups according to the type of electrode and the use of steroids or not. In addition, the impedances of five children who required a reimplantation are reported. Main Outcome Measure The impedances of Nucleus electrodes, either straight or Contour, were measured at regular intervals up to 12 months after surgery. Results Two months after surgery, the impedances in the steroid groups were significantly lower than in the nonsteroid groups (straight electrodes, 3.9 versus 4.7 kOhm, respectively; Contour electrodes, 5.4 versus 6.5 kOhm, respectively). This reduction remained stable over time for the straight electrodes, but for the Contour electrodes, it seemed to disappear after 6 months. The impedances after a second implantation were significantly higher than after a first implantation (median value, 8.8 kOhm after 2 months). Conclusions The application of a single dose of a steroid solution reduces the electrode impedances significantly, and, for the straight electrodes, this effect seems to last. It seems justified to reimplant with caution, because this seems to increase the impedances substantially.

Contralateral suppression of transient evoked otoacoustic emissions: normative data for a clinical test set-up.

Hypothesis Contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) can be used in a clinical set-up using a procedure based on a unique and robust parameter to quantify the magnitude of suppression for a subject. Background TEOAEs can be suppressed by delivering contralateral white noise (WN). This suppression is thought to be mediated via the efferent nerve fibers that innervate the outer hair cells. The ipsilateral TEOAE-eliciting click stimulus level and the contralateral WN level have a strong impact on the recorded level of suppression. Methods TEOAEs were recorded using the nonlinear stimulation mode in two conditions (with and without contralateral WN). An optimal TEOAE-eliciting click stimulus level and contralateral WN level were defined to obtain a unique and robust parameter to quantify the magnitude of suppression. Results Suppression of TEOAEs with contralateral WN can be measured in a clinical set-up using nonlinear stimulation, and the level of suppression is of the same order of magnitude as measures using the linear stimulation recording mode. The level of suppression appears to be “locked” to the interaural difference between ipsilateral TEOAE-eliciting broadband click stimulus level and the contralateral WN level. Conclusions A procedure is proposed to record contralateral suppression in a clinical set-up, and normative data are given for a normal-hearing population (n = 60).

Normal Hearing and Language Development in a Deaf-Born Child

Background: Congenital deafness leads to major problems in speech, language, education, and social integration. Neonatal hearing screening and cochlear implantation now allow early hearing restoration. This article reports on a prospective longitudinal study of the first infant ever who received two cochlear implants in the prelexical period of her life. Methods: The first deaf-born girl ever who received two implants at the ages of 5 and 15 months, respectively, was followed-up with repeated and detailed quantitative assessments from birth to 4 years of age. This consisted of 1) audiologic evaluation (audiometry, speech audiometry, and Categories of Auditory Performance score), 2) linguistic evaluation (monthly video analyses and tests of vocabulary, language skills, grammar, and intelligibility of the child’s speech), and 3) descriptive assessment of the educational setting. Results: All results lie within the 95% confidence interval of hearing peers. The audiologic performance lies at or above average from age 2 years onward. The child started babbling at the normal age of 8 months. Her linguistic skills increased from low percentiles before age 2 to above average from age 2 for comprehension and from age 3 for production. The grammar and intelligibility of the child’s speech increased from low percentiles to average at age 4. The girl entered preschool at the normal age of 2.5 years, and this with only very limited special assistance. Conclusion: This case illustrates the fact that congenital deafness no longer has to lead to abnormal hearing and abnormal speech development. It opens the debate of the ethics of not implanting a deaf child in the first few months of life.

A two-stage bipodal screening model for universal neonatal hearing screening

Objective A model is proposed for universal neonatal hearing screening. Methods The screening model is two-staged because it consists of a first test and, in case of failure (1.4% of the subjects), of a retest 3 weeks later. It is bipodal because it involves both the hospital audiologic department and a central Well Baby Organization. The idea is to have a maximal number of newborns tested at the maternity by trained audiologists and to have the Well Baby Organization trace and chase the missing subjects. The model has been evaluated during 1 calendar year (1999) in a maternity with 2,012 newborns. Result The result is a coverage of 99.3%. Most newborns (97.3%) were tested at the maternity ward with a total time investment of less than 15 minutes per child. The actual test time is 2 minutes, 12 seconds (median value). The Well Baby Organization keeps track of all the results and has to test no more than 2% of the newborns. Sensitivity and specificity were not the primary outcomes of this evaluation, but they were similar to those of a previous study evaluating the screen procedure on a larger scale, giving a sensitivity of approximately 100% and a false alarm rate of 1/1,000. Conclusion These figures demonstrate that universal neonatal hearing screening is feasible within the existing health care structure, with unprecedented coverage, sensitivity, and specificity.

Normative data of the A§E® discrimination and identification tests in preverbal children

Abstract The A§E® is a set of suprathreshold tests for the auditory evaluation of the hearing impaired. A particular population of interest is the hearing-impaired preverbal child. This paper reports on normative data of the A§E® discrimination test in children aged 10 months and of the A§E® identification tests in children aged 2 to 4 years. Normally hearing children of these ages were tested and pass criteria were defined in such a way that 95% of the hearing infants would pass the tests. With these criteria, the A§E® discrimination test is feasible at 10 months of age and the A§E® identification test from 30 months of age. Copyright

Neonatal hearing screening with transient evoked otoacoustic emissions - retrospective analysis on performance parameters

The present paper reports on the implementation of a maternity based neonatal hearing-screening program in a private hospital. A retrospective analysis is performed on the test pass rate, the coverage and the number of children that become lost to follow-up. The data show a steady learning curve with a time course of several years. In the current screening practice, the test pass rate is at 99.0%, the coverage is at 96% (birth rate of 2000 per annum) and almost no babies get lost to follow-up.