Outcome analysis of cochlear implant reimplantation in children.

OBJECTIVES: We review our experience gained in performing cochlear reimplantation in 25 children who have had multichannel cochlear implant device failure at the Cochlear Implant Center of the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital (New York, NY), to assess the feasibility of cochlear reimplantation in children and the effect of reinsertion on audiological performance. STUDY DESIGN: We retrospectively analyzed the outcome of 27 consecutive multichannel cochlear implant reinsertions performed in 25 children at the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital. These reimplantations were performed between 1990 and 1999, with a minimum follow-up of 6 months for both surgical and audiological performance. METHODS: Charts were reviewed for patient factors, findings at the time of initial operation and repeat operation, and results of audiological testing both before and after reimplantation. RESULTS: Surgical complications of reimplantation included two intraoperative cerebral spinal fluid leaks and two late postoperative flap breakdowns with implant extrusions. For the most part, depth of electrode insertion was unchanged. Open-set speech recognition scores and speech perception abilities remained stable or improved compared with results before reimplantation. CONCLUSION: Our results confirm that cochlear implant reimplantation is technically feasible and allows for continued auditory development for the child who has a cochlear implant device failure.

Preventing labyrinthitis ossificans: the role of steroids.

OBJECTIVE: To identify a possible relationship between the administration of steroids at the time of diagnosis of bacterial meningitis and the development of labyrinthitis ossificans. DESIGN: Retrospective analysis of the charts of 38 children requiring cochlear implantation who presented with bacterial meningitis and then developed bilateral profound deafness. The patients' charts were reviewed for age at diagnosis, the type of antibiotic administered, and the administration, dosage, and duration of steroid (dexamethasone) therapy. Labyrinthitis ossificans was established by preoperative computed tomographic and/or magnetic resonance imaging and by the intraoperative findings as described in the operative report. PATIENTS AND METHODS: Patients were 38 children who received cochlear implantation by a single senior otolaryngologist for bacterial meningitis-related deafness. Ten patients' charts (26%) were available for full review; 9 of these 10 patients had documented pneumococcal meningitis and the other patient had Haemophilus influenzae-type meningitis. RESULTS: One of the 6 patients who received steroid therapy at the time of initial illness had documented evidence of labyrinthitis ossificans either radiographically or at the time of surgery. All 4 patients who failed to receive steroid therapy developed labyrinthitis ossificans. The results achieve statistical significance by chi2 analysis and a t test (P<.01). CONCLUSION: The results of this retrospective study are highly suggestive of a role for steroids in preventing the development of labyrinthitis ossificans in children with pneumococcal meningitis.

Cochlear implantation in children with enlarged vestibular aqueducts.

OBJECTIVES: This report details our experience with cochlear implantation in children with both profound sensorineural HL (SNHL) and enlarged vestibular aqueducts (EVAs). It seeks to determine if the abnormal anatomy of EVA predisposes to any adverse events during or after cochlear implantation. STUDY DESIGN: A retrospective review. METHODS: Charts were reviewed for details of the procedure, complications, and audiologic outcome. RESULTS: Between 8/25/93 and 9/16/98, 10 children with EVAs received cochlear implants, of whom 8 children (5 males, 3 females; mean age 7.8 y) had audiologic follow-up of at least 6 months. The implant was inserted without difficulty in all patients. Pulsatile clear fluid via the cochleostomy was observed in five patients, but was easily controlled in each instance. There have been no major complications, although two patient had short-lived postoperative vestibular symptoms and one child has experienced an intermittent pulsing sensation in her head. Speech perception measures were obtained using a battery of tests that assessed the children's ability to perceive speech in both open- and closed-set formats. Two patients were excluded because the implant was placed within the last 6 months. Of the remaining eight children identified with EVAs, seven (86%) demonstrated open-set word recognition. CONCLUSIONS: These favorable results may be attributed in part to HL that occurs relatively late in childhood, allowing implantation in postlingual candidates. Cochlear implantation can be safely and effectively performed in children with SNHL associated with EVAs.

Specific language growth in young children using the CLARION cochlear implant.

General and specific language growth was evaluated in 10 children who had received the CLARION Multi-Strategy Cochlear Implant during the clinical trial. The mean age at implantation was 37 months, and the children were followed for 18 months thereafter. Language comprehension and use were assessed with the Peabody Picture Vocabulary Test, the Reynell Developmental Language Scales, and mean length of utterance (MLU). The mean vocabulary scores indicated a 42-month increase in 18 months. The mean language comprehension increased from 20.4 to 40.8 months, and language use increased from 21.5 to 38.1 months. The mean MLU increased from 1.8 words to 4.8 words during the test period. Results indicated the children learned language at the same rate as their hearing peers of the same language age (except for vocabulary, which was faster), but retained a language delay relative to their hearing peers of the same chronological age.

Auditory perceptual abilities in a child with a nucleus and a Clarion cochlear implant.

This case study will review the performance of a 7-year-old female who was implanted at the age of 3 years 9 months with a Nucleus 22 channel device. This child was deafened from pneumococcal meningis at the age of 8 months and was placed in an early intervention program which uses simultaneous communication (i.e. speech with sign language). The teaching staff of this particular educational setting has collaborated closely with the Cochlear Implant Center at Manhattan Eye, Ear and Throat Hospital and the team's teacher of the deaf. The child utilized the implant on a daily basis for a period of 2 years 10 months. Performance on a variety of auditory perceptual tests were obtained at 1 year and two year intervals. After almost 3 years of implant use, the child suffered an internal receiver failure. The Nucleus device was explanted and the child was implanted with a Clarion Cochlear Implant System. Performance on a similar set of auditory perceptual tests obtained after 3 and 6 months use indicated better performance with the Clarion device. In addition to the scores on the individual tests, a comparison questionnaire was used to obtain impressions from the parents and the school personnel. Results should be reviewed with caution since this study investigates the responses of a single child who uses each of these two different implants and cannot be generalized.

Timing and trials of hearing aids and assistive devices.

Of all the factors under consideration during the evaluation for a cochlear implant, perhaps the most critical is the speech perception ability of the candidate when using appropriate amplification. For children, this issue is often complicated by inadequate training or limited use of the sensory aid. Guidelines for implantation suggest that there be a "lack of benefit from hearing aids" to qualify as a candidate. This "lack of benefit" must be explored when using the most appropriate aid coupled with the proper rehabilitation. In determining candidacy for children, it becomes extremely important to assess benefit using a variety of sensory aids while having access to well-directed auditory intervention. The types of amplification that can be used during the preimplant evaluation stage include conventional behind-the-ear devices, FM units, vibrotactile aids, and frequency transposition aids. Although some of these devices are used more often than others, centers implanting children should be aware of the role that each plays in the evaluation process. To determine the frequency with which these devices are used as well as the types of strategies that are emphasized in the preimplant training interval, a questionnaire was developed to gather information from the cochlear implant facilities in the United States. The results of this survey will be presented to demonstrate training and device trends that are incorporated during the preimplant process. Additionally, the use of frequency transposition hearing aids as part of the preimplant training procedure will be explored. The facility at Manhattan Eye, Ear and Throat Hospital has studied these devices in a small group of adults and children. Data pertaining to the speech perceptual abilities obtained with both the TranSonic and the Emily will be presented and compared to results with the Nucleus cochlear implant system.

Surgical techniques for cochlear implantation in the very young child.

Early cochlear implantation to treat prelingually deafened children has been shown to improve speech perception and overall performance. The current age limit for implantation is 24 months in accordance with US Food and Drug Administration guidelines, but it is believed that earlier implantation is possible and may result in better performance. Implantation in children younger than 36 months, however, is complicated by the altered anatomy of the temporal bone in this young age group. We have developed specific modifications in the cochlear implantation technique for this young age group. This technique was used in implantation for 17 children younger than 36 months. The ages ranged from 16 to 36 months and averaged 30 months. All patients except one had complete electrode insertion without complication. The technique of cochlear implantation must be modified not only for differences in anatomy in these young children but also for the expected continued growth of the temporal bone and related structures. Cochlear implantation can be safely performed on children as young as 16 months.

Cochlear implant mechanical failures.

Cochlear implants have proven to be an effective treatment for profoundly deafened individuals. Unfortunately, like most mechanical devices, these implants occasionally cease to function. The rate at which the cochlear implant fails, however, does not appear to be the same in adults and children. The failure rate for children far exceeds that observed in adults. The overall failure rate reported by Cochlear Corporation notes that whereas only 3% of the adults have had this type of problem, 9% of the children have had failed internal receivers. This research reports on the experiences of a large implant facility in the Northeast. The clinical presentation and the evaluation of children suspected of having an implant failure are reviewed. The mechanical causes for failures are analyzed. Intraoperative findings and results of reimplantation surgery are presented. The possible causes for the increased incidence of failure in children are discussed.

Success of children with cochlear implants in mainstream educational settings.

The availability of cochlear implant technology has made mainstreaming a more reachable social and academic goal for profoundly deaf children. Traditionally, the profoundly deaf child has required more self-contained education. It has been the hard-of-hearing child who reached the mainstream education classroom during the elementary years. Cochlear implant recipients, implanted early and receiving appropriate educational services that maximize learning across all domains, have shown a significant trend toward moving from a more self-contained to a less restrictive educational environment. Children with implants are making these transitions earlier than the larger majority of profoundly deaf children using traditional amplification.

Cochlear implant performance in a deaf child of deaf parents: a case study.

Marie represents a unique case in the population of cochlear implant users, in that she is from a family of deaf individuals. Her auditory perceptual performance after 2 years of implant use is commensurate with that of other children of similar ages and durations of deafness. Although her speech production performance is also not atypical, the special circumstances in the home might cause additional delay. Studies have traditionally shown that deaf children of deaf adults exhibit superior ability in both social and academic domains when compared to deaf children of hearing parents. The cochlear implant provides yet another tool to add to the already-identified advantage extended this group by their family circumstance. It is unfortunate that these children for whom the device can offer enhanced abilities may be the very children that are denied access to it by the deaf community.

Programming the cochlear implant based on electrical acoustic reflex thresholds: patient performance.

The electrical acoustic reflex threshold (EART) has been shown to be a reliable estimate of behavioral comfort levels in both child and adult cochlear implant patients. The purpose of this study was to investigate the potential for using EARTs for programming the Nucleus cochlear implant. EARTs and behavioral comfort levels were obtained from 7 adult implant patients. Two programs or "maps" were made for each patient, one based on behavioral comfort levels and one based on EARTs. Performance on open set tests of speech recognition was measured with each map. Mean data suggest that speech perception is similar with both maps. Analysis of individual data revealed that, whereas 2 subjects performed better with the C-level maps, the remaining 5 subjects tended to perform either better with the EART map or equally well with both maps. These results suggest that EARTs may be an adequate substitute for comfort levels when programming the implant for patients who are unable to make reliable psychophysical judgments.

Temporal bone imaging for cochlear implantation.

Computerized tomography (CT) imaging of the inner ear structures is helpful when evaluating a patient for cochlear implantation. The accuracy of CT scan imaging in determining the presence of cochlear ossification was assessed. A retrospective study of 104 implant patient charts, operative reports, and CT scans was performed. The CT scan was in agreement with the operative findings in 78% of patients included in the study. Twenty-two percent were found to have ossification at surgery which was not detected radiographically. One patient with extensive otospongiosis and an obstructed cochlea on CT scan had a patent cochlea demonstrated by magnetic resonance imaging (MRI) which was corroborated at surgery. In 32 children with postmeningitic hearing loss, the CT scan had only a 53% accuracy in assessing cochlear ossification. Since 69% of these patients were found to have some degree of cochlear ossification, otologists should expect to encounter some degree of bony obstruction within the basal turn of the cochlea even when the CT scan is normal. Nevertheless, cochlear implantation can successfully be performed in these cases.

The relationship between electrical acoustic reflex thresholds and behavioral comfort levels in children and adult cochlear implant patients.

The accuracy with which behavioral comfort levels could be predicted by the electrically elicited acoustic reflex threshold (EART) was examined in 35 Nucleus Cochlear Implant patients (16 adults and 19 children). EARTs were obtained by stimulating bipolar pairs of electrodes through the Nucleus Diagnostic Programming System and monitoring the change in middle ear admittance in the ear contralateral to the implanted ear. EARTs were successfully elicited in 24 patients. EARTs differed from behavioral comfort levels by a mean of 19.4 stimulus level units for adults and 9.6 stimulus level units for children. While EARTs were found to be acceptably close to behavioral comfort levels in four adults and eight children, EARTs significantly overestimated or underestimated comfort levels in the rest. The results of this study suggested that while the EART does not accurately predict comfort levels in all cases, it may provide valuable information regarding levels which should not be exceeded when programming the cochlear implant. Cautious use of information available from the EART may prove useful for programming the cochlear implant in children or adults who are unable to make reliable psychophysical judgments.

Vowel perception strategies of normal-hearing subjects and patients using Nucleus multichannel and 3M/House cochlear implants.

Vowel perception strategies were assessed for two "average" and one "star" single-channel 3M/House and three "average" and one "star" Nucleus 22-channel cochlear implant patients and six normal-hearing control subjects. All subjects were tested by computer with real and synthetic speech versions of [symbol: see text], presented randomly. Duration, fundamental frequency, and first, second, and third formant frequency cues to the vowels were the vowels were systematically manipulated. Results showed high accuracy for the normal-hearing subjects in all conditions but that of the first formant alone. "Average" single-channel patients classified only real speech [hVd] syllables differently from synthetic steady state syllables. The "star" single-channel patient identified the vowels at much better than chance levels, with a results pattern suggesting effective use of first formant and duration information. Both "star" and "average" Nucleus users showed similar response patterns, performing better than chance in most conditions, and identifying the vowels using duration and some frequency information from all three formants.

Speech changes following reimplantation from a single-channel to a multichannel cochlear implant.

The speech of a postlingually deafened preadolescent was recorded and analyzed while a single-electrode cochlear implant (3M/House) was in operation, on two occasions after it failed (1 day and 18 days) and on three occasions after stimulation of a multichannel cochlear implant (Nucleus 22) (1 day, 6 months, and 1 year). Listeners judged 3M/House tokens to be the most normal until the subject had one year's experience with the Nucleus device. Spectrograms showed less aspiration, better formant definition and longer final frication and closure duration post-Nucleus stimulation (6 MO. NUCLEUS and 1 YEAR NUCLEUS) relative to the 3M/House and no auditory feedback conditions. Acoustic measurements after loss of auditory feedback (1 DAY FAIL and 18 DAYS FAIL) indicated a constriction of vowel space. Appropriately higher fundamental frequency for stressed than unstressed syllables, an expansion of vowel space and improvement in some aspects of production of voicing, manner and place of articulation were noted one year post-Nucleus stimulation. Loss of auditory feedback results are related to the literature on the effects of postlingual deafness on speech. Nucleus and 3M/House effects on speech are discussed in terms of speech production studies of single-electrode and multichannel patients.

Auditory perception changes after reimplantation in a child cochlear implant user.

The ability to remove cochlear implants from children and subsequently reimplant a more complex device in the same ear was the concern of this single case study. A postlinguistically deafened child, J.L., received a single-channel cochlear implant 1 yr after contracting meningitis and suffering a profound bilateral sensorineural hearing loss. After 3 yr of successful implant use, J.L. suffered an internal coil failure. She was then explanted and reimplanted with a multichannel cochlear implant in the same ear. This case report details her speech perception skills with her single-channel cochlear implant, a vibrotactile aid, and a multichannel cochlear implant. Results from auditory perceptual measures suggest that the explantation/reimplantation process was technically feasible with no adverse effects on J.L.'s ability to utilize a more sophisticated device and to exceed her previous performance levels.