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PubMed2000

The prognostic value of promontory electric auditory brain stem response in pediatric cochlear implantation.

OBJECTIVE: To test the hypothesis that children with clear promontory electrically evoked auditory brain stem responses (prom-EABRs) would outperform, after cochlear implantation, children who had no prom-EABR preoperatively. DESIGN: A prospective study was undertaken on 47 implanted children assigning them to two groups (group A: 35 children with a clear wave e-V in the preoperative prom-EABR and group B: 12 children with no prom-EABR). Speech perception and speech intelligibility were assessed annually up to 3 yr after implantation with the IOWA sentence test (level A and level B), Connected Discourse Tracking, Categories of Auditory Performance, and Speech Intelligibility Rating. t-test and Mann-Whitney U test were used to compare the above outcome measures in the two groups. RESULTS: There was no statistically significant difference between the two groups on any of the outcome measures at any interval. Moreover, the small differences observed showed no consistent trend toward either group of children. Further analysis revealed that the outcomes have not been affected by possible confounding factors (age at implantation, duration of deafness, preoperative unaided pure-tone thresholds, and number of inserted electrodes). CONCLUSIONS: The results suggest that children with no prom-EABR performed at levels comparable with children who had clear promontory responses preoperatively. The prognostic value of prom-EABR is limited and absence of a prom-EABR is not, by itself, a contraindication for cochlear implantation. However, in selected cases (congenital malformations, cochlear nerve dysplasia or suspected aplasia, narrow internal auditory canal, etc.) the presence of a prom-EABR is a positive finding in the assessment of candidates for cochlear implantation as it confirms the existence of intact auditory neurones.

Audiometry, Pure-Tone↗
PubMed2004

The auditory performance in children using cochlear implants: effects of mental function.

OBJECTIVE: Mental function is considered to affect the post-operative outcomes of deaf children with cochlear implants. The purpose of this study is to evaluate the effect of mental function on the auditory performance in children with cochlear implants. METHODS: In a retrospective review of data, 26 pre-lingual deafened children received pre-operative evaluation of mental function and were divided into normal and retarded groups. Categories of auditory performance scale (CAP) was conducted at 1-year intervals after implantation. ANCOVA was used for statistic analysis. RESULTS: The average scores of auditory performance in normal group (n=14) were 3.93 (S.D. 1.07) and 5.86 (S.D. 0.95) at 1- and 2-year post-implantation. While the average scores in the retarded group were 2.5 (S.D. 1.51) and 4.17 (S.D. 1.85), both groups demonstrated obvious improvement in speech perception (F 103.12, P<0.001) during the first 2 post-operative years. The auditory performance in the normal group was significantly superior to the retarded group (F 8.67, P<0.01). However, the interaction between the duration of the device use and mental status showed no significant difference in the auditory perception performance (F 1.575, P=0.222). CONCLUSIONS: The results revealed the mental function plays as one of the predictive parameters of auditory performance in profoundly hearing impaired children after cochlear implantation.

Child↗
PubMed1999

Comparison of two methods for selecting minimum stimulation levels used in programming the Nucleus 22 cochlear implant.

Minimum stimulation levels for active electrodes in a Nucleus 22 cochlear implant were set at threshold (clinical default value) and raised levels (M = +2.04 dB) to determine if raised levels would improve recipients' understanding of soft speech sounds with the SPEAK speech coding strategy. Eight postlinguistically deaf adults participated in a 4-phase A1B1A2B2 test design. Speech recognition was evaluated with consonant-vowel nucleus-consonant (CNC) words in quiet and sentences in noise, both presented at 50, 60, and 70 dB SPL during 2 weekly sessions at the end of each phase. Group mean scores were significantly higher with the raised level program for words and phonemes at 50 and 60 dB SPL and for sentences at 50 and 70 dB SPL. All participants chose to use the raised level program in everyday life at the end of the study. The results suggest that clinical use of a raised level program for Nucleus 22 recipients has the potential to make soft sounds louder and, therefore, more salient in everyday life. Further research is needed to determine if this approach is appropriate for other cochlear implant devices.

Acoustic Stimulation↗
PubMed2004

Immunogenicity of pneumococcal vaccination of patients with cochlear implants.

BACKGROUND: Pneumococcal meningitis is a rare but potentially fatal complication of cochlear implantation. METHODS: A prospective study was conducted of the immunogenicity of pneumococcal vaccination in 174 patients with cochlear implants (CIs). The cohort was divided into groups of patients with impaired hearing due to meningitis (P(1)), cranial malformations (P(2)), or an unknown cause (P(3)) and was stratified by age as follows: <2 years (A(1)), 2-5 years (A(2)), and >5 years (A(3)). We determined immunoglobulin (Ig) levels for IgG subclasses 1-4 and serum concentrations of antibodies against pneumococci before and 4-6 weeks after vaccination. Group A(1) received the 7-valent pneumococcal conjugate vaccine (PCV-7), group A(2) received PCV-7 or the 23-valent pneumococcal polysaccharide vaccine (PPV-23), and group A(3) received PPV-23. RESULTS: IgG, IgM, and IgG1 levels were significantly lower in group P(1), compared with the other patient groups and with historic data for healthy control subjects, suggesting a decreased antibody response. Group P(1) had lower levels of pneumococcal antibodies, compared with groups P(2) and P(3) before vaccination (P<.05, pneumococcal serotypes 4 and 9V). Irrespective of the underlying condition, all patients showed a sufficient antibody response after 1 dose of vaccine. In children 2-5 years of age, PCV-7 was significantly more immunogenic than PPV-23. CONCLUSIONS: PCV-7 should be administered to all CI recipients younger than 6 years and older than 6 years who are at an increased risk for bacterial meningitis. CI recipients with a history of bacterial meningitis should undergo immunological evaluation.

Adolescent↗
PubMed1990

Electrical stimulation of the round window: a selection procedure for single-channel cochlear implantation.

Many suggestions have been made as to the most appropriate tests for the selection of patients for cochlear implantation. One of the most appropriate tests when selecting patients for a round window extracochlear device is stimulation of the round window itself by a temporary electrode of the same size. Fourteen patients have been tested, 7 of whom were judged to have a good response to electrical stimulation. Six patients have gone on to permanent implantation with a round window cochlear implant.

Acoustic Impedance Tests↗
PubMed2006

Four years' experience with the minimally invasive surgical approach in cochlear implant surgery.

This is a prospective study on 808 profoundly or totally deaf patients who underwent either unilateral or bilateral cochlear implantation, involving a minimally invasive surgical approach, at the Medical University of Hannover's Department of Otolaryngology between May 2001 and May 2005. Advanced Bionics, Cochlear and MED-EL devices were used, the latter having been in use at our department since the beginning of 2003. The aim of our investigation was to determine the optimal surgical technique, evaluate safety aspects and gauge patient satisfaction with this minimally invasive surgical approach during cochlear implantation. Surgical technique is analysed. Complications such as skin flap problems did not occur. The use of this minimally invasive surgical technique did not increase the surgical risk. This procedure proved both cosmetically and psychologically beneficial for patients, especially for children and their parents.

Adult↗
PubMed2005

Facial nerve stimulation after cochlear implantation.

OBJECTIVES: This study was designed to compare the incidence and nature of facial nerve stimulation (FNS) in patients receiving cochlear implants (CI) manufactured by Cochlear Corporation, Advanced Bionics Corporation, and MedEl. STUDY DESIGN: Retrospective chart review at a tertiary referral center. METHODS: The charts of 600 patients who received CIs from 1993 to 2003 with at least 1 year of follow-up were reviewed for significant FNS (FNS on at least 1 channel at functional stimulation levels). Data collected included age, sex, etiology of deafness, device type, electrode, FNS onset after initial stimulation, number and location of electrode contacts causing FNS, and loudness level at which FSN occurred. Nucleus straight and perimodiolar electrodes were also compared. RESULTS: Thirty-nine of 600 (6.5%) patients had FNS on at least one channel, (MedEl 3 of 43 [7.0%], Nucleus 29 of 440 [6.6%], and Clarion 7 of 117 [6.0%]). The incidence of FNS in Nucleus perimodiolar electrodes (16 of 250 [6.4%]) was similar to straight electrodes (13 of 190 (6.8%]), as was the mean number of electrodes causing FNS per patient (11 vs. 12). However, straight electrodes caused stimulation at significantly softer perceived loudness levels than perimodiolar electrodes (P < .0001). CONCLUSIONS: In this large series of CI FNS, the overall incidence of FNS is consistent with previous reports. All devices had a similar incidence of FNS, but perimodiolar electrodes produced FNS only at significantly higher loudness levels than straight electrodes, making them preferable for patients at risk for FNS receiving Nucleus devices.

Adolescent↗
PubMed1995

Postoperative imaging of the multichannel cochlear implant.

PURPOSE: To present the postoperative radiographic appearance of the multichannel cochlear implant and to suggest criteria for the radiographic evaluation of postimplant patients. METHODS: One hundred forty-one patients, 73 female and 68 male, had multichannel cochlear implants inserted. One hundred thirty-five intraoperative radiographs, 31 postoperative radiographic examinations, and 10 postoperative CT examinations were retrospectively reviewed. RESULTS: In 135 patients, a Stenver's or anteroposterior projection confirmed the normal placement of the implant by demonstrating the electrodes to be regularly spaced and gently curved within the first turn of the cochlea. The insertion depth was determined by counting the number of electrodes that projected medial to the cochlear promontory. In 5 patients in whom intracochlear placement of the electrode array could not be confirmed on plain radiographs, CT demonstrated the location of the electrode array. In 3 patients with postoperative infections, CT either correctly identified or excluded the presence of a collection beneath the implant. CONCLUSION: Plain radiographs of the temporal bone are sufficient for the postoperative treatment of the majority of postimplant patients. CT should be performed when plain radiographs cannot adequately show the location of the electrode array or if postoperative infection is suspected.

Adolescent↗
PubMed1999

Effects of electrode configuration and frequency allocation on vowel recognition with the Nucleus-22 cochlear implant.

OBJECTIVE: This study was conducted to understand vowel recognition in cochlear implants as a function of the cochlear location and separation of the stimulated electrode pairs and as a function of the matching between speech spectral information and the location of the stimulated electrodes. DESIGN: Four-electrode speech processors with a continuous interleaved sampling speech processing strategy were implemented through a custom interface in five subjects implanted with the Nucleus-22 cochlear implant. The temporal envelopes from four broad frequency bands were used to modulate 500 pps, 100 microsec/phase interleaved pulse trains delivered to four electrode pairs. Ten different frequency allocations and five sets of four-electrode configurations were tested. Each frequency allocation represented the same cochlear extent but different cochlear locations based on Greenwood's frequency-to-place formula. Recognition of multi-talker medial vowels was measured for each combination of parameters with no period of practice or adjustment. RESULTS: Results showed that recognition of multi-talker vowels was highly dependent on frequency allocation for all electrode configurations. For a given electrode configuration maximum vowel recognition was observed with a specific frequency allocation. When the stimulated electrodes were shifted basally by 3 mm, the frequency allocation that produced the best performance also shifted basally by 3 mm. A similar pattern of vowel recognition was observed as a function of frequency allocation for electrode configurations that had the same apical-most electrode in each pair, regardless of location of the basal-most electrode in the pair. Subjects with different electrode insertion depths had similar trends in vowel recognition for each frequency allocation. CONCLUSIONS: For a given electrode configuration, the best performance was obtained with processors with a specific frequency allocation. In addition, the apical-most member of each electrode pair had a much stronger influence on vowel recognition in electric hearing. Finally, results from this study also suggest that over time, patients with implants can partially adapt to a basal shift in place of stimulation.

Adult↗
PubMed2004

GJB2 gene mutations in cochlear implant recipients: prevalence and impact on outcome.

OBJECTIVE: To determine the prevalence of GJB2 gene mutations in patients undergoing cochlear implantation (CI) and their impact on rehabilitative outcome following implantation. DESIGN: Prospective determination of GJB2 mutation by sequence analysis by denaturing high-performance liquid chromatography and its correlation with outcome following CI. SETTINGS: Two tertiary academic medical centers. PATIENTS: Subjects who have met the audiologic criteria and have undergone CI. RESULTS: Of 77 cochlear implant recipients screened, 13 (18%) harbored a detectable sequence alteration in the GJB2 gene. Only 3 of these 13 patients had hearing loss clearly attributable to a biallelic GJB2 mutation. There were 2 patients with homozygous mutations, including a 35delG and a 167delT mutation, and a third with a compound heterozygous mutation. Of the remaining 10 patients, 8 had 1 deafness allele, while 2 had a normal polymorphism that was not believed to be implicated in the hearing loss. Six patients had the common 35delG mutation: 5 patients had heterozygous mutations, which are probably not related to the underlying hearing loss (a second deafness allele cannot be ruled out in these cases because of the screening methodology used), while 1 patient had a homozygous mutation, which was clearly implicated in the patient's deafness. Rehabilitative outcome among those with detectable sequence alterations, as well as the 3 patients with biallelic mutations, varied but were similar on average when compared with outcomes seen in our entire CI population. CONCLUSIONS: A large percentage of implant candidates harbor mutations or sequence alterations in the GJB2 gene, although only a small number of these changes are biallelic and a clear cause of the hearing loss. These results demonstrate that patients with GJB2-related deafness clearly benefit from CI.

Adolescent↗
PubMed1997

Cochlear implantation in a district general hospital: problems and complications in the first five years.

Fifty-three patients, 34 adults and 19 children have been implanted over the first five years of the cochlear implant programmed at the North Riding Infirmary (NRI). For a small centre, based at a district general hospital, our complication rate compare favourably with others: 11.7 per cent adult and 10.5 per cent paediatric major complications. Data on all patients was gathered prospectively as part of the national cochlear implant programme, and we report and discuss all complications from this centre.

Adolescent↗
PubMed1988

Open-set word recognition with the 3M/Vienna single-channel cochlear implant.

The author visited Innsbruck (Austria) to evaluate the performance of nine of the better patients implanted in Europe with the 3M/Vienna single-channel cochlear implant. Word- and sentence-level speech recognition tests recorded in German by two speakers from Austria were presented. Performance varied from 15% to 86% correct word recognition on the sentence material, 11% to 57% correct word recognition with word lists, and 21% and 66% correct phoneme recognition on the word tests. These results confirm earlier studies indicating that high levels of open-set word recognition without visual cues can be obtained with the 3M/Vienna single-channel cochlear implant.

Cochlear Implants↗
PubMedDate not supplied

Interviews with deaf children about their experiences using cochlear implants.

Within the framework of a longitudinal study of deaf children with cochlear implants, 11 children with implants were interviewed. The objective was to shed light on what it is like for a child to use a cochlear implant, based on these children's own experience with implants, which ranged from 5.0 to 7.5 years. Six of the children were in schools for the deaf, five in regular classes. All but one used an implant daily. The children appreciated that an implant enabled them to perceive sounds in the environment. Some of the children in regular classes could take part in one-to-one conversations with teachers but had difficulty following teaching and discussions. This observation was consistent with what the children's parents and teachers had maintained. Peer interaction was said to be best when other children had the use of at least some signs.

Attitude to Health↗
PubMed2002

The role of age in pediatric cochlear implantation.

OBJECTIVE: To document progress, benefit and importance of age in paediatric cochlear implantation. DESIGN: The EARS (Evaluation of Auditory Responses to Speech) test battery was performed on 33 prelingually deaf children at regular intervals up to 36 months following implantation. All children participated in individually tailored intensive audiological rehabilitation programs after receiving their implants. In this respect, it was attempted to evaluate speech perception scores in children implanted before and after the age of 3 in a homogenous group. RESULTS: All children demonstrated encouraging improvements over time in their speech recognition abilities. Furthermore, it was observed that the children who were implanted under the age of 3 achieved higher levels of speech perception performance. CONCLUSION: In order to shorten the process of central maturation of the auditory system, it is desirable to implant the children as young as possible. Early intervention seems to be the ideal strategy in enabling prelingually deaf children to derive maximum benefit from cochlear implantation.

Age Factors↗
PubMed1997

Speech intelligibility as a function of the number of channels of stimulation for normal-hearing listeners and patients with cochlear implants.

OBJECTIVE: One goal was to determine for normal-hearing listeners the number of channels of stimulation necessary to achieve a high level of speech understanding. The second goal was to determine whether patients with a six-channel cochlear implant could achieve the same level of speech understanding as normal-hearing subjects listening to speech processed through six channels. METHODS: Speech signals were processed, for normal-hearing listeners, either in the manner of cochlear-implant processors with 2-9 fixed channels, or in the manner of a processor which picked, on each update cycle, 6 of 16 channels. RESULTS: For the most difficult test material eight fixed channels were necessary to achieve the level of performance achieved with the "n of m" processor. Some cochlear implant patients with a six-channel continuous interleaved sampling processor achieved the same level of performance as normal-hearing subjects listening to speech via six channels. CONCLUSIONS: A signal processor for cochlear implants with eight channels should produce the same level of intelligibility as a processor with many more channels. Processors using continuous interleaved sampling technology can provide a signal which results in the same level of speech understanding as normal, acoustic stimulation.

Cochlear Implantation↗
PubMed2005

Displacement of electrodes of a cochlear implant into the vestibular system: intra- and postoperative electrophysiological analyses.

A cochlear implant device is normally inserted into the scala tympani via a posterior tympanotomy and cochleostomy. There has been no previous report of displacement of the array into the vestibular part of the labyrinth. The authors present and discuss the audiological and electrophysiological measurements of a case in which part of the array herniated through into the vestibule.

Acoustic Impedance Tests↗
PubMed2005

Cochlear implant magnet displacement with minor head trauma.

OBJECTIVES: Manufacturers have introduced cochlear implants (CIs) with removable magnets to allow for magnetic resonance imaging after placement. The purpose of this study was to describe magnet displacement as a new CI complication and to suggest a possible treatment option to prevent its recurrence. STUDY DESIGN: Retrospective case series. METHODS: The records of 3 young males who experienced CI magnet dislodgement were reviewed and compared against records from the institutional implant database. RESULTS: Magnet displacement was observed only in young males (14% of male children) who received CI with removable magnets. This occurred 13-14 months after CI placement. Magnets were replaced under general anesthesia, and the scalp was bolstered with a dermal allograft. Recurrent magnet dislodgement was encountered in 1 patient, 6 months later. CONCLUSIONS: Magnet displacement may be a relatively common complication after minor head trauma in pediatric patients with certain CIs that have removable magnets.

Child, Preschool↗