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PubMedDate not supplied

Assessment of auditory skills in 140 cochlear implant children using the EARS protocol.

Auditory performance of cochlear implant (CI) children was assessed with the Listening Progress Profile (LiP) and the Monosyllabic-Trochee-Polysyllabic-Word Test (MTP) following the EARS protocol. Additionally, the 'initial drop' phenomenon, a recently reported decrease of auditory performance occurring immediately after first fitting, was investigated. Patients were 140 prelingually deafened children from various clinics and centers worldwide implanted with a MEDEL COMBI 40/40+. Analysis of LiP data showed a significant increase after 1 month of CI use compared to preoperative scores (p < 0.01). No initial decrease was observed with this test. Analysis of MTP data revealed a significant improvement of word recognition after 6 months (p < 0.01), with a significant temporary decrease after initial fitting (p < 0.01). With both tests, children's auditory skills improved up to 2 years. Amount of improvement was negatively correlated with age at implantation.

Adolescent↗

PubMed2003

Correlation between NRT measurement and behavioural levels in patients with the Nucleus 24 cochlear implant.

Aim of this study was to determine the relationship between the electrically evoked whole nerve action potential (EAP) and T- and C-level for subjects using the Nucleus 24 cochlear implant system. EAP thresholds were measured using the Neural Response Telemetry system of the Nucleus 24 device. Twelve Nucleus 24 cochlear implant users took part in this study. EAP thresholds were compared with the behavioural measures of T- and C-levels used to programme the speech processor. The EAP and the T- and C-levels were obtained, on the same day, 1 month after cochlear implant activation. EAP thresholds were seen to fall between the T- and C-level. On average, EAP thresholds fell at 72% of the map dynamic range. The majority of absent answers were found in three of the 12 patients, and out of a total of 195 activated electrodes an EAP was recorded in 169. These data show that Neural Response Telemetry is a valuable clinical tool in the Nucleus cochlear implant system, providing information concerning integrity of the implant and status of the peripheral auditory nerves.

Adolescent↗

PubMed1996

[Cochlear implant management of young children].

INTRODUCTION: Since 1988, more than 450 children have received cochlear implants at the Department of Otolaryngology of the Medizinische Hochschule Hannover. Among them are 38 children who underwent surgery before the age of two. Due to increasing experience with this technique, the mean age at implantation has decreased over time so that most children nowadays receive implants between the ages of two and five. In terms of the critical periods of both development of the auditory system and the acquisition of language, it is advantageous for even younger children to receive implants soon after detection of deafness. However, the present diagnostic tools do not allow proper estimation of residual hearing and additional handicaps. Therefore longer periods of hearing aid use and audioverbal training are mandatory before implantation. Additional objections against early implantation are biosafety problems such as head growth, the high incidence of otitis media, and the specific surgical anatomy. This paper outlines criteria for patient selection, the surgical concept, postoperative rehabilitation, and complications. PATIENTS: Twenty-six children suffered from postmeningitic deafness and beginning obliteration of the cochlea as shown by repeated high resolution CT scans. Nine children had congenital deafness which was detected early in life and showed no improvement after proper hearing aid fitting and audioverbal training for speech development. Three children had severe inner ear malformations detected by CT scans. All children had no ABR or CAP responses in ECoG. Their developmental, language, and neuropaediatric status was examined. SURGERY: Thirty-five children received the Nucleus Mini 22 cochlear implant; three children received the Clarion 1.2 device. The surgery was not different from adult surgery. Special care was given to proper fixation and placement of the electrode in the drilled out mastoid to compensate for head growth. POSTOPERATIVE RESULTS: All children wear the speech processor regularly. They are able to detect everyday sounds and suprasegmental features of speech after a few months. After one year, the child begins to understand and produce speech; after two years speech understanding has been achieved and normal language development starts with small sentences. The complication rate was not higher than in other age groups of patients. Fitting and tune-up of the speech processor required a broad range of experience and a specialized team working at the children's implant center. CONCLUSION: Early implantation in children is both possible and effective in selected cases. Due to an improved early detection of deafness, it should be possible to increase the percentage of children with early cochlear implantation.

Child↗

PubMed2006

[Multi-slice spiral CT imaging in the post-operative assessment of cochlear implanted electrode].

OBJECTIVE: To evaluate the usefulness of multi-slice spiral CT (MSCT) in the post-operative assessment of cochlear implanted electrode. METHODS: Twenty-three cochlear implant recipients were enrolled in this study. All patients were examined with a SOMATOM Sensation 16-slice CT scanner (Siemens) using the following parameters: 120 kV, 100 mAs, 0. 75 mm collimation, 1 mm reconstruction slice thickness and increment, a pitch factor of 1, and a FOV of 100 mm. The axial images of interested ears were reconstructed with 0.1 mm increment and a FOV of 50 mm, and then volume rendering technique (VRT) reconstruction were done on the work station. RESULTS: The electrode arrays were detected on axial CT images. Both inner ear and electrode array could be displayed on one image simultaneously. VRT provided an intuitionistic view of the relationship between electrode array and cochlea VRT showed the number of the electrode array in 20 patients implanted with Combi 40 + standard electrode array and demonstrated the shape, position, and insertion depth. The electrode array number determined by VRT was in accordance with the surgical findings in 18 patients, and was underestimated in two patients. In 3 patients with Combi 40 + compressed electrode array, only 4 to 5 electrodes arrays were clearly identified and others were not observed. CONCLUSION: MSCT with VRT can provide useful three-dimensional information of the electrode array and indicate the exact relationship between electrode array and cochlea.

Adolescent↗

PubMed1997

[Value of auditory evoked potentials of the brain stem in patients with a Digisonic cochlear implant].

We report our techniques of electrically elicited Auditory Brainstem Responses (eABR) in Digisonic DX 10 cochlear implanted patients and summarize the theoretical interests of objectives measures in pre-, per- and post-operative periods of the cochlear implantation process. This report demonstrates the major interest of eABR during rehabilitation with a cochlear implant. EABR allowed us to detect the lack of device integrity in one electrode in one patient. The quality of electrically elicited responses can contribute to appreciate the electrophysiological responses during electrical stimulation. We found a very strong correlation between the objective thresholds (obtained by means of eABR) and subjective ones (obtained by means of behavioral methods); this is of major interest in the pediatric populations.

Acoustic Stimulation↗

PubMed1993

[Patient selection for adult cochlear implantation and its experience].

From 1986 to 1992, 61 adults with bilateral profound hearing loss visited our hospital for assessment as candidates for cochlear implantation. The selection process consists of the following steps: 1) taking a clinical history, 2) general otological examinations, 3) pure tone audiometry 4) hearing aid evaluation, 5) promontory stimulation testing and 6) CT scans and MR Imaging of the temporal bone. We informed patients and their families of cochlear implantation as well. Consequently 7 out of 61 cases (11.7%) were selected and underwent multi-channel cochlear implantation. Twenty-eight cases were judged to have better hearing with a hearing aid because of a residual hearing. Twenty-one cases were considered to be inappropriate candidates after informing of the cochlear implant procedure. Needless to say, the promontory stimulation testing and imaging studies are significant in patient selection, however, there was only a few who were excluded by these examinations.

Adult↗

PubMed2003

Pneumococcal vaccination for cochlear implant candidates and recipients: updated recommendations of the Advisory Committee on Immunization Practices.

In October 2002, CDC recommended that all persons with cochlear implants receive age-appropriate pneumococcal vaccination with 7-valent pneumococcal conjugate vaccine (PCV7) (Prevnar), 23-valent pneumococcal polysaccharide vaccine (PPV23) (Pneumovax), or both according to the Advisory Committee on Immunization Practices (ACIP) schedules for persons at high risk. CDC issued these recommendations on the basis of preliminary data suggesting an increased risk for pneumococcal meningitis in persons with cochlear implants. Findings of a recent investigation by CDC, the Food and Drug Administration (FDA), and state health departments support this recommendation. Children aged <6 years with a cochlear implant had a substantially greater risk for having pneumococcal meningitis, compared with children in the general U.S. population of the same age. Some children who are candidates for cochlear implants have pre-existing anatomic factors that might contribute to an increased risk for meningitis; however, the recent study was not designed to assess this association.

Adolescent↗

PubMed2006

Cochlear implanted pupils in Scottish schools: 4-year school attainment data (2000-2004).

The Achievements of Deaf Pupils in Scotland (ADPS) project has been tracking the educational attainment of deaf pupils in Scotland's schools since 2000. At the time of writing, the database contains records for 1,752 deaf pupils (2000-2005). Here 4-year aggregate educational attainment data are reported for a subset of 152 school-aged deaf pupils with cochlear implants notified to the ADPS database between June 2000 and June 2004. The data describe primary and secondary school results in reading, writing, and math for this subgroup, as well as placement and communication characteristics. The educational attainment of the group of deaf pupils with cochlear implants is clearly marked when the deaf pupil population is disaggregated for hearing loss, achieving comparatively higher average attainment in both 5-14 Curriculum National Tests (Mathematics in particular) and Standard Grades. Therefore the gap in performance relative to the national population data is reduced for those deaf pupils, although it still widens at higher levels of achievement for the National Tests. Although most pupils with cochlear implants are placed in the mainstream, there is no pattern of migration toward mainstream schools. Some deaf pupils with cochlear implants moved out of mainstream to other types of placement, and this has implications for health-economic cost-utility assessments of cochlear implantation that favor mainstream education by drawing upon the relative cost of different placement types. These findings suggest that the ADPS program of research can contribute school outcome data as valuable real-life outcome measures in wider assessments of the benefit of cochlear implants to deaf children and deaf young people.

Adolescent↗

PubMed1997

Speech recognition at simulated soft, conversational, and raised-to-loud vocal efforts by adults with cochlear implants.

Ten postlinguistically deaf adults who used the Nucleus Cochlear Implant System and SPEAK speech coding strategy responded to vowels, consonants, words, and sentences presented sound-only at 70, 60, and 50 dB sound-pressure level. Highest group mean scores were at a raised-to-loud level of 70 dB for consonants (73%), words (44%), and sentences (87%); the highest score for vowels (70%) was at a conversational level of 60 dB. Lowest group mean scores were at a soft level of 50 dB for vowels (56%), consonants (47%), words (10%), and sentences (29%); all except subject 7 had some open-set speech recognition at this level. For the conversational level (60 dB), group mean scores for sentences and words were 72% and 29%, respectively. With this performance and sound-pressure level, it was observed that these subjects communicated successfully in a variety of listening situations. Given these subjects' speech recognition scores at 60 dB and the fact that 70 dB does not simulate the vocal effort used in everyday speaking situations, it is suggested that cochlear implant candidates and implantees be evaluated with speech tests presented at 60 dB instead of the customary 70 dB sound-pressure level to simulate benefit provided by implants in everyday life. Analysis of individuals' scores at the three levels for the four speech materials revealed different patterns of speech recognition among subjects (e.g., subjects 1 and 5). Future research on the relation between stimuli, sound processing, and subjects' responses associated with these different patterns may provide guidelines to select parameter values with which to map incoming sound onto an individual's electrical dynamic range between threshold and maximum acceptable loudness level to improve speech recognition.

Adult↗

PubMed1992

[Improvement of clinical results by digitalization of a single channel cochlear implant].

For 1973 we have been among the first to claim the multichannel cochlear implant superiority regarding single channel efficacy. However we actually thing that single channel cochlear implant is indispensable in case of total ossified cochlea, and very useful when efficacy/coast ratio must be considered. In order to narrow the gap between multi and single channel device efficacy, we used the new microprocessors possibilities to digitalize the analogic emietter of the single channel system, which we designed in 1987. Owing to a PC keyboard the new emietter allows the speech therapist to select the frequency band width of the input signal, and to determine the threshold level and the dynamic value as a function of six steps values of the stimulus wave frequency. These improvements supply the patient with a better speech intelligibility excepted for vowels discrimination. Comparison of clinical results obtained through the two analogic and digital systems are reported on 4 post lingually and 4 pre lingually deaf patients.

Adolescent↗

PubMed1997

Long-term speech perception in children with cochlear implants compared with children with conventional hearing aids.

OBJECTIVE: To determine the speech perception of children with cochlear implants. SUBJECTS AND METHODS: Speech perception results of seven children with cochlear implants (excellent performers), who showed stable speech recognition scores in the long term, were compared with those of severely hearing-impaired children with conventional hearing aids (reference group). The groups of children were matched according to their mean free-field aided thresholds. RESULTS: The results of the open-set word recognition test were comparable in the two groups. CONCLUSION: If we consider the results of the hearing aid users as the gold standard, the results suggest that speech recognition in selected children with a cochlear implant is close to optimal.

Audiometry, Pure-Tone↗

PubMed2000

Effects of electrode configuration and stimulus level on rate and level discrimination with cochlear implants.

Recent studies have demonstrated that speech perception with cochlear implants can be significantly affected by electrode configuration. Contrary to expectations, broader configurations (monopolar or broad bipolar) produced equal or better speech recognition compared with narrower configurations (narrow bipolar or common ground). One hypothesis that would account for these results is that broader configurations excite larger populations of neurons providing a more robust representation of information on each channel of the prosthesis. It is known that the number of neurons excited by an electrical stimulus increases considerably as the stimulus level increases. Furthermore, many types of discrimination improve as a function of stimulus level. If the discrimination improvements seen with increasing stimulus level are due to increasing the size of the neural population carrying the signal, and if broadening the electrode configuration also increases the size of the activated neural population, then one would expect level and electrode configuration to affect discrimination in similar ways. To test this hypothesis, we studied several types of discrimination as a function of level and electrode configuration in four nonhuman primates with cochlear implants. We tested electrode configurations that produced current fields ranging from very restricted (tripolar) to broad (parallel monopolar). For each configuration, pulse-rate discrimination, amplitude-modulation-frequency discrimination, and level discrimination were tested at current levels spanning much of the psychophysical dynamic range. Results showed large effects of current level on discrimination in many cases. However, effects of electrode configuration at comparable levels within the dynamic range were smaller or absent. Furthermore, the effect of level on discrimination was independent of electrode configuration in most cases even though the rate of spread of neural activation with level is expected to depend on electrode configuration. Possible interpretations of these results are that (1) the current level adjustments necessary to achieve comparable loudness for the various configurations significantly countered any effects of electrode configuration on the size of the activated neural population, or (2) the effects of level on discrimination do not result from its effects on the spatial extent of neural activation.

Animals↗

PubMed2003

Modulation masking in cochlear implant listeners: envelope versus tonotopic components.

It is hypothesized that channel-interaction in cochlear implant listeners as measured in a modulation-masking experiment would be influenced by both the tonotopic overlap between masker and signal as well as an interaction between their envelopes. Two experiments were conducted to measure the effects of maskers with noisy and steady-state envelopes on modulation detection by four adult Nucleus-22 cochlear implant listeners, as a function of tonotopic distance between the masker and the signal. In the first experiment, we measured detection thresholds for a 50-Hz modulation in the envelope of a 500-Hz carrier pulse train, in the presence of a masker stimulating regions basal and apical to, as well as overlapping with, the signal. The maskers had two kinds of envelopes: (i) amplitude-modulated by flat-spectrum noise (NAM) and (ii) steady-state (SS(peak)) at a level corresponding to the maximum of the noise fluctuation range. In general, modulation thresholds obtained in the presence of the NAM maskers significantly exceeded thresholds obtained with the corresponding SS(peak) maskers. The ratio p of the threshold modulation depth m obtained with the NAM masker to that obtained with the SS(peak) masker was defined as a conservative index of "envelope masking." In the second experiment, p was determined for two different tasks: the detection of modulation at 20 Hz and steady-state intensity increment detection. Compared to the 50-Hz modulation detection results, the ratio p was reduced for the 20-Hz modulation detection task and even more so for the steady-state increment detection task. It is concluded that channel-interaction can be significantly increased in cochlear implant listeners when dynamic stimuli are used in place of steady-state stimuli.

Adult↗

PubMed2004

Nonword imitation by children with cochlear implants: consonant analyses.

OBJECTIVES: To complete detailed linguistic analyses of archived recordings of pediatric cochlear implant users' imitations of nonwords; to gain insight into the children's developing phonological systems and the wide range of variability in nonword responses. DESIGN: Nonword repetition: repetition of 20 auditory-only English-sounding nonwords. SETTING: Central Institute for the Deaf "Education of the Deaf Child" research program, St Louis, Mo. PARTICIPANTS: Eighty-eight 8- to 10-year-old experienced pediatric cochlear implant users. MAIN OUTCOME MEASURES: Several different consonant accuracy scores based on the linguistic structure (voicing, place, and manner of articulation) of the consonants being imitated; analysis of the errors produced for all consonants imitated incorrectly. RESULTS: Seventy-six children provided a response to at least 75% of the nonword stimuli. In these children's responses, 33% of the target consonants were imitated correctly, 25% of the target consonants were deleted, and substitutions were provided for 42% of the target consonants. The children tended to correctly reproduce target consonants with coronal place (which involve a mid-vocal tract constriction) more often than other consonants. Poorer performers tended to produce more deletions than the better performers, but their production errors tended to follow the same patterns as the better performers. CONCLUSIONS: Poorer performance on labial consonants suggests that scores were affected by the lack of visual cues such as lip closure. Oral communication users tended to perform better than total communication users, indicating that oral communication methods are beneficial to the development of pediatric cochlear implant users' phonological processing skills.

Child↗

PubMed2006

[Complications in cochlear implantation].

OBJECTIVE: The objective [corrected] of this paper is to present the surgical complications in cochlear implant, in a serie of 346 patients, submitted to surgery by the same surgical team with the subsequent control and follow-up for a long period of time. We show the description and the handling of each complication. MATERIAL AND METHODS: A follow-up was carried out on 346 cochlear implant patients by the same surgical team, from February 1993 to March 2004. The complications were assessed and their handling and follow-up is reported. The series includes 211 children and 135 adults. RESULTS: The complication rate was 9.8% (n = 34). The complications found were: Intraoperatory Complications: Cerebrospinal Fluid Leaks (CSF), 7; Facial nerve injury, 1; excessive thinning of the posterior wall, 2; inmediate post operatory complications: infection of the surgical wound, 4; post operatory persistent pain, 1; Tinnitus, 2; late complications: Mastoiditis, 2; extrusion of the stimulating receptor, 1; facial nerve stimulation, 5; late infections of the stimulation receptor, 2; technical failure of the implanted system, 7. Neither alteration or migration was found in the receptor placing. CONCLUSIONS: The cochlear implant surgery has a low morbility. We found no cases of meningitis due to this procedure.

Adult↗

PubMed1998

Cochlear implantation in a patient with profound hearing loss with the A1555G mitochondrial mutation.

OBJECTIVE: This study aimed to describe the performance of a cochlear implant in a patient with profound hearing loss with the A1555G mitochondrial mutation. SETTING: The study was conducted at two university hospitals. PATIENT: A 50-year-old Japanese man in whom bilateral profound hearing loss developed after administration of streptomycin at the age of 23 participated. The pedigree of the family showed exclusively maternal transmission of hearing impairment. INTERVENTION: Genetic study and auditory rehabilitation with a cochlear implant were performed. RESULTS: The A1555G point mutation was identified from the patient's mitochondrial DNA. Since activation of the implant, the patient has been using it successfully with a monosyllable recognition score of 78% using Japanese word lists for speech audiometry. CONCLUSIONS: The current case indicated that cochlear implantation may be a valuable choice of therapy for the patient with profound hearing loss with the A1555G mutation. The excellent auditory performance with a cochlear implant suggests that hearing loss associated with this mutation is primarily caused by insult to the cochlear tissue containing rich mitochondria (i.e., hair cells or stria vascularis or both), not to the cochlear nerve and its central connections.

Antibiotics, Antitubercular↗

PubMed2004

Cochlear implant positioning in children: a survey of patient satisfaction.

INTRODUCTION: The past decade has been witness to significant diminution in incision size and placement for pediatric cochlear implantation at our institution. Furthermore, the orientation of the long axis of the implant relative to the skull base plane has generally evolved from a retro-verted to ante-verted direction to accommodate the ear level receiver stimulator and the new minimal access technique. OBJECTIVE: To characterize the cosmetic, functional and clinical implications of this evolution in cochlear implant positioning by means of a patient satisfaction survey. METHODS: A survey of patient satisfaction was administered to 100 cochlear implant recipients or their parents. The survey elicits the patient's level of satisfaction with respect to implant position and functional limitations. In addition, the angle formed by the long axis of the implant and the skull base plane (implant angle) was determined from lateral skull radiographs to detect the temporal evolution in implant positioning. RESULTS: Analysis of the radiographs revealed an implant angle of 65.4-125 degrees in patients implanted prior to 1997, an implant angle of 56.3-87.5 degrees in patients implanted from 1997 to 2001, and an implant angle of 35.1-78.1 degrees after 2002. In spite of this evolution in positioning, the patient satisfaction survey did not reveal any change in incidence of cosmetic, functional or clinical problems. DISCUSSION: The significant changes in incision and implant positioning represent a technical evolution in pediatric cochlear implant surgery. The fact that patients have been consistently satisfied over time suggests that the cosmetic, functional and clinical implications are minimal.

Adolescent↗

PubMed2004

Imaging procedures in cochlear implant patients--evaluation of different radiological techniques.

The purpose of this study was to evaluate the feasibility and usability of different radiologic methods (single-slice computed tomography (CT), multi-slice CT and rotational tomography (RT)) for assessment of the position of cochlear implant electrodes. Cochlear implants in an isolated human temporal bone and in a complete formalin-fixed cadaver head were examined and the electrode position was determined. Subsequently, the labyrinth bone was isolated out of the cadaver head and histologically examined to compare the results of histology with imaging. Single-slice CT reliably identifies the electrode inside the human cochlea; however, due to the technically based large electrode artifact its position inside the cochlear spaces (e.g. electrode position in scala tympani or scala vestibuli) cannot be detected. Multi-slice CT of the cadaver head also showed artifacts that complicate the assessment of electrode position. Using RT the electrode artifact is small and therefore the electrode position within the cochlear spaces, scala tympani versus scala vestibuli, can be assessed. This technique was also applicable in a complete cadaver head, which is in contrast with former studies. In conclusion, CT allows the identification of electrode arrays inside the human cochlea. Multi-slice CT permits a much more precise depiction of the electrode inside the cochlea. RT alone has minimized electrode artifacts to a high extent and permits the assessment of the electrode position within the scala tympani or scala vestibuli. As RT was performed successfully in a complete cadaver head, further studies for evaluation of the intracochlear electrode position can now be performed in patients.

Angiography, Digital Subtraction↗