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Results for “Cochlear Implants”

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PubMed1999

The application of three-dimensional magnetic resonance imaging rendering of the inner ear in assessment for cochlear implantation.

OBJECTIVE: To study the use of three-dimensional (3D) rendering of T2-weighted magnetic resonance imaging (MRI) images into 3D models of the inner ear in the preoperative assessment for cochlear implantation. STUDY DESIGN: A retrospective case review of cochlear implant candidates undergoing preoperative imaging studies to determine their suitability for surgical implantation. SETTING: A tertiary referral center for the northwest area of England with an established 10-year-old program in cochlear implantation. PATIENTS: Selected adult and pediatric patients referred for cochlear implant assessment from 1996 to 1998, who underwent computerized tomography (CT) and MRI studies. INTERVENTION: Diagnostic imaging modality to assess the structure and patency of the inner ear. MAIN OUTCOME MEASURES: To see how detailed anatomic information provided by these 3D models influenced surgical decisions. RESULTS: Four case studies (with their 3D models) are presented to illustrate different points of interest. CONCLUSION: These 3D models provide the implanting surgeon with precise, detailed, and easily interpretable information about the cochlea, which help to guide surgical implantation, or in certain cases, to decide against attempting surgery in the presence of unfavorable anatomic factors.

Child↗

PubMed2004

Tinnitus and cochlear implantation.

Tinnitus is a common experience, but there is very marked heterogeneity of aetiology, perception and the extent of distress among individuals who experience tinnitus. In view of this, a modern approach to tinnitus should consider homogeneous groups of individuals. This review considers tinnitus experiences in patients undergoing cochlear implantation, this being of interest because the prevalence of tinnitus in this patient group prior to surgery may shed some light on the link between cochlear dysfunction and tinnitus Second, any change in tinnitus experience as a result of electrode placement surgery or cochlear implant activation has relevance for patient counselling and informed consent. Finally, in recent tinnitus retraining therapy literature there has been the suggestion that unilateral sound therapy for tinnitus patients may set up an unhelpful asymmetry of input to the auditory system, with possible exacerbation of contralateral tinnitus. Unilateral cochlear implant use represents the most dramatic asymmetry possible and hence is a test of that hypothesis. Relevant papers (n = 32) were identified from literature databases. The standard of reporting tinnitus results was inconsistent. Tinnitus is experienced by up to 86% of adult cochlear implant candidates, but is not universal and is only troublesome in a small proportion (reported as 27% in one study). Electrode insertion may induce tinnitus in a small (up to 4%) number of patients, but this is rare. Cochlear implant device use is associated with reduction of tinnitus intensity and awareness in up to 86% of patients, and rarely with exacerbation (up to 9%). There are some indications in the literature that the more complex the simulation strategy, the larger that effect. Specifically, unilateral cochlear implant use was generally associated with reduction of contralateral tinnitus (in up to 67% of individuals) rather than exacerbation, and so the assertion that unilateral sound therapy for tinnitus is contraindicated is not proven.

Cochlea↗

PubMedDate not supplied

Labyrinthine ossification secondary to childhood bacterial meningitis: implications for cochlear implant surgery.

Of 20 children who underwent cochlear implantation for profound sensorineural hearing loss secondary to bacterial meningitis, 14 had round-window and cochlear ossification at surgery. Preoperative polytomography demonstrated ossification in 11 of these. The incidence of ossification was highest after meningitis secondary to pneumococcal pneumonia. In only one of four children with severe ossification of the labyrinth was implant surgery unsuccessful. Preliminary results indicate that mild labyrinthine ossification is not a contraindication to cochlear implantation.

Bacterial Infections↗

PubMed1997

Conservation of residual hearing with cochlear implantation.

HYPOTHESIS: The goals of this work were (a) to review the pre- and postsurgical auditory thresholds in a consecutive sample of cochlear implant recipients to determine the fate of residual hearing, and (b) to obtain preliminary indication of the value of a multicenter longitudinal study of residual hearing in implant patients. BACKGROUND: Indications for cochlear implantation have been expanded to include severely hearing impaired (SHI) adults and may someday include SHI children. Implantation of individuals with more residual hearing is a concern owing to the possible development of better devices that may make use of residual hearing within the lifetime of implanted children if not that of adults. Preservation of residual hearing would be a desirable outcome of implant surgery; however, conventional thought is that implantation destroys any remaining hearing. This study was undertaken to assess if and how often conservation of hearing occurred after implantation in a sample of multichannel implant recipients. METHODS: Records of 50 profoundly hearing impaired consecutively implanted patients were examined for pre- and post-surgical audiometric results. Standard audiometric techniques were used for all testing procedures. Forty patients were considered to have some hearing conserved based on a response obtained at any one of the three speech frequencies prior to implantation. The most recent postimplantation audiometric results were used providing data from users with 1-41 months of use. RESULTS: Twenty-one of 40 implanted subjects were found to have responses in at least one of the speech frequencies both pre- and postsurgery, with the majority of those displaying responses at all three frequencies. In this preliminary retrospective study, it did not appear that duration of cochlear implant use, gender, level of preoperative hearing, or length of electrode insertion were related to outcome. There were insufficient data to draw conclusions on individual devices. CONCLUSIONS: Conservation of hearing occurred in approximately half of the subjects reviewed. There is no indication of what factors contributed to the preservation of hearing in those with postsurgical residual hearing or if that hearing is usable. The study does suggest that a larger multicenter longitudinal study would be of value of determine what factors may be related to conserved hearing in implanted patients.

Adult↗

PubMed1991

[Ethical and economical considerations on cochlear implants in developing countries].

An important factor that all cochlear implant teams have to deal with one way or another is the coast of the prostheses. This problem takes on very special characteristics in developing countries. This paper is based on the authors' experience in establishing the cochlear implant program of the "Hospital General Manuel Gea Gonzalez", a public hospital in Mexico City, and tries to determine which should be the optimal characteristics of an implant to be used in developing countries.

Cochlear Implants↗

PubMed2002

Patients utilizing a hearing aid and a cochlear implant: speech perception and localization.

OBJECTIVE: The purpose of this pilot study was to document speech perception and localization abilities in patients who use a cochlear implant in one ear and a hearing aid in the other ear. DESIGN: We surveyed a group of 111 cochlear implant patients and asked them whether they used a hearing aid on their unimplanted ear. The first three patients who were available were tested on word and sentence recognition and localization tasks. Speech stimuli were presented from the front in quiet and in noise. In the latter conditions, noise was either from the front, the right, or the left. Localization was tested with noise bursts presented at 45 degrees from the right or left. In addition we asked the patients about their abilities to integrate the information from both devices. RESULTS: Speech perception tests in quiet showed a binaural advantage for only one of the three patients for words and none for sentences. With speech and noise both in front of the patient, two patients performed better with both devices than with either device alone. With speech in front and noise on the hearing aid side, no binaural advantage was seen, but with noise on the cochlear implant side, one patient showed a binaural advantage. Localization ability improved with both devices for two patients. The third patient had above-chance localization ability with his implant alone. CONCLUSIONS: A cochlear implant in one ear and a hearing aid in the other ear can provide binaural advantages. The patient who did not show a clear binaural advantage had the poorest hearing aid alone performance. The absolute and relative levels of performance at each ear are likely to influence the potential for binaural integration.

Cochlear Implants↗

PubMed2005

[Cochlear implants using the Ultracision harmonic scalpel].

We have evaluated the utility, indications and disadvantages of the Ultracision harmonic scalpel, in the cochlear implants, and his advantages compare to other electrocoagulation's systems. These aspects were evaluated in 50 cases of cochlear implants, made along the last years. We concluded that the Ultracision harmonic scalpel is indicated, mainly, in the otology field, in these situations in wich the cochlear implant is in the cochlea, and is mandatory the use of an electrocoagulation system. In this situation, the Ultracision harmonic scalpel was quick, safe and sure, and with many advantages, over the traditional scalpel and the bipolar diathermy.

Cochlear Implantation↗

PubMed2001

Variation in speech perception scores among children with cochlear implants.

OBJECTIVE: The objective of this study was to identify common factors affecting speech perception scores in children with cochlear implants. DESIGN: Speech perception data for 167 implanted children were collected at two cochlear implant centres in Melbourne and Sydney. The data comprised audition-alone scores on open-set word and sentence tests. Children were selected on the basis that they had a Nucleus 22-electrode cochlear implant. The average age of the children was 5 yr. Information was also collected about 12 factors that may have influenced speech perception scores for each child. Analysis of covariance was used to identify factors that significantly affected speech perception scores. Pearson pairwise correlation coefficients were also calculated for all factors analyzed. RESULTS: The analyses in this study identified factors that accounted for 51%, 34%, and 45% of the variance in phoneme, word and sentence perception scores. Scores decreased by 1.4 to 2.4% per year of profound deafness prior to implantation. Children who normally use oral communication scored significantly higher than children normally using sign or simultaneous oral and sign communication. Children implanted in Sydney scored higher on average than children implanted in Melbourne. CONCLUSIONS: The results show that a significant part of the variation in speech perception scores is systematically related to audiological and environmental factors for each child. The reasons for significant differences between children using different communication modes or from different clinics were not identified.

Adolescent↗

PubMed2003

Evidence of improving cost-effectiveness of pediatric cochlear implantation.

OBJECTIVES: To examine the cost-effectiveness of pediatric cochlear implantation over time. METHODS: A prospective study based on ninety-eight children implanted between 1989 and 1996 at Nottingham's Paediatric Cochlear Implantation Programme, UK. The influence of outcomes and other variables on total costs was examined using multivariate regression analysis. RESULTS: Having controlled for potential confounding variables, total cost was negatively related to year of implant and positively related to the number of hours of rehabilitation (p=.000). CONCLUSIONS: Having controlled for outcomes (Categories of Auditory Performance and Speech Intelligibility Rating), the cost-effectiveness improved over time. This finding may be due to a learning curve and have policy implications.

Child, Preschool↗

PubMed2006

Hearing-impaired children in the United Kingdom, I: Auditory performance, communication skills, educational achievements, quality of life, and cochlear implantation.

OBJECTIVES: The objectives of this study were to identify variables that are associated with differences in outcome among hearing-impaired children and to control those variables while assessing the impact of cochlear implantation. STUDY DESIGN: In a cross-sectional study, the parents and teachers of a representative sample of hearing-impaired children were invited to complete questionnaires about children's auditory performance, spoken communication skills, educational achievements, and quality of life. Multiple regression was used to measure the strength of association between these outcomes and variables related to the child (average hearing level, age at onset of hearing impairment, age, gender, number of additional disabilities), the family (parental occupational skill level, ethnicity, and parental hearing status), and cochlear implantation. RESULTS: Questionnaires were returned by the parents of 2858 children, 468 of whom had received a cochlear implant, and by the teachers of 2241 children, 383 of whom had received an implant. Across all domains, reported outcomes were better for children with fewer disabilities in addition to impaired hearing. Across most domains, reported outcomes were better for children who were older, female, with a more favorable average hearing level, with a higher parental occupational skill level, and with an onset of hearing-impairment after 3 years. When these variables were controlled, cochlear implantation was consistently associated with advantages in auditory performance and spoken communication skills, but less consistently associated with advantages in educational achievements and quality of life. Significant associations were found most commonly for children who were younger than 5 years when implanted, and had used implants for more than 4 years. These children, whose mean (preoperative, unaided) average hearing level was 118 dB, were reported to perform at the same level as nonimplanted children with average hearing levels in the range from 80 dB to 104 dB, depending on the outcome measure. CONCLUSIONS: When rigorous statistical control is exercised in comparing implanted and nonimplanted children, pediatric cochlear implantation is associated with reported improvements both in spoken communication skills and in some aspects of educational achievements and quality of life, provided that children receive implants before 5 years of age.

Adult↗

PubMed2001

Noise enhances modulation sensitivity in cochlear implant listeners: stochastic resonance in a prosthetic sensory system?

Cochlear implants restore auditory sensitivity to the profoundly hearing-impaired by means of electrical stimulation of residual auditory nerve fibers. Sensorineural hearing loss results in a loss of spontaneous activity among the remaining auditory neurons and is accompanied by a reduction in the normal stochastic nature of neural firing in response to electric stimulation. It has been hypothesized that the natural stochasticity of the neural response is important for auditory signal processing and that introducing some optimal amount of noise into the stimulus may improve auditory perception through the implant. In this article we show that, for soft but audible stimuli, an optimal amount of "prosthetic" noise significantly improves sensitivity to envelope modulation in cochlear implant listeners. A nonmonotonic function relates modulation sensitivity and noise level, suggesting the presence of stochastic resonance.

Adult↗

PubMed1992

Performance over time with a nucleus or Ineraid cochlear implant.

This investigation determined whether the audiological performance of cochlear implant users varied with experience. Thirteen Nucleus and 14 Ineraid subjects were evaluated at 1, 9, and 18 mo after cochlear implant connection. Ten Nucleus and five Ineraid subjects were tested at 30 mo. On average, the ability of the subjects to recognize words and phonemes in an audition-only condition improved during the first 9 mo, as did their ability to recognize spondees in noise. The phoneme scores continued to improve during the next 9 mo. Environmental sound recognition improved gradually; significant improvement from the 1 mo scores was not noted until 18 mo. About half of the subjects who demonstrated poor word recognition at 1 mo showed significantly improved percent word correct scores by 18 mo. The Nucleus and Ineraid subjects did not differ in their patterns of change over time. An information transmission analysis performed on the subjects' consonant confusion matrices showed relatively little change for the nasality and place features during the first 18 mo, and relatively large change for the voice, duration, and frication features. Most improvement in the feature scores occurred during the first 9 mo.

Cochlear Implants↗

PubMed2002

Magnetic resonance imaging versus computed tomography in pre-operative evaluation of cochlear implant candidates with congenital hearing loss.

Recent reports indicate that the cochlear nerve may be absent in some cases of congenital sensorineural hearing loss. The aim of this prospective study was to determine the incidence of cochlear nerve anomaly in cochlear implant candidates with congenital hearing loss using magnetic resonance imaging (MRI). Twenty-seven patients with congenital profound bilateral sensorineural hearing loss who were being evaluated for the cochlear implant procedure were studied. These patients had high-resolution computerized tomography (CT), through the petrous bone in axial sections. MRI examinations consisted of T1 and turbo spin echo (TSE) T2-weighted 3 mm axial images, and additional 3D Fourier Transform T2-weighted TSE sequences obtained on three different planes (axial, perpendicular and parallel to the internal auditory canal (IAC) i.e. oblique sagittal and coronal, respectively) for the purpose of cochlear nerve demonstration. Results showed that all of the 14 patients with normal CT of the temporal bone, had four distinct nerves in the distal part of the IAC on TSE-MRI. Thirteen patients demonstrated various bony malformations of the cochleovestibular system on CT. MRI revealed the absence of the cochleovestibular nerve in four patients where the IAC was very narrow or completely absent on CT. One patient with severe Mondini malformation who had an enlarged IAC demonstrated an isolated absent cochlear nerve.

Adolescent↗

PubMed2005

Atypical cortical responses underlie poor speech perception in children using cochlear implants.

Variability in speech perception abilities after years of cochlear implant use could reflect differences in central auditory processing of the electrical input provided. Cortical responses were measured in 23 experienced pediatric cochlear implant users who were 12.3+/-3.1 years of age at testing and had used their implants for 6.0+/-2.9 years. All had prelingual onset of deafness. An observer identified blind three types of cortical waveforms ranging from those similar to previous reports to more atypical responses. Children displaying atypical types of responses were implanted at a wide range of ages and had significantly poorer behavioral speech perception scores (P<0.05) than their peers with expected waveforms. Results suggest a persistent immaturity and/or abnormal organization in the auditory cortex in some children.

Age Factors↗

PubMed1988

[Rehabilitation of cochlear implant patients].

Pre- and post-surgical treatment of cochlear implant patients is discussed. Before surgery training of lipreading ability, auditory training with conventional hearing aids and counselling should be offered. After surgery the main focus lies on auditory training with the cochlear implant; communication training in a group and counselling should be offered too.

Cochlear Implants↗

PubMedDate not supplied

Intelligibility of vowels produced by post-lingually deafened cochlear implant users.

The present study addresses the effect of cochlear implantation on the intelligibility of vowels produced by 20 post-lingually deafened Dutch subjects. All subjects received the Nucleus-22 cochlear implant (3 WSP and 17 MSP processors). Speech recordings were made pre-implantation and three and twelve months post-implantation with the implant switched on and off. Vowel intelligibility (monophthongs only) was determined using a panel of listeners. For all implanted subjects intelligibility was measured in a noisy background. For seven poorly speaking subjects it was also measured in a quiet background. After implantation with the Nucleus-22 device the results showed that vowel intelligibility, measured for all subjects in a noisy background, increased for most of them (about 15), while it increased for about half the number of poorly speaking subjects measured in a quiet background. Twelve months after implantation vowel intelligibility, measured for all subjects in noise, appeared to be based on first and second formant information. This was also found for the subgroup of seven subjects performing poorly pre-implantation when analysed separately. However, vowel intelligibility for this subgroup, when measured in a quiet background, was based also on vowel duration. The differences between the overall result in noise and the results of the subgroup in quiet should be attributed mainly to the noise and not to aspects of poor speech production in the subgroup. In addition, this study addresses the relationship between the intelligibility scores and objective measurements of vowel quality performed in a previous study. The results showed that the vowel intelligibility scores are mainly determined by the position of the second formant frequencies.

Adult↗

PubMed1999

The benefit of cochlear implantation in the Japanese elderly.

The purpose of this study was to evaluate the benefit of cochlear implant for Japanese elderly people with profound hearing loss. A questionnaire was administered to the five Japanese elderly people over 65 years old with the Nucleus 22 channel device and their family. The questionnaire was designed to gain insight into the patient's daily use and to evaluate the quality of life. Elderly patients who were implanted with the Nucleus device showed good ability to identify environmental sound and revealed no significant deterioration compared to younger patients. Implanted patients showed some difficulties in understanding speech in the noisy environment and conversation among several persons. Nevertheless, 80% of patients over 65 and their family reported communication benefits in the family and in social activities. In addition, 80% of the patients reported that they felt the better or improved quality of life after the implantation. All patients considered the implant was good for their life and would recommend a cochlear implant to a deaf friend. It is notable that 60% of patients and their family report that the recipients have become more cheerful. This study showed the cochlear implant contributes to the better quality of life in the Japanese elderly.

Aged↗

PubMed2003

A software tool for analyzing multichannel cochlear implant signals.

A useful and convenient means to analyze the radio frequency (RF) signals being sent by a speech processor to a cochlear implant would be to actually capture and display them with appropriate software. This is particularly useful for development or diagnostic purposes. sCILab (Swiss Cochlear Implant Laboratory) is such a PC-based software tool intended for the Nucleus family of Multichannel Cochlear Implants. Its graphical user interface provides a convenient and intuitive means for visualizing and analyzing the signals encoding speech information. Both numerical and graphic displays are available for detailed examination of the captured CI signals, as well as an acoustic simulation of these CI signals. sCILab has been used in the design and verification of new speech coding strategies, and has also been applied as an analytical tool in studies of how different parameter settings of existing speech coding strategies affect speech perception. As a diagnostic tool, it is also useful for troubleshooting problems with the external equipment of the cochlear implant systems.

Cochlear Implants↗