PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cochlear Implants”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,477 records · Page 82Linked to original sources
PubMed2003

Early-deafened adult cochlear implant users: assessment of outcomes.

OBJECTIVE: To determine whether adults deafened in the prelingual and perilingual stages of speech development realize objective and subjective benefits from cochlear implantation. METHOD: Retrospective analysis of the open-set speech recognition and subjective data such as use and quality of life. RESULTS: Between 1989 and 1999, 198 deafened adults underwent cochlear implantation at Sunnybrook and Women's College Health Sciences Centre. Of these, 44 patients were deafened pre- or perilingually. These subjects were implanted with a Nucleus 22, Nucleus 24 (Cochlear Corporation, Denver, Colorado, USA), or Clarion (Advanced Bionics Corporation, Sylmar, California, USA) device. The average age at implantation was 34 years (range 14-62 years). Significant differences in speech perception, as measured by a composite score of open-set word, phoneme, and sentence recognition, were found among groups who differed by type of education and communication training received in childhood. CONCLUSION: By and large, open-set speech recognition in prelingually and perilingually deafened adults is inferior to that achieved in postlingually deafened adults and varies according to the type of communication training they received. However, cochlear implants have significantly improved the overall communication skills and quality of life in all subgroups of patients.

Adolescent↗
PubMed1990

Relationships among loudness indexes in cochlear-implant patients.

The purpose of the experiment was to determine if the most-confortable-listening (MCL) levels and loudness-discomfort levels (LDLs) can be predicted from threshold measurements obtained from patients with cochlear implants using direct electrical stimulation. Psychophysical measurements of thresholds, MCLs, and LDLs with 125-Hz and 2000-Hz sinusoids were obtained from 16 patients with cochlear-implants 1 month after the connection of their ineraid processor (an auditory prosthesis). In general, the correlation coefficients among the loudness indexes obtained with a 125-Hz stimulus were similar to those for a 2000-Hz stimulus. Correlations between thresholds and MCLs were moderate, whereas correlations for thresholds and LDLs were fair. Correlations between MCLs and LDLs were high. This suggests that LDLs cannot be predicted from thresholds. On the other hand, these preliminary data suggest that MCLs may be reliably predicted from thresholds or LDLs to set the gain on a cochlear-implant processor.

Adult↗
PubMed1990

[Acoustically induced slow vertex potentials of patients with single channel inductive cochlear implant].

Acoustically induced slow vertex potentials (SVP) of 12 patients with single channel inductive cochlear implant were recorded in order to objectively evaluate the effect of this device on rebuilding hearing ability of totally deaf patients. We have found that the shape of SVP in patients was the same as that in healthy person and the average latency of every wave evoked by clicks of maximal comfortable loudness was close to those evoked by 60 and 70 dB nHL clicks in healthy people, but the average dynamic range was only 15 dB, and became smaller when the active electrode was put on the round window membrane. All these objectively prove that the acoustic stimulation elicited by single channel inductive cochlear implant is strong enough to activate the residual spiral ganglion cells and produce auditory sensation in cerebral cortex via the same central pathway as it is in the healthy.

Adolescent↗
PubMedDate not supplied

Vowel and consonant identification tests can be used to compare performances in a multilingual group of cochlear implant patients.

Vowel and consonant identification tests were conducted in the sound-only condition in a multilingual group of 13 totally deaf patients who are users of the Ineraid multichannel cochlear implant. Native languages ranged across French, German, Italian, Spanish, Albanian and Swahili. We found high correlations (r > -0.83) among vowel or consonant identification scores and 'subjective ranking' scores established on the basis of a subjective evaluation of the patient's speech reception abilities in the sound-only condition. Detailed analysis demonstrates that the identification of vowel and consonant is dominated by the perception of acoustic cues characteristic of the set of stimuli used as well as by the strengths and weaknesses of the speech processing of the cochlear implant system. We did not find any systematic pattern in the results that could be related to the native language of the patients. These results suggest that vowel as well as consonant identification tests are effective means to compare the performance of cochlear implant patients even across different native languages. They also indicate that, in the future, one can conduct a fewer number of the many different (e.g. nonsense-syllable, word, sentence, speech-tracking) tests when evaluating the speech recognition abilities of patients with the implant.

Adolescent↗
PubMed2001

[Cochlear implantation with implant Combi 40+ produced by MED-El].

The paper reports three cases of cochlear implantation using implant Combi 40+ produced by Med-El (Austria). Short-term postoperative testing results demonstrate an appreciable progress in hearing. Changes in speech discrimination and speech production are evaluated.

Adolescent↗
PubMedDate not supplied

Cochlear implant for tinnitus. Case reports.

Various forms of electrical stimulation are effective in reducing tinnitus in some patients. Our experience with cochlear implant patients who have preimplant tinnitus demonstrated that about half experienced relief after the implant. We present five patients who underwent cochlear implant exclusively for tinnitus relief. Results are mixed with only one definite success. Electrical stimulation and our current research efforts are discussed.

Aged↗
PubMed1997

The central auditory system and auditory deprivation: experience with cochlear implants in the congenitally deaf.

In the present paper we briefly review the response of the central auditory system to auditory deprivation and describe recent experimental and clinical experience with cochlear implants. While the central auditory system undergoes marked changes in response to auditory deprivation, it would appear that at least a rudimentary cochleotopic organisation is maintained at the level of the brainstem and auditory cortex in animals deafened from birth. Moreover, recent studies have demonstrated the ability of the central auditory system to undergo functional reorganisation in response to changes in the pattern of afferent activity. Clinical experience has shown that deaf children with little or no prior auditory experience can obtain significant benefit from cochlear implants, provided the device is fitted at a young age. Furthermore, factors predicting successful clinical outcomes with these devices reflect the importance of auditory experience, either prior to an acquired loss or with the use of a cochlear implant. These findings suggest that functional reorganisation within the central auditory pathway can at least partially account for improvements in clinical performance over time.

Adult↗
PubMed1999

Management of cochlear implant infections.

OBJECTIVE: The aim of this study was to illustrate and discuss management of cochlear implant infections. STUDY DESIGN: The study design was a retrospective case review. SETTING: This study was performed at a tertiary referral center with an associated Veterans Administration Hospital. PATIENTS: Postlingually deafened adults who had revision surgery for delayed cochlear implant infections were included in this study. INTERVENTION: Medical and surgical management of device infection without explantation. MAIN OUTCOME MEASURES: Eradication of infection without loss of speech reception. RESULTS: All four patients were successfully managed without explantation. CONCLUSIONS: Explantation of an infected but functioning multichannel implant is not mandatory in the absence of systemic sepsis.

Adult↗
PubMed1998

Facial nerve stimulation by a cochlear implant in a hemodialysis patient with bone of low mineral density.

Facial nerve stimulation by an activated cochlear implant was noted in a 56-year-old patient who had undergone cochlear implant with a Nucleus 22 implant 2 years previously as treatment for total sensorineural hearing loss following meningitis at age 54. Past history was complicated by total renal failure for which hemodialysis had been required during the past 13 years. Facial spasm occurred 5 months postoperatively with activation of the basal electrodes (channels 13 and 15 of the implant). The facial stimulation was eliminated by deprogramming these electrodes. High-resolusion computed tomography (CT) scanning was unable to demonstrate lucency of the otic capsule and cochlear ossification, but basal electrodes of the implant could be identified near the labyrinthine segment of the facial nerve. To further evaluate bone changes in the patient, the total and regional bone mineral density (BMD) of the head and radius was measured by dual energy X-ray absorptiometry. All BMD values of the patient were markedly low when compared to those of 62 other hemodialysis patient. These findings demonstrate that facial nerve stimulation can occur in the presence of low impedance due to cortical bone changes induced by long-term hemodialysis.

Absorptiometry, Photon↗
PubMed2000

The piezoelectric cochlear implant: concept, feasibility, challenges, and issues.

A better understanding of the fundamental phenomena occurring in both the healthy and the artificially stimulated cochlea will greatly aid in the engineering of more effective cochlear implant devices and will, in general, enhance mankind's knowledge of inner ear function. This study was initiated to probe the feasibility of use of artificial piezoelectric transducer devices, both for the understanding of cochlear phenomena and as a possible cochlear implant. Aspects of feasibility of such an implant, the issues involved, the materials science challenges that need to be overcome to fabricate such a device, and results from initial in vivo experiments are discussed.

Acoustic Stimulation↗
PubMed2005

Measurement and analysis of access resistance and polarization impedance in cochlear implant recipients.

BACKGROUND: Impedance measurements are commonly performed at the end of cochlear implant surgery, not only to confirm that all electrodes are working but also to monitor the impedances of the newly implanted electrodes. The current method of testing allows the determination of only the overall electrode impedance but not its components, access resistance and polarization impedance. To determine whether any longitudinal change in the electrode impedance is caused by a change in the endocochlear environment or rather caused by a change in the surface quality of the electrode, it is necessary to extract access resistance and polarization impedance. METHODS: We applied an impedance model that enabled us to calculate access resistance and polarization impedance after measurement of electrode impedance at three points along the voltage waveform. RESULTS: The results show that the value of the components of electrode impedance varied with time after surgery: access resistance increased slowly over time, whereas polarization impedance increased up to Week 2 but decreased after commencement of electrical stimulation at that stage. These results are consistent with the hypothesis that a layer of fibrous tissue forms around the electrode within the cochlear canal, resulting in a slow increase of access resistance, whereas a layer of proteins forms on the surface of the electrode in the early phase after implantation. Electrical stimulation appears to disperse this surface layer, thereby reducing both the polarization impedance and electrode impedance. CONCLUSION: The method presented enables the extraction of more detailed information about the longitudinal changes in the intracochlear environment after cochlear implantation.

Acoustic Impedance Tests↗
PubMed1994

Subjective benefits reported by adult Nucleus 22-channel cochlear implant users.

A questionnaire was mailed to a consecutive series of 23 adult, postlingually deafened, Nucleus 22-channel, cochlear implant recipients and their relatives to evaluate subjective benefits of cochlear implantation. All implantees had used their device for a minimum of 6 months. Responses were received from 20 implantees (87%) and 17 relatives (74%). Substantial improvements were reported by the respondents in speech recognition with lipreading, voice quality, independence, and communication confidence. Slightly less benefit was noted in speech recognition without lip reading. Respondents noted an increased recognition of environmental sounds and a reduction in tinnitus. Overall, 85% of implantees and 94% of their relatives were moderately to very satisfied with the device, and most indicated that they would recommend the device for others. Satisfaction correlated well with independence and confidence. Poor correlations were found between satisfaction and objective scores of sentence recognition, both in audition-only and audition-plus-vision conditions.

Adult↗
PubMed2004

Living with cochlear implants: experiences of 17 adult patients in Sweden.

The aim of this grounded theory study was to gain a deeper understanding of what it means to profoundly deaf adults to undergo cochlear implantation and their experience of living with it daily. The aim of grounded theory is theorizing, i.e. constructing from data an explanatory scheme that systematically integrates various concepts and their relationships. The study group consisted of 10 women and seven men (age 29-78 years; mean age 56.5 years), who had had their cochlear implant (CI) for between 1 and 12 years (mean 4.1 years). Open taped interviews were carried out and analysed. The core category, coming back to life, defines a psychological process basic to existence, elucidating the existential value of hearing, including perceived harmony in life and becoming a part of the living world as important dimensions. This core concept is related to four additional emerging categories in a temporal order. Preventing disappointment concerns the decision to undergo the operation governed by the conception of having nothing to lose combined with low expectations of successful outcomes. Waiting in silence relates to experiences during the postoperative period such as sensations from the head and uncertainty about the outcome of surgery. The 'switch-on' was experienced as a significant revelation and the emotionally loaded starting point for their coming back to life. Retraining the brain concerns the lengthy audiovisual learning process. finally resulting in 'a car sounding like a car'. Strengthening of self-worth concerns psychosocial outcomes of cochlear implantation, in terms of less dependency and increased social participation. CIs provide a substantial improvement in the quality of life, as identified in the emerging generic process of coming back to life, fundamental for psychological existence.

Adult↗
PubMed2006

Minimization of cochlear implant stimulus artifact in cortical auditory evoked potentials.

OBJECTIVE: To compare two methods of minimizing cochlear implant artifact in cortical auditory evoked potential (CAEP) recordings. METHODS: Two experiments were conducted. In the first, we assessed the use of independent component analysis (ICA) as a pre-processing filter. In the second, we explored the use of an optimized differential reference (ODR) for minimizing artifacts. RESULTS: Both ICA and the ODR can minimize the artifact and allow measurement of CAEP responses. CONCLUSIONS: When using a large number of recording electrodes ICA can be used to minimize the implant artifact. When using a single electrode montage an optimized differential reference is adequate to minimize the artifact. SIGNIFICANCE: The use of an optimized differential reference could allow cortical evoked potentials to be used in routine clinical assessment of auditory pathway development in children and adults fit with cochlear implants.

Artifacts↗
PubMed2000

Mastoiditis and acute otitis media in children with cochlear implants: recommendations for medical management.

Acute otitis media (OM) or mastoiditis is a very dangerous condition for the ear after cochlear implantation. However, acute OM is very common in childhood and can occasionally occur in an implanted ear. Most cases of acute OM can be successfully treated with intravenous high-dosage antibiotics. In cases of mastoiditis and clinical signs of mastoid abscess, retroauricular drainage is necessary to prevent infection of the implant bed. In a series of 366 children given implants (1 to 14 years), acute OM occurred in 5.6% during a follow-up period of 1 to 8 years. Seven ears had to be opened by means of myringotomy. Five ears were opened by retroauricular incision with mastoid revision on the implanted side. Adenoidectomy and use of ventilation tubes before cochlear implantation, as well as careful subtotal mastoidectomy during the implantation, can reduce the incidence of acute OM in children after implantation. Early and subsequent treatment with operative mastoid drainage can prevent implant loss and should be performed at the implantation center.

Acute Disease↗
PubMed1995

Deafness in childhood: 3. Cochlear implants: who, why and what are the results?

Some profound or totally deaf children cannot benefit from a hearing aid. In some cases a cochlear implant may be successful. The system compromises a small cable implanted into the inner ear, and externally-worn devices to collect and transmit the sounds to the ear. The cable consists of electrodes that respond to different frequencies of speech, imitating the action of the inner ear. It is not possible to predict the outcome in individual cases. At best, the child may subsequently be able to speak fluently and hear without lip-reading. At least, the child should be able to hear some background noise such as traffic, and be able to improve his or her lip-reading skills. It may take up to a year before improvements begin to show. The implant is intended to be permanent. Cochlear implants are still at a relatively early stage of development. Progress is cautious but the results so far are very encouraging. The entry gate is widening and the number of children being accepted for treatment is increasing.

Child↗
PubMed1995

Issues in protocol design for cochlear implant clinical trials in children: the Clarion Pediatric Study.

Clinical trials of the Clarion multichannel cochlear implant in postlingually deaf adults have been ongoing since 1991, and clinical investigation of the device in children is projected to begin in the first quarter of 1995. The purpose of this paper is to present some of the issues encountered in developing research protocols for clinical trials of cochlear implants in the pediatric population, with special reference to the protocol that will be employed in the Clarion pediatric investigation.

Child↗