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 1,369 records · Page 76Linked to original sources
PubMed2003

Fluoroscopically assisted cochlear implantation.

HYPOTHESIS: Real-time intraoperative fluoroscopy is a useful adjunct to cochlear implantation in selected cases. The advantages include the avoidance of complications such as extracochlear array placement, intrameatal array insertion, and avoidance of significant bending or kinking. This is particularly useful when implanting a severely abnormal cochlea. BACKGROUND: The technique was initially developed for laboratory study of electrode prototypes in cadaver temporal bones to evaluate insertion dynamics and mechanisms of intracochlear trauma. The technique was subsequently adapted for use in live surgeries. METHODS: Live surgeries were performed using fluoroscopic guidance on nine patients. RESULTS: Five patients were implanted with the Nucleus 24 RCS during preclinical trials. Two patients with severe cochlear malformations were implanted with a Nucleus CI24M straight array. Two patients with severe cochlear ossification were implanted with the Nucleus CI24 double array. Appropriate insertions were achieved without electrode damage in all cases. CONCLUSIONS: Intraoperative fluoroscopy is a useful adjunct to cochlear implantation, which can be performed with minimum risk to the patient and operating room staff if the outlined precautions are taken. Intraoperative fluoroscopy is indicated in cases where the intracochlear behavior of the electrode array cannot be predicted, a condition encountered when implanting new electrode designs, cases with severely malformed inner ears, or cases of severe intraluminal obstruction requiring a double-array insertion.

Adolescent↗
PubMed1997

Preliminary conversation with the parents before cochlear implantation.

OBJECTIVE: To provide parents of hearing-impaired children about to undergo cochlear implantation with an opportunity to discuss their expectations and the pedagogical implications of surgery. SETTING: Parents and children participate in discussions at the medical center where the cochlear implantation will take place. PATIENTS: More than 700 children and their parents have participated. OUTCOMES: Parents of congenitally deaf children differ somewhat in their expectations and behavior from the parents of postlingually deafened children.

Child, Preschool↗
PubMed2006

Cochlear implantation trauma and noise-induced hearing loss: Apoptosis and therapeutic strategies.

Cochlear implantation trauma and noise-induced hearing loss both involve a physical disruption of the organ of Corti and may involve several mechanisms of cell death at the molecular level, i.e., necrosis, necrosis-like programmed cell death (PCD; type 2 PCD), and apoptosis (type 1 PCD). This article reviews several promising therapeutic strategies that are currently being developed. One of these promising new strategies involves the use of a highly effective peptide inhibitor of the c-Jun N-terminal kinase cell death signal cascade (i.e., D-JNKI-1) to prevent apoptosis of injured auditory hair cells. Our recent studies showed prevention of cochlear implantation-induced hearing loss by infusing this peptide into the cochlea of guinea pigs. Another otoprotective therapy under investigation is the application of mild hypothermia to protect the cochlea from the development of a hearing loss that follows exposure to a physical trauma, e.g., electrode array insertional trauma. These forward-looking strategies have the potential of improving hearing outcomes after cochlear implantation and providing novel means of otoprotection from noise-induced trauma.

Animals↗
PubMed1994

Nonorganic hearing loss in cochlear implant candidates.

Five patients undergoing assessment for cochlear implantation have been found to have a nonorganic hearing loss (pseudohypacusis). This phenomenon has not been reported previously in this patient population. The cases are presented and the causes, detection, and management of this condition are discussed.

Adolescent↗
PubMed1996

Speech recognition with a CIS strategy for the ineraid multichannel cochlear implant.

Wilson et al. proposed a new sound-processing strategy for multichannel cochlear implants, the Continuous Interleaved Sampling (CIS) strategy. Their study was performed on seven American patients, selected for their excellent performance with the Ineraid multichannel cochlear implant, and involved refined testing of several parameter modifications of the CIS strategy during a 1-week period. At the end of the week, the CIS strategy produced large improvements in speech-recognition tests for all subjects. To evaluate the generality of this promising result, the goal of this study was to assess whether similar improvements of performance could be observed in a typical population of Ineraid users and implemented as a clinical protocol. Therefore we designed one unique, predetermined CIS processor that could be temporarily fitted to the patients in < 2 h, and we evaluated speech recognition with consonant-and vowel-identification tests in a group of patients with performances ranging from star to almost chance levels and speaking six different native languages. Scores of vowel and consonant identifications obtained with this predetermined CIS processor and with the standard processor of the Ineraid system were compared in 15 Ineraid users. Fourteen of 15 patients had significantly better scores of consonant identification with the new CIS strategy. The group mean scores of vowel identification with either strategy were not statistically different. In agreement with these observations, most patients immediately reported that the CIS strategy sounded subjectively "more clear" for real-time speech recognition. It is now possible to implement a CIS speech-coding strategy as a standard clinical procedure to improve speech-recognition performances of all Ineraid users.

Adolescent↗
PubMed1990

A young meningitically deaf child with a cochlear implant: a case study.

This study describes the development of the auditory, cognitive, linguistic, and social domains of a child deafened by meningitis at 20 months of age. He received a 3M/House cochlear implant at 27 months and is believed to be the youngest child to receive a cochlear implant. He was seen for intervention emphasizing audiometric conditioning and testing and language (speech and sign) stimulation for a period of 2:9 years (6 months pre-implant to 2:3 years post-implant). Videotapes of intervention; interviews with parents, teachers, and clinicians; test results; and medical and clinical reports were documented from pre-implant to two years post-implantation. The child regressed in all areas evaluated following his illness and subsequent deafness and cochlear implantation. At about one year after implantation, his social and cognitive skills began to improve. By two years after implantation (chronological age (CA) = 4:6), his abilities in all areas except auditory reception and speech had progressed to about the 4:0 age level. He communicates primarily through signs and seems to derive environmental sound and speech duration cues from the implant. Although it is difficult to separate the effects of the implant from maturational factors, he now willingly uses the implant simultaneously with his hearing aid on the non-implanted ear every day and seems to be functioning well with them. He responds inconsistently to his name when called, and consistently provides appropriate signed responses to questions. His imitative skills are improving; he can discriminate one- vs two-syllable words; and produces limited spontaneous speech. His cognitive and social abilities are at least age-appropriate and he signs 3- and 4-word combinations.

Audiometry↗
PubMed1998

Gap detection as a measure of electrode interaction in cochlear implants.

Gap detection thresholds were measured as an indication of the amount of interaction between electrodes in a cochlear implant. The hypothesis in this study was as follows: when the two stimuli that bound the gap stimulate the same electrode, and thus the same neural population, the gap detection threshold will be short. As two stimuli are presented to two electrodes that are more widely separated, the amount of neural overlap of the two stimuli decreases, the stimuli sound more dissimilar, and the gap thresholds increase. Gap detection thresholds can thus be used to infer the amount of overlap in neural populations stimulated by two electrodes. Three users of the Nucleus cochlear implant participated in this study. Gap detection thresholds were measured as a function of the distance between the two electrode pairs and as a function of the spacing between the two electrodes of a bipolar pair (i.e., using different modes of stimulation). The results indicate that measuring gap detection thresholds may provide an estimate of the amount of electrode interaction. Gap detection thresholds were a function of the physical separation of the electrode pairs used for the two stimuli that bound the gap. Lower gap thresholds were observed when the two electrode pairs were closely spaced, and gap thresholds increased as the separation increased, resulting in a "psychophysical tuning curve" as a function of electrode separation. The sharpness of tuning varied across subjects, and for the three subjects in this study, the tuning was generally sharper for the subjects with better speech recognition. The data also indicate that increasing the separation between active and reference electrodes has limited effect on spatial selectivity (or tuning) as measured perceptually.

Acoustic Stimulation↗
PubMed1991

[Multi-electrode extra-cochlear implants].

From july 1987 through july 1989, we have performed eight extra-cochlear implants for the rehabilitation of bilateral total deafness. In this paper we develop this experience, to give the positive aspects but also the negative ones and we give the reasons why we prefer currently the intra-cochlear implant. However this implant and its method are a good solution in case of an ossified cochlea.

Cochlear Implants↗
PubMedDate not supplied

Medical or surgical complications related to the Nucleus multichannel cochlear implant.

A questionnaire was sent to 152 surgeons to survey complications associated with the implantation of the Nucleus multichannel cochlear implant. Complications were categorized as life-threatening; major, if they necessitated revision surgery; or minor, if they resolved spontaneously or with minimal treatment. A total of 55 complications occurred in 459 reported operations for an overall complication rate of 11.8%. There were no deaths, but there was one life-threatening complication, a case of meningitis. There were 23 (4.8%) major complications, most of which involved flap design or electrode insertion (and included the case of meningitis). There were 32 (7%) minor complications. Most of the complications might have been avoided by proper training, planning of the operations, and careful attention to detail. We recommend that all prospective implant surgeons attend a device-specific training course and practice in the temporal bone laboratory.

Cochlear Implants↗
PubMed1994

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

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

Acoustic Stimulation↗
PubMedDate not supplied

Perceptual capabilities with the cochlear implant: implications for aural rehabilitation.

While the cochlear implant provides only limited auditory information, profoundly deaf children continue to show significant gains in hearing performance and speech production abilities. The evidence has indicated that children receiving consistent auditory training demonstrate more progress with the implant than those children in less auditory-type environments. As a result, the House Ear Institute is developing extended training protocols to help optimize implant performance. A three-component framework is detailed to include: (1) the production/perception model, (2) a comprehension/bottom-up approach, and (3) strategical methods of delivery (multisensory versus unisensory). The purpose of such development is to integrate "hearing" into home, classroom, and individualized therapy settings to better facilitate growth in listening skills and speech development within a psycholinguistic context.

Achievement↗
PubMed2004

The topographical anatomy of the round window and related structures for the purpose of cochlear implant surgery.

The treatment of total deafness using a cochlear implant has now become a routine medical procedure. The tendency to expand the audiological indications for cochlear stimulation and to preserve the remnants of hearing has brought new problems. The authors have studied the topographical anatomy of the internal structures of the ear in the area where cochleostomy is usually performed and an implant electrode inserted. Ten human temporal bones were obtained from cadavers and prepared in a formalin stain. After dissection of the bone in the area of round and oval windows, the following diameters were measured using a microscope with a scale: the transverse diameters of the cochlear and vestibular scalae at the level of the centre of the round window and 0.5 mm anteriorly to the round window, the distance between the windows and the distances from the end of the spiral lamina to the centre of the round window and to its anterior margin. The width of the cochlear scala at the level of the round window was 1.23 mm, and 0.5 mm anteriorly to the round window membrane it was 1.24 mm. The corresponding diameters for the vestibular scala are 1.34 and 1.27 mm. The distances from the end of the spiral lamina to the centre of the round window and to its anterior margin are 1.26 and 2.06 respectively. The authors noted that the two methods of electrode insertion show a difference of 2 mm in the length of the stimulated spiral lamina. The average total length of the unstimulated lamina is 2.06 and 4.06 in the two situations respectively.

Cochlear Implantation↗
PubMed1997

Preoperative temporal bone computed tomography scan and its use in evaluating the pediatric cochlear implant candidate.

Preoperative computed tomography (CT) scan evaluation of the temporal bones in cochlear implant candidates plays a crucial role in determining candidacy and the side of implantation. The CT scans allow the surgeon to carefully review the anatomy of the inner ear and mastoid cavity in order to predict any potential difficulties or complications that may be encountered during the implant insertion. We retrospectively reviewed 50 preoperative CT scans of the temporal bone in children who have been successfully implanted. In these scans, we assessed the degree of mastoid pneumatization, cochlear anatomy and patency, size of the vestibular aqueduct, cochlear aqueduct, and internal auditory canal. We analyzed our findings and measurements and compared our results with the degree of difficulty noted in the insertion of the implant, the number of electrodes inserted in each case, and the overall complication rate. From this radiographic review, we have created a checklist for cochlear implant surgeons in order to highlight key features that need to be recognized in the temporal bone scan in preoperative evaluation of cochlear implant candidates.

Adolescent↗
PubMedDate not supplied

Stapedius reflex to electrical stimulation in a patient with a cochlear implant.

In a patient with a multichannel cochlear implant, it was possible to demonstrate stapedius reflex contraction to intracochlear electrical stimulation. Using a standard immittance measurement technique, characteristics of the electrically evoked reflex were compared to analogous characteristics of the acoustically evoked reflex. Latency-intensity functions were similar for the two modes of excitation, but reflex waveform morphology and amplitude growth functions were different.

Acoustic Stimulation↗
PubMedDate not supplied

Deaf culture, cochlear implants, and elective disability.

The use of cochlear implants, especially for prelingually deafened children, has aroused heated debate. Members and proponents of Deaf culture vigorously oppose implants both as a seriously invasive treatment of dubious efficacy and as a threat to Deaf culture. Some find these arguments persuasive; others do not. And in this context arise questions about the extent to which individuals with disabilities may decline treatments to ameliorate disabling conditions. When they do so, to what extent may they call upon society to provide supportive services and accommodations?

Adult↗
PubMed1994

[The Poznan program of the treatment of deafness by multichannel cochlear implants].

The authors presented 5 deaf patients with postlingual deafness and application of cochlear implant "Nucleus Mini System 22". In details operative technics and postoperative proceeding were described as well as rehabilitation results in 3-6 months after operation. The authors consider, that in adults with postlingual deafness, application of cochlear implants were giving very good effects.

Adult↗
PubMed1995

Regional cerebral activation during auditory stimulation in patients with cochlear implants.

OBJECTIVE: To evaluate a possible change in the regional cerebral blood flow (rCBF) in the language-related cortical areas of the brain during stimulation of a cochlear implant. METHODS: The rCBF was measured by single-photon emission tomography and inhalation of Xenon Xe 133, providing information on the regional functional level of the brain. A supplementary single-photon emission tomographic scan was also performed, using technetium Tc 99m hexamethylpropyleneamineoxime as a flow marker. The rCBF was measured during rest (baseline) and during auditory stimulation by presenting white noise and running speech to the ear with the implant. PATIENTS: Five deaf patients who had undergone intracochlear or extracochlear implantation surgery. RESULTS: As in subjects with normal hearing, notable activation was not found in the relevant primary auditory cortex on stimulation with white noise. Two of the patients with implants had an increase in the rCBF in the relevant contralateral hemisphere on stimulation with running speech, but in the other three patients, a notable increase was not detected. This lack of increase in the rCBF on speech stimulation was consistent with the lack of speech recognition experienced by the subjects when using the implant. In one subject, the implant had a beneficial effect on speech understanding that was associated with a significant increase in the cerebral blood flow in the Broca's speech area and Wernicke's second speech area. CONCLUSIONS: Although the results are preliminary, the single-photon emission tomographic technique may be useful when evaluating the function of a cochlear implant. The method may also help select patients and/or ears for cochlear implantation. Four of five patients had functional defects of auditory relevant cortical areas, suggesting that their deafness might be associated with central impairment in addition to their cochlear defects.

Acoustic Stimulation↗