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PubMed1996

[Considerations on the rehabilitation of the hearing in cochlear implant patients].

In this study, the Cochlear Implant Programme of the ENT Department of Ospedale Civile di Venezia, is presented. Between 1989 and 1994, after a rigorous selection process, 36 patients were selected to be implanted with a cochlear prostheses: 28 with the multichannel Nucleus 22 device, 5 with the Clarion implant and 3 with the single channel Med-E1 BTE device. The distribution of the patients according to age, etiology, duration of auditory deprivation, age at onset of deafness, is presented. The different speech-coding strategies of the Nucleus system (Wearable Speech Processing, Multipeak speech processing and Spectral Maximum Sound processor) and the stimulation mode (common ground, bipolar, bipolar + 1) as well as the Clarion speech coding strategy (Continuous Interleaved Samples and Compressed Analog) are briefly discussed. The rehabilitation programme, the specific speech recognition assessment test batteries-Consonant Confusion Test, Vocal Confusion Test, Speech Tracking, MAC battery-as they are employed in our department, are presented. As we have analyzed our results, certain factors appear as predicting a favourable outcome: - age of onset of deafness; postlingual patients, who have developed communication skills compare favourably to the perilingual group. - durations of auditory deprivation, as it is related to surviving cells in the cochlea: the shorter the period of deafness, the better the results. - length of electrode insertion, as it is determined by ossification of the cochlea. - high dynamic range of the MAP. - percent of activated electrodes: a number of 10 active electrodes or less predicts a poor outcome. - for simplification reasons, a new variable is introduced-Auditory Deprivation Index- and its positive correlation to the performance presented. - the time period of experience with the device, length and quality of rehabilitation and family support have to be mentioned.

Adolescent↗

PubMed1999

The effect of long-term deafness on speech recognition in postlingually deafened adult CLARION cochlear implant users.

Research suggests that duration of deafness prior to cochlear implantation affects postoperative speech recognition in adults. Duration of deafness usually is defined as the number of years between the onset of profound deafness and implantation. The purpose of this study was to examine the effects of duration of deafness--expressed as percentage of life with deafness--independent of age at implantation on postoperative speech recognition in adult postlingually deafened CLARION Multi-Strategy Cochlear Implant users. Speech recognition tests (CID sentences and NU6 words) were administered to 202 consecutively implanted adults preoperatively and at 3 and 6 months after initial device fitting. Patients implanted at a younger age and those with smaller percentages of their lives with deafness achieved the highest levels of short-term postoperative speech recognition. Patients who had been deaf for > or =60% of their lives demonstrated a slower rate of speech recognition improvement than those with shorter durations of deafness, but still continued to improve with increased implant experience.

Adult↗

PubMed2004

Toward a battery of behavioral and objective measures to achieve optimal cochlear implant stimulation levels in children.

OBJECTIVES: Children require audible and comfortable stimulation from their cochlear implants immediately after device activation. To accomplish this, a battery of objective measures may be needed that could include the electrically evoked stapedius reflex (ESR), compound action potential from the auditory nerve (ECAP), and/or auditory brain stem response (EABR). In the present study, the following specific research questions were asked: In children using cochlear implants, 1) Can the ECAP, EABR, and ESR be recorded at the time of cochlear implantation? 2) What is the feasibility of measuring the ECAP, EABR, and the ESR repeatedly without the use of sedation over the first year of implant use? 3) Do ECAP, EABR, and ESR thresholds or behavioral measures change over time? 4) What is the relation between ECAP, EABR, and ESR thresholds and behavioral measures of threshold and comfortably loud levels? DESIGN: In 68 children, ECAP, EABR, and ESR responses as well as behavioral measures of stimulation threshold and maximum stimulation were recorded at regular intervals over the first year of implant use. In each child, responses were recorded to electrical pulses provided by three different electrodes along the implanted array. Visual inspections of the stapedius reflex (V-ESR) evoked by activation of the same three electrodes at the time of surgery were performed in an additional 20 children. RESULTS: ECAP and EABR measures were obtained in more than 84% of electrodes tested and 89% of children tested both in the operating room at the time of implant surgery (OR) and after surgery in nonsedated children. ESRs were recorded by using immittance measures in more than 65% of electrodes tested and 67% of children tested by 3 mo of implant use, but this technique was less successful in the OR and during early stages of device use. V-ESRs and ECAP thresholds were higher in the OR than ESRs and ECAPs at postoperative recording times. EABR and ECAP thresholds did not significantly change over the first 6 and 12 mo of implant use, respectively, whereas ESR thresholds increased. Behavioral measures of threshold decreased over time, whereas maximum stimulation levels rose over time. Behavioral measures of threshold and loudness were highly correlated at all test times. ECAP, EABR, and behavioral measures were lower when evoked by an electrode at the apical end of the implanted array than by more basal electrodes. Behavioral thresholds could be predicted mainly by ECAP thresholds, whereas maximum stimulation levels could best be predicted by ESR thresholds; both were significantly affected by the age at implantation. CONCLUSIONS: A combination of nonbehavioral measures can aid in the determination of useful cochlear implant stimulation levels, particularly in young children and infants with limited auditory experience. These measures can be made in the operating room and can be repeated after surgery when needed. Correction factors to predict threshold stimulation levels should be based on ECAP thresholds or EABR thresholds if necessary. Correction factors should be made for at least one apical and mid-array electrode, should take into account the age of the child, and may have to be revised during the first year of implant use. Maximum stimulation levels may be best determined by using the ESR.

Acoustic Stimulation↗

PubMed2006

Conditioning pulse trains in cochlear implants: effects on loudness growth.

HYPOTHESIS: The addition of a high-rate (5 kpps) conditioning pulse train to the input signal of cochlear implants will result in shallower loudness growth across the dynamic range of cochlear implant patients. BACKGROUND: High-rate conditioning pulse trains have been shown to increase the dynamic range of sinusoidal stimuli for cochlear implant recipients in a manner consistent with stochastic resonance. This study further characterizes the effects of conditioning stimuli on loudness by examining the loudness growth functions for sinusoidal stimuli both with and without conditioning. METHODS: Seven post-lingually deafened adults using the Clarion CII cochlear implant participated in this study. The loudness growth functions of each subject were characterized using sinusoidal stimuli, both with and without the presence of a high-rate conditioner. Loudness was measured using magnitude estimation. RESULTS: The loudness growth functions of all seven subjects demonstrate an increase in dynamic range for sinusoidal stimuli with the addition of the conditioning pulse train. Shallower loudness growth is seen across the dynamic range with the addition of a conditioner. This result was shown for loudness growth fitted to exponential, power, and cumulative gaussian functions. CONCLUSION: The addition of high-rate conditioning pulse trains to sinusoidal stimuli presented to cochlear implant recipients results in larger dynamic ranges, with more gradual increases in loudness growth across the dynamic range. This suggests that signal-processing strategies incorporating conditioning may be clinically useful, requiring less compression of the input signal and leading to less distortion perceived by cochlear implant patients.

Adult↗

PubMed1995

Cochlear implantation in the elderly.

The purpose of this study was to compare the audiologic and surgical results of elderly patients receiving cochlear implants with other adult patients, and to evaluate the benefit of cochlear implantation in the geriatric population. Twenty-eight patients, aged 60 to 80 years, who received the Nucleus 22 channel cochlear implant were studied retrospectively. Mean audiologic test scores increased significantly after implantation. Postoperative audiologic test scores of this elderly population are comparable to those of a matched group of younger adult patients. The surgical procedure was well tolerated in all elderly patients, and there were two postoperative complications requiring revision procedures. A questionnaire was used to assess implant use and the impact of cochlear implantation on the quality of life in this elderly population. Average implant use per day was 13.8 hours, and 65% of patients were able to recognize voices over the telephone. More than 80% of patients believed that their quality of life had improved significantly, that their self-confidence had increased, and that their decision regarding implantation was correct. The results of this study indicate that elderly patients with bilateral, profound, sensorineural hearing loss should not be denied consideration for cochlear implantation based on age alone.

Aged↗

PubMed1998

The LAURA Pediatric Cochlear Implant Program in Antwerp: what have we learnt in 5 years?

The LAURA Cochlear Implant Program at the University of Antwerp was initiated 5 years ago. Up to now 50 children have received the LAURA cochlear implant (Philips Hearing Implants). Our accumulated experience in selecting the patients, counselling their parents, implanting and fitting the device allowed us to gradually modify the inclusion/exclusion criteria for cochlear implantation and achieve very rewarding results. The most important change was the gradual shift towards a younger age at implantation, our youngest implantee being 11 months old. In this paper we describe the rationale for this change, as well as the prerequisites for a successful pediatric cochlear implant program.

Belgium↗

PubMed2004

Revision cochlear implant surgery: causes and outcome.

OBJECTIVE: To review experience with cochlear implant reimplantations, including effect of reinsertion on audiological performance. STUDY DESIGN AND SETTING: Retrospective review of cochlear implant reinsertions in patients seen in a private tertiary neurotologic practice. Forty-three patients (8 adults and 35 children) underwent revision cochlear implant surgery for device failure or upgrade. Findings at initial and repeat operations were noted, including number of electrodes inserted, and speech perception performance data were obtained when available. RESULTS: Five complications occurred in the reinsertion operations, 2 (6%) intraoperative cerebral spinal fluid leaks and 3 (7%) postoperative flap breakdowns with implant extrusion. Number of electrodes inserted was unchanged in 40/43 patients. Speech perception abilities remained stable or improved. CONCLUSION: Cochlear reimplantation is technically feasible and allows for continued auditory stimulation. SIGNIFICANCE: Patients facing reimplantation must be aware of the possibility of differences in sound quality and speech recognition performance with their replacement device, but speech perception ability will typically remain the same or improve.

Adult↗

PubMed2006

Cochlear implantation in prelingually deaf persons with additional disability.

OBJECTIVES: We aimed to identify the frequency with which the following conditions were present as a second disability in cochlear-implanted, prelingually deaf persons: mild and moderate mental retardation; learning disability; attention deficit/hyperactivity disorder; cerebral palsy; congenital blindness; and autism. We also aimed to document the development of auditory perception in patients having one of these additional disabilities. STUDY DESIGN: A retrospective study was designed to pursue the above aims. METHODS: We examined the records of 398 cochlear-implanted, prelingually deaf patients who had received a cochlear implant at least one year previously. Patients were selected who showed a delay in motor, cognitive or emotional development. The selected cases were referred for psychological evaluation in order to identify patients with additional disabilities. We then compared these patients' auditory perception prior to and one year following cochlear implantation. RESULTS: A total of 60 (15 per cent) cochlear-implanted, prelingually deaf patients were diagnosed with additional disabilities. These were classified as: mild mental retardation in eight cases (13.33 per cent); moderate mental retardation in five (8.33 per cent); learning disability in 20 (33.33 per cent); attention deficit/hyperactivity disorder in 15 (25 per cent); cerebral palsy in five (8.33); congenital blindness in three (5 per cent); and autism in four (6.66 per cent). All patients showed significant development in speech perception, except for autistic and congenitally deaf-blind patients. CONCLUSION: Although cochlear implantation is not contraindicated in prelingually deaf persons with additional disabilities, congenitally deaf-blind and autistic patients showed limited development in auditory perception as a main outcome of cochlear implantation. These patients require unique rehabilitation in order to achieve more auditory development.

Adolescent↗

PubMed2001

The importance of human cochlear anatomy for the results of modiolus-hugging multichannel cochlear implants.

HYPOTHESIS: The fact that the anatomy of the basal turn of the human cochlea, especially, is essentially different from that of other species is likely to influence the outcome of cochlear implantation. BACKGROUND: Multichannel cochlear implants give better speech understanding than single-channel devices. They are intended to make use of the tonotopic organization of the cochlea by selectively stimulating subpopulations of the auditory nerve. At higher stimulus levels and with monopolar stimulation, excitation of nerve fibers from other turns may interfere with this concept, especially with modiolus-hugging electrodes. METHODS: A three-dimensional spiraling computer model of the human cochlea, based on histologic data, was used to test the spatial selectivity and the dynamic range before cross-turn stimulation takes place for the Clarion HiFocus implant with and without a positioner. The results were compared with a similar model of the guinea pig cochlea. RESULTS: In humans (in contrast to the guinea pig), a well-designed modiolus-hugging electrode yielded reduced current thresholds and high spatial selectivity without reduction of the useful dynamic range. The apical turn of the human cochlea, however, is largely comparable in this respect with the guinea pig cochlea, where cross-turn stimulation reduces the dynamic range substantially. CONCLUSION: The clinical success of cochlear implantation in humans and the favorable results with modiolus-hugging devices depend on the anatomy of the human cochlea.

Acoustic Stimulation↗

PubMed2002

Cochlear implants in children--a review.

Over the past two decades, cochlear implantation has become a widely accepted treatment of deafness in children. Over 20,000 children have received cochlear implants worldwide. Hearing, language and social development outcomes have been positive. We review current issues in cochlear implantation, candidacy, evaluation, surgery, habilitation, ethics and outcomes.

Child↗

PubMed2003

Cochlear implantation in children with otitis media.

OBJECTIVE: To describe the outcome of cochlear implantation in a cohort of pediatric patients with a history of otitis media. STUDY DESIGN: Retrospective chart review and follow-up phone survey. METHODS: The medical records of patients younger than 48 months of age who underwent cochlear implantation were reviewed for demographics, complications, and history of otitis media and bilateral myringotomy and ventilation tubes. A follow-up phone survey was performed to determine the long-term natural history of otitis media. RESULTS: The records of 126 profoundly deaf pediatric patients were reviewed. Seventy-two percent had a history of at least one episode of otitis media, 31% had a history of greater than three episodes, and 2% had a history of chronic serous otitis media. Twenty-three percent underwent bilateral myringotomy and tubes in the distant past, 6 to 8 weeks before implantation, at the time of implantation, or after implantation. A phone survey was successfully completed for 76 patients with a mean follow-up period of 46 months. There was a significant decrease in the incidence of otitis media after the cochlear implantation in the majority of patients with a history of otitis media with and without a history of bilateral myringotomy and tubes. CONCLUSIONS: Placement of ventilation tubes either before or at the time of cochlear implantation seems to adequately prevent infectious disease-related complications in otitis-prone children. Therefore, implantation should not be delayed, and subsequent episodes of otitis media can be managed by conventional therapy.

Child, Preschool↗

PubMed1996

[The study of the vestibular function in cochlear implant patients].

Fifty-two patients receiving a cochlear implant were evaluated using vestibular function tests. Forty patients received an intracochlear implant. The risk of losing preoperative vestibular function is estimated to be around 50%. The authors suggest to implant with cochlear prosthesis the ear with preoperative decreased or total loss of vestibular function.

Cochlea↗

PubMed2000

Medialization of electrode array in cochlear implantation.

In the last few years, the main thrust of research into cochlear implantation has centred around the development of advanced multi-channel implants. A new area of development is now concentrating on maximizing the potential of each individual electrode in order to improve the quality of hearing. This study involved the medialization of the cochlear implant electrode array using a silastic positioner in five patients. Two parameters were measured, namely current units needed to produce a stapedial reflex, and impedance levels between the electrode and modiolus. On insertion of the cochlear implant, readings were taken before the insertion of the positioner, immediately afterwards and at two months.

Adult↗

PubMed2005

Loudness growth in cochlear implants: effect of stimulation rate and electrode configuration.

In cochlear implant speech processor design, acoustic amplitudes are mapped to electric currents with the intention of preserving loudness relationships across electrodes. Many parameters may affect the growth of loudness with electrical stimulation. The present study measured the effects of stimulation rate and electrode configuration on loudness growth in six Nucleus-22 cochlear implant users. Loudness balance functions were measured for stimuli that differed in terms of stimulation rate, electrode configuration and electrode location; a 2-alternative, forced-choice adaptive procedure (double-staircase) was used. First, subjects adaptively adjusted the amplitude of a 100-pulse-per-second (pps) pulse train to match the loudness of a 1000-pps standard pulse train. For a range of reference stimulation levels, the loudness of the 100-pps stimulus was matched to that of the 1000-pps standard stimulus; loudness balancing was performed for three electrode pairs [(20,22), (1,3), (1,22)]. The results showed that the loudness balance functions between the 100- and 1000-pps stimulation rates were highly subject-dependent. Some subjects' loudness balance functions were logarithmic, while others' were nearly linear. Loudness balance functions were also measured across electrode locations [(20,22) vs. (1,3)] for two stimulation rates (100, 1000 pps). Results showed that the loudness balance functions between the apical and basal electrode pairs highly depended on the stimulation rate. For all subjects, at the 1000-pps rate, the loudness balance functions between the two electrode locations were nearly linear; however, at the 100-pps rate, the loudness balance function was highly nonlinear in two out of six subjects. These results suggest that, for some cochlear implant patients, low-frequency stimulation may be processed differently at different electrode locations; for these patients, acoustic-to-electric amplitude mapping may need to be sensitive to this place-dependent processing when relatively low stimulation rates are used.

Adult↗

PubMed2003

The effect of GJB2 allele variants on performance after cochlear implantation.

OBJECTIVES/HYPOTHESIS: It has been hypothesized that etiology of hearing loss may serve as an independent variable in performance after cochlear implantation. To test this hypothesis, the authors identified pediatric cochlear implant recipients with gap junction protein beta2 (GJB2)-related deafness. The study examines performance outcomes associated with GJB2 deafness-causing allele variants. STUDY DESIGN: Pediatric cochlear implant patients were screened for GJB2 allele variants; statistical comparisons were made with prospectively obtained performance measures. METHODS: From 181 children who participated in a nationwide cochlear implant research program, 122 children were identified with congenital nonsyndromic sensorineural hearing loss and invited to participate. Screening for GJB2 allele variants was completed for 55 children. The children were homogeneous with respect to age (8 or 9 y) and age at implant (before age 5 y). All patients have previously undergone a prospective regimented battery of performance measures. RESULTS: Performance measures were compared between 22 children with and 33 children without mutations to determine whether GJB2 status was a significant predictor of cochlear implant outcomes. Reading and cognitive outcomes were significantly dependent on connexin status. The group of children who tested positive for GJB2-related deafness scored significantly higher on a nonverbal cognitive measure, Block Design, and on a measure of reading comprehension. CONCLUSION: The isolated insult to the cochlea created by GJB2 allele variants allows for preservation of central cognitive function. Better reading performance is seen in children with GJB2-related deafness.

Alleles↗

PubMed1999

Clarion cochlear implants: surgical implications.

The surgical aspects of 34 Clarion cochlear implants, positioned during a five-year period on 31 profoundly-deaf subjects as primary (11 children, 20 adults) and revision surgery (one child, three adults) were taken into consideration. Intra- and post-operative complications related to the specific structure of this device were considered along with the benefits obtained by update of the hardware and surgical approach. A smaller thickness of the internal receiver as well as the shifting from a retro-auricular/sub-temporal (RA-ST) to an endaural-retromastoid (EA-RM) approach have contributed to a dramatic drop in post-operative complications, such as skin defect or device extrusion. Special care should, however, be taken when cochlear implantation is planned in ears with chronic otitis or its surgical sequelae. From the two revised cases (hardware failure, electrode displacement) in whom re-implantation in the same side was performed, it has been demonstrated that the helicoidal shape of the electrode carrier is not inducing any additional trauma to the cochlear structure.

Adolescent↗

PubMed2001

Language-specific, hearing-related changes in vowel spaces: a preliminary study of English- and Spanish-speaking cochlear implant users.

OBJECTIVE: This study investigates the role of hearing in vowel productions of postlingually deafened cochlear implant users. Two hypotheses are tested that derive from the view that vowel production is influenced by competing demands of intelligibility for the listener and least effort in the speaker: 1) Hearing enables a cochlear implant user to produce vowels distinctly from one another; without hearing, the speaker may give more weight to economy of effort, leading to reduced vowel separation. 2) Speakers may need to produce vowels more distinctly from one another in a language with a relatively "crowded" vowel space, such as American English, than in a language with relatively few vowels, such as Spanish. Thus, when switching between hearing and non-hearing states, English speakers may show a tradeoff between vowel distinctiveness and least effort, whereas Spanish speakers may not. DESIGN: To test the prediction that there will be a reduction of average vowel spacing (AVS) (average intervowel distance in the F1-F2 plane) with interrupted hearing for English-speaking cochlear implant users, but no systematic change in AVS for Spanish cochlear implant users, vowel productions of seven English-speaking and seven Spanish-speaking cochlear implant users, who had been using their implants for at least 1 yr, were recorded when their implant speech processors were turned off and on several times in two sessions. RESULTS: AVS was consistently larger for the English speakers with hearing than without hearing. The magnitude and direction of AVS change was more variable for the Spanish speakers, both within and between subjects. CONCLUSION: Vowel distinctiveness was enhanced with the provision of some hearing in the language group with a more crowded vowel space but not in the language group with fewer vowels. The view that speakers seek to minimize effort while maintaining the distinctiveness of acoustic goals receives some support.

Adult↗

PubMed2006

Cochlear implant outcomes and quality of life in the elderly: Manchester experience over 13 years.

OBJECTIVES: To objectively evaluate the clinical and functional outcomes of cochlear implantation in an elderly population. DESIGN: Retrospective comparative study. SETTING: Neurotology unit at Manchester Royal Infirmary, a supraregional tertiary referral centre in collaboration with Adult Cochlear Implant Programme at The University of Manchester. PARTICIPANTS: All cochlear implant procedures (38) undertaken on post-lingually deafened elderly patients (age range at the time of implantation 65-80 years, n = 34) in the period from 1989 to 2002. MAIN OUTCOME MEASURES: Medical and surgical outcomes. Audiological performance outcomes for isolated words, words in sentences in quiet and noise. Functional outcome measures used are self-reported measures of the social, psychological and emotional aspects of quality of life, and the differences between expectations for functional outcomes and the realization of functional outcomes. They included expectation profiles, Glasgow Benefit inventory (GBI) and Glasgow Health Status Inventory Questionnaire (GHSI). RESULTS: There was statistically significant improvement post-implantation of both open and closed set test scores (P < 0.01). Eighty-two percentage of patients were completely satisfied with their cochlear implants. Patients judged that implantation restored half the loss of quality of life that they had experienced as a result of severe-profound deafness with a highly significant (P < 0.001) improvement in overall quality of life after implantation. The commonest post-operative observation was transient mild pyrexia. CONCLUSIONS: The age of a cochlear implant candidate should not be a factor in the candidacy decision-making process. The quality of life of our elderly recipients was significantly improved after cochlear implant.

Age Factors↗