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PubMed2003

Cochlear implantation in human immunodeficiency virus-infected patients.

OBJECTIVE: To evaluate the efficacy of cochlear implants in human immunodeficiency virus-infected individuals and correlate these results with a proposed pathophysiological mechanism of human immunodeficiency virus-associated hearing loss. STUDY DESIGN: Retrospective case series and temporal bone analysis of deceased human immunodeficiency virus-positive patients. SETTING: Tertiary care hospital. PATIENTS: Seven human immunodeficiency virus-positive individuals with profound sensorineural hearing loss. INTERVENTION: Cochlear implantation at New York University Medical Center. METHODS: The surgical outcomes and complications were analyzed. Additionally, electron microscopic and immunohistochemical findings of cadaver temporal bone specimens of other known human immunodeficiency virus-positive individuals were reviewed. The performance results of the human immunodeficiency virus-positive cochlear implant patients were then correlated with the previously hypothesized pathophysiological mechanism of human immunodeficiency virus-associated hearing loss. RESULTS: The patients had a varied performance with cochlear implantation, and as a group performance was good. There were no surgical complications or postoperative complications. The good performance of these patients supports the hypothesis that the mechanism of human immunodeficiency virus-associated deafness involves infiltration, malfunction, and premature degeneration of the hair cells and supportive cells of the cochlea. CONCLUSIONS: Human immunodeficiency virus-positive individuals benefit from cochlear implantation without increased surgical risk.

Adult↗

PubMed2004

Cochlear implantation for children with GJB2-related deafness.

OBJECTIVES/HYPOTHESIS: Mutations in GJB2 are a common cause of congenital sensorineural hearing loss. Many children with these mutations receive cochlear implants for auditory habilitation. The purpose of the study was to compare the speech perception performance of cochlear implant patients with GJB2-related deafness to patients without GJB2-related deafness. STUDY DESIGN: Retrospective case review. METHODS: Pediatric cochlear implant recipients who have been tested for GJB2 mutation underwent chart review. All patients received cochlear implantation at a tertiary referral center, followed by outpatient auditory habilitation. Charts were reviewed for cause and duration of deafness, age at time of cochlear implantation, intraoperative and postoperative complications, duration of use, and current age. Results of standard tests of speech perception administered as a part of the patients' auditory habilitation were reviewed. RESULTS: Twenty patients with GJB2 mutations were compared with 27 patients without GJB2 mutations. There was no statistical difference between patients with and without GJB2-related congenital sensorineural hearing loss with regard to open-set and closed-set speech recognition performance at 12, 24, and 36 months after cochlear implantation. Surgical complications were uncommon. CONCLUSION: Pediatric patients with congenital sensorineural hearing loss without other comorbid conditions (eg, developmental delay, inner ear malformations) perform well when they receive cochlear implantation and auditory habilitation. The presence or absence of GJB2 mutation does not appear to impact speech recognition performance at 12, 24, and 36 months after implantation.

Child, Preschool↗

PubMed2004

Is age at implant the only factor that counts? The influence of working memory on lexical and grammatical development in children with cochlear implants.

In this study, we explored the influence of time factors (age at implant, time with cochlear implant and age), complex working memory and phonological short-term memory on lexical and grammatical development in congenitally deaf children with cochlear implants. Fifteen children (aged 5 years 4 months to 11 years 5 months) were examined with the use of several linguistic and cognitive measures after a minimum of 18 months of implant use. Phonological short-term memory was assessed with non-word repetition, where the percentage of correctly repeated consonants and vowels was counted. For the assessment of lexical acquisition. a novel word learning task was administered. Receptive and expressive grammar was tested. Our results corroborate earlier findings on the influence of phonological short-term memory on novel word learning. The percentage of vowels correctly produced in non-word repetition was more important in this group than age at implant, not only for novel word learning. but also for receptive and expressive grammar.

Age Factors↗

PubMed2005

Speech and language development in cognitively delayed children with cochlear implants.

OBJECTIVE: The primary goals of this investigation were to examine the speech and language development of deaf children with cochlear implants and mild cognitive delay and to compare their gains with those of children with cochlear implants who do not have this additional impairment. DESIGN: We retrospectively examined the speech and language development of 69 children with pre-lingual deafness. The experimental group consisted of 19 children with cognitive delays and no other disabilities (mean age at implantation = 38 months). The control group consisted of 50 children who did not have cognitive delays or any other identified disability. The control group was stratified by primary communication mode: half used total communication (mean age at implantation = 32 months) and the other half used oral communication (mean age at implantation = 26 months). Children were tested on a variety of standard speech and language measures and one test of auditory skill development at 6-month intervals. RESULTS: The results from each test were collapsed from blocks of two consecutive 6-month intervals to calculate group mean scores before implantation and at 1-year intervals after implantation. The children with cognitive delays and those without such delays demonstrated significant improvement in their speech and language skills over time on every test administered. Children with cognitive delays had significantly lower scores than typically developing children on two of the three measures of receptive and expressive language and had significantly slower rates of auditory-only sentence recognition development. Finally, there were no significant group differences in auditory skill development based on parental reports or in auditory-only or multimodal word recognition. CONCLUSIONS: The results suggest that deaf children with mild cognitive impairments benefit from cochlear implantation. Specifically, improvements are evident in their ability to perceive speech and in their reception and use of language. However, it may be reduced relative to their typically developing peers with cochlear implants, particularly in domains that require higher level skills, such as sentence recognition and receptive and expressive language. These findings suggest that children with mild cognitive deficits be considered for cochlear implantation with less trepidation than has been the case in the past. Although their speech and language gains may be tempered by their cognitive abilities, these limitations do not appear to preclude benefit from cochlear implant stimulation, as assessed by traditional measures of speech and language development.

Child, Preschool↗

PubMed1990

Positron emission tomographic study of auditory sensation in a patient with a cochlear implant.

The speech comprehension ability of patients with a cochlear implant is fairly good even when information from the implant device is insufficient. It is presumed that the higher brain system has important roles in discriminating speech. The purpose of the present study was to investigate the function of the auditory cortices of a patient with a cochlear implant before and after sound signal inputs. In this study, we used positron emission computed tomography, which can detect brain activity by providing quantitative measurements of the metabolic rates of oxygen and glucose. Without sound signals, the auditory cortices of the patient showed remarkably low metabolic rates. However, with the cochlear implant device, the activity returned to near normal levels. These findings suggest that the activation of the speech comprehension mechanism of the higher brain system can be initiated by sound signals from the implant device.

Acoustic Stimulation↗

PubMed2005

[The change of the auditory function in children with cochlear implant].

OBJECTIVE: Study the change of the auditory function in children with cochlear implant in different periods. METHOD: This study compared the Nucleus group and the Clarion group in 47 children after cochlear implantation, discussed the auditory change in different periods after surgical procedures and by the Listening Progress Profile (LIP) of Nottingham University. RESULT: The average scores of LIP before the operation and after 3 months, 6 months and 12 months were (8.5 +/- 9.9), (35.0 +/- 8.6), (39.0 +/- 2.4), (40.0 +/- 2.9) in Nucleus group and (5.6 +/- .5), (28.1 +/- 13.4), (34.4 +/- 9.2), (39.8 +/- 3.5) in Clarion group respectively. The improvement of auditory function was significant in the initial 3 months after switch-on but slower from the 3rd to 12th month. CONCLUSION: The testing outcomes of auditory function in both Nucleus group and Clarion group are all close to the full score 1 year after switch-on. The auditory function can be improved in different degrees after the cochlear implantation in children with congenital deafness.

Child↗

PubMed2001

Some measures of verbal and spatial working memory in eight- and nine-year-old hearing-impaired children with cochlear implants.

OBJECTIVE: The purpose of this study was to examine working memory for sequences of auditory and visual stimuli in prelingually deafened pediatric cochlear implant users with at least 4 yr of device experience. DESIGN: Two groups of 8- and 9-yr-old children, 45 normal-hearing and 45 hearing-impaired users of cochlear implants, completed a novel working memory task requiring memory for sequences of either visual-spatial cues or visual-spatial cues paired with auditory signals. In each sequence, colored response buttons were illuminated either with or without simultaneous auditory presentation of verbal labels (color-names or digit-names). The child was required to reproduce each sequence by pressing the appropriate buttons on the response box. Sequence length was varied and a measure of memory span corresponding to the longest list length correctly reproduced under each set of presentation conditions was recorded. Additional children completed a modified task that eliminated the visual-spatial light cues but that still required reproduction of auditory color-name sequences using the same response box. Data from 37 pediatric cochlear implant users were collected using this modified task. RESULTS: The cochlear implant group obtained shorter span scores on average than the normal-hearing group, regardless of presentation format. The normal-hearing children also demonstrated a larger "redundancy gain" than children in the cochlear implant group-that is, the normal-hearing group displayed better memory for auditory-plus-lights sequences than for the lights-only sequences. Although the children with cochlear implants did not use the auditory signals as effectively as normal-hearing children when visual-spatial cues were also available, their performance on the modified memory task using only auditory cues showed that some of the children were capable of encoding auditory-only sequences at a level comparable with normal-hearing children. CONCLUSIONS: The finding of smaller redundancy gains from the addition of auditory cues to visual-spatial sequences in the cochlear implant group as compared with the normal-hearing group demonstrates differences in encoding or rehearsal strategies between these two groups of children. Differences in memory span between the two groups even on a visual-spatial memory task suggests that atypical working memory development irrespective of input modality may be present in this clinical population.

Audiometry, Pure-Tone↗

PubMedDate not supplied

Multicentric field evaluation of a new speech coding strategy for cochlear implants.

In a multicentric study involving 4 European cochlear implant centers, the speech perception abilities of 20 native German-speaking individuals implanted with the Nucleus 22 Channel Cochlear Implant System when using a new spectral peak (SPEAK) speech coding strategy were investigated. This strategy continuously analyzes the speech signal using 20 digital programmable bandpass filters and presents up to 10 spectral maxima to the 22 implanted electrodes. Each subject's performance on a variety of auditory perceptual tasks was evaluated with the experimental encoder (SPEAK), relative to his or her performance in a reference condition. An ABAB experimental design was used whereby each strategy was reversed and replicated. The reference levels of auditory performance were established using the multipeak (MPEAK) speech-processing strategy of the Nucleus speech processor. Only subjects who achieved open-set monosyllable word recognition in the reference condition were included in this study. Significant differences in group mean scores for most speech recognition subtests were obtained for the SPEAK versus the MPEAK strategy. The largest overall improvements were observed for the sentence tests under noisy conditions.

Cochlear Implants↗

PubMed2001

Coding of the fundamental frequency in continuous interleaved sampling processors for cochlear implants.

In this study the perception of the fundamental frequency (F0) of periodic stimuli by cochlear implant users is investigated. A widely used speech processor is the Continuous Interleaved Sampling (CIS) processor, for which the fundamental frequency appears as temporal fluctuations in the envelopes at the output. Three experiments with four users of the LAURA (Registered trade mark of Philips Hearing Implants, now Cochlear Technology Centre Europe) cochlear implant were carried out to examine the influence of the modulation depth of these envelope fluctuations on pitch discrimination. In the first experiment, the subjects were asked to discriminate between two SAM (sinusoidally amplitude modulated) pulse trains on a single electrode channel differing in modulation frequency ( deltaf = 20%). As expected, the results showed a decrease in the performance for smaller modulation depths. Optimal performance was reached for modulation depths between 20% and 99%, depending on subject, electrode channel, and modulation frequency. In the second experiment, the smallest noticeable difference in F0 of synthetic vowels was measured for three algorithms that differed in the obtained modulation depth at the output: the default CIS strategy, the CIS strategy in which the F0 fluctuations in the envelope were removed (FLAT CIS), and a third CIS strategy, which was especially designed to control and increase the depth of these fluctuations (F0 CIS). In general, performance was poorest for the FLAT CIS strategy, where changes in F0 are only apparent as changes of the average amplitude in the channel outputs. This emphasizes the importance of temporal coding of F0 in the speech envelope for pitch perception. No significantly better results were obtained for the F0 CIS strategy compared to the default CIS strategy, although the latter results in envelope modulation depths at which sub-optimal scores were obtained in some cases of the first experiment. This indicates that less modulation is needed if all channels are stimulated with synchronous F0 fluctuations. This hypothesis is confirmed in a third experiment where subjects performed significantly better in a pitch discrimination task with SAM pulse trains, if three channels were stimulated concurrently, as opposed to only one.

Acoustic Stimulation↗

PubMed2001

Conservative management of infections in cochlear implant recipients.

OBJECTIVE: The goal of this study was to evaluate a conservative management strategy of postoperative infection after cochlear implantation. METHODS: A retrospective review of the medical records of 108 cochlear implant patients operated on at the University of California, San Francisco between 1991 and 2000 and 133 cochlear implant patients from the University of Iowa between 1997 and 2000 showed 4 patients with evidence of postoperative infections. The clinical presentation, intervention, laboratory results, and outcome are analyzed in each case. RESULTS: Minimal surgical intervention with limited incision and drainage with prolonged postoperative antibiotics was effective in treating postoperative cochlear implant infections without the need for device removal. Implant function remained unaffected after surgery. CONCLUSION: Postoperative cochlear implant infections can be effectively controlled with limited surgical and prolonged medical management. Chronic implant infections may be explained by a primary immunodeficiency. With appropriate treatment leading to infection control, a conservative management strategy is advocated before consideration of device explantation.

Adolescent↗

PubMed1997

Meriones unguiculatus (Gerbil) as an animal model for the ontogenetic cochlear implant research.

The rehabilitation of prelingually deafened children using cochlear implants still raises several basic problems, e.g. growth of the skull and maturation of the auditory system. Systematic research in these problems requires a reliable animal model. The gerbil (Meriones unguiculatus) was investigated in respect of its suitability as an animal model for ontogenetic cochlear implant research. Gerbil pups were deafened by a single intracochlear application of neomycine on their 14th day after birth before the onset of natural hearing and implanted with an animal specific cochlea implant at day 30 after birth. To maintain the biological relevance the social sounds of gerbils were frequency transformed and used in daily electrostimulation until the 90th day after birth. As well established animal in hearing research the gerbil appears to be an appropriate animal model for ontogenetic cochlear implant research.

Animals↗

PubMed2004

Connexin 26 (GJB2) gene-related deafness and speech intelligibility after cochlear implantation.

HYPOTHESIS: Speech intelligibility in children after cochlear implantation may depend on their deafness cause, including connexin 26 (GJB2) gene-related deafness. BACKGROUND: There is significant variability in the degree of intelligibility, or clarity, of children's speech after cochlear implantation. GJB2 gene-related deafness may be a factor, as preliminary data suggest that pathologic changes do not affect the spiral ganglion cells, which are the neural elements stimulated by the implant, thus favoring better results. METHODS: In an observational retrospective cohort study of pediatric cochlear implantees, 38 patients with nonsyndromic deafness of unknown cause and 1 with keratitisichthyosis-deafness syndrome underwent GJB2 mutation analysis using polymerase chain reaction amplification and direct sequencing. The primary outcome measure assessed was Speech Intelligibility Rating score from postoperative Year 1 (n = 39) to Year 5 (n = 17). Educational setting was considered as a secondary outcome measure. Statistical analysis was double-blinded, with patients and assessors of outcome unaware of GJB2 status. RESULTS: Fourteen patients had GJB2-related deafness and 25 had GJB2-unrelated deafness. Comparisons at Year 3 (n = 31) revealed intelligible speech achieved by 9 of 11 with GJB2-related deafness, compared with only 6 of 20 with GJB2-unrelated deafness (p = 0.017). Ordinal logistic regression analysis on Speech Intelligibility Rating scores found statistically significantly better scores in children with GJB2-related deafness (p < 0.05) both before and after adjustment for confounding variables. A larger proportion with GJB2-related deafness also attended mainstream school (p = 0.01). CONCLUSION: In pediatric cochlear implantees, GJB2-related deafness is a predictor of good speech intelligibility.

Child↗

PubMed1992

Hearing improvement achieved by different cochlear implantation techniques on the same and contralateral ears.

The authors have performed cochlear implantation since 1985. Different implantation techniques have been used: extracochlear, round window and intracochlear implantation combined with different receivers. Right at the beginning, the 8-channel extra-cochlear implant produces good results due to the gradually increasing current needed to obtain the same effectivity (transduction energy). However, no great differences can be observed in speech reception whether round window or intracochlear implants be used. In addition to audiological results, we briefly outline surgical implantation techniques and implant fixation methods and summarize the outlook for long-term cochlear implantation. Six months after operation, contralateral hearing was observed. The hearing presented itself at one or two frequences.

Auditory Threshold↗

PubMed2002

Cochlear implant candidacy and performance trends in children.

Data from Clarion cochlear implant pediatric clinical trials were examined retrospectively to uncover trends in candidacy and postimplant benefit over time. In particular, age at implantation, educational setting, and communication mode were examined with respect to speech perception performance after implantation. The results showed that 1) age at implantation is decreasing, 2) children in oral education programs obtain more benefit from a cochlear implant than children in total communication programs, 3) children who undergo implantation before 2 years of age show greater benefit than children who undergo implantation between 2 and 3 years of age, 4) more younger children are using oral communication than older children, and 5) more children with good auditory skills before implantation and more residual hearing are undergoing implantation. In sum, in the 11 years since implants have been available to children in the United States, candidacy criteria have evolved and benefit has increased as cochlear implant technology has advanced.

Age Factors↗

PubMed2005

GJB2 mutations and additional disabilities in a pediatric cochlear implant population.

BACKGROUND: Children with severe to profound sensorineural hearing loss due to GJB2 mutations have often been deemed good cochlear implant candidates. Studies on children with GJB2 mutations and cochlear implants have typically excluded children with additional disabilities. OBJECTIVE: To investigate the presence of additional disabilities among children with and without GJB2 mutations in a cochlear implant population. METHODS: A retrospective chart review was performed of children with non-syndromic sensorineural hearing loss (SNHL) who received a cochlear implant between 1993 and 2004. RESULTS: Among 108 children within the cochlear implant database; 46 patients met the inclusion criteria of idiopathic non-syndromic hearing loss. Sixteen children had GJB2 mutations, 12 were GJB2 negative, and 17 did not receive GJB2 testing but had no other identifiable etiology or risk factor contributing to hearing loss. The proportion of children with additional disabilities that would affect either pre-operative assessments or post-operative results in the GJB2 positive group was 44% compared to 33% of children in the GJB2 negative. Additional disabilities were present in 41% of the children who did not receive GJB2 testing. The disabilities in the GJB2 positive group included specific learning disability, apraxia, epileptiform aphasia, attention deficit disorder, global developmental delay, and gross motor delay. The GJB2 negative and those children not receiving GJB2 testing had motor delays, language delay, autism, specific learning disability, and attention deficit disorder. The proportion of children with at least 6 months CI use who relied on oral communication was 62% in the GJB2 positive group, 66% in the GJB2 negative group, and 38% in the untested group. A majority of the genetic alleles were 35delG (81%) and 10 of 16 (63%) patients with GJB2 mutations were homozygous 35delG. The rate of developmental diagnoses was similar in patients with homozygous GJB2 compared to compound heterozygous genotypes. CONCLUSIONS: The presence of biallelic GJB2 mutations does not rule out non-hearing related disorders that can have an effect on speech, language and learning. Forty-four percent of children with GJB2 mutations had other conditions that could directly affect pre-implant evaluation and post-implant performance. This rate is similar to the reported prevalence among the overall population of children with hearing loss. All children should have a comprehensive evaluation of development and behavior regardless of the etiology of hearing loss.

Adolescent↗

PubMedDate not supplied

Letting the deaf be deaf. Reconsidering the use of cochlear implants in prelingually deaf children.

In theory, cochlear implants hold out the possibility of enabling profoundly prelingually deaf children to hear. For these children's parents, who are usually hearing, this possibility is a great relief. Yet the decision to have this prosthetic device implanted ought not to be viewed as an easy or obvious one. Implant efficacy is modest and the burdens associated with them can be great. Moreover, the decision to forgo cochlear implantation for one's child, far from condemning her to a world of meaningless silence, opens the child up to membership in the Deaf community, which has a rich history, language, and value system of its own.

Attitude to Health↗

PubMed1999

Communication skills in pediatric cochlear implant recipients.

Detailed longitudinal studies of speech perception, speech production and language acquisition have justified a significant change in the demographics of congenitally and prelingually deaf children who receive cochlear implants. A trend toward earlier cochlear implantation has been justified by improvements in measures assessing these areas. To assess the influence of age at implantation on performance, age 5 years was used as a benchmark. Thirty-one children who received a Nucleus cochlear implant and use the SPEAK speech processing strategy and two children who received a Clarion cochlear implant and use the CIS strategy served as subjects. The subjects were divided into three groups based on age at implantation. The groups comprised children implanted before the age of 3 years (n = 14), children implanted between 3 years and 3 years 11 months (n = 11) and those implanted between 4 years and 5 years 3 months (n = 8). The children were further divided according to whether they used oral or total communication. The earlier-implanted groups demonstrated statistically significant improvements on measures of speech perception. Improvements in speech intelligibility as a function of age at implant were seen but did not reach statistical significance. The results of the present study demonstrate that early implantation promotes the acquisition of speaking and listening skills.

Age Factors↗

PubMed2004

Far advanced otosclerosis: stapes surgery or cochlear implantation?

OBJECTIVE: Nowadays, two surgical alternatives are to be considered in patients with far advanced otosclerosis: stapedectomy and cochlear implantation. The aim of this study was to analyze and compare the hearing and communicative results obtained in two groups of patients affected with far advanced otosclerosis, who were treated with the two different surgical procedures, to assess the proper surgical approach for these patients. DESIGN: Retrospective study. SETTINGS: University hospital and referral audiologic centre. METHODS: We submitted 11 adult patients, affected by far advanced otosclerosis and exhibiting unsatisfactory communicative abilities with hearing aids, to two different procedures: 5 to cochlear implantation, and 6 to stapedotomy followed by hearing aid fitting. The benefits afforded by the two procedures were assessed by means of pure-tone audiometry and speech audiometry in an open field and by means of a speech perception test. MAIN OUTCOME MEASURES: Hearing and communicative outcomes, measured 1 year after intervention. RESULTS: The results achieved in the patients subjected to stapedotomy were unpredictable and variable: very good in some cases but unsatisfactory in others, whereas those who had cochlear implantation all achieved satisfactory results with regard to speech recognition. CONCLUSIONS: Patients who underwent cochlear implantation achieved better hearing and communicative results than those who underwent stapedotomy. Even if the number of patients reported in this study is too small to provide definitive results, and despite the reportedly better results afforded by cochlear implantation, in our opinion, correction of far advanced otosclerosis should first be attempted via stapedotomy, and cochlear implantation should instead be reserved for cases in which stapedotomy is unsuccessful or for which imaging techniques unequivocally reveal a fenestral or cochlear obstruction.

Acoustic Impedance Tests↗