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PubMed2005

Predictive models for cochlear implantation in elderly candidates.

OBJECTIVE: An aging American population carries a high prevalence of profound sensorineural hearing loss. We examined the performance of multichannel cochlear implant recipients in a large database of adult subjects. DESIGN: Nonconcurrent prospective study of a national cohort with multivariate regression analysis of preoperative and postoperative performance variables in multichannel cochlear implant recipients. We applied models of prediction established in previous studies to the observed results. SETTING: Referral centers with active cochlear implant programs. PATIENTS: Adolescents and adults with profound hearing loss (N = 749; age range, 14-91 years). MAIN OUTCOME MEASURE: Postoperative monosyllabic word recognition. RESULTS: The population 65 years and older demonstrated a clinically insignificant 4.6%-smaller postoperative word score compared with the population younger than 65 years. When duration of deafness exceeded 25 years, elderly recipients demonstrated higher word scores than their younger counterparts. A more significant factor affecting outcomes is the ratio of duration of deafness to age at implantation. CONCLUSIONS: Age at implantation carried relatively little predictive value for postoperative performance in subjects 65 years and older. Although a small decrement in mean speech recognition scores was evident, the clinical significance of this difference is questionable when all of the results observed in elderly patients are considered. A shorter percentage of life spent in severe-to-profound sensorineural hearing loss suggests a foundation of acoustic/auditory processing in the elderly cohort that may mitigate potential physiological effects associated with advanced age. This study confirms and extends previous observations that duration of profound deafness and residual speech recognition carry higher predictive value than the age at which an individual receives an implant.

Adolescent↗
PubMed2002

Infant cochlear implantation and anesthetic risk.

In light of the strong trends toward performing cochlear implantation in infants, it is necessary to consider anesthetic issues. Just as anesthetic risk may play an important role in surgical candidacy in the elderly population, anesthesia is also of special consideration in infants. Even healthy infants are known to be at increased risk for anesthetic complications; for this reason, most elective surgical procedures are not routinely done within the first year of life. Therefore, it is necessary to consider anesthetic issues when contemplating the use of cochlear implants in infants less than 12 months of age.

Adolescent↗
PubMed2004

[Tone recognition and electrode discrimination in prelingually deafened cochlear-implant listeners].

OBJECTIVE: To investigate tone recognition and electrode discrimination in prelingually deafened children with the Nucleus device, and to develop guidelines for customized mapping in the implant users. METHODS: Fourteen prelingually deafened children with cochlear implants participated in this study. Tone recognition was measured with a four-alternative, forced choice procedure from 25 consonant-vowel syllables, each of which had four tonal variations. Electrode discrimination was measured using a same-difference procedure on 7 pairs of electrodes covering the entire electrode array. RESULTS: Tone recognition ranged from 35% to 99% correct with a mean of 62.8% and standard deviation of 14.7% in these users. Electrode discrimination had the mean threshold of 3.4 +/- 0.9, with the best performance from the middle electrodes (E 14 and E 17) at 2.6 and the followed performance at the most apical electrode (E 20). CONCLUSION: The results showed significant individual differences from both tone recognition and electrode discrimination, but there is significant correlation between them.

Adolescent↗
PubMed1998

[Indications for the cochlear implant in partial deafness of the adult].

The last (may 1995) NHI Consensus Development Conference on cochlear implant recommends to extend the use of cochlear implant for adult patient suffering from bilateral acquired severe hearing impairment. Its indications are a severe-to-profound sensorineural hearing loss bilaterally presenting an open-set sentence recognition scores less than or equal to 30 percent under best aided conditions. We report the results of our 4 first implantees responding to these criteria, and discuss the mechanisms of the speech intelligibility improvement which has been obtained.

Audiometry, Pure-Tone↗
PubMed1998

Influence of the multichannel cochlear implant on vestibular function.

Vestibular function was examined in 55 adult patients who underwent cochlear implant surgery. The percentages of the patients with normal results on an optokinetic nystagmus test and eye-tracking test before surgery were 85% and 82%, respectively. A caloric stimulation test was performed before surgery, and 67% of patients showed hypofunction or afunction. This same test was performed approximately 1 month after surgery, and 38% of patients showed functional deterioration. After surgery 47% of the patients reported some kind of subjective dizziness. The characteristics of dizziness were divided into three types: early, prolonged, and delayed. Fifty-eight percent of the patients had early type, 34% had prolonged type, and 8% had the delayed type. Eighteen percent of the patients felt dizziness when they used the implant device, indicating that electrical current spread from the implant device to the vestibular nerve. The other 82% of the patients did not report any relationship between the use of their cochlear implants and dizziness.

Adult↗
PubMed2004

Cochlear implantation in 53 patients with otosclerosis: demographics, computed tomographic scanning, surgery, and complications.

OBJECTIVES: To collect data from a large number of cochlear implant recipients with otosclerosis and to make an assessment of these patients' clinical characteristics, computed tomographic scans, surgical findings, and complications, and to quantify the occurrence of postoperative facial nerve stimulation. STUDY DESIGN: Retrospective multicenter study. PATIENTS: Fifty-three patients with otosclerosis from four cochlear implant centers in the United Kingdom and The Netherlands were reviewed. Sixty surgical procedures were performed in these patients: 57 devices were placed in 56 ears. RESULTS: The computed tomographic imaging demonstrated retrofenestral (cochlear) otosclerotic lesions in the majority of patients. Although not statistically significant, the extent of otosclerotic lesions on the computed tomographic scan as categorized in three types tends to be greater in patients with rapidly progressive hearing loss, in patients in whom there is surgically problematic insertion of the electrode array, and in patients with facial nerve stimulation. In four patients, revision surgery had to be performed. Twenty of 53 (38%) patients experienced facial nerve stimulation at various periods postoperatively. CONCLUSION: Cochlear implant surgery in patients with otosclerosis can be challenging, with a relatively high number of partial insertions and misplacements of the electrode array demanding revision surgery. A very high proportion of patients experienced facial nerve stimulation mainly caused by the distal electrodes. This must be discussed with patients preoperatively.

Adult↗
PubMed1991

[Acoustic memory of the speech evoked by a 22-channel cochlear implant].

Immediate recall of serial 6 digits was examined in order to clarify whether the electrical information heard via a 22-channel cochlear implant can give rise to normal acoustic memory or not. Serial 6 digits were generated randomly using the digits 1 through 6. Following results were obtained in 2 patients with the implant prosthesis. 1) There was a normal primary effect, i.e., good performance of recall at the first or two digits, and also a normal recency effect, i.e., an increased probability of recall at the last one or two digits. 2) There was a normal suffix effect or attenuation of the recency effect when the digits were followed by an another irrelevant speech suffix, the "8". 3) The suffix effect, however, was not observed when the digits were followed by a non-speech noise suffix. Thus, in noise suffix mode, probability of recall was increased at the last one or two digits as similarly with in no suffix mode. The primary effect, the recency effect and the suffix effect are already regarded as the characteristic items of acoustic memory produced in subjects with normal hearing ability. Therefore, it was suggested that a speech perception with a 22-channel cochlear implant prosthesis can produce an normal acoustic memory, and that there is a similarity of neurophysiological functions between natural audition and electrical audition. Moreover, it was demonstrated that the patients with the cochlear implant can distinguish between speech and noise.

Auditory Perception↗
PubMed2004

The impact of cochlear implants on young deaf children: new methods to assess cognitive and behavioral development.

Much evidence suggests that, early in life, auditory input and communication are essential for the normal development of language, cognition, and behavior. Thus, deaf children, who experience significant disruptions in auditory input, are likely to show delays not only in the production of oral language but in other important aspects of development such as visual attention and behavioral control. Cochlear implants have shown tremendous promise in restoring auditory information to deaf children and concomitant improvements in speech recognition and production. However, little is known about how cochlear implants affect psychological variables. In this multisite trial, we assess the effects of cochlear implants on a range of developmental outcomes, including visual attention, problem-solving skills, symbolic play, and social adjustment. Measuring these constructs in young children, primarily younger than 2 years, has presented a number of unique challenges. In this article, we describe the methods used to assess these variables in young children and present preliminary findings comparing joint attention and symbolic play skills in a small sample of age-matched deaf and hearing children. As expected, deaf children performed more poorly than hearing children on measures of attention and symbolic play. As auditory input is restored via a cochlear implant, we predict that significant improvements in these variables will be observed.

Attention↗
PubMed1994

An integrity test battery for the Nucleus Mini 22 Cochlear Implant System.

The probability of system failures increases as the number of cochlear implants increases throughout the world. Whether a malfunction is a technical or physiological problem remains to be defined, particularly in very young children, while a psychogenic hearing disorder after implantation must not be excluded in adults. The battery of objective measurements used clinically at the Medizinische Hochschule, Hannover has provided useful diagnostic information for distinguishing possible causes of failure. In a normally functioning device, an electrical signal equivalent to the biphasic rectangular stimulation pulse can be recorded by measuring skin potentials from surface electrodes placed on the mastoid of the implant side and the forehead. The signal from the stimulated implanted electrodes is derived by applying a constant pulse rate. Signal averaging is not necessary. If no signals are observed, a non-functioning device should be suspected. If the device works normally, function of the auditory pathways can be examined by recording the electrically elicited stapedius reflex or electrically evoked brain-stem responses. In our experience with more than 450 cochlear implant patients, eight internal device failures occurred, while an additional three patients had either reduced or no hearing sensations due to a disorder of the auditory pathways.

Acoustic Stimulation↗
PubMed2000

The effect of reduced dynamic range on speech understanding: implications for patients with cochlear implants.

OBJECTIVE: To determine the effect of reduced dynamic range on speech understanding when the speech signals are processed in a manner similar to a 6-channel cochlear implant speech processor. DESIGN: Signals were processed in a manner similar to a 6-channel cochlear implant processor and output as a sum of sine waves with frequencies equal to the center frequencies of the analysis filters. The amplitudes of the sine waves were compressed in a systematic fashion to simulate the effect of reduced dynamic range. The compressed signals were presented to 10 normal-hearing listeners for identification. RESULTS: There was a significant effect of compression for all test materials. The effect of the compression on speech understanding was different for the three test materials (vowels, consonants, and sentences). Vowel recognition was affected the most by the compression, and consonant recognition was affected the least by the compression. Feature analysis indicated that the reception of place information was affected the most. Sentence recognition was moderately affected by the compression. CONCLUSIONS: Dynamic range should affect the speech perception abilities of cochlear implant users. Our results suggest that a relatively wide dynamic range is needed for a high level of vowel recognition and a relatively small dynamic range is sufficient to maintain consonant recognition. We infer from this outcome that, if other factors were held equal, an implant patient with a small dynamic range could achieve moderately high scores on tests of consonant recognition but poor performance on vowel recognition, and that it is more likely for an implant patient with a large dynamic range to obtain high scores on vowel recognition than for an implant patient with a small dynamic range.

Cochlear Implants↗
PubMed2005

Vestibular schwannoma in the only hearing ear: cochlear implant or auditory brainstem implant?

OBJECTIVE: To explore the dilemma faced by neurotologists confronted with the patient who develops a vestibular schwannoma in the only hearing ear, the other having been deaf from birth, and to consider the choice between auditory rehabilitation using a cochlear implant (CI) on the congenitally deaf side and an auditory brainstem implant (ABI) on the tumor side. STUDY DESIGN: A record review of two patients born deaf in one ear and who developed a vestibular schwannoma in the contra lateral ear, who then received a CI in the congenitally deaf ear. SETTING: Tertiary referral center with special experience in vestibular schwannoma surgery, neurofibromatosis type 2 management, and cochlear implantation. RESULTS: Neither patient was a good CI user. At 1 year postimplant, they both scored 0% on abbreviated words and 0% and 7%, respectively, on Bench Kowal Bamford sentences. They scored 54% and 57%, respectively, on City University of New York sentences with lip-reading, and both had fair access to environmental sound scoring at 45% each. CONCLUSIONS: The results from cochlear implantation in the congenitally deaf ear in these patients were poor and suggest that stimulus deprivation in the early stages of the maturation of the auditory pathways is important even for a unilateral hearing loss. Unfortunately, the factors that predict a good ABI result are not known. In these circumstances, the authors advocate the insertion of an ABI at the time of tumor removal, retaining the option of CI in the congenitally deaf ear in the event of a poor outcome with the ABI.

Audiometry, Pure-Tone↗
PubMed1997

The relation between age at the time of cochlear implantation and long-term speech perception abilities in congenitally deaf subjects.

The issue of whether an upper age limit should be set for cochlear implantation in congenitally deaf subjects has often been debated. To gain more insight, the speech perception abilities were analyzed of 12 congenitally deaf subjects whose age at the time of cochlear implantation ranged from 4 to 33 years. Subjects implanted during adulthood only showed progress during the first few months after the speech processor had been fitted and their long-term results were poor compared to those of children implanted early in life. This latter group showed steady improvement over the whole evaluation period. The present results support the notion that the earlier in life implantation is performed, the better the development of speech perception. Based on the progress-over-time profiles and data on actual daily use of the cochlear implant, it can be suggested that implantation of congenitally deaf subjects during or after puberty offers only limited benefit.

Adolescent↗
PubMed2006

The role of intensity upon pitch perception in cochlear implant recipients.

OBJECTIVES: Pitch plays a key role in the perception of speech and music, the recognition of a speaker's voice, and in analyzing complex auditory patterns. To date, little consideration has been given to the influence of stimulation level on pitch perception. The aim of this study was to investigate the impact of a sound's intensity on pitch perception in cochlear implant recipients using monopolar stimulation. STUDY DESIGN: Thirteen patients with an average implant use of 4.13 years took part in this study. All patients were implanted with MedEl Combi 40/40+ cochlear implants. METHODS: In the first part of the study, we performed a pitch ranking procedure to confirm that all patients were able to judge pitch changes. Using a visual scale, study participants were then asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity. RESULTS: Eleven (85%) patients were found to perceive a clear change in pitch with changing stimulus intensity. Statistical analysis showed a strong positive correlation in 10 patients (correlation coefficients between 0.99 and 0.71) and a strong negative correlation in 1 patient (r = -0.92). CONCLUSIONS: The results suggest that a distinct relationship exists between pitch perception and intensity of the stimulus. To date, speech coding strategies do not support these findings. Nevertheless, we believe that for the optimized most natural perception of sounds, especially music, the described particularities of pitch perception need to be respected, and further investigations on this topic are necessary.

Acoustic Stimulation↗
PubMed1991

Results of cochlear implants in children.

About 700 children throughout the world have been implanted to date. Placing a cochlear implant represents no particular problem in the child. The incidence of complications is not high, being of about the same proportion as that in the adult. To obtain the best results, the selection of patients must be correct and carried out by a multi-disciplinary team of specialists, while the operated child must be subject to regular and intensive rehabilitation. The results appear to have become more satisfactory since the duration of sensory deprivation has been made shorter. In cases of congenital deafness in prelingual children, implantation should, ideally, take place before the age of six.

Age Factors↗
PubMed2005

Preoperative differences of cerebral metabolism relate to the outcome of cochlear implants in congenitally deaf children.

In congenitally deaf children, chronological age is generally accepted as a critical factor that affects successful rehabilitation following cochlear implantation (CI). However, a wide variance among patients is known to exist regardless of the age at CI [Sarant, J.Z., Blamey, P.J., Dowell, R.C., Clark, G.M., Gibson, W.P., 2001. Variation in speech perception scores among children with cochlear implants. Ear Hear. 22, 18-28]. In a previous study, we reported that prelingually deaf children in the age range 5-7 years at implantation showed greatest outcome variability [Oh S.H., Kim C.S., Kang E.J., Lee D.S., Lee H.J., Chang S.O., Ahn S.H., Hwang C.H., Park H.J., Koo J.W., 2003. Speech perception after cochlear implantation over a 4-year time period. Acta Otolaryngol. 123, 148-153]. Eleven children who underwent CI between the age of 5 and 7 1/2 years were subdivided into a good (above 65%: GOOD) and a poor (below 45%: POOR) group based on the performance in a speech perception test given 2 years after CI. The preoperative (18)F-FDG-PET (F-18 fluorodeoxyglucose positron emission tomography) images were compared between the two groups in order to examine if regional glucose metabolic difference preexisted before the CI surgery. In the GOOD group, metabolic activity was greater in diverse fronto-parietal regions compared to the POOR group. In the POOR group, the regions related to the ventral visual pathway showed greater metabolic activity relative to the GOOD group. These findings suggest that the deaf children who had developed greater executive and visuospatial functions subserved by the prefrontal and parietal cortices might be successful in auditory language learning after CI. On the contrary, greater dependency on the visual function subserved by the occipito-temporal region due to auditory deprivation may interfere with acquisition of auditory language after CI.

Brain↗
PubMedDate not supplied

Characteristics of fricatives and sentence duration after cochlear implantation.

Ten postlingually deafened patients (5 male, 5 female) were examined after cochlear implantation to measure improvements in their quality of speech. Parameters such as the spectral maximum of fricatives and the duration of utterances were analysed in speech recordings taken at regular intervals after implantation. The speech samples were recorded in an audiological chamber. Parameters were analysed using ST(x) (S-Tools Software). Frequency analyses based on the fast Fourier transform and spectral estimation methods, as well as fundamental frequency and formant extraction (cepstrum, LPC = linear prediction coding) and digital filter implementations were prepared. The results indicate a tendency towards improvement in the spectral maximum of the fricatives and affricates and a shortening of the duration of the fricative parts in affricates and of sentences in nearly all our subjects. These results showed the restored auditory feedback produced by cochlear implantation to have a favourable effect on speech production.

Adolescent↗
PubMed1988

Ineraid (Utah) multichannel cochlear implants.

For the more than 200,000 individuals in the United States with a bilateral profound sensorineural hearing loss, the cochlear implant offers a means of breaking this barrier of total silence. The pioneers in prosthetic research hoped that direct stimulation of the cochlea might at least give an awareness of sound through the auditory sense. There will be a review of five patients who were consecutively implanted with the Ineraid multichannel cochlear implant, with 1 year follow-up. All individuals were postlingually deafened adults and exhibited a bilateral profound hearing loss.

Adult↗