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PubMed1997

Postoperative radiographic assessment of the Combi 40 cochlear implant.

OBJECTIVE: The aims of this study were to establish a plain radiographic technique for the assessment of the postoperative appearance, position, and insertion depth of the Combi 40 cochlear implant and to correlate the radiologic findings with surgical reports. SUBJECTS AND METHODS: In an experimental study, an electrode of the Combi 40 device was inserted into the cochlea of a cadaveric skull. Digital radiographs were obtained in a modified Chausse III projection, in which the skull was placed supine on the radiography table with the infraorbitomeatal line strictly perpendicular to the film cassette. The skull was then rotated 30 degrees away from the side to be examined, and the central X-ray beam was angled 15 degrees cephalad to the infraorbitomeatal line. On these radiographs, the point of cochleostomy was marked by a needle tip and was projected inferior to the vestibule and on a line drawn through the superior semicircular canal and the vestibule. The appearance and position of the electrode was evaluated. An electrode was defined as completely inserted if all electrode contacts projected medial to the line drawn through the superior semicircular canal and the vestibule. We also studied cochlear implant insertion of the Combi 40 device in 37 patients. Postoperative digital radiographs of these patients were obtained and analyzed for the criteria as defined in the cadaveric study. In addition, the insertion depth of the electrode and the angle of insertion were measured on the radiographs. This depth was correlated with depth of insertion as estimated at surgery. RESULTS: The cadaveric study showed that the completely inserted electrode was seen on radiographs as a nonoverlapping spiral within the cochlea. All electrode contacts projected medial to the line drawn through the superior semicircular canal and the vestibule. In all 37 patients, the electrode could be seen without overlapping. According to our criteria, a completely inserted electrode was seen in 32 patients. In these patients, the insertion depth ranged from 21 to 34 mm and the angle of insertion ranged from 350 degrees to 810 degrees. In two patients, we saw a completely inserted electrode with a bend. In three patients, an incompletely inserted electrode was seen. Excellent correlation existed between the radiologic and surgical results with regard to insertion depth (r = .92). CONCLUSION: Digital radiographs obtained in the modified Chausse III projection allow clear depiction of the electrode and avoid overlapping. Such radiographs enable a reliable and accurate assessment of the position and insertion depth of the electrode of this new cochlear implant. Such images can serve as a baseline for further radiographic examinations when extrusion or slippage of the electrode is clinically suspected.

Adult↗
PubMed2004

Cochlear implants in special cases: deafness in the presence of disabilities and/or associated problems.

The aim of the present study is to construct a reference model with the indication for the attitude, the requirements and the resources needed in order to be able to deal with deafness in the presence of disabilities or associated problems. The study group consisted of 13 adults and 18 children affected by profound deafness, with associated problems and disabilities, who were implanted with Clarion and Med-El devices. Selection criteria for candidacy to cochlear implantation and counselling, hospitalization, fitting and speech therapy/rehabilitation are described. Findings were assessed evaluating: (i) use of acoustic feedback, on the ground of Erber's model; (ii) self-sufficiency: assessed by a questionnaire; and (iii) social and family relationships: qualitative judgment based on direct observation, analysis of drawings and structured interviews with family, teachers and therapists. The whole group showed benefit from cochlear implantation, with particular satisfaction for post-lingual deaf-blind adults, as well as for subjects with associated psychopathologies and mental retardation. In conclusion, cochlear implants can improve life quality in profoundly deaf subjects with associated disabilities, increasing both listening and communication skills as well as self-sufficiency while family and social relationships tend to remain stable.

Adult↗
PubMed2006

Vowel recognition via cochlear implants and noise vocoders: effects of formant movement and duration.

Previous work has demonstrated that normal-hearing individuals use fine-grained phonetic variation, such as formant movement and duration, when recognizing English vowels. The present study investigated whether these cues are used by adult postlingually deafened cochlear implant users, and normal-hearing individuals listening to noise-vocoder simulations of cochlear implant processing. In Experiment 1, subjects gave forced-choice identification judgments for recordings of vowels that were signal processed to remove formant movement and/or equate vowel duration. In Experiment 2, a goodness-optimization procedure was used to create perceptual vowel space maps (i.e., best exemplars within a vowel quadrilateral) that included F1, F2, formant movement, and duration. The results demonstrated that both cochlear implant users and normal-hearing individuals use formant movement and duration cues when recognizing English vowels. Moreover, both listener groups used these cues to the same extent, suggesting that postlingually deafened cochlear implant users have category representations for vowels that are similar to those of normal-hearing individuals.

Adult↗
PubMed1999

A comparison of the growth of open-set speech perception between the nucleus 22 and nucleus 24 cochlear implant systems.

OBJECTIVE: To compare the short-term development of open-set speech perception between implementations of the spectral peak (SPEAK) strategy in adults using the Nucleus 22 (N22) Spectra processor and the Nucleus 24 (N24) system with the SPrint processor. STUDY DESIGN: Two sets of patients with a follow-up period of 3 months were compared. SETTING: This study was conducted at the New York University (NYU) Medical Center. PATIENTS: Thirty-six profoundly hearing-impaired adults were included in this study. INTERVENTION: Sixteen adults received the N22 cochlear implant with the Spectra speech processor and twenty adults received the N24 cochlear implant with the SPrint speech processor. MAIN OUTCOME MEASURES: Open-set speech perception for the patients with N22 implants was evaluated preoperatively and postoperatively using the following measures: NU-6 monosyllabic words, Iowa sentences, and CID sentences. CNC words, CUNY sentences, and HINT sentences were used to assess the patients with N24 implants. RESULTS: Results revealed that the N22 and N24 cochlear implant recipients had significant open-set speech recognition 3 and 6 months after implantation. The apparent favorable absolute scores for the patients with N24 implants were equalized when a multivariate analysis was performed to account for their younger age at time of implantation and shorter length of deafness. CONCLUSIONS: The growth of open-set word and sentence recognition in similar between the N22 and N24 cochlear implants. Longitudinal studies are needed to determine if higher ceiling scores are present in the N24. Further exploration of monopolar versus bipolar stimulation is warranted.

Adult↗
PubMed1988

The acceptability of cochlear implants and vibrotactile aids.

To obtain data on the likely acceptability of cochlear implants (and of vibrotactile aids), a questionnaire was sent to profoundly/totally hearing-impaired patients. The patients were asked how they felt about their current communication problems and possible benefits to be obtained from such devices. Of the 153 replies obtained, the combined 'yes' or 'maybe' responses indicated that 58% would accept an implant. The corresponding figure for vibrotactile aids was 73%. The statistically significant factors correlating with cochlear implant acceptance were the patient's expectation of the benefit it would give, the time needed for rehabilitation and the degree of communication difficulty that they suffer. The only significant factor in acceptance of a vibrotactile aid was whether the patient had attended the IHR clinic. This implies that the underlying factor is the patient's knowledge about these devices.

Adolescent↗
PubMed2007

The pattern of auditory brainstem response wave V maturation in cochlear-implanted children.

OBJECTIVE: Maturation of acoustically evoked brainstem responses (ABR) in hearing children is not complete at birth but rather continues over the first two years of life. In particular, it has been established that the decrease in ABR wave V latency can be modeled as the sum of two decaying exponential functions with respective time-constants of 4 and 50 weeks [Eggermont, J.J., Salamy, A., 1988a. Maturational time-course for the ABR in preterm and full term infants. Hear Res 33, 35-47; Eggermont, J.J., Salamy, A., 1988b. Development of ABR parameters in a preterm and a term born population. Ear Hear 9, 283-9]. Here, we investigated the maturation of electrically evoked auditory brainstem responses (EABR) in 55 deaf children who recovered hearing after cochlear implantation, and proposed a predictive model of EABR maturation depending on the onset of deafness. The pattern of EABR maturation over the first 2 years of cochlear implant use was compared with the normal pattern of ABR maturation in hearing children. METHODS: Changes in EABR wave V latency over the 2 years following cochlear implant connection were analyzed in two groups of children. The first group (n=41) consisted of children with early-onset of deafness (mostly congenital), and the second (n=14) of children who had become profoundly deaf after 1 year of age. The modeling of changes in EABR wave V latency with time was based on the mean values from each of the two groups, allowing comparison of the rates of EABR maturation between groups. Differences between EABRs elicited at the basal and apical ends of the implant electrode array were also tested. RESULTS: There was no influence of age at implantation on the rate of wave V latency change. The main factor for EABR changes was the time in sound. Indeed, significant maturation was observed over the first 2 years of implant use only in the group with early-onset deafness. In this group maturation of wave V progressed as in the ABR model of [Eggermont, J.J., Salamy, A., 1988a. Maturational time-course for the ABR in preterm and full term infants. Hear Res 33, 35-47; Eggermont, J.J., Salamy, A., 1988b. Development of ABR parameters in a preterm and a term born population. Ear Hear 9, 283-9] of normal hearing children: a sum of two decaying exponential functions, one showing an early rapid decrease in latency and the other a slower decrease. Remarkably, the time-constants fell well within the ranges described by Eggermont and Salamy (i.e., 3.9 and 68 weeks), consistent with the time-course of the neurophysiological mechanisms presumably involved in auditory pathway maturation during the first 2 years of life: i.e., myelination and increased synaptic efficacy. In contrast, relatively little change in wave V was evident in children with late-onset deafness. In agreement with the notion that EABR maturation follows an apex-to-base gradient as described for ABR, we observed that wave V latencies were longer for the basal than the apical end of the implant electrode array and remained so throughout the study period, whatever the time of onset of deafness. CONCLUSIONS: The findings in the early-onset of deafness group support the theory that auditory pathways remain "frozen" during the period of sensory deprivation until cochlear implant rehabilitation restores the normal chronology of maturational processes. In children with late-onset deafness, however, some maturational processes may occur before the onset of deafness, and thus less additional maturation is required during the first two years of implant use resulting in no significant EABR latency changes being observed in this period. The results suggest that the rehabilitation-induced plasticity of the auditory pathways is, in case of late auditory deprivation, unlikely to result in neurophysiological outcomes similar to those observed in children with early auditory deprivation. SIGNIFICANCE: Changes in EABR wave V latency over the first 2 years of cochlear implant use were found to be well fitted by the sum of two decaying exponential functions in children with early-onset deafness. This is in line with the maturation of ABR wave V latency in normal-hearing children over the first two years of life. Further studies are needed to assess whether the differences observed in terms of auditory pathways maturation are associated with consistent differences in terms of language development.

Adolescent↗
PubMed1995

Importance of auditory-verbal education and parents' participation after cochlear implantation of very young children.

Congenitally deaf children who receive a cochlear implant at a young age have the potential to achieve nearly normal language development. However, parents and rehabilitation therapists must realize that intensive and long-duration auditory-verbal education is required postoperatively to achieve this goal. Furthermore, the success of the therapeutic treatment is best realized if the parents themselves are trained to engage in linguistic interactions with the child within the natural context of the family. This is especially true if the parents are able to creatively guide auditory-verbal training on a daily basis. At the Cochlear Implant Center in Hannover, parents receive training and guidance on the following aspects of postimplant rehabilitation: basic components of auditory-verbal education; significance of collaborative efforts between parents and therapists; importance of exercising linguistic interactions on a daily basis; importance of the parents as communication partners; milestones and developmental stages of listening, speech, and language; interpretation of the child's first auditory and communication efforts after implantation; and future integration of the child into school and society.

Child↗
PubMed2006

Histopathology of the peripheral vestibular system after cochlear implantation in the human.

OBJECTIVES: The objective of this study was to describe the histology of the peripheral vestibular system in temporal bones from patients who in life had undergone cochlear implantation and to correlate the findings with previous reports of vestibular dysfunction after cochlear implantation. This is the first quantitative report of the impact of implantation on the vestibular neuronal end organ. METHODSThere were 19 temporal bones available for histologic study. Of these, 17 were suitable for the description of the morphology of the membranous labyrinth, 8 for counting Scarpa's ganglion cells, and 6 for measuring the densities of vestibular hair cells. The bones were fixed, cut, and stained according to previously published methods. Preferably, the implanted electrode was left in situ. Vestibular hair cells were counted with Nomarski's optics. RESULTS: Differences in Scarpa's ganglion cell counts and hair cell densities between the implanted and nonimplanted sides were not statistically significant. In 59% of the implanted bones, the cochlea was hydropic, and in the majority of these bones the saccule was collapsed. CONCLUSION: Cochlear implantation does not cause deafferentation of the peripheral vestibular system. Cochlear hydrops accompanied by saccular collapse is common and may cause attacks of vertigo of delayed onset, similar to Ménière's syndrome as previously reported in several clinical series. Hydrops could be caused by obstruction of endolymphatic flow in the ductus reuniens or in the hook portion of the cochlea or by damage to the lateral cochlear wall caused by implantation.

Aged↗
PubMed1986

[High-resolution computerized tomography as a supplementary examination prior to cochlear implants].

Patients must be thoroughly tested for their suitability for a cochlear implant. Promontory testing and electrocochleography are of fundamental importance. It is possible to distinguish sensory deafness from other forms by combining the results of both tests. The implantation of intracochlear electrodes requires exact information of the anatomy of the cochlea, the tympanic wall of the cochlea and the endocochlear space. This can be assessed by axial high resolution computed tomographic scans. 8 of 70 patients were inoperable because of cochlea lesions (fractures or malformations). The advantage of computer tomography compared to conventional tomography is the fact that radiation exposure is less while the resolution is nearly the same. If computer tomography and conventional tomography do not reveal any fractures an exploratory tympanotomy should precede the cochlear implant operation in patients with a history of cranio-cerebral trauma.

Audiometry, Evoked Response↗
PubMedDate not supplied

Computed tomography of single-channel cochlear implants.

Computed tomographic (CT) examinations were performed in seven patients after cochlear implant surgery. Preimplantation CT demonstrated the petrous anatomy well and revealed an abnormality in one case. Postimplantation CT adequately assessed electrode position in all cases. Malposition of the active electrode was identified in one patient. Electrode position was correlated with postimplantation audiometric testing. A "transpetrous" projection was used to image perpendicular to the active electrode within the basal turn of the cochlea. A potential pitfall was identified where the ground electrode tip appeared to be embedded in the carotid canal cortex due to partial-volume averaging. With further experience, the clinical utility of CT in cochlear implantation patients will be better defined.

Acoustic Impedance Tests↗
PubMed1994

[Cochlear implant for children: indications and surgical aspects].

Since the late 80s cochlear implants (CI) have proved to be an efficient means to help bilaterally profound deaf patients. The CI is supposed to replace the function of the inner ear. A CI-system consists of an externally worn speech processor and the implants itself with intracochlear electrodes. A preoperative promontory test serves to differentiate between inner ear deafness and non-functioning hearing nerve, but is performed only in the case of adults. In small children results of electrocochleography form the basis for such an assessment. CI-surgery in small children is basically not more complicated than in adults. Whereas cochlear implants in adults are only indicated for late-deafened patients, both small children deafened after having acquired speech as well as deaf born children can learn to understand and develop speech. However, consistent technical and pedagogical rehabilitation is an indispensable prerequisite for success. This is being done in Hannover in a special children-like rehabilitation center where children and 1 parent are trained in-house for 12 times once a week. Results are the better, the shorter the duration of deafness, i.e. if children are implanted already during the 3rd year of age, and deafened children - mostly after meningitis - immediately, if possible. Some children even achieve to develop spontaneous speech with elements of dialects and a nearly-unimpaired level of understanding.

Child↗
PubMed2002

Initial evaluation of the Clarion CII cochlear implant: speech perception and neural response imaging.

OBJECTIVE: To evaluate the new Clarion CII cochlear implant with the perimodiolar HiFocus electrode array, including both speech perception outcomes and the device's capabilities of measuring the electrically evoked compound action potential (eCAP) of the auditory nerve (Neural Response Imaging, NRI). DESIGN: The speech perception scores on CVC words without lip reading were monitored prospectively for the 10 postlingually deaf patients implanted with the Clarion CII device in the period July 2000 until May 2001 in the Leiden University Medical Center. Preoperative and postoperative NRI recordings were made, applying various combinations of monopolar stimulating and recording electrodes with the alternating polarity paradigm available in the test bench software. RESULTS: Nine patients preferred the CIS, one the PPS strategy, none the SAS strategy. With their favorite strategy they acquired significant open set speech understanding within a few weeks, resulting in an average CVC phoneme score of 84% (word score 66%) at the end of the study (follow-up 3 to 11 mo). In speech-shaped noise, the average phoneme recognition threshold (PRT) was reached at a signal to noise ratio just below 0 dB. The NRI recordings had clear N1 and P1 peaks if there was at least one contact between the stimulating and recording electrodes, necessitating just 15 sweeps for a reliable recording. We observed considerable inter-patient and inter-electrode variability, but for a given situation NRI input/output curves were stable over time. More apical contacts generally elicited larger eCAPs. Response amplitudes tended to peak at recording sites around apical and basal stimulating electrodes, suggesting a limited spread of excitation. Preliminary recordings with the forward masking paradigm were consistent with the ones with the alternating polarity scheme. CONCLUSIONS: The Clarion CII is a promising cochlear implant with which our first 10 patients have obtained excellent speech perception results. The NRI system yields high quality signals with a limited number of sweeps at a high sampling rate.

Acoustic Stimulation↗
PubMed2002

Reconsidering cochlear implants: the lessons of Martha's Vineyard.

I distinguish and assess three separate arguments utilized by the opponents of cochlear implants: that treating deafness as a medical condition is inappropriate since it is not a disability; that so treating it sends a message to the Deaf that they are of lesser worth; and that the use of such implants would signal the end of Deaf culture. I give some qualified support to the first and second claim, but find that the principal weight of the argument must be borne by the third argument: that use of the cochlear implants is impermissible because Deaf culture is intrinsically valuable. I show that this claim is, in practice, incompatible with the claim that deafness is not a disability: that the significant disadvantages suffered by the hearing impaired can only be corrected by measures that would end Deaf culture. Since the potential recipients of cochlear implants are, in the main, the prelingually deaf children of hearing parents, the burden of banning the implants would be borne by people who are not members of Deaf culture, and who owe that culture nothing over and above what we all owe cultures in general. I conclude that we cannot ask the parents of these children to sacrifice the interests of their children for the sake of Deaf culture.

Black or African American↗
PubMed1990

Electrode placements for cochlear implants: a review.

Of the variety of different sites that have been proposed and used for cochlear implants, only two are now seeing widespread use. For single-channel electrodes, it appears that a placement at the round window, or just inside it, leads to no disadvantages (and perhaps some advantages) over deeper insertions. For multichannel implants, it appears that intra-cochlear electrodes are, generally speaking, preferable to extra-cochlear ones in a variety of ways, especially as the early fears about the dangers of intra-cochlear placement now seem exaggerated. One way in which extra-cochlear approaches may play an important accessory role in multichannel intra-cochlear implants is in allowing access to the apical end of the cochlea where residual nerve survival is likely to be best. Special considerations may apply for groups of patients who until recently have been implanted relatively infrequently--adults with significant residual hearing and children.

Auditory Threshold↗
PubMed2004

[Changes in interpersonal communication in pre- and perilingually deafened children after cochlear implantation].

People with deep prelingual deafness cannot fluently use oral language as a basic mode of communication. Hearing impaired subjects elaborated their own mode of communication. Cochlear implants as a surgical mode of deafness treatment may create a new chance for prelingually deaf children to develop vocal speech. The aim of this study was to assess changes in interpersonal mode of communication in pre- and perilingually deaf children after cochlear implantation. It was observed, that cochlear implantation stimulates development of oral language. The possibility of hearing perception of oral language it is a chance for a child for fully participation in life of hearing societies.

Adolescent↗
PubMed1995

Outcomes of cochlear implants for New Zealand children and their families.

Six children with multichannel cochlear implants and their families were evaluated by means of multiple measures to determine the impact of the cochlear implant on the child's speech perception, language, communication mode, and behavior and on the parents' stress levels. The children showed quite variable improvements in speech perception with the implant. One child showed marked improvements in language 6 months after implantation. Two of the children had behavior problems preimplantation that showed some improvement after implantation. Parenting stress was very high in some families, but on average, stress was lower and social support networks were more extensive than those previously reported in studies of parents of deaf children in the United States.

Child↗
PubMed2005

Effect of peri-modiolar cochlear implant positioning on auditory nerve responses: a neural response telemetry study.

CONCLUSIONS: There was no evidence that a reduction in current was needed for nerve stimulation as a result of modiolar placement of a cochlear implant. However, modiolus hugging did reduce the spread of excitation for the basal and apical electrodes. This improved stimulation selectivity may result in improved speech discrimination by implant users. OBJECTIVE: To test the effect of modiolar placement of a cochlear implant on stimulation thresholds, and to confirm whether peri-modiolar electrode placement resulted in the hypothesized reduced spread of excitation. MATERIAL AND METHODS: Auditory nerve responses were measured by means of neural response telemetry (NRT) in 14 subjects. All subjects received a Nucleus CI24R(CS) Contour implant. For each subject, the stimulation threshold and response growth rate were determined on all the odd-numbered electrodes, using a masker-and-probe paradigm. In addition, the spatial spread of excitation was measured on electrodes 1, 6, 11, 16 and 20, using a variable-masker paradigm. All NRT measurements were performed intra-operatively, both before and after peri-modular placement of the electrode by removal of surgical stylet. RESULTS: Removal of the stylet had no significant effect on the threshold and growth rate of NRT responses. It caused a reduction in the spread of excitation for electrodes 1, 6 and 20, but not for electrodes 11 and 16.

Adolescent↗