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PubMedDate not supplied

Complications of cochlear implant placement with minimal hair shave.

OBJECTIVE: The goal of this study was to determine if a change to minimal-hair shave preparation has altered the incidence of complications after cochlear implant surgery. MATERIALS AND METHODS: Charts were reviewed on 158 consecutive patients that underwent primary cochlear implant surgery for evidence of minor and major surgical complications with full- or minimal-hair shave preparation. RESULTS: Complications were noted within 6 weeks in 5 of 105 patients in the minimal-hair shave group and 3 of 53 in the full-hair shave group (4.8% v 5.7%, P =.53). Delayed complications were noted in 3 within the minimal-shave group and 1 within the full-shave group (2.9% v 1.9%, P =.58). Only 1 wound complication required replacement of the cochlear implant. CONCLUSIONS: There is no evidence that minimal-hair shave adversely affects rates of wound complications in patents undergoing cochlear implant surgery. Therefore, minimal preoperative scalp shave may be an acceptable alternative to the traditional hair shaving technique.

Adolescent↗

PubMed1999

Multi-channel cochlear implantation in patients with a post-traumatic sensorineural hearing loss.

There are few accounts of cochlear implantation in adults with post-traumatic sensorineural hearing loss. We report our experience with multichannel implantation in three such patients. Two patients experienced no cognitive or communication deficits as a result of their head injury. At nine months post-implant, compared with our experience of non-head-injured implantees, these patients achieved average or above average scores on audiological performance tests. The third patient presented with cognitive, behavioural and communicative deficits. The level of improvement achieved by this patient, when lip-reading was supplemented with electrical stimulation, in both BKB sentence and connected discourse tracking (CDT) tests was comparable with that of the non-head-injured group. However, his absolute performance at nine months post-implant was well below average. Performance at 18 months on BKB sentences and environmental sound recognition showed little change, and was again well below average, however his score on CDT with lip-reading and electrical stimulation improved considerably and was similar to the average achieved by the non-head-injured group. The major difficulties experienced with this patient were increasing depression and low implant use. Considerably more time was spent in the assessment and rehabilitation of this patient and involved liaison with a number of other agencies. When considering such patients for cochlear implantation it is strongly recommended that these additional requirements are taken into account.

Adult↗

PubMed1993

The postnatal growth of the temporal bone and its implications for cochlear implantation in children.

The postnatal growth of the human temporal bone was examined by direct anatomical measurements on 60 cadaver specimens of all ages. The bones were dissected as one would perform cochlear implant surgery using a posterior tympanotomy approach. Nineteen anatomical/surgical landmarks with implications for cochlear implant surgery were identified on each bone and the distance between these points measured. The temporal bone was found to be a complex structure, phylogenetically, anatomically and functionally consisting of four different parts with independent postnatal development. The inner and middle ears were adult size at birth. The external auditory canal and most parts of the temporal bone were subject to significant lateral growth. The size of the pneumatised mastoid increased in all directions. In the facial recess, however, no postnatal growth was observed. Between birth and adulthood an average of 12 mm (SD 5 mm) of growth was seen directly between the sino-dural angle and the round window, the landmarks approximating the implantation site for the receiver-stimulator and the electrode entry point into the inner ear. However, if an electrode leadwire is fixed at a cortical fixation site such as the posterosuperior point of Macewen's triangle, the leadwire would be subject to approximately 20 mm of growth. These results indicate that a paediatric cochlear implant design incorporating an expandable leadwire to accommodate this growth should allow up to 25 mm of leadwire lengthening. The fossa incudis showed no growth relative to the round window and was found to be a convenient fixation site for the electrode array close to the cochlea. From an anatomical and surgical point of view, cochlear implantation in very young children is feasible, provided the electrode array is secured and the design accommodates for controlled leadwire lengthening.

Adolescent↗

PubMed1991

Radiology for cochlear implants.

One fifth of patients selected for cochlear implants have such bony irregularities in the cochlear duct that full insertion of a multichannel electrode array is impossible. Three cases of cochlear deafness are presented where pre- and post-operative radiology played an important part in the management. Standard CT at 2 mm cuts is compared with ultra high resolution CT at 1 mm cuts. The pitfall of poor definition is that the inexperienced surgeon may find himself unexpectedly drilling out an obliterated cochlear duct. Sections 30 degrees caudal to Reid's infra orbito-meatal base line at 1 mm intervals give maximum information for minimum radiation. Plain films show the placement of individual platinum electrode contacts in relation to the spiral 'frequency map' of the cochlea. This is vital information for the audiologist who has to route specific frequencies to specific sites within the ear for a good hearing result.

Adult↗

PubMed2003

[Benefit of bilateral cochlear implantation on congenital prelingually deafened Chinese-speaking children].

OBJECTIVE: To evaluate the benefit of bilateral cochlear implants (BCIs) in prelingually deafened children on hearing rehabilitation as well as on speech and language development. METHOD: Two cases of congenital profound deaf children, who received unilateral cochlear implantation (CI, MEDEL C40+) on the age of 2 and 7.5, respectively, were performed secondary CI in the contralateral ear on their age of 5 and 9.5, respectively. One year after the secondary CI, the cochlear implant aided hearing threshold and speech discrimination rate were tested for both ears separately and together. The pronounce/speech distinct rate of the BCIs users were evaluated by their parents, surgeon and audiologist. RESULT: In comparison to unilateral aided ear, the mean hearing threshold at the frequency 250-4,000 Hz of the 2 cases with BCIs decreased by 13 dB and 11 dB, respectively. The speech discrimination rate of the BCIs users increased by 9% and 10%, respectively. The speech recognition in noise was improved. And their pronounce/speech distinct was improved. CONCLUSION: BCIs can provide a significant benefit in hearing, speech understanding, language development and pronounce/speech rehabilitation for prelingually deafened children.

Child↗

PubMed1993

Channel interactions in patients using the Ineraid multichannel cochlear implant.

Electrode interactions were investigated on two totally deaf patients fitted with the Ineraid multichannel cochlear implant. Currents were applied to the most apical electrode (the 'perturbation' electrode) and their effects on psychophysical thresholds on the other electrodes (the 'test' electrodes) of the intracochlear array were studied. Two experimental protocols were used. In experiment I, we used a detection protocol to study how the perception of signals presented on each test electrode was affected by subthreshold, simultaneous or non-simultaneous stimulation of the perturbation electrode. Strong electrode interactions were observed with simultaneous stimulation and monotonically decreased as a function of electrode separation. Electrode interactions were weak with non-simultaneous stimulation. In experiment II, we used a discrimination protocol to study how the perception of signals presented on the test electrode was affected by suprathreshold, non-simultaneous stimulation of the perturbation electrode. Subjects could discriminate stimulation of 'perturbation+test' versus 'perturbation alone' when the level of stimulation on the test electrode was near threshold. These results demonstrate that strong electrode interactions in the Ineraid multichannel cochlear implant system are generated by electrical field summation due to simultaneous stimulation of different electrodes, and that one can reduce electrode interactions by sequential activation of the electrodes. These observations might help to understand basic phenomena underlying recent significant improvements in speech recognition scores when switching from simultaneous to interleaved pulsatile stimulation in patients wearing the same cochlear implant system (Wilson et al., 1991).

Adult↗

PubMed2004

Central auditory maturation and babbling development in infants with cochlear implants.

OBJECTIVE: To examine the relationship between the maturation of central auditory pathways and the development of canonical (speechlike) babbling in infants with cochlear implants. DESIGN: Comparison of the latencies of the P1 cortical auditory evoked potential and vocalizations produced by subjects before they were fitted with a cochlear implant and at several time points within the first year after implantation. SUBJECTS: Two congenitally deaf children who were implanted with a multichannel cochlear implant at ages 13 and 14 months. INTERVENTIONS: P1 response latencies were recorded in response to a /ba/ stimulus before implantation and at several time points following implantation. Vocalizations produced by the subjects while interacting with their caregiver were audiorecorded twice before implantation and at monthly sessions following implantation. RESULTS: Subjects showed a rapid decrease in P1 latencies resulting in normal P1 latencies within about 3 months after implantation. Before implantation, the vocalizations were primarily of a precanonical nature. After 3 months' experience with the implants, the proportion of canonical vocalizations increased dramatically relative to the number of precanonical utterances. CONCLUSIONS: Results of this study suggest that the development of P1 response latencies and the development of early communicative behaviors may follow a similar developmental trajectory in children implanted early. Although preliminary, these findings indicate that the development of early communicative behaviors following implantation may be positively influenced by the rate of plastic changes in central auditory pathways.

Auditory Pathways↗

PubMed1987

Surgical anatomy of the round window with special reference to cochlear implantation.

When the multi-channel cochlear implant electrode is inserted into the scala tympani through the round window the operation is best performed via a posterior tympanotomy. The view of the round window membrane, however, is incomplete because of its orientation and the fact that it has a conical shape. Nevertheless, a good view along the basal turn is obtained after the antero-inferior overhang of the round window niche and the crista fenestrae have been removed. It might be damaging to drill away the postero-superior overhang as the osseous spiral lamina lies extremely close to the round window membrane.

Animals↗

PubMedDate not supplied

Surgery for an improved multiple-channel cochlear implant.

An improved multiple-channel cochlear implant has been developed. The titanium container with enclosed electronics, the receiver coil, and the connector are embedded in medical-grade Silastic. The upper half of the implant has a diameter of 35 mm and a height of 4.5 mm, and the lower half a diameter of 23 mm and a height of 5 mm. The electrode array has also been designed to reduce the possibility of breakage due to repeated movements over many years. The surgery involves drilling a bed in the mastoid bone for the receiver-stimulator, and fixing the proximal electrode under the mastoid cortex. Gentle insertion of the electrode array through the round window and along the scala tympani is achieved with a specially designed microclaw .

Cochlear Implants↗

PubMed2004

Enhancing temporal cues to voice pitch in continuous interleaved sampling cochlear implants.

The limited spectral resolution of cochlear implant systems means that voice pitch perception depends on weak temporal envelope cues. Enhancement of such cues was investigated in implant users and in acoustic simulations. Subjects labeled the pitch movement of processed synthetic diphthongal glides. In standard processing, noise carriers (simulations) or pulse trains (implant users) were modulated by 400 Hz low-pass envelopes. In modified processing, carriers were modulated by two components: (1) Slow-rate (<32 Hz) envelope modulations, conveying dynamic spectral shape changes crucial for speech; (2) a simplified waveform (e.g., a sawtooth) matching the periodicity of the input diphthong. In both normal listeners and implant users performance was better with modified processing, though temporal envelope cues were less effective with higher F0. Factors contributing to the advantage for modified processing may include increased modulation depth and use of a modulation waveform featuring a rapid onset in each period, resulting in a clearer representation of F0 in the neural firing pattern. Eliminating slow-rate spectral dynamics, so that within-channel amplitude changes solely reflected F0, showed that dynamic spectral variation obscured temporal pitch cues. Though significant, advantages for modified processing were small, suggesting that the potential for developing strategies delivering enhanced pitch perception is limited.

Acoustic Stimulation↗

PubMed2002

Modiolar proximity of three perimodiolar cochlear implant electrodes.

A new generation of cochlear implant electrodes has been designed to position the stimulating contacts close to the modiolus in order to reduce power consumption and increase stimulation selectivity. The purpose of this study was to assess electrode position in the cochlea for three recently designed electrodes. Fifteen cadaveric temporal bones were implanted with one of three perimodiolar electrode arrays: Nucleus Contour; Med-El Combi40+ PM (developmental version); and Clarion HiFocus II. Image-enhanced videofluoroscopy and computer morphometrics were used to assess stimulating contact position relative to the modiolus. The mean distance (+/- 1 standard deviation) to the modiolus for all electrode contacts was 0.33 (+/-0.24), 0.30 (+/-0.27) and 0.16 mm (+/-0.19) for the Contour, Combi40+ PM and HiFocus II arrays, respectively. In addition, dynamic videofluoroscopy was used to correlate device-specific insertion characteristics with contact-to-modiolus distance. All three devices were successful in terms of locating electrode contacts very close to the modiolar wall.

Adult↗

PubMed2005

Development of audiovisual comprehension skills in prelingually deaf children with cochlear implants.

OBJECTIVE: The present study investigated the development of audiovisual comprehension skills in prelingually deaf children who received cochlear implants. DESIGN: We analyzed results obtained with the Common Phrases (Robbins et al., 1995) test of sentence comprehension from 80 prelingually deaf children with cochlear implants who were enrolled in a longitudinal study, from pre-implantation to 5 years after implantation. RESULTS: The results revealed that prelingually deaf children with cochlear implants performed better under audiovisual (AV) presentation compared with auditory-alone (A-alone) or visual-alone (V-alone) conditions. AV sentence comprehension skills were found to be strongly correlated with several clinical outcome measures of speech perception, speech intelligibility, and language. Finally, pre-implantation V-alone performance on the Common Phrases test was strongly correlated with 3-year postimplantation performance on clinical outcome measures of speech perception, speech intelligibility, and language skills. CONCLUSIONS: The results suggest that lipreading skills and AV speech perception reflect a common source of variance associated with the development of phonological processing skills that is shared among a wide range of speech and language outcome measures.

Auditory Perception↗

PubMed2001

Speech perception and functional benefit after multichannel cochlear implantation.

This study was done to investigate the effect of a multichannel cochlear implant on speech perception and the functional benefit of cochlear implantation in Finnish-speaking postlingually deafened adults. Fourteen subjects were enrolled. Sentence and word recognition were studied with open-set tests auditorily only. One year after implantation, the listening performance was assessed by case histories and interviews. Before implantation for subjects with a hearing aid, the mean recognition score was 38% for sentences and 17% for words. One year after switching on the implant, the mean recognition score was 84% for sentences and 70% for words. Before implantation, the majority of the subjects were not aware of environmental sounds and only a few were able to recognize some environmental sounds. One year after switching on the implant, the majority of the subjects were able to use the telephone with a familiar speaker. All the subjects were able to recognize speech auditorily only and had thus gained good functional benefit from the implant.

Acoustic Stimulation↗

PubMed1989

Prognosticating speech performance in multichannel cochlear implant patients.

Twenty patients received multichannel cochlear implants between April 1984 and May 1986 at the University of Utah Medical Center. All patients have been followed for at least 1 year postimplant. Preimplant screening included audiometric testing, electronystagmogram (ENG), promontory stimulation, computed tomography (CT) scanning, and psychological evaluation. Based on postimplant audio-only CID sentence discrimination scores, these patients were divided into three groups: good (CID greater than 79%), intermediate (CID, 21% to 79%), and poor (CID less than 21%). Preimplant factors that correlated with CID scores were hearing loss duration, previous use of hearing aids, lip-reading ability, tinnitus, positive ENG calorics, preimplant pure-tone average, promontory stimulation threshold, and understanding of the project. Only previous hearing aid usage approached statistical significance (p = 0.05). A larger patient sample is needed to verify these results.

Adult↗

PubMed1989

Statistical procedure for the preoperative prediction of the result of cochlear implantation.

Predicting the result of a cochlear implant preoperatively continues to be the best way to prevent an unfavourable outcome. Data from 28 cases (subdivided into two groups by their results) formed the basis for discriminant analysis using different parameters. Allocation to the two groups was found to be satisfactory. Since a jack-knifed design was used, allocation was done on the basis of data material from cases not included in this programme's analysis. Data correlation was described by an equation from which the result can be predicted with adequate accuracy using language competence, duration of deafness on the operated side, speech discrimination and threshold of acoustical sensations on promontory electrostimulation. The equation is applicable to all patients, irrespective of whether their deafness is prelingual or postlingual. Since the patient material was enlarged by 19 additional cases, we were able to confirm that the formula enables a prognosis of sufficient quality.

Adolescent↗

PubMed2003

Neuropsychological testing in the screening for cochlear implant candidacy.

OBJECTIVE: To demonstrate the utility of neuropsychological assessment in the screening process for pediatric cochlear implant candidacy. STUDY DESIGN: Prospective and ongoing evaluation of children with profound bilateral hearing loss using age-specific neuropsychological test batteries. METHODS: Eighteen children who met audiological criteria for cochlear implantation were evaluated by two age-specific neuropsychological tests. The Vineland Adaptive Behavior Scales survey assesses several domains of behavioral functions (communication, daily living skills, socialization, and gross motor skills). The Mullen Scales of Early Learning assesses the child's visual perception, speech and language, and motor abilities. The Leiter International Performance Scale-Revised assesses intellectual ability. RESULTS: All patients underwent the Vineland Adaptive Behavior Scales survey. Overall scores were lower than normative means with a mean composite score in the 7th percentile. In addition, there was a strong inverse correlation between score and age of testing. Ten children were assessed using the Mullen Scales of Early Learning, and, again, there was a strong inverse correlation between score and age of testing. Intellectual ability was assessed in seven children using the Leiter International Performance Scale-Revised and was found to be lower than normative means with a mean score in the 13th percentile. CONCLUSIONS: Neuropsychological testing of profoundly deaf children provides a detailed and accurate assessment of the child's cognitive, behavioral, and motor functions. The profoundly deaf child does not develop at the same rate as normal children in cognitive and behavioral domains. Neuropsychological testing is a useful tool for screening for cochlear implant candidacy and has the potential to track changes before and after implantation.

Adaptation, Psychological↗

PubMed1993

Multichannel cochlear implantation in the rehabilitation of post-traumatic sensorineural hearing loss.

Although there is a 17% to 56% incidence of sensorineural hearing loss following head injury, to our knowledge cochlear implants have not been used in treatment of this problem in patients with cognitive deficits and aphasia. We report our experience with multichannel cochlear implantation in one such patient. The patient is a 26-year-old man with bitemporal lobe damage and T-11 paraplegia. The clinical profile showed emotional lability, perseveration of thought, impulsivity, good visuospatial orientation, and adequate use of oral and written language in conveying basic needs. Audiologic evaluation showed profound sensorineural hearing loss. Middle latency responses suggested intact thalamocortical pathways. The patient was provided with a multichannel cochlear implant with improvement in his speech recognition and functional skills. We conclude that the cochlear implant should be considered in patients with traumatic sensorineural hearing loss with relatively intact cognitive skills.

Adult↗

PubMed2001

Changes in speech intelligibility of postlingually deaf adults after cochlear implantation.

OBJECTIVE: This study examines changes in the intelligibility of CVC words spoken by postlingually deafened adults after they have had 6 to 12 mo of experience with a cochlear implant. The hypothesis guiding the research is that the intelligibility of these speakers will improve after extended use of a cochlear implant. The paper also describes changes in CVC word intelligibility analyzed by phoneme class and by features. DESIGN: The speech of eight postlingually deaf adults was recorded before activation of the speech processors of their cochlear implants and at 6 mo and 1 yr after activation. Seventeen listeners with no known impairment of hearing completed a word identification task while listening to each implant user's speech in noise. The percent information transmitted by the speakers in their pre- and postactivation recordings was measured for 11 English consonants and eight vowels separately. RESULTS: An overall improvement in word intelligibility was observed: seven of the eight speakers showed improvement in vowel intelligibility and six speakers showed improvement in consonant intelligibility. However, the intelligibility of specific consonant and vowel features varied greatly across speakers. CONCLUSIONS: Extended use of a cochlear implant by postlingually deafened adults tends to enhance their intelligibility.

Aged↗