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PubMed2003

Productivity of lexical categories in French-speaking children with cochlear implants.

The productivity of lexical categories was studied longitudinally in a sample of 17 young hearing-impaired French-speaking children with cochlear implants. Age of implantation ranged from 22 months to 76 months. Spontaneous speech samples were collected at six-month intervals over a period of 36 months, starting at the one-word stage. Four general measures of their linguistic production (number of utterances, verbal fluency, vocabulary, and grammatical production) as well as 36 specific lexical categories, according to the CHILDES codes, were computed in terms of tokens, i.e., total number of words. Cochlear-implanted children (CI) were compared to a French database of normally hearing children aged 2-4 compiled by the first author. Follow-up results indicate that, at the two-year post-implantation follow-up, noun, and verb morphology was significantly impaired. At the three-year follow-up, the cochlear-implanted group had recovered on adjectives, determiners and nouns, main verbs, and auxiliaries. The two groups differed significantly in processing locative adverbs, prepositions, pronouns, and verbs (infinitive verb, modal, and modal lexical), but individual variability within the cochlear-implanted group was substantial. Results are discussed in terms of recovery and developmental trends and variability in the acquisition of lexical categories by French children two years and three years post-implantation.

Child↗

PubMed2004

Cortical activation shortly after cochlear implantation.

We evaluated the cortical activations in postlingually deaf cochlear implant (CI) users in the early period (0-2 months) of CI usage. The subjects were 8 early CI users and 8 normal subjects. With tone burst stimuli (1 kHz) delivered to the right side, strong and broad activation of the ipsilateral (right) primary auditory cortex with 2 peaks and weaker activation of the contralateral (left) temporal lobe were observed in early CI users, in a clear contrast with the normal subjects in whom activation was observed in a small area of the contralateral (left) primary cortex. With word stimuli, activation of the superior frontomedian cortex presumably including the supplementary motor area and the neighboring cingulate gyri was observed in early CI users, which was absent in normal subjects. The activation in the immediate association cortices near the primary area was lower in early CI users, while the periphery of the association cortex seemed to be more mobilized.

Acoustic Stimulation↗

PubMed2003

Children's consonant inventories after extended cochlear implant use.

Qualitative descriptions of the consonant inventories of 12 children who have used cochlear implants for at least 5 years are provided, together with description of sound correspondences between children's systems and the ambient language (English). Productions of English words were elicited in a picture-naming task, and a consonant inventory for each child was determined. Results showed that the consonant inventories of children who use cochlear implants are not simply subsets of the inventory of the ambient language, but rather unique sets of segments that may include consonants not in the ambient inventory. Comparison of the inventories of oral communication users and total communication users revealed qualitative differences between the 2 groups, based on the presence or absence of both English and non-English sound segments. Inventories of oral communication users tended to contain more English segments (e.g., alveolar fricatives, velar stops, velar nasals) than did the inventories of total communication users. Conversely, specific non-English segments, such as uvular stops, tended to occur in the inventories of total communication users more than in inventories of oral communication users. Therefore, a complete understanding of the phonological systems of children who use cochlear implants depends on full accounts of their segment inventories. Such understanding may affect decisions regarding habilitation procedures, insofar as successful acquisition of a linguistic system involves not only the inclusion of all ambient sound segments, but also the exclusion of all nonambient ones.

Adolescent↗

PubMed2005

[Speech perception learning in patients with cochlear implants].

A model of speech apprehensibility of postlingual patients after cochlear implantation has been developed. The study of filtrated speech comprehension by persons with normal hearing has used speech material in three 50 Hz spectral bands. The central frequencies were selected by tonotopics of the basilar cochlear membrane. Characteristics of speech comprehension and apprehensibility by recipients of cochlear implants are demonstrated. The model reveals problems of acoustic comprehension facing the implanted patients and shows importance of learning and personality features of the implanted patients for early rehabilitation.

Cochlear Implantation↗

PubMed1997

Assessment of electrostimulation in children supplied with cochlear implants.

OBJECTIVE: In children supplied with cochlear implants (CIs), there is an urgent need for objective tests for the assessment of electrostimulation. SETTING: An optimized procedure for intraoperative and post-operative applications with short duration test time, based on the measurement of the electrical farfield picked up from surface electrodes on the scalp, is presented; therefore, assessment of stimulation is independent of the stimulating electronic circuitry. OUTCOME: The setup was designed for the COMBI40 multichannel CI using a synchronized sampling technique of the amplified signals. The evaluation procedure includes examination of the time course of the signal and calculation of the input output function. With these options, a straightforward judgment of the electrical performance of the implant in situ, reflecting the input to the auditory nerve, is provided.

Child↗

PubMed1998

[Cochlear implants. Prosthetic management of deafness at the turn of the century].

In recent years the cochlear implant has become an established method for rehabilitation of bilateral sensory deafness in adults and children. Intracochlear multichannel stimulation with sophisticated speech coding strategies has proved to be reliable and safe enough for use in adults as well as young children; thus, a few cochlear implant systems with different specifications are currently available. The differences in their hardware and software are discussed. Furthermore, the current indications for cochlear implants in patients whose hearing is severely impaired and important aspects of the preoperative evaluation are presented with special emphasis on difficult cases such as deformities, multihandicapped subjects and very young children. Our results after 12 years of experience and more than 700 implantations suggest that the most important prognostic factor is the duration of deafness.

Adult↗

PubMed1986

Electrically evoked potentials in cochlear implant subjects.

A series of experiments was performed to study electrically evoked potentials as indicators of subject response to cochlear implantation. 1. Brain stem evoked responses to electrical stimulation were compared to those obtained by acoustic stimulation in guinea pigs. The response pattern was similar and was independent of the site of placement of the stimulus electrode (cochlear base or apex) or of the extracochlear ground electrode (eustachian tube or temporalis muscle) when evoked electrically. 2. Electrically evoked middle latency responses were recorded and compared to subjective behavioral thresholds in patients who had received a single channel cochlear implant (House-Urban). The behavioral responses to the same stimuli were similar. 3. Electrically evoked auditory brain stem responses were studied in single channel cochlear implant subjects (3M/House). When evoked electrically, potential latencies were shorter and interpeak intervals narrower than acoustically evoked potentials.

Acoustic Stimulation↗

PubMedDate not supplied

Veria operation updated. I. The trans-canal wall cochlear implantation.

The Veria operation is a non-mastoidectomy technique for cochlear implantation. It uses the transcanal approach to the middle ear and the cochlea. The steps of the procedure are: (1) endaural approach, that offers a wide accessibility to the middle ear structures; (2) inspection of the middle ear anatomy; (3) straightening of the postero-superior bony canal wall, which is usually concave; (4) performing the cochleostomy through the outer ear canal; (5) drilling of the suprameatal hollow, which is used for the accommodation of the electrode excess; (6) drilling of the trans-wall direct tunnel, which is the pathway for the active electrode; (7) alignment of the direct tunnel to the cochleostomy; (8) extension of the incision and preparing of the flaps; (9) creating of the bed and fixing the device; (10) insertion of the electrodes; (11) manipulating the excess of the active electrode, and (12) closing. For this technique, two special instruments have been developed: a special perforator used for the drilling of the direct tunnel for the active electrode, making it completely safe, and a safety electrode forceps used to manipulate the active electrode during insertion. The direct tunnel can be enlarged superiorly permitting insertion of two electrodes, in cases where a double electrode array implant has to be used. The method is an efficient tool for handling all cochlear implant cases, including difficult ones such as revision cases, malformations, cochlear ossifications and poor mastoid development. It is safe without complications in over a hundred cases and easy to learn.

Cochlear Implantation↗

PubMed2005

Effects of cytomegalovirus (CMV) related deafness on pediatric cochlear implant outcomes.

OBJECTIVE: Human cytomegalovirus (CMV) is a commonly recognized viral cause of perinatal sensorineural hearing loss. CMV-infected infants are also at risk for developmental neurological deficits. This retrospective study assesses the impact of CMV-induced deafness on pediatric cochlear implant outcomes. STUDY DESIGN AND SETTING: Thirteen patients from the Johns Hopkins pediatric cochlear implant database were identified with CMV-related deafness. A retrospective review of the medical records of the Johns Hopkins Hospital was performed. RESULTS: The mean age at implantation was 5.6 years. Follow-up audiometric data ranged from 6 to 48 months postoperatively. Mean speech perception scores were 4.5 (out of 6) following implantation. CONCLUSION: We have shown that cochlear implants can provide useful speech comprehension to patients with CMV-related deafness. Speech recognition scores were within the range established by our overall pediatric implant population. SIGNIFICANCE: This observation underscores the importance of a multidisciplinary rehabilitation program following implantation in these patients at risk for cognitive delay.

Antibodies, Viral↗

PubMed1986

Long-term effects of multichannel cochlear implant usage.

A major concern regarding multichannel (multi-electrode) cochlear prosthesis usage has been the possibility of long-term deleterious physiological effects such as the degeneration of spiral ganglion cells, neuronal degeneration, and new bone formation. These effects, if present, would become evident in the deterioration of hearing sensation and performance of the cochlear implant recipient on a battery of audiologic tests. To date, five patients using the Australian multi-electrode multichannel cochlear implant have undergone a 1-year evaluation of the device. The assessment includes a check of electrical threshold and comfort levels for each electrode, sound field pure tone and speech thresholds, the MAC battery, vowel and consonant recognition tests, and speech tracking tasks. All results were compared to those obtained postoperatively following stimulation and a 3-month training period. Results to date have shown no deterioration in implant functioning in all patients tested. Periodic extensive monitoring of all implant recipients is advocated in order to evaluate the possibility of long-term effects.

Audiometry, Pure-Tone↗

PubMed2003

[Binaural advantage on usage of hearing aid together with cochlear implant--examination on speech perception (Japanese monosyllable word list 67-S and Japanese HINT)].

Six cochlear implant recipients with hearing aids in the opposite ear were studied to survey binaural advantage. They were examined in separate tests by using a hearing aid alone, cochlear implant alone, and by using both devices (bimodal condition). Test items used were the Japanese monosyllable word list 67--S and Japanese HINT. Statistically significantly results were obtained in the bimodal condition, three out of six subjects were successful in the monosyllable word test and all successful in the Japanese HINT. We conclude that all subjects enjoyed binaural advantage in speech perception in bimodal condition with no conflict at the recognition level; even when different sounds from cochlear implant and contralateral hearing aid were received. The plasticity of the brain is thought to be of importance in the bimodal condition.

Aged↗

PubMed1999

[Complications of cochlear implant surgery in children and adults].

BACKGROUND: In a retrospective analysis we evaluated the complication rate in 697 patients after cochlear implantation between 1985 and 1995 (366 children, 331 adults; 604 Nucleus, 50 Clarion and 42 other implants). RESULTS: Intraoperatively in 74 cases (10.6%) total or partial cochlear obliteration was found, a CSF gusher occurred in 7 cases. Minor complications such as seroma (8 adults), wound infections (14 patients), emphysema, and swelling were successfully treated with conservative methods and drugs. Seven (2.1%) adults showed facial nerve palsy postoperatively with incomplete recovery only in 2 of them (0.6%). No permanent facial nerve palsy was observed in children. Cholesteatoma developed in 18 adults (5.4%), which was treated by revision surgery. CONCLUSIONS: In conclusion, cochlear implant surgery is a safe procedure with a low complication rate. However, Cochlear implantation should be performed by well experienced ear surgeons who can properly handle intraoperative and postoperative problems. The patients should be informed about the typical risks of ear surgery including implant removal due to infection or technical defects, facial nerve palsy, vertigo and, especially in adults, increased tinnitus.

Adolescent↗

PubMedDate not supplied

Audiological results with the cochlear implant.

Audiological test results from 135 adult, profoundly deaf, single-electrode cochlear implant subjects are presented. Unaided, aided, and cochlear implant warble-tone and speech detection thresholds have been analyzed, as well as word, word stress, and environmental sound discrimination scores. Results indicate that implant thresholds are significantly better than aided thresholds at all frequencies tested and for speech detection. Also, word, word stress, and environmental sound discrimination scores are all significantly better with the implant than with a hearing aid. Although the implant does not provide speech discrimination, subjects report that it does provide valuable speech and sound awareness, which aids in speechreading and voice monitoring. A small group of subjects has shown that an an implant in the poorer ear can also be successfully combined with a hearing aid in the better ear. The audiological test results clearly show that the implant is a viable alternative for the profoundly deaf.

Adolescent↗

PubMed1997

Facial nerve stimulation after Nucleus 22-channel cochlear implantation.

OBJECTIVE: To review the clinical features, radiographic findings, and programming strategies used in our population of patients who developed facial nerve stimulation after cochlear implantation. STUDY DESIGN AND SETTING: Patients referred to our nonprofit, outpatient facility were studied prospectively. PATIENTS: The study consisted of 14 patients with facial nerve stimulation after placement of the Nucleus 22-channel cochlear implant. INTERVENTIONS: Records were reviewed retrospectively, and patients were studied with three-dimensional computed tomographic scanning techniques. Electrical testing was performed, and various cochlear implant programming strategies were evaluated. MAIN OUTCOME MEASURES: Important clinical features were reviewed. The radiographic and anatomical relationships of the facial nerve to the cochlea were evaluated, and the programming strategies used to effectively control facial nerve stimulation were reviewed. RESULTS: Prevalence of facial nerve stimulation in our population was 7%. The most common cause was otosclerosis. Anatomical data confirmed the close proximity of the basal turn of the cochlea and the labyrinthine segment of the facial nerve. There was a high correlation between the electrodes causing symptoms and those found radiographically to be closest to the labyrinthine segment of the facial nerve. We were able to control facial nerve stimulation in all patients through programming mode changes. CONCLUSIONS: Otosclerosis appears to be a risk factor for developing facial nerve stimulation after cochlear implantation, and the site of stimulation appears to be the labyrinthine segment of the facial nerve. Familiarity with more elaborate programming techniques is critical to managing patients with this complication.

Adult↗

PubMed1984

Initial Iowa results with the multichannel cochlear implant from Melbourne.

Two subjects who use the Melbourne multichannel cochlear implant were studied. Live-voice word, consonant, and vowel recognition tests, and a speech-tracking task were administered at regular intervals during the first 90 days after implantation. Results indicated 30-50% correct recognition of vowels (given 9 alternatives) and about 30-60% correct recognition of consonants (given 12 alternatives). Speech tracking showed from two to three times faster rates with the implant and vision compared to a vision-alone condition. After 3-4 months of implant experience, a number of recorded tests from the Minimal Auditory Capabilities battery and the Iowa Cochlear-Implant tests were then administered. These results indicated about 80% recognition of everyday sounds in a five-choice closed-set condition and about 50% recognition of everyday sounds in an open-set condition. The subjects were 50% correct at identifying the accented words in a sentence and about 50% correct at determining the number of syllables in a word. One subject was unable to recognize a sentence as a statement or a question. Background noise (+10 dB S/N) reduced their performance on a four-choice spondee test to chance. Both subjects were able to identify a sound as either a voice or a modulated noise at 95% correct, and both could recognize speaker sex at 95% correct. Neither could discriminate whether two (successive) sentences were spoken by the same speaker or by two different speakers. Remarkably, one subject identified 45% and the other 85% of the words in sentences that were preceded by a contextual picture using sound alone. One subject identified 13% of the words in sentences in sound alone even without contextual information.

Adult↗

PubMed1995

Cochlear implants in chronic suppurative otitis media.

Chronic suppurative otitis media (CSOM) in profoundly deaf patients is a contraindication for cochlear implantation. Eight (6%) of the 126 patients referred to cochlear implantation at this center between 1986 and 1992 became deafened as a result of bilateral CSOM but were otherwise suitable candidates. This study details the methods used in four patients to prepare the septic ear for a sterile device. Two patients had wet radical cavities with residual cholesteatoma, and two had discharging safe perforations resistant to surgical repair. Obliteration of the middle ear cleft with blind pit closure of the ear canal was attempted in all four patients, and cochlear implants were installed at a second operation 3 to 6 months later. The hearing results were as good as in implanted patients without CSOM, and the only complication has been the finding of a cholesteatoma pearl at the second operation in one patient. Fat obliteration of the mastoid and middle ear with blind pit closure of the ear canal can be adapted to make most chronic ears fit for implantation, if the patient is prepared to undergo two operations.

Aged↗

PubMed2006

Auditory stream segregation with cochlear implants: A preliminary report.

Auditory stream segregation was measured in cochlear implant (CI) listeners using a subjective "Yes-No" task in which listeners indicated whether a sequence of stimuli was perceived as two separate streams or not. Stimuli were brief, 50-ms pulse trains A and B, presented in an A_B_A_A_B_A... sequence, with 50 ms in between consecutive stimuli. All stimuli were carefully loudness-balanced prior to the experiments. The cochlear electrode location of A was fixed, while the location of B was varied systematically. Measures of electrode discrimination and subjective perceptual difference were also included for comparison. There was strong intersubject variation in the pattern of results. One of the participants participated in a second series of experiments, the results of which indicated that he was able to perceptually segregate stimuli that were different in cochlear electrode location, as well as stimuli that were different in temporal envelope. Although preliminary, these results suggest that it is possible for some cochlear implant listeners to perceptually segregate stimuli based on differences in cochlear location as well as temporal envelope.

Acoustic Stimulation↗

PubMed2004

Labyrinth dysfunction 8 months after cochlear implantation: a case report.

OBJECTIVE: Investigate whether the cochleostomy is a possible port of entry for pneumolabyrinth and a resulting vertigo in patients provided with a cochlear implant. STUDY DESIGN: Retrospective case review. SETTING: Ludwig-Maximilians University of Munich, Hospital Grosshadern. PATIENT: 62-year-old patient who underwent implantation of a HiFocus II cochlear implant with positioner from Advanced Bionics (CLARION). Eight months postoperatively, the patient reported rotatory vertigo and right-side tinnitus after he had blown his nose harder than usual during an episode of rhinitis. INTERVENTIONS: Preoperative and postoperative testing of both the petrosal bone with a CT scan and of balance function. MAIN OUTCOME MEASURE: Air inclusion in the labyrinth. RESULTS: In contrast to the preoperative high resolution computed tomography (CT) scan, air inclusion was seen in the labyrinth during the episode of vertigo. At the same time, balance function tests with Frenzel glasses revealed both spontaneous and provoked horizontal nystagmus to the right side. At follow-up 8 weeks later, the level of vertigo had significantly decreased. Twelve months later, the control CT showed the cochlear implant positioned correctly and no visible air in the labyrinth. CONCLUSION: It is known that placement of the HiFocus II with Positioner from CLARION requires a relatively large cochleostomy of 1.5 mm. Moreover, in the connective tissue seal between the electrode and the positioner, the latter reaches into the tympanic cavity, and this is possibly the weak point. Further investigation will be needed to determine whether the large cochleostomy with the HiFocus II with positioner increases the predisposition to labyrinth dysfunction.

Cochlear Implantation↗