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At least 199 records · Page 11Linked to original sources
PubMed2004

Conservation of low-frequency hearing in cochlear implantation.

OBJECTIVES: As results with cochlear implants have continued to improve, patients with some remaining cochlear function have become eligible for cochlear implantation. Thus, preservation of acoustic hearing after implantation has gained importance. Hearing preservation can be considered a benchmark for atraumatic implantation preventing neural degeneration from loss of residual hair cells or subsequent to local trauma. In this prospective study, the possibility of preserving low-frequency hearing in cochlear implantation using a modified surgical technique has been explored. MATERIAL AND METHODS: In a prospective study design, 14 subjects with considerable low-frequency hearing of 20-60 dB in the frequency range 125-500 Hz but with unsatisfactory speech understanding with hearing aids of < 35% monosyllabic word understanding were implanted with a MED-EL COMBI-40+ cochlear implant. The insertion depth was intentionally limited to 19-24 mm to prevent damage to low-frequency regions of the cochlea. Pre- and postoperative pure-tone thresholds were measured. RESULTS: Hearing was conserved within 0-10 dB in 9/14 subjects and within 11-20 dB in 3/14; in 2/14 subjects hearing was completely lost in the implanted ear. Thus hearing could at least partially be conserved in 12/14 subjects (86%). Median threshold values decreased by 10, 15, 17.5 and 5 dB at 125, 250, 500 and 1000 Hz, respectively. Even high levels of hearing, e.g. 30 dB at 500 Hz, could be maintained after implantation in some subjects. CONCLUSIONS: This study reports successful conservation of hearing after cochlear implantation using a modified surgical technique. Even high levels of hearing could be maintained, showing that implantation of an intracochlear electrode can be performed atraumatically with preservation of functional structures.

Adult↗
PubMed1991

A case study of a 4-year-old perilingual deaf child implanted with an Ineraid multichannel cochlear implant.

In August 1989, we implanted the first young (age 2-4) perilingual deaf child with the Ineraid multichannel cochlear implant. The child experienced sudden deafness at the age of 3 years 9 months. The time lapse between the onset of deafness and the implantation of the electrode array was only 4 months, but during that time the child completely stopped talking. Electrically evoked auditory brainstem responses were used for diagnosis and follow-up.

Child, Preschool↗
PubMed2004

Complications following adult cochlear implantation: experience in Manchester.

Cochlear implantation is regarded as a safe and effective treatment for the profoundly deaf. However, a proportion of patients suffer complications after implant surgery. This paper examines the complications encountered in 240 adult cochlear implant operations performed in Manchester between June 1988 and June 2002. Minor complications were defined as those that either settled spontaneously or with conservative management. The total number of minor complications was 61 (25.4 per cent of cases). Non-auditory stimulation, which resolved with implant reprogramming, was present in 53 cases (22.1 per cent). Major complications were defined as those requiring further surgery, explantation or causing a significant medical problem, and occurred in 15 patients (6.25 per cent). These included implant extrusion, implant sepsis, electrode migration, flap-related problems, and persistent non-auditory stimulation. Nine of the 15 patients suffering a major complication required explantation. There were no post-operative deaths, cases of meningitis, nor persistent facial palsies in the series.

Adolescent↗
PubMed1993

Evaluation of expandable leadwires for pediatric cochlear implants.

The development of cochlear implants for use in very young children (1-2 years old) will require techniques designed to accommodate temporal bone growth. Previous anatomic studies have shown that the leadwire of a cochlear implant must be capable of expanding up to 20 mm between the round window and the implanted receiver-stimulator in response to skull growth. In the present study morphologic and biomechanical evaluation of five expandable leadwire designs was conducted following their implantation in young cats. Two helical shaped leadwire designs frequently exhibited extensive fibrous tissue adhesions and broke during long-term implantation. In contrast, thin, flexible Silastic envelopes were effective in minimizing tissue adhesions. Residual V- and Z-shaped leadwires, placed in these envelopes, showed little evidence of fibrous tissue adhesions following implantation periods of up to 2 years. Moreover, these leadwires readily expanded both during the growth of the animal and when biomechanical expansion studies performed at the completion of the implant period. These expandable leadwire designs appear to be appropriate candidates for use in pediatric cochlear implants.

Animals↗
PubMed2003

Neural response telemetry in cochlear implant users.

Programming of multichannel cochlear implants requires subjective responses to a series of sophisticated psychophysical percepts. It is often difficult for cochlear implant patients (especially young prelinguistically deaf children) to provide adequate responses for device fitting. However, the neural response telemetry (NRT) system renders possible the measurement of the compound action potential threshold. We performed NRT examinations in 27 cochlear implant users with Nucleus 24-channel cochlear implants. Measurements were obtained from five electrodes (3, 5, 10, 15, and 20) in each patient. Our goal was to look for correlation between behavioral subjective thresholds and compound action potentials. The action potentials could be elicited in 23 patients in all measured electrodes. The NRT threshold values were highly correlated with electrical threshold levels obtained through subjective responses. Our results suggest that the electrically elicited neural responses may yield very important information for device fitting in patients with cochlear implants.

Child↗
PubMed2005

[Voice analysis in pre-lingual cochlear implant adults].

OBJECTIVE: To observe voice characteristic of pre-lingual cochlear implant adults for cochlear implantation and phoniatrics. METHODS: 3s-sustained voice of vowel [ a: ] of 28 pre-lingual cochlear implant adults, 18 pre-lingual deafness adults and 10 adults with normal hearing were analyzed. Specifically, the Voice analyses include fundamental frequency, first formant, second formant, frequency perturbation quotient (FPQ), amplitude perturbation quotient (APQ) and harmonic noise ratio (HNR). The outcomes of 3 groups were compared. RESULTS: The fundamental frequency was lower in cochlear implant group [(175.42+/-25. 31) Hz] than that in deafness group [(210.84+/-54.300) Hz] (P = 0.02). The position of formant of cochlear implant group [F2 = (1264. 64 +/- 152.19) Hz] was more access to normal than that of normal hearing group[ F2 = (1422.44 +/- 232. 37) Hz, P = 0. 02]. FPQ of cochlear implant group (2.09 +/- 1.15) was more access to normal than that of deafness group (5.32+/-4.29, P=0.006). The voice of cochlear implanted and deafness adults were much more different individually. CONCLUSIONS: In the aspect of acoustic characteristic of voice, pre-lingual cochlear implant adults could benefit cochlear implantation finitely. As speech perception of pre-lingual cochlear implant adults was far worse than that of children and post-lingual cochlear implant adults, the general outcome of pre-lingual cochlear implant adults was very limited. Cochlear implant of those candidate should be cautious.

Adolescent↗
PubMed2001

Management of far advanced otosclerosis in the era of cochlear implantation.

OBJECTIVE: To evaluate issues pertaining to cochlear implantation in patients with far advanced cochlear otosclerosis. STUDY DESIGN: Prospective cohort. SETTING: Tertiary care referral center. PATIENTS: Eight adult patients (18 years of age or older) referred for management of profound hearing loss, the cause of which was determined to be otosclerosis. INTERVENTION: Cochlear implantation with multichannel cochlear implant device. MAIN OUTCOME MEASURES: Benefit from cochlear implant as measured by CID sentence scores, incidence and management of facial nerve stimulation, and technical issues pertaining to cochlear implantation in this patient population. RESULTS: All patients demonstrated significant improvement in auditory function as measured by performance on CID sentence scores and ability to engage in telephone conversation. Facial nerve stimulation was present in two of eight patients and was managed with deactivation of the stimulating electrodes. Ossification in the basal turn of the cochlea, detected on preoperative computed tomography, necessitated placement of the electrode into the scala vestibuli in two patients and use of a thinner electrode (Nucleus 24) in a third patient. CONCLUSION: Patients with profound hearing loss secondary to otosclerosis derive excellent benefits from cochlear implantation. Surgical implantation may be complicated by ossification of the cochlea, which can be detected on preoperative computed tomography. Electrode activation may be complicated by facial nerve stimulation, which can be addressed with programming strategies.

Adolescent↗
PubMed2006

Cochlear implantation in psoriasis patients.

Cochlear implantation has become a safe and effective method for the auditory rehabilitation of severe to profound sensorineural hearing loss. Flap problems are the commonest of the surgical complications [Axon PR, Mawman DJ, Upile T, Ramsden RT. Cochlear implantation in the presence of chronic suppurative otitis media. J Laryngol Otology 1997;111:228-32] and the risk increases further when associated with medical conditions predisposing to infection. We present two patients with psoriasis who underwent cochlear implant surgery, discussing the risk of surgical site infection and treatment options to minimise infection.

Adult↗
PubMed1999

Positioning of the receiver-stimulator for the CI-24M cochlear implant in infants.

A new cochlear implant (CI-24M) has recently been released by Cochlear Ltd. The shape and size of the receiver-stimulator differs from that of the CI-22M. Infants as young as one year of age are now receiving cochlear implants. We have examined the likely effect of skull growth following the implantation of a CI-24M cochlear implant in an infant of this age.

Child↗
PubMed2003

Speech recognition in elderly cochlear implant recipients.

The benefits of cochlear implantation in the adult and paediatric populations are well established. Cochlear implantation in the geriatric population still remains controversial because of the misconception that elderly patients might perform poorly. The purpose of this study was to report the speech performance of 16 patients over 65 years of age implanted with a Nucleus multichannel cochlear implant and to compare it with that of a control group of 14 adults aged between 41 and 59 years. At the 12 months postoperative evaluation, no significant differences were detected on speech performances between the elderly patients and the control group. The mean word recognition scores were 72.5% for the elderly group and 82% for the control group. The mean everyday sentence recognition scores were 72.5% for the elderly group and 85.7% for the control group. Overall, the results are encouraging and demonstrate that the elderly population with profound hearing loss obtain significant benefits from cochlear implantation despite the age-related auditory processing problems.

Adult↗
PubMed2006

Brain plasticity under cochlear implant stimulation.

The benefit of cochlear implantation crucially depends on the ability of the brain to learn to classify neural activity evoked by the cochlear implant. Brain plasticity is a complex property with massive developmental changes after birth. The present paper reviews the experimental work on auditory plasticity and focuses on the plasticity required for adaptation to cochlear implant stimulation. It reviews the data on developmental sensitive periods in auditory plasticity of hearing, hearing-impaired and deaf, cochlear-implanted, animals. Based on the analysis of the above findings in animals and comparable data from humans, a cochlear implantation within the first 2 years of age is recommended.

Animals↗
PubMed2000

Benefits of cochlear implantation in elderly patients.

Cochlear implantation in elderly patients is a questionable subject. The purpose of this study was to evaluate the procedure and its outcome, the postoperative course, and the audiologic and social benefits of cochlear implantation in this population. Twenty-seven patients older than 60 years were compared with a control group of 15 adult patients. This retrospective study analyzed data concerning the outcome of the procedure, postoperative course, postoperative orthophonic test results, and answers of a questionnaire assessing the changes in communication, perception, and social outcomes. The procedure was uneventful in both groups. Minor complications were not more frequent in elderly patients. Orthophonic test results were comparable in both groups. At 12 months, 83% of the elderly patients had an open-set speech discrimination score above 60%. The benefits of cochlear implantation in terms of the quality of life are not statistically different with younger patients. Cost-utility analysis might support these findings.

Adult↗
PubMedDate not supplied

Voice and pronunciation of cochlear implant speakers.

Patients with cochlear implants have the ability to exercise auditory control over their own speech production and over the speech of others, which is important for the development of speech control. In the present investigation three groups of 10 subjects were compared. The groups comprised: (1) cochlear implant users, (2) profoundly deaf using traditional hearing aids, and (3) hearing controls. The subjects in three groups were matched in age. While repeating after a model the subjects were recorded and the following linguistic voice variables were analysed: (1) vowel formant space, (2) voice vs. voiceless difference, (3) closure duration and VOT, (4) word accent production, (5) sentence stress production, (6) voice quality, (7) pronunciation quality. Acoustic analysis and perceptual assessment by phoneticians showed that in great majority of variables, subjects with cochlear implants performed better than the profoundly deaf subjects with traditional hearing-aids.

Adolescent↗
PubMed1990

Severe versus profound sensorineural hearing loss in children: implications for cochlear implantation.

The advent of cochlear implants for children has stimulated interest in the specific sensory deficits and communicative capabilities of children with severe or profound bilateral sensorineural hearing loss. Appropriate management of these children and their families requires an appreciation of the multifaceted developmental and educational challenges confronting deaf children, even after cochlear implantation. Evaluation results from 200 children with bilateral sensorineural deafness (63 severe/137 profound, anacusic, and fragmentary) reveal significant differences between these two subpopulations. Within the profoundly impaired group, important differences were also noted in the children's ability to benefit from conventional amplification, depending on residual hearing at or above 1000 Hz. Strategies for assessing auditory function and aided benefit in severely and profoundly hearing-impaired children must involve a pediatric test battery, serial evaluations, and parental cooperation/support. When selecting candidates for cochlear implantation, it is inappropriate to categorize severely hearing-impaired children with those children having profound sensorineural losses. Even profoundly impaired populations are not homogeneous, and rehabilitation potential with conventional amplification must be determined on an individual basis, over time.

Adolescent↗
PubMed2003

[Long term results after cochlear implantation in elderly patients].

BACKGROUND: Cochlear implantation has become the method of choice for the treatment of deaf patients. A better technology of stimulation opened a wider field of patients suitable for cochlear implantation. Aim of the present study was to evaluate to which extent senior patients benefit by cochlear implantation. PATIENTS AND METHODS: 36 patients between 65 and 85 years were tested by the Freiburger speech test for monosyllabic words and by the HSM sentence test with and without noise. The results were compared to those of younger implanted patients (16 - 64 years, n = 101). RESULTS: The speech perception for monosyllabic words did not differ significantly between both groups. A maximum plateau in speech perception for monosyllabic words was reached after 2 years at 55 %. The HSM sentence test revealed significant differences in the increase of speech perception between senior and younger patients in the first post surgical year. After one year elderly patients reached the same perception score as younger patients with a maximum of approximately 80 % after 3 years. At a signal to noise ratio of 15 % younger patients achieved a maximal perception of 55 % after 1 year whereas senior patients needed 4 years to reach this level. CONCLUSIONS: Senior patients benefited by cochlear implantation to the same extent as younger patients did. Senior patients gained a similar speech perception level as younger implanted patients although the elderly needed more time to reach the same scores. Nevertheless, cochlear implantation should not be denied due to age alone.

Aged↗
PubMed2004

A novel speech-processing strategy incorporating tonal information for cochlear implants.

Good performance in cochlear implant users depends in large part on the ability of a speech processor to effectively decompose speech signals into multiple channels of narrow-band electrical pulses for stimulation of the auditory nerve. Speech processors that extract only envelopes of the narrow-band signals (e.g., the continuous interleaved sampling (CIS) processor) may not provide sufficient information to encode the tonal cues in languages such as Chinese. To improve the performance in cochlear implant users who speak tonal language, we proposed and developed a novel speech-processing strategy, which extracted both the envelopes of the narrow-band signals and the fundamental frequency (F0) of the speech signal, and used them to modulate both the amplitude and the frequency of the electrical pulses delivered to stimulation electrodes. We developed an algorithm to extract the fundatmental frequency and identified the general patterns of pitch variations of four typical tones in Chinese speech. The effectiveness of the extraction algorithm was verified with an artificial neural network that recognized the tonal patterns from the extracted F0 information. We then compared the novel strategy with the envelope-extraction CIS strategy in human subjects with normal hearing. The novel strategy produced significant improvement in perception of Chinese tones, phrases, and sentences. This novel processor with dynamic modulation of both frequency and amplitude is encouraging for the design of a cochlear implant device for sensorineurally deaf patients who speak tonal languages.

Algorithms↗
PubMed2004

Device fixation and small incision access for pediatric cochlear implants.

OBJECTIVE: Small incision cochlear implant surgery has been advocated to improve cosmesis and reduce post-operative morbidity. However, with standard small incision techniques, it is not possible to securely fix the device in place. This risks displacement of the device, particularly in active children. This paper describes the development of a technique which combines secure ligature tie-down of the device with a small incision. METHODS: A 25 mm skin incision is positioned close to the hair line behind the pinna. Specially modified instruments are used to drill a well for the receiver-stimulator pedestal down to dura. In younger children, ligature tie-down holes are drilled through the calvarium. Alternative methods for older children are described. Outcome data are reviewed. RESULTS: One hundred children have been implanted with the small incision technique. No complications have occurred related to the current technique (maximum follow up 22 months). In five cases, during early development of the technique, the receiver-stimulator device was only secured by a tight periosteal pocket. In one of these cases, the device became dislodged from its well. CONCLUSIONS: Secure fixation of the receiver-stimulator unit of a cochlear implant is particularly important in children because of the risk of displacement with trauma. The conventional means of securing the device with a ligature has been combined with modified small incision techniques to meet this requirement successfully.

Adolescent↗