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PubMed2004

Short-term versus long-term antibiotic prophylaxis in cochlear implant surgery.

OBJECTIVE: The objective of this study to evaluate antibiotic prophylaxis options for cochlear implant surgery. Does long-term antibiotic prophylaxis have any advantage over a single perioperative dose in preventing postoperative infection? STUDY DESIGN: We conducted a retrospective case review. PATIENTS: A total of 292 adult and pediatric patients who underwent cochlear implantation during a 15-year period (1988-2003) were reviewed. MAIN OUTCOME MEASURE: Minor and major postoperative wound infections in first 4 weeks. RESULTS: There were four major and eight minor complication among 292 patients (complication rate 4.1%). The infection rate was higher in patients who had either C incision (11.1%) or extended endaural incision (7.5%) and in patients with a preexisting medical condition. The infection rate was also higher in patients who had long-term antibiotics (5.6% and 13% in the 5-d and 7-d regimes) compared with short-term (single-dose) group. CONCLUSION: Long-term antibiotic prophylaxis did not have any advantage over single perioperative dose. Predisposing medical conditions and extensive surgical incisions were associated with a greater severity of infections and higher risk of wound complications.

Adolescent↗
PubMed1995

Melody recognition and musical interval perception by deaf subjects stimulated with electrical pulse trains through single cochlear implant electrodes.

The perception of musical pitch was investigated in postlinguistically deaf subjects with cochlear implants. Stimuli consisted of sequences of biphasic electrical pulse trains at rates which represented the tones of the equal-tempered musical scale, delivered at equalized comfortable loudness levels to selected single bipolar electrodes along the array of the Nucleus cochlear implant. Seventeen subjects correctly identified a mean of 44% of rhythmically intact familiar tunes, presented in an open-set paradigm. Three subjects were tested with a closed set of melodies without rhythmic cues. The results showed relatively higher recognition scores at lower pulse rates, although melody recognition remained possible up to rates of approximately 600-800 pulses per second. Stimulation of apical electrodes yielded higher recognition scores than of basal electrodes. The perception of musical intervals, defined as frequency ratios between two trains of stimulus pulse rates, was investigated in an interval intonation labeling experiment, for intervals ranging from a minor 3rd to a major 6th. Within a range of low pulse rates, subjects defined the intervals mediated by electrical pulse rate by the same ratios which govern musical intervals of tonal frequencies in normal-hearing listeners. It may be concluded that temporal cues are sufficient for the mediation of musical pitch, at least for the lower half of the range of fundamental frequencies commonly used in music.

Adult↗
PubMed2001

The effect of the audallion BEAMformer noise reduction preprocessor on sound localization for cochlear implant users.

OBJECTIVE: To assess the effect of the Audallion BEAMformer noise reduction preprocessor on the sound localization ability of children fitted unilaterally with the Nucleus 22-channel cochlear implant. DESIGN: Eight children aged 11 to 14 yr participated. Using three arrays of six loudspeakers, each child was tested in a semi-reverberant sound proof booth representative of a small office environment. The six loudspeakers were positioned 30 degrees apart in the horizontal plane at a distance of 1 m, spanning 150 degrees either directly in front of or to the left or right of the subject. The stimulus to be localized was a 300 msec broadband noise with a rise/decay of 50 msec. Subjects were tested with the BEAMformer in four possible settings, including one single microphone control condition, with each of the three loudspeaker arrays. One block of 60 forced-choice speaker identification trials was presented for each of the 12 listening conditions. On each trial, the stimulus was emitted by one of the six loudspeakers, randomly selected. RESULTS: Results demonstrated that subjects were unable to discriminate among sound sources arrayed horizontally in space using the cochlear implant microphone alone, or in combination, with the BEAMformer microphone located on the other ear. Results also showed that using the BEAMformer did not bias the perception of spatial location. CONCLUSIONS: The localization of acoustic stimuli in pediatric cochlear implant users was unaffected by the use of the Audallion BEAMformer. The apparent origin of most sounds appears to be pulled toward the implanted ear. Further studies are needed to validate findings.

Acoustic Stimulation↗
PubMed1990

Parents' evaluations of the effects of the 3M/House cochlear implant on children.

A questionnaire was used to obtain parents' opinions of their children's 3M/House cochlear implant. Responses were received from parents of 132 children aged 3 through 17. Seventy-five percent of the parents were satisfied overall with the implant; 25% were not. The parents were more positive about the implant than they felt their children were. Fifty-seven percent, 34%, and 9% of the parents reported that the implant performed better, the same, or worse, respectively, than their implant counselors said it would. Almost all of the parents (98%) said they would recommend the implant to other parents. The parents thought that the effect of the implant on environmental sound perception and speech production was superior to its effect on speech perception. Environmental sound perception was a more substantial predictor of parental satisfaction than was speech perception or speech production. About half of the parents felt that the size and cords of the external processor were problematic. Adolescent children wore their implants less than preadolescent children. It was concluded that the majority of the parents thought the 3M/House cochlear implant provided real-world benefits for their children.

Adolescent↗
PubMed1997

Speech perception performance of nucleus multichannel cochlear implant users with partial electrode insertions.

OBJECTIVE: The present investigation examined the speech perception performance of five children with ossified cochleas who received partial insertions of the Nucleus 22-channel cochlear implant. DESIGN: The partial-insertion subjects' preimplant and 1.5 yr postimplant performance on a battery of speech perception tests was compared to the average performance of age-matched control subjects who received full electrode insertions. All the partial-insertion subjects were fit with their Nucleus cochlear implant between the ages of 2 and 5 yr, and had used their device for at least 1.5 yr. More extended comparisons also were made for the two partial-insertion subjects who had used their cochlear implants for a longer period of time. RESULTS: The subjects with partial electrode insertions performed similarly to the control group at both the preimplant and 1.5 yr postimplant intervals. Furthermore, the partial-insertion subjects showed continued improvements in speech perception performance with increased device experience past 1.5 yr, again similar to the full-insertion control group. CONCLUSIONS: The present results suggest that partial insertion of a multichannel implant device is an appropriate and feasible approach to the surgical management and auditory rehabilitation of children with extensive or complete ossification of the cochlea.

Child, Preschool↗
PubMed2006

Polyarteritis nodosa and cochlear implantation.

Polyarteritis nodosa is a systemic disease which affects the small to medium-sized muscular arteries. Sudden or progressive, bilateral hearing loss is a presenting otologic manifestation. To date, no case of cochlear implantation in patients with polyarteritis nodosa has been reported. The authors present a case of polyarteritis nodosa (confirmed by biopsy) in a 71-year-old man with progressive, bilateral sensorineural hearing loss who underwent cochlear implantation. A successful full insertion of the Nucleus 3G electrode array was achieved without surgical or post-operative complications. The patient immediately showed a positive subjective response and, at three month post-operative evaluation, had gained useful open-set speech perception. A review of five temporal bone cases with hearing loss and polyarteritis nodosa revealed the possibility of fibrosis and ossification in the basal turn of the cochlea, of which the surgeon should be aware prior to cochlear implantation.

Aged↗
PubMed2000

Teachers' ratings of functional communication in students with cochlear implants.

The study examined factors associated with teachers' ratings of functional communication skills of students with cochlear implants. Deaf students living in and around a metropolitan area were surveyed to locate 51 with cochlear implants. Teachers rated each student's functional use of the implant, given three defined ratings. Additional information regarding sex, communication option, placement, home language, rural or nonrural address, etiology, and presence or absence of an additional disability was gathered. Chi-square analyses of the data were performed. The data indicated that students with a known etiology and a rural address, and who used sign language at home or school, were less likely than others to use the implant as a primary channel for receptive communication. The authors suggest that the teacher's role in implant use warrants more attention. Speech-language pathologists, otologists, audiologists, and parents of deaf children should consider all factors related to successful implant use before advocating or choosing this financially, emotionally, and therapeutically challenging option.

Adolescent↗
PubMedDate not supplied

Performance of adult Ineraid and Nucleus cochlear implant patients after 3.5 years of use.

Forty-two postlingually deafened adult patients, 21 with a formant extraction version of the Nucleus cochlear implant and 21 with the Ineraid cochlear implant (analog processing), were evaluated on a series of speech perception tests after using their implants for about 3.5 years. A wide range of performance was observed across patients for both devices. All but 4 patients showed an enhancement in their lipreading ability with the implant. Word recognition averaged about 14-19% correct, and word recognition in sentences averaged about 43-49% correct for the two implant groups. Average performance was superior with the Ineraid implant on consonant recognition in noise. An information transmission analysis suggested that vowel perception was influenced by first- and third-formant frequency for the Nucleus, and first-formant and fundamental frequency for the Ineraid patients. It appeared that the Ineraid device was more effective, on average, at conveying information about consonant nasality and frication. For consonant perception, nasality and frication contributed most to the total information transmitted for both implant types. Both devices had difficulty conveying information about vowel second-formant frequency and consonant place information. These scores at 3.5 years are substantially elevated from preoperative performance and, overall, the patients clearly benefit from their implant.

Adult↗
PubMed2001

The effect of a multichannel cochlear implant on phoneme perception.

This study was done to investigate the effects of a multichannel cochlear implant on phoneme perception in Finnish-speaking postlingually deafened adults. Phoneme recognition was studied with 100 prerecorded nonsense syllables (open-set) presented at 70 dB SPL, auditorily only, in a free-field situation. Ten subjects were tested before implantation both with and without a hearing aid (HA), and 3, 6 and 12 months after switching on the implant. Before implantation without a HA, the subjects did not recognize vowels, consonants or syllables. Four of the subjects used a HA before implantation, and the mean recognition scores of these subjects were 34% for vowels, 28% for consonants and 13% for syllables. One year after switching on the implant, the mean recognition scores were 77% for vowels, 66% for consonants and 46% for syllables. According to phonological analysis vowels appear to be easier to perceive than consonants during the first stage after multichannel cochlear implantation.

Acoustic Stimulation↗
PubMedDate not supplied

Vowel discrimination with the single-electrode cochlear implant: a pilot study.

Eight normal-hearing individuals and six single-electrode cochlear implant users were asked to discriminate tape recorded pairs of spoken monosyllables consisting of 11 English syllabic nuclei (see formula in text) bounded by the consonant frame. A same-different paradigm was used. Most normal-hearing subjects discriminated all pairs intended by the talker as different; two normal listeners confused monosyllables containing (see formula in text). Cochlear implant users showed some intersubject variation, but for the 6 subjects, discriminations were consistent enough to allow the data to be pooled for analysis. The pooled data for these four subjects indicated that high front and high back vowels were discriminable from low vowels. The basis for the discriminations is difficult to evaluate, since the naturally spoken stimuli varied with respect to formant frequencies, fundamental frequency, intensity, and duration.

Adult↗
PubMed2006

Cochlear implants: cortical plasticity in congenital deprivation.

Congenital auditory deprivation (deafness) leads to a dysfunctional intrinsic cortical microcircuitry. This chapter reviews these deficits with a particular emphasis on layer-specific activity within the primary auditory cortex. Evidence for a delay in activation of supragranular layers and reduction in activity in infragranular layers is discussed. Such deficits indicate the incompetence of the primary auditory cortex to not only properly process thalamic input and generate output within the infragranular layers, but also incorporate top-down modulations from higher order auditory cortex into the processing within primary auditory cortex. Such deficits are the consequence of a misguided postnatal development. Maturation of primary auditory cortex in deaf animals shows evidence of a developmental delay and further alterations in gross synaptic currents, spread of activation, and morphology of local field potentials recorded at the cortical surface. Additionally, degenerative changes can be observed. When hearing is initiated early in life (e.g., by chronic cochlear-implant stimulation), many of these deficits are counterbalanced. However, plasticity of the auditory cortex decreases with increasing age, so that a sensitive period for plastic adaptation can be demonstrated within the second to sixth months of life in the deaf cat. Potential molecular mechanisms of the existence of sensitive period are discussed. Data from animal research may be compared to electroencephalographic data obtained from cochlear-implanted congenitally deaf children. After cochlear implantation in humans, three phases of plastic adaptation can be observed: a fast one, taking place within the first few weeks after implantation, showing no sensitive period; a slower one, taking place within the first months after implantation (a sensitive period up to 4 years of age); and possibly a third, and the longest one, related to increasing activation of higher order cortical areas.

Animals↗
PubMed1998

The AllHear Cochlear Implant and Tinnitus.

The authors have studied the effect of AllHear cochlear implants on tinnitus. We describe five cases of deaf patients with tinnitus and show that the implant device had a good effect on tinnitus in four. We also discuss one case in which the tinnitus was caused by electrical stimulation. The authors conclude that AllHear cochlear implants have a good effect on tinnitus in the majority of patients.

Journal Article↗
PubMed1989

Word recognition by 50 patients fitted with the Symbion multichannel cochlear implant.

We describe the word recognition ability of 50 patients who use the multichannel cochlear implant manufactured by Symbion, Inc. The median scores for open set tests involving auditory stimulation alone were: 14% correct (range 0 to 60) for monosyllabic words, 44% correct (range 0 to 100) for spondees, and 45% correct (range 0 to 100) for words in the Everyday CID Sentences. In the visual stimulation condition of the Everyday CID Sentences, the median score was 64% correct (range 0 to 100). In the visual plus auditory stimulation condition, the median score was 99% correct (range 46 to 100). These results demonstrate that relatively good speech understanding can be achieved using a cochlear implant which employs only a few channels of stimulation and which simultaneously activates monopolar electrodes.

Acoustic Stimulation↗
PubMed2002

Intracochlear insertion of electrodes using hyaluronic acid in cochlear implant surgery.

Hyaluronic acid has been proposed as a lubricant for improving the outcome of cochlear implant surgery. We describe a method which includes coating the electrodes with a thin layer of hyaluronic acid as well as using a droplet of the lubricant on the cochleostomy to provide additional magnification, like a lens, that facilitates the insertion of the electrode array. The use of hyaluronic acid reduces trauma to the cochlea and avoids contaminating perilymph by blood or by saline used during the operation. It is an efficacious and reliable method for cochlear implant surgery.

Cochlear Implantation↗