Cochlear implant reimplantation.

The objective of this study was to determine whether insertion length and number of active channels remained the same after reimplantation of a cochlear implant. A retrospective case review of 170 consecutively implanted multichannedl cochlear implants was conducted. Seventeen of these devices had to be replaced. Data were analyzed for the Nucleus cochlear implant users who were reimplanted in the same ear. For most subjects, insertion length and number of channels remained unchanged, but a few subjects experienced substantial decreases. When the whole group was considered, a small but statistically significant drop was noted for both parameters. In conclusion, although reimplantation is technically possible, the first procedure provides the optimal surgical environment.

Complications of pediatric cochlear implantation.

Cochlear implantation has been established as a method of auditory rehabilitation for selected deaf children. However, as with any surgical procedure, complications can occur and may be particularly devastating in children. In this retrospective study, complications encountered in 100 consecutive cochlear implant surgeries in children were analyzed. Surgical problems were limited to one case of delayed, transient facial paresis and one cerebrospinal fluid gusher. These findings demonstrate that cochlear implantation can be performed safely with careful preoperative planning and meticulous surgical technique.

Single-channel to multichannel conversions in pediatric cochlear implant recipients.

Speech perception skills were measured in five children who had received a 3M/House single-channel cochlear implant and were subsequently upgraded to a multichannel cochlear implant (Nucleus). A rationale was developed based upon performance with the single-channel device and anticipated performance with the multichannel device. All subjects demonstrated improved acoustic thresholds with the multichannel device. Three of the children demonstrated improvements on identification tasks and two on word recognition tasks.

Prelingually deafened children's performance with the nucleus multichannel cochlear implant.

The speech perception abilities of 19 children with onset of deafness before age 3 years was examined after they received the Nucleus multichannel cochlear implant. The children were divided into two groups based on age at onset of deafness: children with congenital deafness (n = 8) and children with onset of deafness after birth but before age 3 (n = 11). There was no statistically significant difference between the scores of the two groups of subjects on 12 of the 13 speech perception tests administered. This finding suggests that children who are born deaf have the potential to derive the same benefit from cochlear implants as do children who have had some exposure to spoken language before the onset of their deafness. Examination of performance in terms of communication mode revealed that prelingually deafened children with implants who used oral communication obtained significantly higher scores on only 2 of the 13 speech perception measures than did children who used total communication. The data suggest that communication mode does not appear to account for large differences in speech perception performance among prelingually deafened children with multichannel cochlear implants.

Longitudinal evaluation of communication skills of children with single- or multichannel cochlear implants.

Performance on speech perception, speech production, and language tests was measured over time in children who used the 3M/House or the Nucleus cochlear implant. The speech perception and production results demonstrated higher performance levels and faster rates of learning for the multichannel than for the single-channel users. The performance of the children with the single-channel implant on the speech perception and production measures reached a plateau by 1.5 years post implant, whereas the children using the multichannel device continued to show improvement after 2 or more years of implant use. Changes in language were limited over time with no obvious difference in performance as a function of type of implant.

Speech perception abilities of children with cochlear implants, tactile aids, or hearing aids.

The purpose of this experiment was first, to compare the performance of three matched groups of experimental subjects who used either a single-channel cochlear implant, a multichannel cochlear implant, or a two-channel vibrotactile aid on a battery of speech perception measures, and second, to compare the performance of subjects with residual hearing who used hearing aids to that of the three groups of experimental subjects. The results revealed that the subjects using hearing aids achieved the highest scores on all measures. The performance of the group of multichannel implant users was significantly higher than that of the single-channel implant users on tests involving discrimination of speech features, categorization of stress patterns, closed-set identification of familiar words, and identification of common phrases with and without visual cues. The performance of the subjects using 3M/House and Tactaid II devices was similar on all tests except those requiring integration of auditory or tactile cues and visual cues, on which the 3M/House device users achieved significantly higher scores than did the Tactaid II device users.

Comparison of speech perception abilities in deaf children with hearing aids or cochlear implants.

The speech perception abilities of deaf children with a single- or multi-channel cochlear implant are compared with those of deaf children who derive substantial benefit from conventional hearing aids. The children with hearing aids have unaided pure-tone thresholds ranging from 90- to 110-dB HL through at least 2000 Hz, and aided thresholds of 30- to 60-dB HL. The group data show that the speech perception scores of the subjects with hearing aids were significantly higher than those of the subjects with implants on a range of speech perception measures. Although a few subjects with implants achieved scores as high as those who used hearing aids, the majority did not. Even though the children with implants receive substantial benefit from their devices, they continue to have limited auditory perception abilities relative to their peers who derive benefit from conventional hearing aids. The data highlight the importance of establishing hearing aid benefit in potential candidates for implant.

Performance of deaf children with cochlear implants and vibrotactile aids.

A longitudinal study is under way to examine the speech perception and production skills of deaf children who use a single- or multi-channel cochlear implant, or a two-channel tactile aid. The speech perception data showed that the majority of subjects who achieved the highest scores on a range of measures used the multi-channel cochlear implant. The production data showed that all three types of sensory aids were effective in promoting production skills, with the cochlear implant users showing the greatest gains in this area.

Comparison of sensory aids in deaf children.

A speech perception hierarchy has been developed and applied to assess the influence of cochlear implants and tactile aids on the acquisition of auditory, speech, and language skills in deaf children. Encouraging improvements were noted with both types of sensory aids at the detection level. The House 3M and Nucleus cochlear implant designs appear to offer advantages over the Tactaid II in providing ancillary speech perception cues to deaf children. Preliminary observations suggest that the multichannel cochlear implant design may be superior to the single-channel coding scheme.

The role of cochlear implants in deaf children.

Advances in technology regarding cochlear implantation and electroacoustic stimulation of the inner ears of deaf children has created cautious enthusiasm. The safety of cochlear implantation is now reasonably well established and language performance measures made over time are encouraging. When coupled with an effective (re)habilitation program, the cochlear implant promises to favorably influence the potential of deafened children.

Relationships among selected measures of single-channel cochlear implant performance.

Relationships among a number of pre- and postimplant variables measured in 20 adults implanted with a single-channel cochlear implant were examined through a variety of univariate and multivariate statistical techniques. A large number of variables were analyzed to yield information on the relationships between pre- and postimplant performance, and among a variety of postimplant measures. Variables included: age; etiology and nature of deafness; type of implant worn; pre- and postimplant warble tone and speech detection thresholds; postimplant performance on the Monosyllable-Trochee-Spondee (MTS) and Environmental Sounds tests; postimplant electrical thresholds, uncomfortable loudness levels, and dynamic range; I.Q. scores; and postimplant discourse tracking performance with and without the implant. The difference score on the discourse tracking task, representing the auditory advantage over performance with lipreading alone, related substantively to a combination of variables including type of unit worn (Sigma versus Alpha), nature of deafness (progressive versus sudden), and etiology (meningitis versus nonmeningitis). Additionally, MTS and Environmental Sounds test scores were found to relate to one another and to etiology and nature of deafness.

Cochlear implants for deaf children.

Fifteen profoundly deaf patients under the age of 18 years have received a 3M/House cochlear implant. The surgical procedure employed is essentially the same as that used in adults with a few modifications to accommodate for the smaller dimensions of the mastoid process and the thinness of the scalp and temporal squama. Pediatric subjects receive timing and intensity information at similar thresholds as adults implanted with this device which contributes to improvement in speech production to various degrees. All subject groups demonstrated significant language delays as a result of their profound hearing losses. Postimplantation, more growth was seen in receptive than in expressive language skills. However, the growth observed did not exceed that expected in profoundly deaf children as reported in the literature. Language growth as a result of the cochlear implant alone is yet to be documented in our patients.

Cochlear implantation in the Mondini inner ear malformation.

We report the case of a profoundly deaf 4-year-old boy with congenital deafness as a result of Mondini's dysplasia. The Mondini inner ear malformation is the result of arrested labyrinthine development during embryogenesis and is characterized by both bony and membranous anomalies of the inner ear. The dysplastic cochlear anatomy does not preclude successful cochlear implantation, and electrical threshold measurements are similar to those recorded in pediatric subjects deafened as a result of other causes.

Long-term intracochlear implantation in man.

Whether long-term intracochlear implantation and direct electrical stimulation of the acoustic nerve will induce intracochlear bone growth or cause further degeneration of a severely compromised auditory system is an important clinical consideration. Thin-section CT evaluations of the cochleas of six subjects who have used their cochlear implant devices on a daily basis for 3 or more years demonstrated no evidence of osteoneogenesis of the cochlea in the vicinity of the active electrode. No corrosion of the electrode or insulation material was noted on electron microscopy of an explanted electrode system. Electrical threshold and dynamic range measurements have remained stable or even improved during the period of observation. Performance measures using a variety of audiologic tests and speech-tracking scores have demonstrated stability of performance.

Cochlear implant candidate selection.

In recent years there has been an increased acceptance of the cochlear implant as an appropriate sensory aid for selected hearing-impaired individuals with profound losses. With the Food and Drug Administration's release of the 3M/House single channel cochlear implant on November 29, 1984 and the Nucleus 22-channel cochlear implant on October 31, 1985 it is anticipated that many new groups of otologists and audiologists will have direct involvement in this exciting new approach to the management of patients with profound hearing impairments. This report reviews our cochlear implant selection protocol for the severe to profound adult hearing-impaired population.

Speech-tracking performance in single-channel cochlear implant subjects.

This study evaluated 20 deaf adults' ability to understand connected discourse under two conditions: (a) lipreading alone (LA), and (b) lipreading plus electrical stimulation by a single-channel cochlear implant (LI). Performance was evaluated using the speech-tracking procedure, which required the deaf receiver to repeat verbatim textual material read by another individual. The reception of ongoing speech was measured in terms of the number of words repeated correctly per minute. The results revealed, on the average, a significantly higher tracking rate in the LI condition (28.6 wpm) than the LA condition (16.4 wpm). There was a significant learning effect across sessions for both conditions. Subjects who were previous hearing aid users achieved a significantly higher tracking rate in the LI condition than did subjects who had no previous experience with amplification. Significant subject differences were present as a function of condition. Sixteen of the 20 subjects achieved higher tracking rates in the LI than in the LA condition. However, 4 of these 16 subjects showed similar relative gains in both conditions and 3 showed a decrease in performance in the LA condition over time. The remaining 4 subjects showed nearly equivalent tracking rates in both conditions over time. The data suggest that the majority of subjects were able to learn to make use of the cues provided by electrical stimulation by a single-channel cochlear implant to enhance their lipreading skills, at least for highly redundant material in a communicative situation.