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R D Battmer

Publications and source records attributed to R D Battmer.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Cochlear implant in patients with residual hearing].

INTRODUCTIONS: Cochlear implants are used for the rehabilitation of bilaterally deaf patients. Due to the improvements in speech processing they might be also useful for patients with residual hearing and some speech understanding. METHODS: Pre- and postoperative speech understanding scores in 26 patients receiving implants were evaluated in a retrospective study. RESULTS: The preoperative pure-tone threshold in the implanted ear was between 80 and 115 dB in the frequency range of 500 to 2000 Hz. On the contralateral side the mean threshold was 10 dB better. The mean score for the number test was 11.3%, for the monosyllables below 5%. Postoperatively speech understanding improved significantly up to 97% for numbers and 48% for monosyllables (tested with the Freiburger Speech Test). Cochlear implantation also benefits patients with residual hearing and some speech understanding with hearing aids under optimum conditions. The speech understanding scores must be below certain limits. General selection criteria cannot yet be specified. The individual decision must be based upon several criteria, especially the speech understanding scores in quiet and noise under optimum conditions. A prospective study is needed to develop generally applicable criteria.

Audiometry, Pure-Tone↗
PubMed1997

Performance in quiet and in noise with the Nucleus Spectra 22 and the Clarion CIS/CA cochlear implant devices.

The demographic characteristics and functional results from two cochlear implant adult patient groups are reported. The first group of subjects, implanted with the Nucleus Mini 22 Cochlear Implant System utilized the SPEAK coding strategy available in the SPECTRA 22 speech processor. The second group of subjects, implanted with the Clarion Cochlear Implant System used the CIS coding strategy with the exception of one patient utilizing the CA speech coding strategy. Data are available for 130 Nucleus subjects who were evaluated following 1 month of use of the SPEAK coding strategy. Data for the second group of subjects became available following administration of the Nucleus test battery to 38 Clarion subjects with varying implant experience. The test results presented include one common open set speech perception measure for all patients, the Freiburger monosyllabic word (FMW) tests. Additional subsequent test measures were taken from an adaptive test protocol assessing performance in quiet and quiet and two noise conditions. The results of this study conclude that both subject groups displayed similar distribution of performance scores on Freiburger Monosyllabic Words despite the large difference in group numbers. Both device groups also demonstrated a similar degree of deterioration in performance with increased background noise. This paper describes the results observed for each group.

Adolescent↗
PubMed1997

Nucleus double electrode array: a new approach for ossified cochleae.

INTRODUCTION: The ossified cochlea is still a special surgical issue that requires a special surgical procedure. The current cochlear implants only have one electrode lead, which can be placed only partially in the drilled out basal turn. The small number of used active electrodes leads to worse performance as compared with patients with full insertion. METHODS: To overcome this limitation, a special electrode was developed consisting of two arrays. One array with 11 active electrode rings is placed in the drilled out basal turn, the second array with 10 active electrodes in the opened second turn. The number of inserted electrodes can be significantly increased. The surgery is similar to that in nonossified cochleae. After the posterior tympanotomy, the bridge is removed and the incus is located. A cochleostomy is performed at the basal turn and the new-built tissue removed. A second cochleostomy is placed below the cochleariform process. In most cases, the second turn is not obliterated and the second electrode array can be fully inserted. RESULTS: The surgical procedure was in all nine cases uneventful. Intraoperative stapedius reflex could be recorded with elevated thresholds. The wide variety of stimulation modes and sites allows an individual fitting to maximize the performance. All patients show a gap in the pitch scale between the apical and the basal array. The pitch variation is much smaller in the apical array. All patients have some benefit from the additional apical array and an improved performance. CONCLUSION: The nucleus double electrode array is an advanced treatment option for patients with ossified cochleae. The receiver/stimulator is a regular nucleus cochlear implant.

Cochlea↗
PubMed1997

Comparison of preoperative electrostimulation data using an ear-canal electrode and a promontory needle electrode.

OBJECTIVE: To compare the electrical stimulation results of the ear-canal electrode with those of a promontory needle. PATIENTS AND METHODS: In thirty-three adult patients, the ear-canal electrode test was compared with the needle electrode promontory test with respect to sound perception, rhythm detection, frequency, and disturbing side effects. RESULTS: The ear-canal electrode test, in comparison with the needle electrode promontory test, resulted in vibrotactile sensation in addition to auditory sensation in some patients, less auditory fatigue, higher threshold levels, and lower discomfort levels. CONCLUSION: Reliable assessment of deafness in children requires, in addition to electrical stimulation, determination of the electrical evoked auditory brainstem response with the patient under anesthesia.

Adult↗
PubMed1997

Intraoperative test of auditory nerve function.

OBJECTIVE: To develop a preoperative objective test of auditory nerve function for the assessment of cochlear implant candidacy, especially in children. PATIENTS AND METHODS: We stimulated electrically with a ball electrode before insertion of the implant. First the stimulus was applied bipolar between the promontory and the round window. To record auditory brain stem responses (EABRs) very high stimulus intensities were needed, which was not possible in all patients. RESULTS: By stimulation in the basal turn of the cochlea, evoked potentials could be derived. Although in some patients the facial nerve was stimulated as a side effect, auditory evoked potentials could be recorded. A facial muscle artifact can be differentiated from the EABRs by latency and the slope of the input-output function. CONCLUSION: For the present, the only reliable test seems to be the EABR recording stimulated within the cochlea.

Adolescent↗
PubMed1997

Monitoring the electrode position during acoustic neuroma surgery.

OBJECTIVE: To obtain information about the auditory brain stem responses during auditory brain stem implantation. SETTING: Operating room during acoustic neuroma surgery. METHODS: Electrical stimulation of the auditory system during acoustic neuroma surgery, by placement of a monopolar or bipolar electrode on the nerve or nerve entry zone of the brain stem, and monitoring of the evoked auditory brain stem responses (EABR) recorded from the scalp. In some patients, a multichannel silicon electrode array was placed at the foramen of Luschka. Biphasic rectangular current pulses were applied, and EABRs were recorded. RESULTS: Usually the derived potentials consisted of three peaks with a latency below 4 ms. Sometimes we got a complex of two or more peaks. The interpeak interval between the first and second peak was about 0.7 to 1.0 ms, independently of the stimulating electrode position, but the absolute latency of the first peak increased from a minimum of 0.7 ms stimulated at the foramen of Luschka to a maximum of 1.3 ms stimulated at the nerve.

Cochlear Implantation↗
PubMed1997

Performance of the new Clarion speech processor 1.2 in quiet and in noise.

OBJECTIVE: To evaluate the benefit of the new Clarion speech processor 1.2. STUDY DESIGN: Fifty-two subjects who received a Clarion cochlear implant during 1993 and 1995 were upgraded with the new Clarion speech processor 1.2. All subjects were tested with a speech test battery in quiet and in noise, first with the 1.0 processor and 1 month later with the new 1.2 processor. To avoid ceiling or floor effects, the subjects were divided into three groups according to their test results with the Freiburger Monosyllabic Word Test (group A < 10%, group B 10-50%, and group C > 50%). RESULTS: The results indicated that all subjects had an improvement with the new speech processor. This improvement was statistically significant (p < 0.05) for group C in all conditions, and for group B in the tests with noise. CONCLUSION: While the better and good performers improved their test scores significantly, low performers seemed to derive little benefit from the technical improvements of the same speech processing strategy. Perhaps this group might gain more from a different processing scheme.

Child, Preschool↗
PubMed1996

[The Clarion cochlear implant--technical principles, initial clinical experiences and results].

BACKGROUND: Certain design characteristics of the Clarion device (Advanced Bionics Corp.) make it significantly different from other cochlear implant systems. It has a preformed electrode array to be placed closer to the modiolus, thus providing a more efficient coupling of the electrical signal to the auditory nerve; a telemetric function which permits the evaluation of the implant electronics; and two different speech processing strategies. The strategies are continuous interleaved sampling (CIS) and compressed analog (CA); both can be programmed into the same speech processor and alternatively selected by the patients, as they desire. The surgical procedure is only slightly different from the procedure familiar from the Nucleus system with the exception of a significantly larger cochleostomy. PATIENTS: The results of a series of speech tests designed to evaluate benefit in terms of speech understanding were administered to the first ten Clarion patients and compared to the results of a similar group of patients using the Nucleus system and the M Peak method. From a data-base of more than 300 Nucleus users, it was possible to select ten subjects who had near-equivalent data for onset of deafness, duration of deafness, and age at implantation (so-called matched pairs). In the majority of cases, etiology and course of deafness (progressive or sudden) could also be matched. RESULTS: It was found that the Clarion patients had higher test scores than the Nucleus patients after two weeks, three months, and six months after implantation. This positive experience with the Clarion device encouraged us to continue implanting this system in patients. As of September 1995, 106 patients (including 35 children between the ages of two and fourteen) are currently enrolled in the study. CONCLUSIONS: A final assessment of results with the Clarion implant is not possible because of the short follow-up. In any case, it appears that the patients with this implant system achieve faster open-set speech understanding and that it is accomplished with less effort in programming and shorter rehabilitation time.

Adolescent↗
PubMed1996

[Cochlear implant management of young children].

INTRODUCTION: Since 1988, more than 450 children have received cochlear implants at the Department of Otolaryngology of the Medizinische Hochschule Hannover. Among them are 38 children who underwent surgery before the age of two. Due to increasing experience with this technique, the mean age at implantation has decreased over time so that most children nowadays receive implants between the ages of two and five. In terms of the critical periods of both development of the auditory system and the acquisition of language, it is advantageous for even younger children to receive implants soon after detection of deafness. However, the present diagnostic tools do not allow proper estimation of residual hearing and additional handicaps. Therefore longer periods of hearing aid use and audioverbal training are mandatory before implantation. Additional objections against early implantation are biosafety problems such as head growth, the high incidence of otitis media, and the specific surgical anatomy. This paper outlines criteria for patient selection, the surgical concept, postoperative rehabilitation, and complications. PATIENTS: Twenty-six children suffered from postmeningitic deafness and beginning obliteration of the cochlea as shown by repeated high resolution CT scans. Nine children had congenital deafness which was detected early in life and showed no improvement after proper hearing aid fitting and audioverbal training for speech development. Three children had severe inner ear malformations detected by CT scans. All children had no ABR or CAP responses in ECoG. Their developmental, language, and neuropaediatric status was examined. SURGERY: Thirty-five children received the Nucleus Mini 22 cochlear implant; three children received the Clarion 1.2 device. The surgery was not different from adult surgery. Special care was given to proper fixation and placement of the electrode in the drilled out mastoid to compensate for head growth. POSTOPERATIVE RESULTS: All children wear the speech processor regularly. They are able to detect everyday sounds and suprasegmental features of speech after a few months. After one year, the child begins to understand and produce speech; after two years speech understanding has been achieved and normal language development starts with small sentences. The complication rate was not higher than in other age groups of patients. Fitting and tune-up of the speech processor required a broad range of experience and a specialized team working at the children's implant center. CONCLUSION: Early implantation in children is both possible and effective in selected cases. Due to an improved early detection of deafness, it should be possible to increase the percentage of children with early cochlear implantation.

Child↗
PubMed1995

Matched-pair comparisons for adults using the Clarion or Nucleus devices.

The prospective, matched-pair study comparing users of the Clarion system and the Nucleus system seems to indicate that the patients using the Clarion system are obtaining open-set speech understanding at a faster rate than Nucleus patients. The sample size in this study is very small at present, but with increasing numbers of Clarion patients, we will carry on with this study. Further, it remains to be seen whether or not the observed advantage will continue for the Clarion users in the longer term.

Cochlear Implants↗
PubMed1995

Postoperative results for adults and children implanted with the Clarion device.

Our experience with deaf adults and children who have received the Clarion multistrategy implant are very encouraging. Because of certain programming characteristics of the current device, access to the compressed analog coding strategy has been limited. We expect to see this change in the near future. The CIS strategy, however, appears to provide patients with important, full-spectrum speech information so that they accommodate to the auditory sensations rapidly and begin to interpret sound into meaningful speech within a short time.

Adolescent↗