Short- and long-term results of stapedotomy and stapedectomy with a teflon-wire piston prosthesis.

We analyzed the results of 604 cases of primary stapes surgery performed between 1974 and 1997 with replacement of the stapes by a 0.6- or 0.8-mm Schuknecht Teflon-wire piston. At long-term follow-up (1 to 21 years; mean, 7 years), the residual air-bone gap was 10 dB or less in 79% of the cases. The hearing results and postoperative complications were comparable to those reported by authors who used the same evaluation criteria. Although the aim of the surgery was to perform a small stapedotomy with a narrow footplate perforation (0.8 mm), a large stapedotomy or a stapedectomy was performed in 134 cases (22.2%) because of surgical or anatomic conditions. Our results show that the larger footplate perforations allowed a better correction of the air-bone gap at the lower frequencies. The ears with larger perforations did not show a higher incidence of sensorineural hearing loss.

Histopathology of cochlear implants in humans.

The insertion of an intrascalar electrode array during cochlear implantation causes immediate damage to the inner ear and may result in delayed onset of additional damage that may interfere with neuronal stimulation. To date, there have been reports on fewer than 50 temporal bone specimens from patients who had undergone implantation during life. The majority of these were single-channel implants, whereas the majority of implants inserted today are multichannel systems. This report presents the histopathologic findings in temporal bones from 8 individuals who in life had undergone multichannel cochlear implantation, with particular attention to the type and location of trauma and to long-term changes within the cochlea. The effect of these changes on spiral ganglion cell counts and the correlation between speech comprehension and spiral ganglion cell counts were calculated. In 4 of the 8 cases, the opposite, unimplanted ear was available for comparison. In 3 of the 4 cases, there was no significant difference between the spiral ganglion cell counts on the implanted and unimplanted sides. In addition, in this series of 8 cases, there was an apparent negative correlation between residual spiral ganglion cell count and hearing performance during life as measured by single-syllable word recognition. This finding suggests that abnormalities in the central auditory pathways are at least as important as spiral ganglion cell loss in limiting the performance of implant users.

[Long-term results of canal wall down mastoidectomy]. / Résultats à long terme de l'évidement pétro-mastoïdien en technique ouverte.

INTRODUCTION: This study evaluates the anatomical and functional long-term results of canal wall down mastoidectomy. METHOD: We analyse the results of 259 primary, one stage canal wall down mastoidectomies with type III, IV or V ossiculoplasty performed between 1974 and 1998. The indication for surgery was chronic active otitis with cholesteatoma or resistant to conservative treatment. RESULTS: In the long term, 1-24 (mean 7) years after surgery, 95% of the ears showed a dry, self-cleaning cavity and were disease-free. Hearing was preserved or improved in 70% of cases. Surgical revision due to of residual cholesteatoma was necessary in 16 cases (6%). The number of postoperative outpatient visits necessary to treat multiple minor problems was up to 10 visits per patient during the first 6 months after surgery and then gradually decreased over the years. DISCUSSION: The results achieved with canal wall down mastoidectomy are satisfactory in the long term, but the cavities required a high degree of postoperative outpatient care.

Multiple myeloma presenting with external ear canal mass.

The manifestations of multiple myeloma are protean and related to bony osteolytic lesions, and to medullar and renal insufficiency. We report a patient who presented with otalgia as the inaugural symptom of multiple myeloma. Local irradiation combined with systemic chemotherapy led to the disappearance of the temporal bone mass and the accompanying symptoms. To date, 24 months after the diagnosis, the patient is still in remission. The literature on otological involvement in multiple myeloma is reviewed. Symptoms are non-specific and include hearing loss, tinnitus, dizziness, facial paralysis, and otalgia. The diagnosis of multiple myeloma should be considered in the presence of a temporal bone mass.

Ossiculoplasty by interposition of a minor columella between the tympanic membrane and stapes head.

This study analyzes short- and long-term results of 436 ossiculoplasties accomplished by a minor columella sculptured in the remnants of the incus and placed between the tympanic membrane and stapes head. Most cases were operated on by a transcanal approach through an ear speculum, under local anesthesia. Cases in which an associated mastoidectomy was performed to remove diseased tissue are excluded. The residual air-bone gap was < 20 dB in 86.1% of cases 2 months after surgery, in 77.0% 1 year later, and then remained stable over time, even in patients seen 5 to 15 years after the operation. Complications were rare. A total sensorineural hearing loss occurred in two cases (0.4%), the cause of which remained unexplained. Other complications included a high-frequency hearing loss in 10 (2.3%) cases, tinnitus in 12 (2.7%), and transitory vertigo in two (0.4%). We conclude that this type of ossiculoplasty is a simple but adequate procedure for primary restoration of hearing in chronic otitis media if the stapes is intact and mobile.

Speech recognition with a CIS strategy for the ineraid multichannel cochlear implant.

Wilson et al. proposed a new sound-processing strategy for multichannel cochlear implants, the Continuous Interleaved Sampling (CIS) strategy. Their study was performed on seven American patients, selected for their excellent performance with the Ineraid multichannel cochlear implant, and involved refined testing of several parameter modifications of the CIS strategy during a 1-week period. At the end of the week, the CIS strategy produced large improvements in speech-recognition tests for all subjects. To evaluate the generality of this promising result, the goal of this study was to assess whether similar improvements of performance could be observed in a typical population of Ineraid users and implemented as a clinical protocol. Therefore we designed one unique, predetermined CIS processor that could be temporarily fitted to the patients in < 2 h, and we evaluated speech recognition with consonant-and vowel-identification tests in a group of patients with performances ranging from star to almost chance levels and speaking six different native languages. Scores of vowel and consonant identifications obtained with this predetermined CIS processor and with the standard processor of the Ineraid system were compared in 15 Ineraid users. Fourteen of 15 patients had significantly better scores of consonant identification with the new CIS strategy. The group mean scores of vowel identification with either strategy were not statistically different. In agreement with these observations, most patients immediately reported that the CIS strategy sounded subjectively "more clear" for real-time speech recognition. It is now possible to implement a CIS speech-coding strategy as a standard clinical procedure to improve speech-recognition performances of all Ineraid users.

First field trials with a portable CIS processor for the Ineraid multichannel cochlear implant.

The continuous interleaved sampling (CIS) strategy is a promising sound processing strategy for multichannel cochlear implants which provides immediate improvements in speech recognition when tested on Ineraid users: patients with only a few hours of experience (in laboratory testing) with the CIS strategy score better than with the Ineraid prosthesis they used since they, were implanted. The goal of this study was to evaluate the benefits that can be gained by the use of the new strategy in every day life. Two patients, implanted with the Ineraid multichannel cochlear implant, were equipped with a portable numerical processor programmed to implement a high rate CIS strategy. Their speech recognition was evaluated periodically with consonant and vowel identification tests for more than 6 months of use. Tests were also made with the Ineraid processor during the same experimental sessions and patients were regularly interviewed about their experience. Performance with the portable CIS processor was superior or equal to that obtained previously in the laboratory with the same strategy. Both patients achieved the best scores in 6 years of cochlear implant use. Qualitative reports from the patients suggest that the CIS strategy can improve "hearing" performance of cochlear implant users in many important situations of every day life. Altogether, these results hold great promises for all users of the Ineraid multichannel cochlear implant.

Modified canal wall-up mastoidectomy with mastoid obliteration for severe chronic otitis media.

Mastoid tympanoplasty with a canal wall-up technique provides better conditions for a healthy skin lining than canal wall-down techniques. The formation of retraction pockets in residual pneumatized cavities is however a major cause of cholesteatoma recurrence with canal wall-up techniques. We have therefore attempted to combine the advantages of both canal wall-down and canal wall-up techniques. The posterior wall is kept up, the mastoid is obliterated with adipose tissue, the attic is exteriorized in the ear canal and hearing is restored with a minimal-size hypotympanic cavity only. Preliminary results from 41 cases with a follow-up of 6 months to 6 years suggest that skin conditions in the enlarged ear canal are adequate and that cholesteatoma do not recur.

Ineraid cochlear implant in the ossified cochlea: surgical techniques and results.

Extensive ossification of the cochlea is a common finding in patients with total deafness caused by meningitis, labyrinthitis, or otosclerosis. When the cochlea is totally ossified, the prognosis for achieving free-running speech without lip reading is poor. However, subtotal ossification with residual cochlear patency in the upper basal turn, the middle turn, or the apical turn can be maximally exploited by selective insertion of electrodes. Results can be surprisingly adequate in spite of the poor anatomic conditions. Computed tomography and exploratory cochleotomy, in which electrically evoked auditory brainstem responses are elicited and recorded by intracochlear stimulation are good diagnostic indicators of ossification and residual auditory nerve excitability. "Apical cochleostomy" is an adequate procedure to help penetrate the basal turn in retrograde insertion of the cochlear implant electrode array. Results of this study indicate that the surgical technique and placement of the Ineraid electrode array play a major role in the ability of the patient to achieve understanding of free-running speech.

[The use of PCR for detecting pathogenic microorganisms in water]. / Utilisation de la méthode PCR pour la recherche de micro-organismes pathogènes dans l'eau.

This replication method, which was introduced in 1985, has been used to find and identify microorganisms in the environment, among others in samples of soil, sediments and waters. A gene or a DNA fragment specific to a microorganism is replicated in vitro by a chain reaction catalyzed by DNA polymerase (PCR: Polymerase Chain Reaction) and analyzed by electrophoretic procedures. At the moment in most legislations bacteriological criteria for drinking water depend on E. coli and other bacteria referring to fecal contamination (fecal coliforms and enterococci). Absence of these bacteria does not necessarily exclude contamination of water with protozoa or virus. Detection of the latter by common methods is difficult and time-consuming. Application of PCR to these purposes is interesting. During the last years several protocols have been developed such as methods for the detection of E. coli, bacteria referring to fecal contamination, pathogens like Legionella pneumophila as well as Salmonella and Shigella, enterovirus and protozoa i.e. Giardia. Compared to the traditional methods an obvious advantage of the new methods lies in their velocity, sensitivity and specificity. This review introduces to several different applications of PCR. Although this method is still restricted to specialized laboratories at the moment, it will gain importance as a complement to traditional methods for the detection of pathogenic microorganisms in water as soon as simple tests will be available.

Vowel and consonant identification tests can be used to compare performances in a multilingual group of cochlear implant patients.

Vowel and consonant identification tests were conducted in the sound-only condition in a multilingual group of 13 totally deaf patients who are users of the Ineraid multichannel cochlear implant. Native languages ranged across French, German, Italian, Spanish, Albanian and Swahili. We found high correlations (r > -0.83) among vowel or consonant identification scores and 'subjective ranking' scores established on the basis of a subjective evaluation of the patient's speech reception abilities in the sound-only condition. Detailed analysis demonstrates that the identification of vowel and consonant is dominated by the perception of acoustic cues characteristic of the set of stimuli used as well as by the strengths and weaknesses of the speech processing of the cochlear implant system. We did not find any systematic pattern in the results that could be related to the native language of the patients. These results suggest that vowel as well as consonant identification tests are effective means to compare the performance of cochlear implant patients even across different native languages. They also indicate that, in the future, one can conduct a fewer number of the many different (e.g. nonsense-syllable, word, sentence, speech-tracking) tests when evaluating the speech recognition abilities of patients with the implant.

Diagnosis of cerebellopontine angle tumors.

Between 1980 and 1990, 9,176 patients suffering from otoneurological disorders were investigated in our clinic. Sixty-six (0.72%) internal auditory canal or other cerebellopontine angle tumors (CPAT) were diagnosed. Brainstem auditory evoked potentials (BAEP), interaural time discrimination, and magnetic resonance imaging (MRI) revealed to be the most sensitive and efficient tests for the detection of CPAT. However, the investigation of otoneurological symptoms cannot be limited to BAEP and MRI on the a priori of a hypothetical CPAT. Electrophysiologic tests such as impedancemetry, and electronystagmographic testing are also needed to elucidate the many causes of otoneurological symptoms.

Electrically evoked auditory brainstem responses in cochlear implant patients.

Electrically evoked auditory brainstem responses (EABR) were recorded in completely deaf patients implanted with Ineraid multichannel cochlear implants. Clear and reproducible EABR were obtained from all patients. Parametric differences with auditory brainstem responses (ABR) were demonstrated and can be explained by the different natures of both types of stimulations (electric versus acoustic). Evidence is given that other well-known properties of auditory evoked responses, like 'binaural interaction' or suppression of responses in a forward masking paradigm, can be observed in EABR of implanted patients.

Exploratory cochleotomy. Assessment of auditory nerve excitability and anatomical conditions in cochlear implant candidates.

The exploratory cochleotomy is a new diagnostic procedure for the selection of cochlear implant candidates. We use this procedure to assess the excitability of the auditory nerve, the patency of the cochlea and to detect undesirable side effects of electrical stimulation, such as facial nerve activation. The exploratory cochleotomy is a limited surgical procedure performed under local anesthesia in adults and light sedation in children. It is combined with the recording of electrically evoked brainstem responses elicited by an intracochlear probe electrode.

Geneva experience with the Ineraid multichannel cochlear implant.

Ineraid is a multichannel intracochlear implant of recent design that can provide high levels of speech recognition to totally deaf patients. We chose this device when it became available in 1985 because of our clinical and research interests. We had no commercial ties and could therefore critically assess the value of this implant in an array of patients, including congenital deafness, ossified cochleas and perilingual children.

Indication of a relation between speech perception and temporal resolution for cochlear implantees.

In order to better understand the reasons for success or failure of a cochlear implant system for various patients, it appears necessary to analyze the patients' basic psychophysical capacities in relation to speech perception. Five patients with intracochlear multichannel Ineraid implants were studied in terms of their performance on temporal analysis in relation to their perception of consonants. For temporal analysis we measured the detection of a silent gap in noise and of an interval between two clicks. For consonant perception we established a confusion matrix based on 12 consonants presented in a vowel-consonant-vowel context using the vowel /a/. The results showed a correlation between temporal resolution for two successive clicks at the most basal cochlear electrode used, and the perception of place of articulation of consonants. This finding indicates that delivering fine temporal coding can be crucial for the success of an implant and that for a given subject, optimal capacity for temporal resolution may serve as a criterion for choosing a basal electrode.

Intracochlear potential distribution with intracochlear and extracochlear electrical stimulation in humans.

Intracochlear potential distributions were measured from subjects implanted with the Ineraid multichannel cochlear implant. The electrode array provided direct accessibility for obtaining measurements. Different modes of stimulation were used. The findings with intracochlear monopolar stimulation seem to confirm that significant low-resistance pathways, in which currents can flow into or out of the cochlea, are located in the basal turn. The results with extracochlear stimulation only show small intracochlear potential gradients. This finding suggests that no substantial currents flow along the auditory nerve fibers when extracochlear stimulation is used. These results concur with the electrically evoked auditory brain stem responses, in that intracochlear stimulation consistently elicited auditory brain stem responses, whereas responses elicited at or near the round window by extracochlear stimulation were weak or absent.

Two genes encoding the soybean translation elongation factor eEF-1 alpha are transcribed in seedling leaves.

A cDNA and a genomic DNA library from soybean (Glycine max L.) were used to identify and sequence two genes coding for the alpha-subunit of the translation elongation factor eEF-1. Within the coding part, the two genes (tefS1 and tefS2) diverge in 80 wobble positions thus yielding an identical protein composed of 447 amino acids. The soybean protein has about 95% similarity with eEF-1 alpha proteins of Arabidopsis thaliana and tomato. Both genes S1 and S2 contain, within the coding part at a site seemingly unique to higher plants, a single short intron of 86 and 116 nucleotides, respectively. The untranslated leader part of both genes is interrupted by a large intron (partially sequenced). Genes S1 and S2 are transcribed in young leaves. cDNA and gene-specific oligonucleotide probes interact with a unique transcript of close to 1.9 kb. Northern hybridization studies using RNAs from dark- and light-grown seedlings show that light sharply increases the level of stable transcripts (1.9 kb). A peak value is measured after about 3 h of illumination, afterwards the transcript concentration drops to about 10% of the peak value. Genes S1 and S2 follow a similar transcription pattern in developing seedling leaves, which is distinct from that of the rbcS genes measured in parallel experiments. According to northern results, S1 transcripts are more abundant in leaves at all measured stages of development than S2 transcripts.