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Biomedical subjects

P Montandon

Publications and source records attributed to P Montandon.

At least 19 recordsLinked to original sources
PubMed1998

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.

Aged↗
PubMed1996

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.

Adolescent↗
PubMed1996

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.

Adolescent↗
PubMed1995

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.

Adult↗
PubMed1992

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.

Acoustic Stimulation↗
PubMed1992

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.

Adult↗
PubMed1992

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.

Adolescent↗
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↗
PubMed1991

Restoration of hearing with type V tympanoplasty.

Type V tympanoplasty with fenestration of the oval window and protection of the round window in a residual hypotympanic cavity can be considered as the last-chance procedure for rehabilitation of hearing in ears with 'canal wall down' or other conditions. The review of 64 cases suggests that restoration of hearing can be adequate in the majority of cases.

Adipose Tissue↗
PubMed1991

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.

Cochlea↗
PubMed1991

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.

Cochlear Implants↗
PubMed1991

Bilateral electrical stimulation of a congenitally-deaf ear and of an acquired-deaf ear.

Two identical multichannel intracochlear prostheses were implanted in the same patient. The first prosthesis, implanted in the congenitally-deaf right ear, elicited clear sound perception but no speech recognition. After 2 years, a second prosthesis, implanted in the acquired-deaf left ear, enabled the patient to understand speech without lip-reading. Brainstem and middle-latency evoked potentials were similar with electrical stimulation of both ears and resembled those evoked by acoustic stimuli in subjects with normal hearing. Cortical electric and magnetic responses differed for right- and left-sided electrical stimulation suggesting that stimulation of the congenitally-deaf ear elicited an abnormal activation of the auditory cortex. These results suggest that only cortical responses were affected by the different histories of deafness of the ears.

Cochlear Implants↗
PubMed1991

[The "Ineraid" multichannel cochlear implant].

In Geneva from 1985 to November 1990, we have implanted 21 Ineraid TM multichannel-cochlear implants in 18 totally deaf patients. On the basis of our experience we have divided the patients in 2 categories: optimal cases and difficult cases. Optimal cases had post lingual deafness and adequate anatomical conditions for implantation. They all recovered understanding of free running speech without lip-reading. Difficult cases had ossified cochlea or pre-and-perilingual deafness: results are variable and less predictable. The cochlear implant is both an artificial sense organ and a prosthetic device. With the aid of the prothesis the patient can hear. When the processor stops functionning the patient is again totally deaf. Implanted deaf patients require life-long technical and medical support.

Cochlear Implants↗
PubMed1991

[Surgical treatment of Ménière's disease by sacculotomy, cochleo-sacculotomy and transtympanic aerators].

Sixty-two patients suffering from severe Ménière's disease with invalidating vertigo attacks were treated between 1976 and 1987 by three minoir surgical procedures: sacculotomy (19), cochleo-sacculotomy (15) or a transtympanic ventilation tube (28). The results were assessed after the second post-operative year according to the criteria of the American Academy of Otolaryngology (1985). The overall success rate for vertigo control was 79% with sacculotomy, 80 with cochleo-sacculotomy and 82% with transtympanic ventilation tubes. Severe permanent hearing-losses occurred in 20% after sacculotomy and cochleo-sacculotomy. Drop-attacks were not improved. These three surgical procedures give similar results with respect to vertigo control without any vital risk. The precise mechanisme of action in these procedures is not yet well understood.

Evaluation Studies as Topic↗
PubMed1990

Binaural interaction in a cochlear implant patient.

Binaural interaction was demonstrated in electrically evoked brainstem responses (EBRs) of a bilaterally implanted patient. A clear binaural difference waveform (BD), consisting of a negative peak near 3.6 ms followed by a positive peak near 4.4 ms, was found by subtracting the recordings with diotic stimulation from the sum of the recordings with monotic stimulation. These results are consistent with those reported for normal subjects and suggest that neural processing in this patient might resemble those ordinarily used in binaural hearing. They strengthen the argument that EBRs in cochlear implant patients do result from activity in auditory brainstem neurons and suggest a method for aligning the positions of the intracochlear electrodes.

Brain Stem↗