Magnetic resonance imaging with the Digisonic SP Neurelec cochlear implant.

The goal of this study was to evaluate the MR compatibility of the Neurelec Digisonic SP cochlear implant by performing in vitro and in vivo tests. All tests were performed on 1.5 T machine. Torque and force were measured to observe a potential displacement of the internal receiver. Demagnetisation of the internal magnet was monitored inside the MRI scanner and outside the MRI scanner (in the MRI room). Potential-induced voltage on electrodes was measured in vitro, performing the usual MR sequences. Heating around the internal receiver was measured after the same MR sequences. Following in vitro tests, in vivo MR imaging (brain and posterior fossa MRI) was performed to evaluate the induced signal void and geometrical distortion. In vivo test was performed with one volunteer who had a cochlear implant device fixed to the surface of the skin with a bandage. All the in vitro tests were in compliance with standard EN 45502-2-3 relating to Cochlear Implants. In vivo MRI scans demonstrated an image distortion for spin echo sequences of 7 cm maximum around the internal magnet. Magnetic resonance imaging with the Neurelec Digisonic SP cochlear implant is possible with no measurable adverse effects for either the patient or the device. Image artefact around the internal magnet, however, is unavoidable.

[The conventional hearing aid]. / La prothèse auditive conventionnelle.

The conventional hearing aid has benefited from the progress made in electronic miniaturization and digital signal processing. The prescriber should be familiar with these improvements, the anatomic and acoustic limitations related to hearing aids, the possibilities of surgical rehabilitation, as well as the indications for other auditive rehabilitation techniques (bone conduction hearing, middle ear implant, and cochlear implant). A hearing aid should be prescribed within a precise context taking into account patient history, clinical examination, audiometric testing, and choice of the device. Optimal management of a hearing device for a child should be conducted within an adapted network including a specialized ENT physician, audiophonology, a qualified hearing prosthetist, a speech therapist, etc.).

[Intraoperative auditory monitoring in acoustic neurinoma surgery]. / Monitoring auditif et chirurgie du neurinome de l'acoustique.

Intraoperative auditory monitoring in acoustic neuroma surgery is used to improve residual hearing. Three techniques are available: monitoring of brainstem auditory evoked potentials, of electrocochleography or of direct eighth nerve compound action potential. The three techniques with their advantages and disadvantages are discussed. The current trend is to monitor brainstem auditory evoked potentials using digital filtering or to monitor the eighth nerve compound action potential.

A longitudinal study on postoperative hearing thresholds with the Vibrant Soundbridge device.

The Vibrant Soundbridge is a semi-implantable middle ear hearing device used in the rehabilitation of adults with sensorineural hearing loss. In order to evaluate the long-term effects of the implanted part of the device, audiological data from 39 patients implanted over several implant sites across France were collected and analyzed retrospectively. The mean follow-up time was 16 months; 25 patients had a follow-up period of over 1 year. Surgery was uneventful in all cases. The present study of the 39 implanted patients with a mid- to long-term follow-up found a statistically significant modification of hearing thresholds (pre- versus postoperative) for frequencies of 0.5 and 4 kHz. However, the shift of threshold was rather limited (2.79 and 3.34 dB, respectively), and this variation was not statistically different from the evolution of the opposite non-operated ear.

[Management of head and neck Langerhan's cell histiocytosis in children]. / Du diagnostic à la prise en charge des localisations ORL de l'histiocytose Langerhansienne chez l'enfant.

OBJECTIVES: Langerhan's cell histiocytosis is an uncommon disease characterized by abnormal proliferation of Langerhan's cells into different organs and tissues. Head and neck involvement is commonly described and presents a difficult management challenge. We report our experience at the Lille University Hospital and review the main features of this disease and current management strategies. PATIENTS AND METHODS: We analyzed retrospectively 25 cases of Langerhan's cell histiocytosis treated in our center between 1978 and 2001. Attention was focused on head and neck involvement in order to assess the clinical, therapeutic, and prognostic significance of these localizations. RESULTS: Head and neck involvement is frequently encountered in Langerhan's cell histiocytosis. Although morbidity and mortality are changed little by this localization, management decisions are greatly affected. A multidisciplinary approach is necessary. CONCLUSION: Current therapeutic approaches are in favor of a wait and see policy or chemotherapy instead of aggressive local treatments including surgery or radiotherapy.

[Clinical implications of acoustic neuromas growth rate in volumetric study]. / Etude volumétrique de la croissance des neurinomes de l'acoustique.

OBJECTIVE: The pattern of neuroma growth is of great importance in choosing the appropriate management. This paper tests the clinical impact of tumor growth rate assessed by volumetry. There is a conviction that some slowly growing tumors could be observed for many years. METHOD AND PATIENTS: Volume measurements were performed on T1- weighted MR images (spin echo sequences) after injection of gadolinium using a special dedicated software. The studied group included 17 patients in whom at least two MRI examinations were carried out and tumor growth was confirmed. The intervals between initial and the first follow-up examination were 14.2 months on the average. In 7 cases tumor evolution was observed in 2 periods (3 MRI studies) and in 4 cases in 3 periods (4 MRI studies). RESULTS: The growth rate depended on tumors volume and clinical stage (P<0.01). Small tumors can be observed more safely than advanced tumors because their increase in mass is lower. CONCLUSION: The observation with the tumoral volume measurements appears to be a useful and accurate tool to estimate the tumor growth rate. The growth rate is a major factor for choosing the appropriate management.

A multicenter study of the Vibrant Soundbridge middle ear implant: early clinical results and experience.

OBJECTIVE: The Vibrant Soundbridge (VBS; Symphonix Devices, Inc., San Jose, CA, U.S.A.) is an active, semi-implantable, middle ear hearing device that directly drives the ossicular chain and is used in the treatment of patients with mild to severe sensorineural hearing loss. The benefits of the VBS and the effects of surgery were examined and compared with the preoperative aided condition in 25 patients with implants. STUDY DESIGN: Single-subject repeated-measures evaluations were performed with each patient acting as his or her own control. Objective audiologic measures and subjective questionnaires also were used. SETTING: Five tertiary referral and teaching hospitals. SUBJECTS: Adult patients had bilateral sensorineural hearing loss (average hearing loss, 56 dB; range, 33-80 dB). Twenty-one patients had worn a conventional hearing aid before surgery (11 binaurally, 10 monaurally). Four patients had not used a conventional hearing aid before surgery. INTERVENTION: Rehabilitative. RESULTS: No significant change in residual hearing after surgery was observed. Functional gain was significantly superior with the VBS. No significant differences were observed for aided speech recognition in quiet. A significant improvement in communication in various listening conditions was reported with the VBS as compared with conventional hearing aids. CONCLUSION: The VBS surgical implantation procedure does not affect the residual hearing level in the implanted ear, nor does it present any unacceptable risk. Measurable benefit from the VBS in comparison with conventional amplification was demonstrated with regard to the provision of superior usable amplification and greater ease in communication in daily listening environments for the majority of patients.

[Bacterial epidemiological study of acute otitis media in children observed at home in the Nord Pas-de-Calais region]. / Etude de l'épidémiologie bactérienne de l'otite moyenne aiguë de l'enfant observée en ville dans la région Nord Pas-de-Calais.

BACKGROUND: The aim of this work is the study of the bacteriologic epidemiology of acute otitis media in infants observed at home in Nord Pas-de-Calais area, and the analysis of bacteria associated to recurrent otitis and clinical failure. OBSERVATIONS: A total of 295 specimens of ear pus specimens were collected from children (mean age: 18 months; average: one month-12 years). Pneumococcus strains were isolated from 52% of samples and 80% of these showed resistance to penicillin. H. influenzae was found in 35% of specimens and the half produced a beta lactamase. Pneumococcus is the predominant pathogen isolated in prolonged otitis media, while H. influenzae is preferentially found during recurrent otitis media. The main bacteriologic cause of failure traitement was penicillin-intermediate or -resistant pneumococci. The therapy administered 48 to 72 hours before collection of ear pus sample in therapeutic failure was ineffective (oral cephalosporins or macrolides), or administered to low dosage (50 mg/kg/j). CONCLUSION: Our results demonstrate, in opposition to other studies, Streptococcus pneumoniae as the most frequent pathogen in acute otitis media. They also show the excellent correlation between antibiotic therapy and clinical failures.

[The monaural pseudo-stereophonic hearing aid (BAHA) in unilateral total deafness: a study of 29 patients]. / Appareillage mono pseudo stéréophonique par BAHA dans les cophoses unilatérales: à propos de 29 patients.

For many years, unilateral total deafness has been considered a minor handicap which does not require the fitting of a hearing aid. If the condition did give a major problem, the usual recommendation for this type of hearing loss was a CROS system which, in addition to problems of function and aesthetics, gave poor results. Faced with increasing demands from these patients, and given the good performance of bone conduction implants (BAHA), we decided to try to implant these devices on the deaf side, which allowed, by way of transcranial conduction, stimulation of the functioning ear and the re-establishment of a certain degree of stereophonic hearing. This study of 29 patients who were tested by stereophonic audiometry pre- and post-implantation shows that this type of aiding is beneficial, with improvement of the threshold of intelligibility against background noise of between 5 and 15 dB during Hirsch's test, correction of the "dead angle" on the deaf side, and improvement in localisation of sound in space. From the functional point of view, 88% of patients were satisfied with their aid, which they wore for 8 or 9 hours per day, and had a marked improvement in their hearing performance under various conditions which had proved very difficult for them before they were fitted with the aid. These results all demonstrate the effectiveness of the implant used in this way. The fact that sounds are received on the totally deaf side goes a long way towards establishing satisfactory hearing. True stereophonic hearing could not be established in any of the cases, because this requires input from two ears. It is for this reason that we have termed this type of aid as monaural pseudo-stereophonic.

Correlation between Ki-67 index and some clinical aspects of acoustic neuromas (vestibular schwannomas).

Evaluation of the proliferation activity of neuromas has a practical meaning when there are doubts about the complete resection of the tumor. Evaluation of the clinical aspects connected with increased proliferation activity may have a much broader application. The aim of this study was to correlate selected clinical and radiologic aspects of vestibular schwannomas with the results of the Ki-67 index. The studied group included 23 males and 20 females. Unilateral neuromas were stated in 38 cases (mean age, 52.2 years) and bilateral tumors in 5 cases (mean age, 44.2 years). The immunohistochemical tests (Ki-67) were performed on the specimens preserved in formalin and stored in paraffin. The Ki-67 index was estimated in a semiquantitative study. The mean value of Ki-67 index was 1.86%. In case of unilateral neuromas (n = 38), the average Ki-67 index was 1.74%. In 5 cases of bilateral tumors, the index amounted to 2.79% (P = 0.278). No significant correlation was found by comparing the value of the Ki-67 index with the age of patients (P = 0.410: r = 0.128). Significant differences in the value of the Ki-67 index were noted in the sub-groups of tumors that were evaluated radiologically as growing and stable. The mean value of Ki-67 index was 3.17% in the first subgroup; in stable neuromas, it was significantly lower, amounting to 1.11% (P = 0.020). Such results may confirm that the growth rate of vestibular schwannomas varies and may explain the difficulties in estimating the growth of neuromas on the basis of clinical aspects only.

Cochlear fossa enhancement at MR evaluation of vestibular Schwannoma: correlation with success at hearing-preservation surgery.

PURPOSE: To describe a sign in magnetic resonance (MR) imaging that could reflect the state of the cochlear nerve before hearing-preservation surgery in small vestibular schwannomas. MATERIALS AND METHODS: Thirty-one patients with serviceable hearing underwent 1.5-T MR imaging before hearing-preservation surgery. The presence of cochlear fossa enhancement on T1-weighted spin-echo images obtained after the administration of contrast material was compared with the results of hearing-preservation surgery. RESULTS: Cochlear fossa enhancement was present in 13 patients, and all of them had total hearing loss after surgery. There was no cochlear fossa enhancement in 18 patients; 15 maintained serviceable hearing after surgery, and three had postoperative hearing loss with no serviceable hearing (sensitivity, 81%; specificity, 100%). CONCLUSION: Cochlear fossa enhancement on T1-weighted spin-echo images seems to be a reliable sign for analyzing the state of the cochlear nerve. The absence of cochlear fossa enhancement could become an additional criterion for selecting the surgical approach in vestibular schwannomas.

[Prosthetic rehabilitation of unilateral anakusis. Study with stereoaudiometry]. / Réhabilitation prothétique B.A.H.A des cophoses unilatérales. Etude par la stéréaudiométrie.

We studied the clinical and stereoaudiometric results in two patients with unilateral anakusis who were rehabilitated with a bone-transmission prosthesis (B.A.H.A.) on the deaf side. Clinically, both patients improved considerably, recovering their capacity to communicate, particularly in a noisy environment. Sound localization tests demonstrated that the sound source was not precisely localized in space. Inversely, the spatial discrimination tests and the multidirectional tests showed an important improvement in comprehension of speech, particularly in the dead space of the defective hemifield. This recovery was certainly related to improved perception of high frequencies via intracranial transmission enabled by the prosthesis.

The growth of acoustic neuromas in volumetric radiologic assessment.

OBJECTIVE: The volumetric assessments of neuroma were applied for radiologic observation of tumor growth. The hypothesis that most of neuromas are stable or show only slight growth was tested. STUDY DESIGN: This was an observational study. SETTING: The study was performed in the university centers. PATIENTS: The study group included 27 patients with 15 unilateral tumors and 12 bilateral tumors. All patients had at least 2 magnetic resonance imaging (MRI) examinations, and the average interval between initial and control examinations was 11.4 months. MAIN OUTCOME MEASURE: Volume measurements were performed on T1- weighted MRI spin echo sequences after injection of gadolinium using special software. Growth of the tumors was estimated by comparison of the results of three measurements from the initial and control MRI examinations. RESULTS: The growth was confirmed in 17 of 27 tumors (63%). Growth was found in 10 of 12 neuromas of neurofibromatosis type 2 (83.7%). In 15 unilateral neuromas, growth was found in 7 (43%). Unilateral neuromas were observed for a shorter period of time (6.3 months) than bilateral tumors (14.7 months). The correlation between a neuroma volume gain and the follow-up period was statistically significant (p = 0.003, r = 0.544). CONCLUSIONS: The growth of tumors can be confirmed despite a short follow-up period.

BOR and BO syndromes are allelic defects of EYA1.

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disease characterized by varying combinations of branchial, otic and renal anomalies. By positional cloning, a candidate gene, EYA1, homologous to the drosophila eyes absent gene, has recently been identified at 8q13.3 and shown to underlie this syndrome. The name branchio-oto (BO) syndrome has been used to describe a similar combination of branchial and otic anomalies, without the association of renal anomalies. Whether BOR and BO syndromes involve the same gene was unknown. To address this question, we analyzed two large independent families for which each of the 8 affected members present exclusively with BO syndrome. In both families, linkage analysis mapped the causative gene to the same chromosomal region as EYA1. A search for mutations in 9 of the EYA1 coding exons identified a 2-bp insertion segregating in one family and an 8-bp deletion segregating in the other. These results demonstrate that EYA1 also underlies BO syndrome, and that BOR and BO syndromes are allelic defects of this gene.

[Results of hearing preservation in surgery of vestibular schwannoma. Value of combined retrosigmoid and middle fossa approaches]. / Résultats de la conservation de l'audition dans la chirurgie du schwannome vestibulaire. Intérêt de la voie combinée sus-pétreuse et rétrosigmoïde.

We report our experience of hearing preservation in acoustic neurinoma surgery, using combined retrosigmoid and middle fossa approaches. Fifty neurinomas operated on between 1987 and 1994 were included in this retrospective study. Hearing preservation surgery was performed for patients with grade II or grade III tumors (mean average tumor diameter: 14.4 mm), presenting with normal or serviceable pre-operative hearing (pure tonal average decrease less than 50 dB, speech discrimination score better than 50%). Isolated middle fossa approach was used in 3 cases, isolated retrosigmoid approach in 2 cases. The 45 other cases were operated on using both routes during the same procedure. Total removal of the tumor with anatomic facial preservation was performed in all cases. No death occurred. The facial function assessed 3 months after surgery was good in 84% of cases (House-Brackmann grades I or II). The mean follow-up was 42 months. Post-operative hearing was measurable in 48% of cases and serviceable in 30% of cases. The size of the tumor and the level of preoperative hearing appear to be the most important predictive criteria for successful hearing preservation.

Anatomic basis for auditory brainstem implant.

Profound bilateral retrocochlear deafness cannot respond to a cochlear implant. For such patients only electrical stimulation of the cochlear nucleus complex can achieve, at best, a partial restoration of hearing. Based on the experience of the W.F. House group at the House Ear Institute in Los Angeles, we have developed an implantable device with many surface electrodes. A personal study has enabled us to establish the main relationships of the nucleus with the aim of inserting the device in contact with it, and to verify its effectiveness in the region. Histological study of anatomic specimens has shown the presence of spheroid neurone, considered to be the secondary neurone of the auditory pathway, at the level of the area of implantation.

[Our experience of meatotomy in the treatment of paranasal sinus diseases]. / Notre expérience des méatotomies dans le traitement des affections sinusiennes.

Results are presented of patients treated by endonasal microsurgery in the ORL clinic of the Lille UCH between January 1986 and July 1990. The principal affections treated were: chronic sinusitis, aspergillosis and Killian's polyp. The objective of the technique employed, which has evolved progressively, was in each case to eradicate the infectious focus or its cause, and to maintain satisfactory ventilation and drainage of the maxillary sinus. The technique used is described, and results presented based on the responses received from a questionnaire sent to 164 patients.

A physical study of vibrating membranes in developing a middle ear prosthesis.

We present a prosthesis meant to replace the tympano-ossicular set as well as the measuring apparatus for developing and characterizing this prosthesis. Such biocompatible materials as silicone elastomer and Teflon are used. Effects due to aging and sterilization have been negligible. Comparisons with anatomic specimens have yielded good results. Furthermore, the first clinical trials with this prosthesis have been promising.