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Biomedical subjects

Olivier Sterkers

Publications and source records attributed to Olivier Sterkers.

At least 19 recordsLinked to original sources
PubMed2006

Auditory brainstem implantation to rehabilitate profound hearing loss with totally ossified cochleae induced by pneumococcal meningitis.

Hearing rehabilitation by cochlear implantation is not always possible in case of total ossification after pneumococcal meningitis. We report 3 cases of postmeningitis profound hearing loss with total cochlear ossification in adults who underwent auditory brainstem implantation (Nucleus 22, Cochlear Inc., Lane Cove, Australia) between 1999 and 2004. The postoperative follow-up period ranged from 1 to 6 years. Eleven to 15 out of 22 electrodes were activated. All patients had significant speech discrimination in the sound-only mode and an enhanced lip-reading performance with the implant. Auditory brainstem implants are an efficient means of auditory rehabilitation and may be considered in selected cases of bilateral profound hearing loss with the impossibility of cochlear implantation.

Adult↗
PubMed2006

Combined electroacoustic stimulation in conventional candidates for cochlear implantation.

OBJECTIVE: To report on combined ipsilateral electrical and acoustic stimulation in a subset of conventional candidates for cochlear implantation where preoperative pure tone thresholds were </=60 dB HL for 250 and 500 Hz. METHODS: Subjects were 10 adults implanted with the Nucleus 24 Contour Advance perimodiolar electrode array. Soft surgical procedures were strictly observed: </=1.5-mm cochleostomy hole placed anterior and inferior to the round window, a Healon bubble placed over the opening to prevent entry of foreign bodies, and no suction applied. The electrode array was inserted 17 mm to the first marker rib using the recommended 'advance-off-stylet' technique. Pure tone hearing threshold levels were recorded pre-, and postoperatively at 1-2 and 6-12 months. Speech recognition was tested for cochlear implant (CI) alone and combined with ipsilateral hearing aid for 7 subjects who retained significant residual hearing in the implanted ear at 1-2 months after operation. RESULTS: There were 3/10 cases where 1-2 months after operation low-frequency responses were considered vibrotactile only (>85-110 dB HL, 250-500 Hz). In the remaining 7 cases, residual hearing was maintained up to at least 6 months after operation with minor changes. Insertion depth angles in these cases ranged from 285 to 420 degrees . For these subjects, the mean preoperative score for words presented at 65 dB SPL was 22%. Mean postoperative scores were 56% for CI alone, and 68% for CI plus ipsilateral hearing aid (p < 0.05, paired t). For sentences presented in multitalker babble noise at 5 dB SNR, mean scores were 61% CI alone, and 75% CI+IpsiHA (p < 0.01, paired t). CONCLUSIONS: Hearing was conserved during surgery and over time in 70% of conventional candidates implanted with the Nucleus 24 Contour Advance CI who had significant levels of preoperative low-frequency residual hearing (</=60 dB HL). These conventional candidates for CI also benefited from improved speech recognition in noise when using combined ipsilateral electrical and acoustic stimulation.

Acoustic Stimulation↗
PubMed2006

What's new in ion transports in the cochlea?

Recent advances in the field of the physiology of inner ear fluids permitted the characterization of the molecular mechanisms involved in critical processes such as the absorption of K(+) through cochlear sensory hair cells (mechanoelectrical transduction) or the secretion of K(+) by marginal cells of the stria vascularis. In addition, new pathways for ion circulations were evidenced. Mutations of transporters involved in some of these pathways, especially in K(+) recycling through gap junction systems, and in local pH regulation, are among the most frequent etiologies of genetic deafness in humans.

Acid-Base Equilibrium↗
PubMed2006

Atypical haemangioma of the internal auditory meatus: a case report.

Haemangiomas involving the internal auditory meatus (IAM) are rare and can mimic other frequent lesions of the IAM such as schwannomas by their clinical and imaging aspects. The case of a patient with an atypical IAM haemangioma fluctuating in size is reported to highlight this diagnostic possibility. A 36-year-old female presented with a sudden and recurrent left sensorineural hearing loss (SNHL). Three consecutive MRIs were performed in a 10-month period of preoperative observation. They showed a fluctuation of the tumour signal and size. The surgical removal was performed via a translabyrinthine approach. Pathological findings were consistent with the diagnosis of a heamangioma. MRI and CT findings suggested the diagnosis of IAM heamangioma, but the rapid variation in size and signal was misleading. This phenomenon may be due to haemorrhage or oedema, and can be accompanied by a deterioration of the hearing function. Early surgical resection is the treatment of choice and allows to confirm the diagnosis.

Adult↗
PubMed2006

[Effects of noise on inner ear].

The effects of noise on health depend both on individual factors and characteristics of sound exposure. In case of acoustic trauma, reversible or irreversible lesions of inner ear components are possible. Most often there is immediately an acute tinnitus and hearing loss. Audiometric tests demonstrate hearing loss on the high frequency, generally focused on 4 kHz. Immediate treatment is recommended even there is no currently indicator of the ability to restore hearing. New perspectives on treatment are directed to local treatment and/or using new procedure as antioxidative treatment. Occupational and leisure are the two conditions in which chronic exposure to noise is found. Detection and prevention of noise-induced hearing loss is easier in case of industrial workers than in case of noise exposition for musicians and other sounds and stage technicians or concert managers, and of course non-professional with exposure to amplified music.

Ear, Inner↗
PubMed2006

Intratumoral and brainstem hemorrhage in a patient with vestibular schwannoma and oral anticoagulant therapy.

OBJECTIVE: To report the first case of spontaneous intratumoral and brainstem hemorrhage in a patient with a vestibular schwannoma. STUDY DESIGN: Case report and review of the literature. SETTING: University-based, tertiary referral center. PATIENT: A 73-year-old woman with a vestibular schwannoma, anti-vitamin K overdose, and arterial hypertension experienced a rapid onset of headache, facial palsy, diplopia, and hoarseness. INTERVENTIONS: The patient was admitted to the intensive care unit and treated with vitamin K and corticoids. MAIN OUTCOME MEASURES: Clinical and radiologic findings. RESULTS: At admission, the magnetic resonance imaging and computed tomographic scans showed an intratumoral hemorrhage. The patient entered a coma 24 hours after the onset of the symptoms. At that time, the computed tomographic scan demonstrated a massive intratumoral and brainstem hemorrhage. The patient died 3 days later. CONCLUSION: Intratumoral, subarachnoid, and brainstem hemorrhages can occur in patients with vestibular schwannoma. Oral anticoagulant therapy is a risk factor for tumor-related hemorrhage.

Administration, Oral↗
PubMed2006

Residual hearing conservation and electroacoustic stimulation with the nucleus 24 contour advance cochlear implant.

OBJECTIVE: To assess the conservation of residual hearing in recipients of the Nucleus 24 Contour Advance cochlear implant (CI) and the benefits of combined electrical and acoustic stimulation. STUDY DESIGN: Prospective multicenter study. SETTING: CI clinics in Western Europe. PATIENTS: Adult candidates for conventional cochlear implantation with a minimum preoperative word recognition score of 10% in the ear to be implanted. INTERVENTION: "Soft-surgery" protocol, including a 1- to 1.2-mm anterior and inferior cochleostomy hole with the electrode array, inserted 17 mm using the "advance-off-stylet" technique. Patients with postoperative pure-tone hearing threshold levels (HTLs) of 80 dB hearing loss or less at 125 and 250 Hz and 90 dB hearing loss or less at 500 Hz were refitted with an in-the-ear hearing aid for combined ipsilateral electrical and acoustic (El-Ac) stimulation. MAIN OUTCOME MEASURES: A questionnaire to collect information regarding surgery. Pure-tone HTLs measured at intervals. Word recognition tested in quiet and sentence recognition tested in noise at 10 and 5 dB signal-to-noise ratio (SNR). HEARING CONSERVATION RESULTS: HTL data were available for 27 patients. HTLs were conserved within 20 dB of preoperative levels for 33, 26, and 19% of patients for 125, 250, and 500 Hz, respectively. However, the recommended soft-surgery protocol was strictly followed in only 12 of 27 patients. For these 12 patients, hearing thresholds were conserved within 20 dB for 50, 50, and 33% of patients. Median threshold increases were 40 dB (range, 250-500 Hz) for the whole group and 23 dB for the strict surgery group. Ten patients retained sufficient HTLs to enter the El-Ac user group. SPEECH RECOGNITION RESULTS: Group mean recognition scores for nine El-Ac users for words presented at 65 dB sound pressure level were 45% for CI alone and 55% for CI + ipsilateral hearing aid (p < 0.05, paired t). For sentences presented in noise at 5 dB SNR, mean word scores were 46% CI alone and 56% CI + ipsilateral hearing aid (p < 0.01, paired t). CONCLUSION: Hearing was conserved for conventional candidates for cochlear implantation where the recommended soft-surgery protocol was strictly adhered. Combined ipsilateral electrical and acoustic stimulation provided considerable benefits for speech recognition in noise, equivalent to between 3 and 5 dB SNR, compared with CI alone.

Acoustic Stimulation↗
PubMed2006

Glucocorticoids inhibit diastrophic dysplasia sulfate transporter activity in otosclerosis by interleukin-6.

HYPOTHESIS/OBJECTIVE: Otosclerosis is a bone remodeling disorder localized to the otic capsule and associated with inflammation. In vitro, increased activity of the diastrophic dysplasia sulfate transporter (DTDST), which is implicated in bone metabolism, has been reported. Because glucocorticoids modulate the bone turnover and inhibit inflammatory processes, we investigated the effect of dexamethasone (Dex) on interleukin-6 and DTDST in otosclerosis. STUDY DESIGN: The authors conducted a prospective, case-control study. MATERIALS AND METHODS: Primary cell cultures were obtained from stapes and external auditory canals in otosclerosis (n = 21) and control patients (n = 18). Assays with [H]Dex evaluated specific binding sites in otosclerotic and control stapes. The effects of Dex (10 to 10 M) and RU486 (10 M), a glucocorticoid antagonist, were studied on DTDST activity by sulfate uptake. IL-6 secretion was measured in culture media before and after Dex (10 M, 24 hours). The effect of IL-6 (10 M, 24 hours) was assessed on DTDST activity in control stapes. RESULTS: : The number of specific Dex-binding sites was similar in all stapedial cultures. Dex inhibited DTDST activity (19.4 +/- 1.02 vs. 29.4 +/- 3.94 pmol/microg prot/5 minutes) only in otosclerotic stapes. This effect was dose-dependent, antagonized by RU 486 and only observed 24 hours after Dex exposure. Interleukin (IL)-6 stimulated DTDST activity in normal stapes, whereas Dex inhibited IL-6 production only in otosclerotic stapes. CONCLUSION: Dex inhibits the DTDST activity, at least in part, through a reduction of IL-6 secretion only in otosclerotic cells. This effect is mediated through the glucocorticoid receptors and may lead to the reduction of bone turnover.

Analysis of Variance↗
PubMed2005

Detection of labyrinthine fistulas in human temporal bone by virtual endoscopy and density threshold variation on computed tomographic scan.

OBJECTIVE: To assess the sensitivity of the routine computed tomographic (CT) scan of the temporal bone coupled to a virtual endoscopy, with density threshold variation, in detecting small fistulas in human temporal bone specimens. DESIGN: Single-blind, before-after trial. SETTING: This study was carried out in a research laboratory in collaboration with a radiology department. PATIENTS: Five human adult temporal bone specimens were included. INTERVENTIONS: The fistulas were created with calibrated burrs (0.3, 0.5, and 0.8 mm) in the 3 semicircular canals and in the promontory of 3 temporal bones. Two other temporal bones served as controls. All bones underwent CT scan (1-mm section thickness) before and after dissection. Three-dimensional images were obtained from CT scan native axial views at different density reconstruction thresholds. The virtual endoscope was placed in the middle ear cavity looking to the inner ear wall. The threshold at which a bony defect appeared on virtual endoscopic images (opening threshold in Hounsfield units [H]) was noted for each location. MAIN OUTCOME MEASURES: Opening thresholds before and after dissection. RESULTS: On standard axial views, fistulas smaller than 0.5 mm were not visualized. By virtual endoscopy, all fistulas could be visualized. The opening threshold decreased after fistula creation in the semicircular canals (1244 +/- 50.5 H [n = 36] vs 778 +/- 52.4 H [n = 34]; P<.001; 1-way analysis of variance and Dunnett multiple comparisons posttest) and in the promontory (1541 +/- 37.8 H [n = 12] vs 1334 +/- 35.1 H [n = 8]; P<.001). The opening thresholds in the control specimens remained unchanged after dissection. CONCLUSION: Virtual endoscopy with variation of reconstruction threshold allows the detection of small labyrinthine fistulas with diameters of 0.3 mm or smaller.

Adult↗
PubMed2005

[Auditory rehabilitation].

Auditory rehabilitation depends of the cause and the severity of the hearing loss (or deafness). Hearing losses dues to middle ear pathologies can beneficiate of medical or surgical treatments, by ossicular prostheses, if it is necessary to restore the function of the ossicles chain. In the sensorineural hearing losses, with inner ear pathology, the use of auditory aid is immediately considered. In the cases for which they are insufficient because of severity of the hearing loss or not suitable because of local non-tolerance, it is possible to use middle ear implant or cochlear implant. The indications of the auditory brainstern implants remain at this day limited to the total bilateral hearing losses due to a complete destruction of cochleae and auditory nerves. These therapeutic orientations are selected after a multidisciplinary evaluation of the deaf person, evaluation that allows the characterization of the hearing loss and its repercussion. In all the cases, the restoration of a bilateral hearing has to be done if possible, making an improvement of the speech comprehension, mainly in the noisy situations, as well as the localization of the sound sources.

Cochlear Implants↗
PubMed2005

Preservation of residual hearing with cochlear implantation: how and why.

CONCLUSIONS: Hearing may be conserved in adults after implantation with the Nucleus Contour Advance perimodiolar electrode array. The degree of hearing preservation and the maximum insertion depth of the electrode array can vary considerably despite a defined surgical protocol. Residual hearing combined with electrical stimulation in the same ear can provide additional benefits even for conventional candidates for cochlear implantation. OBJECTIVES: We present preliminary results from a prospective multicentre study investigating the conservation of residual hearing after implantation with a standard-length Nucleus Contour Advance perimodiolar electrode array and the benefits of combined electrical and acoustic stimulation. MATERIAL AND METHODS: The subjects were 12 adult candidates for cochlear implantation recruited according to national selection criteria. A "soft" surgery protocol was defined, as follows: 1-1.2-mm cochleostomy hole anterior and inferior to the round window; Nucleus Contour Advance electrode array inserted using the "Advance-off-stylet" technique; and insertion depth controlled by means of three square marker ribs left outside the cochleostomy hole. These procedures had been shown to reduce insertion forces in temporal bone preparations. Variations in surgical techniques were monitored using a questionnaire. Pure-tone thresholds were measured pre- and postoperatively. Patients who still retained thresholds <90 dB HL for frequencies up to 500 Hz were re-fitted with an in-the-ear (ITE) hearing aid. Word recognition was tested in quiet and sentence perception in noise for the cochlear implant alone and in combination with an ipsilateral hearing aid. RESULTS: Hearing threshold level data were available for 12 patients recruited from 6 of the centres. Median increases in hearing threshold levels were 23, 27 and 33 dB for the frequencies 125, 250 and 500 Hz, respectively. These median increases include the data for two patients who had total loss of residual hearing due to difficulties encountered during surgery. "Cochlear view" X-ray images indicated that the depth of insertion varied between 300 and 430 degrees, despite modest variations in the length of the electrode inserted (17-19 mm). The insertion angle had some influence on the preservation of residual hearing at frequencies of 250-500 Hz. Six of the 12 patients retained sufficient hearing for effective use of an ipsilateral ITE hearing aid (< or = 80 dB HL at 125 and 250 Hz; < or = 90 dB HL at 500 Hz). Word recognition scores in quiet were improved from 10% to 30% with the cochlear implant plus ipsilateral hearing aid in 3 patients who had at least 3 months postoperative experience. Signal:noise ratio thresholds for sentence recognition were improved by up to 3 dB. Patients reported that they experienced greatly improved sound quality and preferred to use the two devices together.

Adult↗
PubMed2005

Conservative management versus surgery for small vestibular schwannomas.

A high rate of deterioration in hearing function and the loss of patient compliance during conservative management should be taken into account when considering hearing preservation strategies for patients with vestibular schwannoma (VS). To compare conservative management with surgery for solitary small VS. Among 693 patients followed up for VS between 1991 and 2002, 114 (16%) intracanalicular VSs (stage 1) and 302 (44%) VSs measuring <15 mm in the cerebellopontine angle (stage 2) were included in this study. Initially, surgery was performed in 305 (73%) cases (50 stage 1, 255 stage 2) and 111 (27%) were managed conservatively (64 stage 1, 54 stage 2) by means of annual MRI scans and audiometry. Conservative management was chosen in patients aged >60 years and in those who refused surgery. In this subgroup, the mean follow-up period was 33 months (range 6-111 months). In the conservative management group, 47% of VSs showed significant growth, 47% were stable and 6% showed regression. Seventeen patients (15%) were operated on secondarily for tumour growth and 1 (1%) was irradiated for tumour growth and because surgery was contraindicated. Deterioration of hearing function by > or =1 class was observed in 56% of cases, 34% of patients were initially in hearing class D and only 10% showed stable hearing function. Of the conservative management group, 17% were lost during follow-up. After surgery, grade 1 or 2 facial function was obtained in 86% of cases. Following hearing preservation attempts (n=137), 54% of patients were in hearing classes A-C.

Adolescent↗
PubMed2005

Comparison between intraoperative observations and electromyographic monitoring data for facial nerve outcome after vestibular schwannoma surgery.

A four-channel device may enhance the sensitivity of electromyography (EMG). Determination of stimulation thresholds (STs) below 0.05 mA improves facial prognostic information after vestibular schwannoma (VS) surgery. To compare intraoperative observations with electromyographic data for predicting the immediate facial function outcome after VS surgery.A total of 111 VS patients operated on and intraoperatively monitored using four-channel facial EMG between October 2002 and September 2003 were included in this multicentre, prospective study. Mascular activity detection was performed in the frontal, orbicularis oculi, orbicularis oris and platysma muscles. Intraoperative observations were made concerning adhesion and nerve stretch, and facial function was graded (House-Brackmann classification) at postoperative Days 1 and 8.Facial function at postoperative Days 1 and 8 was related to the intraoperative nerve STs at the brainstem and in the adhesion zone (range 0.01-3 mA for a response > 100 microV). At postoperative Day 8, good facial function (Grades 1 or 2) was observed in 93% of cases for STs in the adhesion zone of 0.01-0.04 mA, 85% for STs of 0.05-0.3 mA and 79% for STs > 0.3 mA. These STs were related to the degree of tumor adhesion and not to the nerve stretch. The maximal EMG response was detected in the frontal or platysma muscles in 26% of cases, and in the orbicularis oris and orbicularis oculi muscles in 74%.

Adolescent↗
PubMed2005

Four-channel electromyography of the facial nerve in vestibular schwannoma surgery: sensitivity and prognostic value for short-term facial function outcome.

OBJECTIVE: To evaluate the short-term facial prognostic value of a four-channel facial electromyographic device in vestibular schwannoma surgery. STUDY DESIGN: Eighty-nine vestibular schwannomas operated on and intraoperatively monitored by a four-channel facial electromyographic device between October 2002 and September 2003 were included in this prospective study. Detection was performed in frontal, orbicularis oculi, orbicularis oris, and platysma muscles. MAIN OUTCOME MEASURE: Facial function grading at postoperative Days 1, 8, 30, and 180 (House-Brackmann classification). SETTING: Tertiary referral center. RESULTS: Postoperative facial function at Day 180 was assessed as Grade 1 or 2 in 80%, as Grade 3 or 4 in 16%, and as Grade 5 or 6 in 4% (n=80). The postoperative facial function was related to the intraoperative nerve stimuli thresholds (range, 0.01-3 mA for a response >100 microV) near the brainstem and the proximal-to-distal ratio of the stimulation threshold. A proximal threshold between 0.01 and 0.04 mA had a positive predictive value of 94% for good facial function (Grade 1 or 2). The proximal threshold was lower in patients with improving or stable facial function in comparison with those with a delayed deterioration between Days 8 and 30. The stimulation threshold at the adhesion zone was related to the immediate facial function outcome. The maximal electromyographic response was detected in the frontal muscle or the platysma in 27% of cases and in orbicularis oris and oculi in 73% of cases. CONCLUSION: A four-channel device may enhance electromyographic sensitivity. Determination of stimulation threshold below 0.05 mA yields facial prognostic information.

Adolescent↗
PubMed2005

Consensus statements on the BAHA system: where do we stand at present?

After more than 25 years of clinical experience, the BAHA (bone-anchored hearing aid) system is a well-established treatment for hearing-impaired patients with conductive or mixed hearing loss. Owing to its success, the use of the BAHA system has spread and the indications for application have gradually become broader. New indications, as well as clinical applications, were discussed during scientific roundtable meetings in 2004 by experts in the field, and the outcomes of these discussions are presented in the form of statements. The issues that were discussed concerned BAHA surgery, the fitting range of the BAHA system, the BAHA system compared to conventional devices, bilateral application, the BAHA system in children, the BAHA system in patients with single-sided deafness, and, finally, the BAHA system in patients with unilateral conductive hearing loss.

Adult↗
PubMed2004

Long-term functional outcome in facial nerve graft by fibrin glue in the temporal bone and cerebellopontine angle.

The aim of this study was to evaluate the functional outcome of facial nerve repair with fibrin glue in end-to-end anastomosis and intermediate nerve graft. Thirty-six patients undergoing facial nerve repair by end-to-end anastomosis or facial nerve grafting using exclusively fibrin glue between 1986 and 1999 were included in this retrospective study. The population comprised ten vestibular schwannomas (28%), nine temporal bone fractures (25%), seven facial nerve schwannomas (19%), four facial nerve hemangiomas (11%), two iatrogenic facial nerve interruptions (6%) and four miscellaneous facial nerve lesions (11%). Data were reviewed concerning etiology, location of the nerve interruption, type of repair and postoperative facial function according to the repaired facial nerve recovery scale (A: normal; B: independent movements of eyelid and mouth; C: strong closure of eyelids and mouth; D: incomplete eyelid closure; E: minimal movement; F: no movement). Eleven patients (31%) underwent end-to-end nerve anastomosis and 25 (69%) underwent intermediate facial nerve grafting. The mean follow-up period was 50 months (range: 3-95). Among patients followed-up more than 18 months (n = 20), a score of B or C was obtained in 16 patients (80%), a score D in 2 cases (10%) and a score E in 2 cases (10%). The type of repair and the site of interruption did not influence the results. Fibrin glue is a simple, rapid and efficient means of facial nerve repair. In case of intraoperative facial nerve interruption, this type of repair can be attempted in any location at the time of the tumor removal.

Adolescent↗
PubMed2004

Large deletion of the GJB6 gene in deaf patients heterozygous for the GJB2 gene mutation: genotypic and phenotypic analysis.

Recent investigations identified a large deletion of the GJB6 gene in trans to a mutation of GJB2 in deaf patients. We looked for GJB2 mutations and GJB6 deletions in 255 French patients presenting with a phenotype compatible with DFNB1. 32% of the patients had biallelic GJB2 mutations and 6% were a heterozygous for a GJB2 mutation and a GJB6 deletion. Biallelic GJB2 mutations and combined GJB2/GJB6 anomalies were more frequent in profoundly deaf children. Based on these results, we are now assessing GJB6 deletion status in cases of prelingual hearing loss.

Connexin 26↗