Calculation of the Faradaic Impedance of the Electrode-Tissue Interface Improves Prediction of Behavioral T/C Levels in Cochlear Implant Patients.

Background: Fitting of cochlear implants is a labor-intensive process, and therefore automated fitting procedures are being sought. The objective of this study was to evaluate if decomposition of the complex impedance of the electrode-tissue interface could provide additional parameters that show improved correlation with the behavioral T/C levels.

Methods: A new method for decomposing the complex impedance of the electrode-tissue interface was developed and tested in 18 patients in a prospective study in a tertiary otologic referral center.

Prediction of Behavioral T/C Levels in Cochlear Implant Patients Based Upon Analysis of Electrode Impedances.

Background: Fitting cochlear implants in babies and noncooperative patients is cumbersome and time consuming. Therefore, objective parameters have been sought in order to predict the subjective threshold (T) and maximum comfort (C) levels. Measurements of the electrically evoked compound action potentials (ECAPs) have been widely used for this purpose, yet the correlation between these objective measures and the subjective T/C levels is weak to moderate.

Influence of the pre- or postlingual status of cochlear implant recipients on behavioural T/C-levels.

Introduction: Previous auditory experience modifies the sensitivity of the auditory cortex to the afferent activity of the auditory pathways and may influence the threshold (T) and comfort (C) levels in patients receiving a cochlear implant (CI). Literature data on this particular topic is very scarce.

Objective: This study aimed to evaluate the differences in T/C-levels between pre- and postlingually implanted cochlear implant patients.

The Bony Obliteration Tympanoplasty in Pediatric Cholesteatoma: Long-term Hearing Results.

Objective: To present the hearing results of a 5-year longitudinal study in a pediatric population undergoing surgery for extensive cholesteatoma using a canal wall up (CWU) approach with bony obliteration of the mastoid and epitympanic space, with a standard residual rate of 5.8%, a recurrence rate of 2.9%, and all ears waterproof, free of otorrhea and all external ear canals patent and self-cleaning.

Treatment of traumatic stapediovestibular luxation: case report with the introduction of a new technique and review of literature.

Objective: Stapediovestibular luxations are rare lesions that are most commonly caused by direct, penetrating trauma to the external ear canal. In this type of ossicular dislocation, disruption of the annular ligament or footplate fracture may lead to a perilymphatic fistula (PLF) presenting with cochleovestibular symptoms including (progressive) sensorineural hearing loss, tinnitus, and vestibular symptoms. The objective of this article is to define the optimal treatment of stapediovestibular luxations and review the literature on this topic.

Prognostic significance of electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.

Objective: To assess the prognostic significance of pre-operative electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.

Methodology: Retrospective study design in a tertiary referral neurology unit. We studied a total of 123 patients with unilateral vestibular schwannoma who underwent microsurgical removal of the lesion.

Earlier intervention leads to better sound localization in children with bilateral cochlear implants.

We present sound localization results from 30 children with bilateral cochlear implants. All children received their implants sequentially, at ages from 6 months to 9 years for the first implant and 1.5-12 years for the second implant, with delays of 10 months to 9 years.

Sound localization, sound lateralization, and binaural masking level differences in young children with normal hearing.

Objectives: In this study, procedures for measuring sound localization, sound lateralization, and binaural masking level differences (BMLDs) in young children were developed. Sensitivity for these tasks was assessed in large groups of children between 4 and 9 yr of age to investigate potential developmental trends.

Design: Sound localization was measured in the sound field, with a broadband bell-ring presented from one of nine loudspeakers positioned in the frontal horizontal field.

Bilateral cochlear implants in children: binaural unmasking.

Bilateral cochlear implants (CIs) may offer deaf children a range of advantages compared to unilateral CIs. However, speech perception in noise is mainly facilitated by better-ear effects and much less by interaural comparisons or true 'binaural' hearing. Little is known about the development of the binaural auditory system with CIs provided at a young age.

Overview of safety imaging methods for newly designed cochlear implant electrodes.

Different individual test methods and protocols have been reported for the in-vitro evaluation of temporal bones implanted with newly designed cochlear implant electrodes, prior to human implantation. In practice, however, these methods may not always give the required information. In this study, a large battery of tests has been evaluated using the electrode as a fixed parameter.

Transient depression of inner ear function after stapedotomy: skeeter versus CO(2) laser technique.

Performing stapes surgery for otosclerosis is known to be potentially irreversibly harmful to the inner ear function in about 1% of the cases. An early postoperative transient depression of the bone conduction thresholds is frequently detected after stapes surgery. The purpose of this study was to compare the evolution of bone conduction thresholds after primary stapedotomy with two different techniques: skeeter versus CO(2) laser stapedotomy.

High resolution micro-CT scanning as an innovative tool for evaluation of the surgical positioning of cochlear implant electrodes.

X-ray microtomography (micro-CT) is a new technique allowing for visualization of the internal structure of opaque specimens with a quasi-histological quality. Among multiple potential applications, the use of this technique in otology is very promising. Micro-CT appears to be ideally suited for in vitro visualization of the inner ear tissues as well as for evaluation of the electrode damage and/or surgical insertion trauma during implantation of the cochlear implant electrodes.

Allograft tympanoplasty.

Tympano-ossicular allografts are human transplants of the tympanic membrane alone or with the ossicles included. The authors review its use in their department since the introduction of the technique 40 years ago by J. Marquet.

Pitch estimation of a deeply inserted cochlear implant electrode.

In this short communication, we evaluate the place-pitch relation of a newly designed, deeply inserted, cochlear implant electrode. The insertion depths ranged from 471 degrees to 662 degrees. Pitch perception was measured in eight subjects with monopolar stimulation on each electrode contact at intensities of 50% and 80% of the dynamic range.

Basic fitting and evaluation parameters of a newly designed cochlear implant electrode.

Objective: To validate a newly designed cochlear implant electrode (TRACE) in the standard monopolar mode and compare it to a patient group implanted with a standard Nucleus Contour cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active surface area for stimulation, but the position in the scala tympani is different from that of the Nucleus Contour electrode.

Material And Methods: The following parameters, used in cochlear implant fitting and evaluation procedures, were determined: the threshold and comfort stimulation current levels; the electrode impedances; and the phoneme discrimination and speech recognition scores using the ACE speech algorithm.

Long-term evaluation of the effect of intracochlear steroid deposition on electrode impedance in cochlear implant patients.

Objective: To evaluate the long-term effect of intracochlear steroid deposition on electrode impedance in patients with cochlear implants.

Study Design: A retrospective study was carried out comparing the impedances of cochlear implant electrodes with and without a single application of steroids in the cochlea.

Patients: Ninety two implanted children with an average age of 5 years (range, 0.

Design, construction and mechanical optimisation process of electrode with radial current flow in the scala tympani.

A 48 contact cochlear implant electrode has been constructed for electrical stimulation of the auditory nerve. The stimulating contacts of this electrode are organised in two layers: 31 contacts on the upper surface directed towards the habenula perforata and 17 contacts connected together as one longitudinal contact on the underside. The design of the electrode carrier aims to make radial current flow possible in the cochlea.

Results of 100 vestibular schwannoma operations.

Between 1991 and 2000, 154 cerebello-pontine angle (CPA) tumors were seen at the University ENT-department of the Sint-Augustinus Hospital, Antwerp. Amongst these, 127 were vestibular schwannomas detected by MR-imaging. Noteworthy is that in 5% of these, the ABR latencies were within normal limits.

Outcome of cochlear implantation at different ages from 0 to 6 years.

Objective: To evaluate the outcome of cochlear implantation in young children in relation to the age at implantation.

Study Design: A retrospective longitudinal and cross-sectional analysis of pediatric cochlear implant patients.

Patients: All children with congenital deafness who underwent implantation before the age of 6 years (n = 48 for the longitudinal analysis and n = 70 for the cross-sectional analysis)

Interventions: All children received a multichannel cochlear implant.

The use of malleus allografts in ossiculoplasty.

Objective: To assess the functional performance of remodeled malleus allografts in a malleus-footplate assembly in terms of hearing results and mid long-term stability.

Study Design: A retrospective study of 60 consecutive patients who underwent a malleus allograft ossiculoplasty from 1993 until 2000. In all cases the incus and the stapedial arch were missing as the result of cholesteatoma (49), chronic otitis (5), incus necrosis resulting from stapes prosthesis (5), and congenital ossicular malformations (1).

Middle ear status in ears showing high admittance tympanograms. Clinical value of the use of the two-component 678 Hz oto-admittance tympanogram.

The present paper reports on the results of a retrospective study using 678 Hz susceptance-conductance tympanometry performed on abnormally high admittant middle ears. High admittance was proven to be caused by (partial) disruption or lysis of the ossicular chain. Retrospective analysis shows that 678 Hz tympanometry seems to be more accurate in the differential diagnosis of ossicular chain disruptions compared to CT-imaging of the ossicular chain (88% versus 81% correct identification respectively).

Otosclerosis: a genetically heterogeneous disease involving at least three different genes.

Otosclerosis is caused by abnormal bone homeostasis of the otic capsule, resulting in hearing impairment in 0.3%-0.4% of the white population.

A Two-stage bipodal screening model for universal neonatal hearing screening.

Objective: A model is proposed for universal neonatal hearing screening.

Methods: The screening model is two-staged because it consists of a first test and, in case of failure (1.4% of the subjects), of a retest 3 weeks later.

Contralateral suppression of transient evoked otoacoustic emissions: normative data for a clinical test set-up.

Hypothesis: Contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) can be used in a clinical set-up using a procedure based on a unique and robust parameter to quantify the magnitude of suppression for a subject.

Background: TEOAEs can be suppressed by delivering contralateral white noise (WN). This suppression is thought to be mediated via the efferent nerve fibers that innervate the outer hair cells.