Audiological Outcomes and Associated Factors after Pediatric Cochlear Reimplantation

Cochlear implants are the most common and successful sensory neuroprosthetic devices. However, reimplantation can be required for medical reasons, device failure, or technological upgrading. Resolving the problem driving the intervention and offering stable or better audiological results are the main challenges. We aimed to analyze the success rate of this intervention and to identify factors influencing speech perception recovery after reimplantation in the pediatric population. We retrospectively collected the causes and the outcomes of 67 consecutive reimplantations in one cochlear implant center over 30 years. Reimplantation resolved the cause without recurrence for 94% of patients. The etiology of deafness, time since implantation, indication of reimplantation, sex, and age did not influence word discrimination test scores in silence, 3 years after surgery. However, adherence to a speech rehabilitation program was statistically associated with gain in perception scores: +8.9% [−2.2; +31.0%] versus −19.0% [−47.5; −7.6%] if no or suboptimal rehabilitation was followed (p = 0.0037). Cochlear reimplantation in children is efficient and is associated with predictable improvement in speech perception, 3 years after intervention. However, good adherence to speech rehabilitation program is necessary and should be discussed with the patient and parents, especially for the indication of reimplantation for technological upgrading

Reliability and complications of 500 consecutive cochlear implantations.

International audienceOBJECTIVES: To assess device failures as well as early postoperative, late postoperative, and medical complications occurring after cochlear implantation and to discuss their causes and treatments. Study DESIGN: Retrospective study of 500 consecutive cochlear implantations. SETTING: Tertiary referral center. PATIENTS: All patients receiving cochlear implants at our institution between 1989 and 2006. MAIN OUTCOME MEASURES: All complications and treatments were systematically reviewed with a maximum follow-up of 18 years. The number of reimplantations was calculated according to follow-up duration to determine the cochlear implant survival rate. Specific risks of reimplantation were calculated for groups with differing durations of implantation. RESULTS: The overall rate of complications was 16.0% (79 of 500), with minor complications accounting for 5.6%; major complications, 3.2%; and reimplantations, 7.2%. Reasons for revision surgery were device failure, infection, trauma, and "soft device failure" (failure despite normal results from integrity testing). Revision surgery was performed in 51 of the 500 cases (10.2%), and other complications were managed medically (28 of 500; 5.6%). The rate of hard and soft device failures was 6% (30 of 500). Seventy-two percent of reimplantations occurred within 5 years. The risk of severe infection (eventually requiring explantation) was 1.4% (7 of 500). There was 1 case of transient facial palsy following surgery (0.2%), and the incidence of postsurgical meningitis was 0. CONCLUSIONS: Cochlear implantation is a safe technique with a relatively low complication rate; however, certain complications may require specific attention to prevent or correct them

Modeling of Auditory Neuron Response Thresholds with Cochlear Implants

International audienceThe quality of the prosthetic-neural interface is a critical point for cochlear implant efficiency. It depends not only on technical and anatomical factors such as electrode position into the cochlea (depth and scalar placement), electrode impedance, and distance between the electrode and the stimulated auditory neurons, but also on the number of functional auditory neurons. The efficiency of electrical stimulation can be assessed by the measurement of e-CAP in cochlear implant users. In the present study, we modeled the activation of auditory neurons in cochlear implant recipients (nucleus device). The electrical response, measured using auto-NRT (neural responses telemetry) algorithm, has been analyzed using multivariate regression with cubic splines in order to take into account the variations of insertion depth of electrodes amongst subjects as well as the other technical and anatomical factors listed above. NRT thresholds depend on the electrode squared impedance (β = -0.11 ± 0.02, P < 0.01), the scalar placement of the electrodes (β = -8.50 ± 1.97, P < 0.01), and the depth of insertion calculated as the characteristic frequency of auditory neurons (CNF). Distribution of NRT residues according to CNF could provide a proxy of auditory neurons functioning in implanted cochleas

Effects of Electrode Array Length on Frequency-Place Mismatch and Speech Perception with Cochlear Implants

International audienceFrequency-place mismatch often occurs after cochlear implantation, yet its effect on speech perception outcome remains unclear. In this article, we propose a method, based on cochlea imaging, to determine the cochlear place-frequency map. We evaluated the effect of frequency-place mismatch on speech perception outcome in subjects implanted with 3 different lengths of electrode arrays. A deeper insertion was responsible for a larger frequency-place mismatch and a decreased and delayed speech perception improvement by comparison with a shallower insertion, for which a similar but slighter effect was noticed. Our results support the notion that selecting an electrode array length adapted to each individual's cochlear anatomy may reduce frequency-place mismatch and thus improve speech perception outcome

L’âge du Fer en Basse-Normandie. Gestes funéraires en Gaule au Second-Âge du Fer. Volumes I et II

Cet ouvrage est la publication des actes du 33e colloque international de l’AFEAF, qui s’est tenu à Caen, du 20 au 24 mai 2009. De même que le colloque, il comprend deux parties. La première, qui contient dix-sept contributions, traite de l’actualité des recherches sur l’Âge du fer en Basse-Normandie, une région qui a connu un renouvellement important de la documentation permettant d’appréhender les dynamiques d’occupation et les formes d’organisation territoriale durant la Protohistoire. Plusieurs bilans synthétiques concernant l’habitat rural, les sites fortifiés et la culture matérielle, sont, entre autres, proposés ici. La seconde partie de l’ouvrage traite du thème de la mort et des pratiques funéraires durant la période Ve-Ier siècles avant J.-C. ; elle contient vingt-deux contributions. Ce sujet a été abordé en privilégiant quelques axes de réflexion, de façon à faciliter les comparaisons entre régions. À travers des bilans synthétiques, le thème spécialisé du colloque est traité à l’échelle de la Gaule, avec les éclairages de plusieurs régions de l’Europe celtique.This is the publication of the proceedings of the 33rd AFEAF symposium held in Caen from the 20th to the 24th of May 2009. Like the symposium, this book is divided in two parts. The first part, with its 17 contributions, deals with the current knowledge about the Iron Age in Lower Normandy. An important renewal of the documentation concerning this region allows a better understanding of the occupational processes and territorial organization existing throughout Protohistory. This first part also includes several summary reports on rural settlements, fortified sites as well as finds. The second part of the book, with 22 contributions, deals with the subject of death and funerary practices during the 5th to 1st centuries BC. The subject was discussed focussing on a chosen number of thoughts as to make it easier to compare between different regions. Various summary reports allow an overview of this specialized topic throughout Gaul with perspectives from other regions of Celtic Europe