Biological Response Dynamics to Cochlear Implantation: Modeling and Modulating the Electrode-Tissue Interface.

OBJECTIVE: The present study primarily aims to study and model the impedance dynamics following cochlear implant (CI) surgery in humans. Secondarily, to observe how the modulation of a single-dose topic dexamethasone alters this response. DESIGN: CI impedance and impedance subcomponents were measured in a day-by-day basis between CI surgery and its activation ( 1 month). Impedance dynamics were mathematically modeled. Furthermore, we conducted a randomized double-blind placebo-controlled clinical trial to evaluate the effect of dexamethasone application. RESULTS: The model showed good fitting for all impedance's measures and both modulations over time. The clinical impedance and impedance subcomponents showed different patterns between groups during the first week postimplantation. Single-dose topical dexamethasone had a transient effect on Impedances, postponing (for 3 days) but not preventing the rise in impedance and its application was mainly effective at the base of the cochlea. CONCLUSIONS: The proposed mathematical fitting properly resembles the impedance dynamics in humans and their modulation due to the dexamethasone. The impedance subcomponents' dynamic pattern showed a time-course consistent with the biological processes of the foreign body reaction. Single-dose topic dexamethasone has a temporal reduction effect in impedance values on the basal turn of the cochlea but does not prevent the rise on the long-term.

Measuring the Electrical Status of the Bionic Ear. Re-thinking the Impedance in Cochlear Implants.

As in any biophysical electrode-tissue environment, impedance measurement shows a complex relationship which reflects the electrical characteristics of the medium. In cochlear implants (CIs), which is mostly a stimulation-oriented device, the actual clinical approach only considers one arbitrary time-measure of the impedance. However, to determine the main electrical properties of the cochlear medium, the overall impedance and its subcomponents (i.e., access resistance and polarization impedance) should be described. We here characterized, validated and discussed a novel method to calculate impedance subcomponents based on CI measurement capabilities. With an electronic circuit of the cochlear electrode-tissue interface and its computational simulation, the access resistance and polarization impedance were modeled. Values of each electrical component were estimated through a custom-made pulse delivery routine and the acquisition of multiple data points. Using CI hardware, results fell within the electronic components nominal errors (± 10%). Considering the method's accuracy and reliability, it is readily available to be applied in research-clinical use. In the man-machine nature of the CI, this represents the basis to optimize the communication between a CI electrode and the spiral ganglion cells.

Toward Self-Measures in Cochlear Implants: Daily and "Homemade" Impedance Assessment.

Introduction: Cochlear implant (CI) impedance reflects the status of the electro neural interface, potentially acting as a biomarker for inner ear injury. Most impedance shifts are diagnosed retrospectively because they are only measured in clinical appointments, with unknown behavior between visits. Here we study the application and discuss the benefits of daily and remote impedance measures with software specifically designed for this purpose. Methods: We designed software to perform CI impedance measurements without the intervention of health personnel. Ten patients were recruited to self-measure impedance for 30 days at home, between CI surgery and activation. Data were transferred to a secured online server allowing remote monitoring. Results: Most subjects successfully performed measurements at home without supervision. Only a subset of measurements was missed due to lack of patient engagement. Data were successfully and securely transferred to the online server. No adverse events, pain, or discomfort was reported by participants. Discussion: This work overviews a flexible and highly configurable platform for self-measurement CI impedance. This novel approach simplifies the CI standard of care by reducing the number of clinical visits and by proving useful and constant information to CI clinicians.

Competencias de los residentes de Atención Primaria en el manejo de los problemas prevalentes de oído, nariz y garganta / Competencies of Primary Care residents in the management of prevalent problems of the ear, nose and throat

Los problemas de oído, nariz y garganta son un motivo frecuente de consulta en Atención Primaria. Numerosos estudios han reportado que los médicos de Atención Primaria perciben una capacitación insuficiente en el manejo de estos problemas. El objetivo de este estudio fue evaluar las competencias en el diagnóstico y tratamiento de problemas prevalentes de Otorrinolaringología de médicos residentes de Atención Primaria en un hospital universitario, en Buenos Aires, Argentina, mediante la implementación de un examen clínico objetivo estructurado. Participaron 25 residentes, de Pediatría (7), de Medicina Interna (10) y de Medicina Familiar (8). Los de Medicina Familiar y Pediatría tuvieron mejor desempeño que los de Medicina Interna. Los residentes de Atención Primaria demostraron competencias disímiles en el manejo de problemas prevalentes de Otorrinolaringología. Se detectaron áreas de oportunidad de mejora comunes para los tres grupos, que proporcionaron dirección y motivación en futuros aprendizajes, tanto en conocimientos como en habilidades.

Ear, nose and throat problems are very common in Primary Care settings. Numerous studies have reported that Primary Care physicians feel dissatisfied with their performance and insufficient training to diagnose and manage these problems. The objective of this study was to assess the competency in diagnosis and management of prevalent ear, nose and throat problems in medical residents of Family Medicine, Internal Medicine and Pediatrics at a University Hospital in Buenos Aires, Argentina, using an Objective Structured Clinical Examination. The participants were 25 residents of Pediatrics (7), Internal Medicine (10) and Family Medicine (8). Residents of Family Medicine and Pediatrics showed better performance than residents of Internal Medicine. Residents of Primary Care demonstrated dissimilar competencies in the management of prevalent ear, nose and throat problems. Areas of common improvement opportunities were detected for the three groups, which provided direction and motivation in future learnings in both knowledge and skills.

[Competencies of Primary Care residents in the management of prevalent problems of the ear, nose and throat]. / Competencias de los residentes de Atención Primaria en el manejo de los problemas prevalentes de oído, nariz y garganta.

Ear, nose and throat problems are very common in Primary Care settings. Numerous studies have reported that Primary Care physicians feel dissatisfied with their performance and insufficient training to diagnose and manage these problems. The objective of this study was to assess the competency in diagnosis and management of prevalent ear, nose and throat problems in medical residents of Family Medicine, Internal Medicine and Pediatrics at a University Hospital in Buenos Aires, Argentina, using an Objective Structured Clinical Examination. The participants were 25 residents of Pediatrics (7), Internal Medicine (10) and Family Medicine (8). Residents of Family Medicine and Pediatrics showed better performance than residents of Internal Medicine. Residents of Primary Care demonstrated dissimilar competencies in the management of prevalent ear, nose and throat problems. Areas of common improvement opportunities were detected for the three groups, which provided direction and motivation in future learnings in both knowledge and skills.

Los problemas de oído, nariz y garganta son un motivo frecuente de consulta en Atención Primaria. Numerosos estudios han reportado que los médicos de Atención Primaria perciben una capacitación insuficiente en el manejo de estos problemas. El objetivo de este estudio fue evaluar las competencias en el diagnóstico y tratamiento de problemas prevalentes de Otorrinolaringología de médicos residentes de Atención Primaria en un hospital universitario, en Buenos Aires, Argentina, mediante la implementación de un examen clínico objetivo estructurado. Participaron 25 residentes, de Pediatría (7), de Medicina Interna (10) y de Medicina Familiar (8). Los de Medicina Familiar y Pediatría tuvieron mejor desempeño que los de Medicina Interna. Los residentes de Atención Primaria demostraron competencias disímiles en el manejo de problemas prevalentes de Otorrinolaringología. Se detectaron áreas de oportunidad de mejora comunes para los tres grupos, que proporcionaron dirección y motivación en futuros aprendizajes, tanto en conocimientos como en habilidades.

Cochlear implantation is safe and effective in patients with MYH9-related disease.

BACKGROUND: MYH9-related disease (MYH9-RD) is a rare syndromic disorder deriving from mutations in MYH9, the gene for the heavy chain of non-muscle myosin IIA. Patients present with congenital thrombocytopenia and giant platelets and have a variable risk of developing sensorineural deafness, kidney damage, presenile cataract, and liver abnormalities. Almost all MYH9-RD patients develop the hearing defect, which, in many individuals, progresses to severe to profound deafness with high impact on quality of life. These patients are potential candidates for cochlear implantation (CI), however, no consistent data are available about the risk to benefit ratio of CI in MYH9-RD. The only reported patient who received CI experienced perisurgery complications that have been attributed to concurrent platelet defects and/or MYH9 protein dysfunction. METHODS: By international co-operative study, we report the clinical outcome of 10 patients with MYH9-RD and severe to profound deafness who received a CI at 8 institutions. RESULTS: Nine patients benefited from CI: in particular, eight of them obtained excellent performances with restoration of a practically normal hearing function and verbal communication abilities. One patient had a slightly worse performance that could be explained by the very long duration of severe deafness before CI. Finally, one patient did not significantly benefit from CI. No adverse events attributable to MYH9-RD syndrome were observed, in particular no perisurgery bleeding complications due to the platelet defects were seen. Patients' perioperative management is described and discussed. CONCLUSIONS: CI is safe and effective in most patients with MYH9-RD and severe to profound deafness and should be offered to these subjects, possibly as soon as they develop the criteria for candidacy.

Cochlear implantation in a bilateral endolymphatic sac tumor patient. A case report.

At the present time, the optimal management of patients with locally aggressive ELSTs includes: early diagnosis, surgical complete excision and long term follow up to monitor for recurrent disease. The presence of bilateral tumors produces a significant risk for bilateral profound hearing loss. We report the unusual case of bilateral endolymphatic sac tumor in a 14-year-old girl who presented bilateral anacusis and in whom a cochlear implant was performed after removal of the second tumor.