title: Modeling of Auditory Neuron Response Thresholds with Cochlear Implants.
abstract: The 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.
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France ; Audiology Department I-PAudioM, INSERM U1051 Unit, Institute for Neurosciences of Montpellier, 34081 Montpellier, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Venail
authors.affiliation: Department of Medical Information and Biostatistics, University Hospital of Montpellier, Montpellier, France ; U 1061, CIC 1001, INSERM, 34295 Montpellier, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Mura
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Akkari
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Mathiolon
authors.affiliation: Neuroradiology Department, University Hospital Gui de Chauliac, 34295 Montpellier, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Menjot de Champfleur
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France.
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Piron
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France.
authors.forename: Marielle
authors.initials: M
authors.lastname: Sicard
authors.affiliation: Audiophonology and Speech Disorders Department, Institute Saint Pierre, 34250 Palavas, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Sterkers-Artieres
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France ; Audiology Department I-PAudioM, INSERM U1051 Unit, Institute for Neurosciences of Montpellier, 34081 Montpellier, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Mondain
authors.affiliation: ENT Department and University Montpellier 1, University Hospital Gui de Chauliac, 34295 Montpellier, France ; Audiology Department I-PAudioM, INSERM U1051 Unit, Institute for Neurosciences of Montpellier, 34081 Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Uziel
mesh_terms: D000293:Adolescent; D000328:Adult; D001309:Auditory Threshold / Q000502:physiology*; D003054:Cochlear Implants; D004567:Electrodes, Implanted; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D015999:Multivariate Analysis; D009474:Neurons / Q000502:physiology*; D055815:Young Adult