title: Electrically evoked compound action potentials are different depending on the site of cochlear stimulation.
abstract: One of the many parameters that can affect cochlear implant (CI) users' performance is the site of presentation of electrical stimulation, from the CI, to the auditory nerve. Evoked compound action potential (ECAP) measurements are commonly used to verify nerve function by stimulating one electrode contact in the cochlea and recording the resulting action potentials on the other contacts of the electrode array. The present study aimed to determine if the ECAP amplitude differs between the apical, middle, and basal region of the cochlea, if double peak potentials were more likely in the apex than the basal region of the cochlea, and if there were differences in the ECAP threshold and recovery function across the cochlea. ECAP measurements were performed in the apical, middle, and basal region of the cochlea at fixed sites of stimulation with varying recording electrodes. One hundred and forty one adult subjects with severe to profound sensorineural hearing loss fitted with a Standard or FLEXSOFTelectrode were included in this study. ECAP responses were captured using MAESTRO System Software (MED-EL). The ECAP amplitude, threshold, and slope were determined using amplitude growth sequences. The 50% recovery rate was assessed using independent single sequences that have two stimulation pulses (a masker and a probe pulse) separated by a variable inter-pulse interval. For all recordings, ECAP peaks were annotated semi-automatically. ECAP amplitudes were greater upon stimulation of the apical region compared to the basal region of the cochlea. ECAP slopes were steeper in the apical region compared to the basal region of the cochlea and ECAP thresholds were lower in the middle region compared to the basal region of the cochlea. The incidence of double peaks was greater upon stimulation of the apical region compared to the basal region of the cochlea. This data indicates that the site and intensity of cochlear stimulation affect ECAP properties.
authors.affiliation: a Antwerp University Hospital , Antwerp , Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: van de Heyning
authors.affiliation: b Instituto de ORL , Buenos Aires , Argentina.
authors.forename: Santiago L
authors.initials: SL
authors.lastname: Arauz
authors.affiliation: c Ear Science Centre, School of Surgery , The University of Western Australia , Nedlands , Australia.|d Ear Science Institute Australia Implant Centre , Subiaco , Australia.
authors.forename: Marcus
authors.initials: M
authors.lastname: Atlas
authors.affiliation: e Medizinische Universität Wien, Universitätsklinik für Hals-, Nasen- und Ohrenkrankheiten , Vienna , Austria.
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Baumgartner
authors.affiliation: f Universitätsklinik für HNO, Kopf- und Halschirurgie, Inselspital Bern , Bern , Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Caversaccio
authors.affiliation: c Ear Science Centre, School of Surgery , The University of Western Australia , Nedlands , Australia.|d Ear Science Institute Australia Implant Centre , Subiaco , Australia.
authors.forename: Ronel
authors.initials: R
authors.lastname: Chester-Browne
authors.affiliation: b Instituto de ORL , Buenos Aires , Argentina.
authors.forename: Patricia
authors.initials: P
authors.lastname: Estienne
authors.affiliation: g Hospital Universitario La Paz, Institute for Health Research (IdiPAZ) , Madrid , Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gavilan
authors.affiliation: h Centre Hospitalier Universitaire de Rennes , Rennes , France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Godey
authors.affiliation: e Medizinische Universität Wien, Universitätsklinik für Hals-, Nasen- und Ohrenkrankheiten , Vienna , Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gstöttner
authors.affiliation: i Capital Medical University, Beijing Tongren Hospital , Beijing , China.
authors.forename: Demin
authors.initials: D
authors.lastname: Han
authors.affiliation: j Klinik und Poliklinik für Hals-, Nasen und Ohren- Krankheiten , Universität Würzburg , Würzburg , Germany.
authors.forename: Rudolph
authors.initials: R
authors.lastname: Hagen
authors.affiliation: f Universitätsklinik für HNO, Kopf- und Halschirurgie, Inselspital Bern , Bern , Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Kompis
authors.affiliation: k St. Petersburg ENT and Speech Research Institute , St. Petersburg , Russia.
authors.forename: Vlad
authors.initials: V
authors.lastname: Kuzovkov
authors.affiliation: g Hospital Universitario La Paz, Institute for Health Research (IdiPAZ) , Madrid , Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Lassaletta
authors.affiliation: h Centre Hospitalier Universitaire de Rennes , Rennes , France.
authors.forename: Franc
authors.initials: F
authors.lastname: Lefevre
authors.affiliation: i Capital Medical University, Beijing Tongren Hospital , Beijing , China.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Li
authors.affiliation: l Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde , Klinikum der Universität München , München , Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Müller
authors.affiliation: m London Health Sciences Centre , London , Canada.
authors.forename: Lorne
authors.initials: L
authors.lastname: Parnes
authors.affiliation: a Antwerp University Hospital , Antwerp , Belgium.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kleine Punte
authors.affiliation: n Bradford Royal Infirmary , Bradford , United Kingdom.
authors.forename: Christopher
authors.initials: C
authors.lastname: Raine
authors.affiliation: o Otolaryngology, Head & Neck Surgery Unit, School of Surgery , University of Western Australia, Fremantle Hospital , Fremantle , Australia.
authors.forename: Gunesh
authors.initials: G
authors.lastname: Rajan
authors.affiliation: p Clinica Rivas, Centro Medico Otologico , Bogota , Colombia.
authors.forename: Adriana
authors.initials: A
authors.lastname: Rivas
authors.affiliation: p Clinica Rivas, Centro Medico Otologico , Bogota , Colombia.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Rivas
authors.affiliation: n Bradford Royal Infirmary , Bradford , United Kingdom.
authors.forename: Nicola
authors.initials: N
authors.lastname: Royle
authors.affiliation: q Universitätsklinik für Hals- Nasen- Ohrenheilkunde Innsbruck , Innsbruck , Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Sprinzl
authors.affiliation: r Universitätsklinik für Hör-, Stimm- und Sprachstörungen Innsbruck , Innsbruck , Austria.
authors.forename: Kurt
authors.initials: K
authors.lastname: Stephan
authors.affiliation: s Institute of Physiology and Pathology of Hearing , Warsaw , Poland.|t World Hearing Center , Nadarzyn , Poland.|u Institute of Sensory Organs , Nadarzyn , Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Walkowiak
authors.affiliation: k St. Petersburg ENT and Speech Research Institute , St. Petersburg , Russia.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Yanov
authors.affiliation: m London Health Sciences Centre , London , Canada.
authors.forename: Kim
authors.initials: K
authors.lastname: Zimmermann
authors.affiliation: r Universitätsklinik für Hör-, Stimm- und Sprachstörungen Innsbruck , Innsbruck , Austria.
authors.forename: Patrick
authors.initials: P
authors.lastname: Zorowka
authors.affiliation: s Institute of Physiology and Pathology of Hearing , Warsaw , Poland.|t World Hearing Center , Nadarzyn , Poland.|u Institute of Sensory Organs , Nadarzyn , Poland.
authors.forename: Henryk
authors.initials: H
authors.lastname: Skarzynski
mesh_terms: D000200:Action Potentials; D000328:Adult; D003051:Cochlea / Q000503:physiopathology; D019929:Cochlear Implantation / Q000379:methods; D003054:Cochlear Implants; D004558:Electric Stimulation / Q000379:methods*; D005072:Evoked Potentials, Auditory; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: ART; Amplitude; Apical; Basal; Cochlea; Cochlear implant; Double peak; ECAP; Electrode; Middle; Recovery sequence; Threshold