Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns
IntroductionIntracochlear electrocochleography (ECochG) is increasingly being used to measure residual inner ear function in cochlear implant (CI) recipients. ECochG signals reflect the state of the inner ear and can be measured during implantation and post-operatively. The aim of our study was to a...
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Frontiers Media S.A.
2023-08-01
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| Series: | Frontiers in Neurology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fneur.2023.1181539/full |
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| author | Klaus Schuerch Klaus Schuerch Wilhelm Wimmer Christian Rummel Marco Domenico Caversaccio Marco Domenico Caversaccio Stefan Weder Stefan Weder |
| author_facet | Klaus Schuerch Klaus Schuerch Wilhelm Wimmer Christian Rummel Marco Domenico Caversaccio Marco Domenico Caversaccio Stefan Weder Stefan Weder |
| author_sort | Klaus Schuerch |
| collection | DOAJ |
| description | IntroductionIntracochlear electrocochleography (ECochG) is increasingly being used to measure residual inner ear function in cochlear implant (CI) recipients. ECochG signals reflect the state of the inner ear and can be measured during implantation and post-operatively. The aim of our study was to apply an objective deep learning (DL)-based algorithm to assess the reproducibility of longitudinally recorded ECochG signals, compare them with audiometric hearing thresholds, and identify signal patterns and tonotopic behavior.MethodsWe used a previously published objective DL-based algorithm to evaluate post-operative intracochlear ECochG signals collected from 21 ears. The same measurement protocol was repeated three times over 3 months. Additionally, we measured the pure-tone thresholds and subjective loudness estimates for correlation with the objectively detected ECochG signals. Recordings were made on at least four electrodes at three intensity levels. We extracted the electrode positions from computed tomography (CT) scans and used this information to evaluate the tonotopic characteristics of the ECochG responses.ResultsThe objectively detected ECochG signals exhibited substantial repeatability over a 3-month period (bias-adjusted kappa, 0.68; accuracy 83.8%). Additionally, we observed a moderate-to-strong dependence of the ECochG thresholds on audiometric and subjective hearing levels. Using radiographically determined tonotopic measurement positions, we observed a tendency for tonotopic allocation with a large variance. Furthermore, maximum ECochG amplitudes exhibited a substantial basal shift. Regarding maximal amplitude patterns, most subjects exhibited a flat pattern with amplitudes evenly distributed over the electrode carrier. At higher stimulation frequencies, we observed a shift in the maximum amplitudes toward the basal turn of the cochlea.ConclusionsWe successfully implemented an objective DL-based algorithm for evaluating post-operative intracochlear ECochG recordings. We can only evaluate and compare ECochG recordings systematically and independently from experts with an objective analysis. Our results help to identify signal patterns and create a better understanding of the inner ear function with the electrode in place. In the next step, the algorithm can be applied to intra-operative measurements. |
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| issn | 1664-2295 |
| language | English |
| last_indexed | 2024-03-12T15:33:41Z |
| publishDate | 2023-08-01 |
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| spelling | doaj.art-b26f4b38d99140e5aa5bb039954d20b42023-08-09T16:59:54ZengFrontiers Media S.A.Frontiers in Neurology1664-22952023-08-011410.3389/fneur.2023.11815391181539Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patternsKlaus Schuerch0Klaus Schuerch1Wilhelm Wimmer2Christian Rummel3Marco Domenico Caversaccio4Marco Domenico Caversaccio5Stefan Weder6Stefan Weder7Department of ENT, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, SwitzerlandHearing Research Laboratory, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, SwitzerlandDepartment of Otorhinolaryngology, TUM School of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, GermanySupport Center for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, SwitzerlandDepartment of ENT, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, SwitzerlandHearing Research Laboratory, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, SwitzerlandDepartment of ENT, Head and Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, SwitzerlandHearing Research Laboratory, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, SwitzerlandIntroductionIntracochlear electrocochleography (ECochG) is increasingly being used to measure residual inner ear function in cochlear implant (CI) recipients. ECochG signals reflect the state of the inner ear and can be measured during implantation and post-operatively. The aim of our study was to apply an objective deep learning (DL)-based algorithm to assess the reproducibility of longitudinally recorded ECochG signals, compare them with audiometric hearing thresholds, and identify signal patterns and tonotopic behavior.MethodsWe used a previously published objective DL-based algorithm to evaluate post-operative intracochlear ECochG signals collected from 21 ears. The same measurement protocol was repeated three times over 3 months. Additionally, we measured the pure-tone thresholds and subjective loudness estimates for correlation with the objectively detected ECochG signals. Recordings were made on at least four electrodes at three intensity levels. We extracted the electrode positions from computed tomography (CT) scans and used this information to evaluate the tonotopic characteristics of the ECochG responses.ResultsThe objectively detected ECochG signals exhibited substantial repeatability over a 3-month period (bias-adjusted kappa, 0.68; accuracy 83.8%). Additionally, we observed a moderate-to-strong dependence of the ECochG thresholds on audiometric and subjective hearing levels. Using radiographically determined tonotopic measurement positions, we observed a tendency for tonotopic allocation with a large variance. Furthermore, maximum ECochG amplitudes exhibited a substantial basal shift. Regarding maximal amplitude patterns, most subjects exhibited a flat pattern with amplitudes evenly distributed over the electrode carrier. At higher stimulation frequencies, we observed a shift in the maximum amplitudes toward the basal turn of the cochlea.ConclusionsWe successfully implemented an objective DL-based algorithm for evaluating post-operative intracochlear ECochG recordings. We can only evaluate and compare ECochG recordings systematically and independently from experts with an objective analysis. Our results help to identify signal patterns and create a better understanding of the inner ear function with the electrode in place. In the next step, the algorithm can be applied to intra-operative measurements.https://www.frontiersin.org/articles/10.3389/fneur.2023.1181539/fullECochGdeep learningelectrophysiologycochlear implantshearing losssignal processing |
| spellingShingle | Klaus Schuerch Klaus Schuerch Wilhelm Wimmer Christian Rummel Marco Domenico Caversaccio Marco Domenico Caversaccio Stefan Weder Stefan Weder Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns Frontiers in Neurology ECochG deep learning electrophysiology cochlear implants hearing loss signal processing |
| title | Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns |
| title_full | Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns |
| title_fullStr | Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns |
| title_full_unstemmed | Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns |
| title_short | Objective evaluation of intracochlear electrocochleography: repeatability, thresholds, and tonotopic patterns |
| title_sort | objective evaluation of intracochlear electrocochleography repeatability thresholds and tonotopic patterns |
| topic | ECochG deep learning electrophysiology cochlear implants hearing loss signal processing |
| url | https://www.frontiersin.org/articles/10.3389/fneur.2023.1181539/full |
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