Journal article
Access and Polarization Electrode Impedance Changes in Electric-Acoustic Stimulation Cochlear Implant Users with Delayed Loss of Acoustic Hearing
Journal of the Association for Research in Otolaryngology, Vol.23(1), pp.95-118
02/2022
DOI: 10.1007/s10162-021-00809-z
PMCID: PMC8782980
PMID: 34686938
Abstract
Acoustic hearing can be preserved after cochlear implant (CI) surgery, allowing for combined electric-acoustic stimulation (EAS) and superior speech understanding compared to electric-only hearing. Among patients who initially retain useful acoustic hearing, 30-40 % experience a delayed hearing loss that occurs 3 or more months after CI activation. Increases in electrode impedances have been associated with delayed loss of residual acoustic hearing, suggesting a possible role of intracochlear inflammation/fibrosis as reported by Scheperle et al. (Hear Res 350:45-57, 2017) and Shaul et al. (Otol Neurotol 40(5):e518-e526, 2019). These studies measured only total impedance. Total impedance consists of a composite of access resistance, which reflects resistance of the intracochlear environment, and polarization impedance, which reflects resistive and capacitive properties of the electrode-electrolyte interface as described by Dymond (IEEE Trans Biomed Eng 23(4):274-280, 1976) and Tykocinski et al. (Otol Neurotol 26(5):948-956, 2005). To explore the role of access and polarization impedance components in loss of residual acoustic hearing, these measures were collected from Nucleus EAS CI users with stable acoustic hearing and subsequent precipitous loss of hearing. For the hearing loss group, total impedance and access resistance increased over time while polarization impedance remained stable. For the stable hearing group, total impedance and access resistance were stable while polarization impedance declined. Increased access resistance rather than polarization impedance appears to drive the increase in total impedances seen with loss of hearing. Moreover, access resistance has been correlated with intracochlear fibrosis/inflammation in animal studies as observed by Xu et al. (Hear Res 105(1-2):1-29, 1997) and Tykocinski et al. (Hear Res 159(1-2):53-68, 2001). These findings thus support intracochlear inflammation as one contributor to loss of acoustic hearing in our EAS CI population.
Details
- Title: Subtitle
- Access and Polarization Electrode Impedance Changes in Electric-Acoustic Stimulation Cochlear Implant Users with Delayed Loss of Acoustic Hearing
- Creators
- Viral D Tejani - Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA, USA. viral-tejani@uiowa.eduHyejin Yang - Department of Biomedical Engineering, University of Ulsan, Ulsan, South KoreaJeong-Seo Kim - Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA, USAHelin Hernandez - Department of Biostatistics, University of Iowa, Iowa City, IA, USAJacob J Oleson - Department of Biostatistics, University of Iowa, Iowa City, IA, USAMarlan R Hansen - Department of Molecular Physiology and Biophysics, University of Iowa Hospitals and Clinics, Iowa City, IA, USABruce J Gantz - Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USAPaul J Abbas - Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA, USACarolyn J Brown - Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA, USA
- Resource Type
- Journal article
- Publication Details
- Journal of the Association for Research in Otolaryngology, Vol.23(1), pp.95-118
- DOI
- 10.1007/s10162-021-00809-z
- PMID
- 34686938
- PMCID
- PMC8782980
- ISSN
- 1525-3961
- eISSN
- 1438-7573
- Grant note
- P50 DC 00242 / National Institute on Deafness and Other Communication Disorders
- Language
- English
- Date published
- 02/2022
- Academic Unit
- Communication Sciences and Disorders; Molecular Physiology and Biophysics; Biostatistics; Neurosurgery; Otolaryngology
- Record Identifier
- 9984211770702771
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