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Geys M, Sijgers L, Dobrev I, Dalbert A, Röösli C, Pfiffner F, Huber A. ZH-ECochG Bode Plot: A Novel Approach to Visualize Electrocochleographic Data in Cochlear Implant Users. J Clin Med 2024; 13:3470. [PMID: 38929998 PMCID: PMC11205027 DOI: 10.3390/jcm13123470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/08/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Background: Various representations exist in the literature to visualize electrocochleography (ECochG) recordings along the basilar membrane (BM). This lack of generalization complicates comparisons within and between cochlear implant (CI) users, as well as between publications. This study synthesized the visual representations available in the literature via a systematic review and provides a novel approach to visualize ECochG data in CI users. Methods: A systematic review was conducted within PubMed and EMBASE to evaluate studies investigating ECochG and CI. Figures that visualized ECochG responses were selected and analyzed. A novel visualization of individual ECochG data, the ZH-ECochG Bode plot (ZH = Zurich), was devised, and the recordings from three CI recipients were used to demonstrate and assess the new framework. Results: Within the database search, 74 articles with a total of 115 figures met the inclusion criteria. Analysis revealed various types of representations using different axes; their advantages were incorporated into the novel visualization framework. The ZH-ECochG Bode plot visualizes the amplitude and phase of the ECochG recordings along the different tonotopic regions and angular insertion depths of the recording sites. The graph includes the pre- and postoperative audiograms to enable a comparison of ECochG responses with the audiometric profile, and allows different measurements to be shown in the same graph. Conclusions: The ZH-ECochG Bode plot provides a generalized visual representation of ECochG data, using well-defined axes. This will facilitate the investigation of the complex ECochG potentials generated along the BM and allows for better comparisons of ECochG recordings within and among CI users and publications. The scripts used to construct the ZH-ECochG Bode plot are provided by the authors.
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Affiliation(s)
- Marlies Geys
- Department of Otorhinolaryngology, Head & Neck Surgery, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
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Panario J, Bester C, O'Leary S. Predicting Postoperative Speech Perception and Audiometric Thresholds Using Intracochlear Electrocochleography in Cochlear Implant Recipients. Ear Hear 2024:00003446-990000000-00289. [PMID: 38816899 DOI: 10.1097/aud.0000000000001506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
OBJECTIVES Electrocochleography (ECochG) appears to offer the most accurate prediction of post-cochlear implant hearing outcomes. This may be related to its capacity to interrogate the health of underlying cochlear tissue. The four major components of ECochG (cochlear microphonic [CM], summating potential [SP], compound action potential [CAP], and auditory nerve neurophonic [ANN]) are generated by different cochlear tissue components. Analyzing characteristics of these components can reveal the state of hair and neural cell in a cochlea. There is limited evidence on the characteristics of intracochlear (IC) ECochG recordings measured across the array postinsertion but compared with extracochlear recordings has better signal to noise ratio and spatial specificity. The present study aimed to examine the relationship between ECochG components recorded from an IC approach and postoperative speech perception or audiometric thresholds. DESIGN In 113 human subjects, responses to 500 Hz tone bursts were recorded at 11 IC electrodes across a 22-electrode cochlear implant array immediately following insertion. Responses to condensation and rarefaction stimuli were then subtracted from one another to emphasize the CM and added to one another to emphasize the SP, ANN, and CAP. Maximum amplitudes and extracochlear electrode locations were recorded for each of these ECochG components. These were added stepwise to a multi-factor generalized additive model to develop a best-fit model predictive model for pure-tone audiometric thresholds (PTA) and speech perception scores (speech recognition threshold [SRT] and consonant-vowel-consonant phoneme [CVC-P]) at 3- and 12-month postoperative timepoints. This best-fit model was tested against a generalized additive model using clinical factors alone (preoperative score, age, and gender) as a null model proxy. RESULTS ECochG-factor models were superior to clinical factor models in predicting postoperative PTA, CVC-P, and SRT outcomes at both timepoints. Clinical factor models explained a moderate amount of PTA variance ( r2 = 45.9% at 3-month, 31.8% at 12-month, both p < 0.001) and smaller variances of CVC-P and SRT ( r2 range = 6 to 13.7%, p = 0.008 to 0.113). Age was not a significant predictive factor. ECochG models explained more variance at the 12-month timepoint ( r2 for PTA = 52.9%, CVC-P = 39.6%, SRT = 36.4%) compared with the 3-month one timepoint ( r2 for PTA = 49.4%, CVC-P = 26.5%, SRT = 22.3%). The ECochG model was based on three factors: maximum SP deflection amplitude, and electrode position of CM and SP peaks. Adding neural (ANN and/or CAP) factors to the model did not improve variance explanation. Large negative SP deflection was associated with poorer outcomes and a large positive SP deflection with better postoperative outcomes. Mid-array peaks of SP and CM were both associated with poorer outcomes. CONCLUSIONS Postinsertion IC-ECochG recordings across the array can explain a moderate amount of postoperative speech perception and audiometric thresholds. Maximum SP deflection and its location across the array appear to have a significant predictive value which may reflect the underlying state of cochlear health.
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Affiliation(s)
- Jared Panario
- Department Otolaryngology, University of Melbourne, Melbourne, Victoria, Australia
| | - Christofer Bester
- Department Otolaryngology, University of Melbourne, Melbourne, Victoria, Australia
| | - Stephen O'Leary
- Department Otolaryngology, University of Melbourne, Melbourne, Victoria, Australia
- Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
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Czurda R, Wesarg T, Aschendorff A, Beck RL, Hocke T, Ketterer MC, Arndt S. Investigation of Maximum Monosyllabic Word Recognition as a Predictor of Speech Understanding with Cochlear Implant. J Clin Med 2024; 13:646. [PMID: 38337340 PMCID: PMC10856473 DOI: 10.3390/jcm13030646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 02/12/2024] Open
Abstract
Background: The cochlear implant (CI) is an established treatment option for patients with inadequate speech understanding and insufficient aided scores. Nevertheless, reliable predictive models and specific therapy goals regarding achievable speech understanding are still lacking. Method: In this retrospective study, 601 cases of CI fittings between 2005 and 2021 at the University Medical Center Freiburg were analyzed. We investigated the preoperative unaided maximum word recognition score (mWRS) as a minimum predictor for post-interventional scores at 65 dB SPL, WRS65(CI). The WRS65(CI) was compared with the preoperative-aided WRS, and a previously published prediction model for the WRS65(CI) was reviewed. Furthermore, the effect of duration of hearing loss, duration of HA fitting, and etiology on WRS65(CI) were investigated. Results: In 95.5% of the cases, a significant improvement in word recognition was observed after CI. WRS65(CI) achieved or exceeded mWRS in 97% of cases. Etiology had a significant impact on WRS65(CI). The predicted score was missed by more than 20 percentage points in 12.8% of cases. Discussion: Our results confirmed the minimum prediction via mWRS. A more precise prediction of the expected WRS65(CI) is possible. The etiology of hearing loss should be considered in the indication and postoperative care to achieve optimal results.
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Affiliation(s)
- Ronja Czurda
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Thomas Wesarg
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Antje Aschendorff
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Rainer Linus Beck
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Thomas Hocke
- Cochlear Deutschland GmbH & Co., KG, Mailänder Straße 4 a, 30539 Hannover, Germany;
| | - Manuel Christoph Ketterer
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Susan Arndt
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
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Jafari Z, Fitzpatrick EM, Schramm DR, Rouillon I, Koravand A. An Umbrella Review of Cochlear Implant Outcomes in Children With Auditory Neuropathy. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:4160-4176. [PMID: 37647160 DOI: 10.1044/2023_jslhr-23-00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
PURPOSE The objective of this overview of systematic reviews (SRs; umbrella review) was to systematically summarize and critically appraise current evidence of cochlear implant (CI) outcomes in children with auditory neuropathy spectrum disorder (ANSD). METHOD This study was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. The methodological quality and the risk of bias in the included SRs were assessed using A MeaSurement Tool to Assess systematic Reviews 2 checklist and the Risk of Bias in Systematic Reviews tool, respectively. RESULTS According to eight included SRs, children with ANSD achieve CI outcomes (speech perception performance) similar to their peers with sensorineural hearing loss. In children with postsynaptic ANSD (cochlear nerve deficiency), cochlear nerve hypoplasia is associated with better speech recognition outcomes compared with cochlear nerve aplasia, especially in the absence of additional disabilities. Except for one study, the overall quality of the included SRs was critically low, and except for three studies, evidence of a high risk of bias was identified in other included SRs. CONCLUSIONS Current evidence supports CI benefits for children with ANSD. To improve the quality of evidence, well-designed, prospective studies with appropriate sample sizes, using valid outcome measures, clarifying matching criteria, and taking into account the role of confounding factors are essential.
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Affiliation(s)
- Zahra Jafari
- Audiology and Speech-Language Pathology Program, University of Ottawa, Ontario, Canada
| | - Elizabeth M Fitzpatrick
- Audiology and Speech-Language Pathology Program, University of Ottawa, Ontario, Canada
- Child Hearing Laboratory, CHEO Research Institute, Ottawa, Ontario, Canada
| | - David R Schramm
- Department of Otolaryngology-Head and Neck Surgery, University of Ottawa, Ontario, Canada
- Department of Otolaryngology-Head and Neck Surgery, The Ottawa Hospital, Ontario, Canada
| | - Isabelle Rouillon
- Speech and Language Pathology, and Otolaryngology Department, Necker Hospital, Paris, France
| | - Amineh Koravand
- Audiology and Speech-Language Pathology Program, University of Ottawa, Ontario, Canada
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Panario J, Bester C, O'Leary SJ. Characteristics of the Summating Potential Measured Across a Cochlear Implant Array as an Indicator of Cochlear Function. Ear Hear 2023; 44:1088-1106. [PMID: 36935398 PMCID: PMC10426787 DOI: 10.1097/aud.0000000000001347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 01/13/2023] [Indexed: 03/21/2023]
Abstract
OBJECTIVES The underlying state of cochlear and neural tissue function is known to affect postoperative speech perception following cochlear implantation. The ability to assess these tissues in patients can be performed using intracochlear electrocochleography (IC ECochG). One component of ECochG is the summating potential (SP) that appears to be generated by multiple cochlear tissues. Its qualities may be able to detect the presence of functional inner hair cells, but evidence for this is limited in human cochleae. This study aimed to examine the IC SP characteristics in cochlear implantation recipients, its relationship to preoperative speech perception and audiometric thresholds, and to other IC ECochG components. DESIGN This is a retrospective analysis of 113 patients' IC ECochG recordings across the array in response to a 500 Hz tone burst stimulus. Responses to condensation and rarefaction stimuli were then subtracted from one another to emphasize the cochlear microphonic and added to one another to emphasize the SP, auditory nerve neurophonic, and compound action potential. Patients were grouped based on their maximum SP deflection being large and positive (+SP), large and negative (-SP), or minimal (0 SP) to further investigate these relationships. RESULTS Patients in the +SP group had better preoperative speech perception (mean consonant-vowel-consonant phoneme score 46%) compared to the -SP and 0 SP groups (consonant-vowel-consonant phoneme scores 34% and 36%, respectively, difference to +SP: p < 0.05). Audiometric thresholds were lowest for +SP (mean pure-tone average 50 dB HL), then -SP (65 dB HL), and highest for 0 SP patients (70 dB HL), but there was not a statistical significance between +SP and -SP groups ( p > 0.1). There were also distinct differences between SP groups in the qualities of their other ECochG components. These included the +SP patients having larger cochlear microphonic maximum amplitude, more apical SP peak electrode locations, and a more spatially specific SP magnitude growth pattern across the array. CONCLUSIONS Patients with large positive SP deflection in IC ECochG have preoperatively better speech perception and lower audiometric thresholds than those without. Patterns in other ECochG components suggest its positive deflection may be an indicator of cochlear function.
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Affiliation(s)
- Jared Panario
- Department Otolaryngology, University of Melbourne, Victoria, Australia
| | - Christofer Bester
- Department Otolaryngology, University of Melbourne, Victoria, Australia
| | - Stephen John O'Leary
- Department Otolaryngology, University of Melbourne, Victoria, Australia
- Royal Victorian Eye and Ear Hospital, Victoria, Australia
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Tejani VD, Kim JS, Etler CP, Skidmore J, Yuan Y, He S, Hansen MR, Gantz BJ, Abbas PJ, Brown CJ. Longitudinal Electrocochleography as an Objective Measure of Serial Behavioral Audiometry in Electro-Acoustic Stimulation Patients. Ear Hear 2023; 44:1014-1028. [PMID: 36790447 PMCID: PMC10425573 DOI: 10.1097/aud.0000000000001342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
OBJECTIVE Minimally traumatic surgical techniques and advances in cochlear implant (CI) electrode array designs have allowed acoustic hearing present in a CI candidate prior to surgery to be preserved postoperatively. As a result, these patients benefit from combined electric-acoustic stimulation (EAS) postoperatively. However, 30% to 40% of EAS CI users experience a partial loss of hearing up to 30 dB after surgery. This additional hearing loss is generally not severe enough to preclude use of acoustic amplification; however, it can still impact EAS benefits. The use of electrocochleography (ECoG) measures of peripheral hair cell and neural auditory function have shed insight into the pathophysiology of postimplant loss of residual acoustic hearing. The present study aims to assess the long-term stability of ECoG measures and to establish ECoG as an objective method of monitoring residual hearing over the course of EAS CI use. We hypothesize that repeated measures of ECoG should remain stable over time for EAS CI users with stable postoperative hearing preservation. We also hypothesize that changes in behavioral audiometry for EAS CI users with loss of residual hearing should also be reflected in changes in ECoG measures. DESIGN A pool of 40 subjects implanted under hearing preservation protocol was included in the study. Subjects were seen at postoperative visits for behavioral audiometry and ECoG recordings. Test sessions occurred 0.5, 1, 3, 6, 12 months, and annually after 12 months postoperatively. Changes in pure-tone behavioral audiometric thresholds relative to baseline were used to classify subjects into two groups: one group with stable acoustic hearing and another group with loss of acoustic hearing. At each test session, ECoG amplitude growth functions for several low-frequency stimuli were obtained. The threshold, slope, and suprathreshold amplitude at a fixed stimulation level was obtained from each growth function at each time point. Longitudinal linear mixed effects models were used to study trends in ECoG thresholds, slopes, and amplitudes for subjects with stable hearing and subjects with hearing loss. RESULTS Preoperative, behavioral audiometry indicated that subjects had an average low-frequency pure-tone average (125 to 500 Hz) of 40.88 ± 13.12 dB HL. Postoperatively, results showed that ECoG thresholds and amplitudes were stable in EAS CI users with preserved residual hearing. ECoG thresholds increased (worsened) while ECoG amplitudes decreased (worsened) for those with delayed hearing loss. The slope did not distinguish between EAS CI users with stable hearing and subjects with delayed loss of hearing. CONCLUSIONS These results provide a new application of postoperative ECoG as an objective tool to monitor residual hearing and understand the pathophysiology of delayed hearing loss. While our measures were conducted with custom-designed in-house equipment, CI companies are also designing and implementing hardware and software adaptations to conduct ECoG recordings. Thus, postoperative ECoG recordings can potentially be integrated into clinical practice.
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Affiliation(s)
- Viral D Tejani
- Department of Otolaryngology-Head and Neck Surgery, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa, USA
| | - Jeong-Seo Kim
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa, USA
- Hearing Research Laboratory, Samsung Medical Center, Seoul, South Korea
| | - Christine P Etler
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Jeffrey Skidmore
- Department of Otolaryngology-Head and Neck Surgery, Eye and Ear Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Yi Yuan
- Department of Otolaryngology-Head and Neck Surgery, Eye and Ear Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Shuman He
- Department of Otolaryngology-Head and Neck Surgery, Eye and Ear Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Molecular Physiology and Biophysics, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Bruce J Gantz
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Paul J Abbas
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa, USA
| | - Carolyn J Brown
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City, Iowa, USA
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Haggerty RA, Hutson KA, Riggs WJ, Brown KD, Pillsbury HC, Adunka OF, Buchman CA, Fitzpatrick DC. Assessment of cochlear synaptopathy by electrocochleography to low frequencies in a preclinical model and human subjects. Front Neurol 2023; 14:1104574. [PMID: 37483448 PMCID: PMC10361575 DOI: 10.3389/fneur.2023.1104574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 06/19/2023] [Indexed: 07/25/2023] Open
Abstract
Cochlear synaptopathy is the loss of synapses between the inner hair cells and the auditory nerve despite survival of sensory hair cells. The findings of extensive cochlear synaptopathy in animals after moderate noise exposures challenged the long-held view that hair cells are the cochlear elements most sensitive to insults that lead to hearing loss. However, cochlear synaptopathy has been difficult to identify in humans. We applied novel algorithms to determine hair cell and neural contributions to electrocochleographic (ECochG) recordings from the round window of animal and human subjects. Gerbils with normal hearing provided training and test sets for a deep learning algorithm to detect the presence of neural responses to low frequency sounds, and an analytic model was used to quantify the proportion of neural and hair cell contributions to the ECochG response. The capacity to detect cochlear synaptopathy was validated in normal hearing and noise-exposed animals by using neurotoxins to reduce or eliminate the neural contributions. When the analytical methods were applied to human surgical subjects with access to the round window, the neural contribution resembled the partial cochlear synaptopathy present after neurotoxin application in animals. This result demonstrates the presence of viable hair cells not connected to auditory nerve fibers in human subjects with substantial hearing loss and indicates that efforts to regenerate nerve fibers may find a ready cochlear substrate for innervation and resumption of function.
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Affiliation(s)
- Raymond A. Haggerty
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kendall A. Hutson
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - William J. Riggs
- Department of Otolaryngology, The Ohio State University, Columbus, OH, United States
| | - Kevin D. Brown
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Harold C. Pillsbury
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Oliver F. Adunka
- Department of Otolaryngology, The Ohio State University, Columbus, OH, United States
| | - Craig A. Buchman
- Department of Otolaryngology, Washington University in St. Louis, St. Louis, MO, United States
| | - Douglas C. Fitzpatrick
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Bayri Ulukan M, Ciprut A. Intracochlear electrocochleography findings in cochlear implant recipients with auditory neuropathy spectrum disorder. Int J Pediatr Otorhinolaryngol 2023; 170:111596. [PMID: 37267660 DOI: 10.1016/j.ijporl.2023.111596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/21/2023] [Accepted: 05/03/2023] [Indexed: 06/04/2023]
Abstract
OBJECTIVES This study aimed to compare intracochlear electrocochleography (ECochG) findings in a group of cochlear implant (CI) recipients with auditory neuropathy spectrum disorder (ANSD) with a group of CI recipients with sensorineural hearing loss (SNHL). Auditory outcome and spectral resolution findings were also compared among CI recipients with and without cochlear microphonic (CM) responses. METHODS This single-center, prospective cohort study was undertaken at a tertiary referral center. CM responses by the intracochlear ECochG test were recorded in CI recipients at 0.25-2 kHz. Speech, spatial, and hearing quality (SSQ) outcomes and spectral resolution measured with the spectral-temporally modulated ripple test were obtained for each recipient. The study included 62 implanted ears in 46 recipients, of which 59% (n = 27) were male and 41% (n = 19) were female. Twenty-nine ears with ANSD and 33 ears with SNHL were included. The mean age of the participants was 11 years. The results compared the intracochlear ECochG findings of the ANSD group with those of the SNHL group. RESULTS Participants were divided into two groups with and without obtainable CM responses. CM responses were obtained in 13 of 29 ears in the ANSD group and 14 of 33 ears in the SNHL group. CM thresholds obtained were better according to behavioral audiometric responses in some frequencies in the ANSD group. No significant difference was found in the auditory outcome and spectral resolution among CI recipients with and without CM responses. CONCLUSIONS Intracochlear ECochG has a limited potential clinical value for monitoring ANSD. CM thresholds obtained using ECochG may not reflect behavioral hearing thresholds.
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Affiliation(s)
- Merve Bayri Ulukan
- Marmara University, Health Sciences Institute, Istanbul, Turkey; Cochlear, Turkey.
| | - Ayca Ciprut
- Marmara University, Medical School, Audiology Department, Istanbul, Turkey
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Bo D, Huang Y, Wang B, Lu P, Chen WX, Xu ZM. Auditory and Speech Outcomes of Cochlear Implantation in Children With Auditory Neuropathy Spectrum Disorder: A Systematic Review and Meta-Analysis. Ann Otol Rhinol Laryngol 2023; 132:371-380. [PMID: 35499129 DOI: 10.1177/00034894221092201] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE The aim of this meta-analysis was to critically assess the effect of cochlear implantation on auditory and speech performance outcomes of children with auditory neuropathy spectrum disorder (ANSD). MATERIAL AND METHODS A systematic literature search was conducted on PubMed, EMbase, and Web of Science. The outcomes included speech recognition score, Categories of Auditory Performance (CAP), Speech Intelligibility Rating (SIR) score, and open-set speech perception. Results were expressed as standardized mean difference (SMD) or risk ratio (RR) with a 95% confidence interval (95% CI). RESULTS A total of 15 studies was included in this meta-analysis. Pooled data showed that, there were no significant differences between ANSD and sensorineural hearing loss (SNHL) groups in terms of speech recognition score (SMD = 0.01, 95% CI: -0.45, 0.47; P = .959),CAP (SMD = 0.71, 95% CI: -0.13, 1.54; P = .098), SIR score (SMD = -0.09, 95% CI: -0.49, 0.32; P = .667), and open-set speech perception (RR = 0.85, 95% CI: 0.69, 1.05; P = .142). Sensitivity analysis by removing individual studies one at a time showed that the overall estimate and level of heterogeneity did not change substantially. CONCLUSION The current evidence suggested that children with ANSD who underwent cochlear implants achieved comparable effects in auditory and speech performance as children with non-ANSD SNHL.
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Affiliation(s)
- Duan Bo
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
| | - Yue Huang
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
| | - Bing Wang
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
| | - Ping Lu
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
| | - Wen-Xia Chen
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
| | - Zheng-Min Xu
- Department of Otolaryngology-Head and Neck Surgery, Children's Hospital of Fudan University, Shanghai, China
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Summating Potential as Marker of Intracochlear Position in Bipolar Electrocochleography. Ear Hear 2023; 44:118-134. [PMID: 35894668 DOI: 10.1097/aud.0000000000001259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Cochlear implantation criteria include subjects with residual low-frequency hearing. To minimize implantation trauma and to avoid unwanted interactions of electric- and acoustic stimuli, it is often recommended to stop cochlear implantation before the cochlear implant (CI) reaches the cochlear partition with residual hearing, as determined by an audiogram. For this purpose, the implant can be used to record acoustically evoked signals during implantation, including cochlear compound action potentials (CAP), cochlear microphonics (CMs), and summating potentials (SPs). The former two have previously been used to monitor residual hearing in clinical settings. DESIGN In the present study we investigated the use of intracochlear, bipolar SP recordings to determine the exact cochlear position of the contacts of implanted CIs in guinea pig cochleae (n = 13). Polarity reversals of SPs were used as a functional marker of intracochlear position. Micro computed tomography (µCT) imaging and a modified Greenwood function were used to determine the cochleotopic positions of the contacts in the cochlea. These anatomical reconstructions were used to validate the SP-based position estimates. RESULTS The precision of the SP-based position estimation was on average within ± 0.37 octaves and was not impaired by moderate hearing loss caused by noise exposure after implantation. It is important to note that acute hearing impairment did not reduce the precision of the method. The cochleotopic position of CI accounted for ~70% of the variability of SP polarity reversals. Outliers in the dataset were associated with lateral CI positions. Last, we propose a simplified method to avoid implantation in functioning parts of the cochlea by approaching a predefined frequency region using bipolar SP recordings through a CI. CONCLUSIONS Bipolar SP recordings provide reliable information on electrode position in the cochlea. The position estimate remains reliable after moderate hearing loss. The technique presented here could be applied during CI surgery to monitor the CI approach to a predefined frequency region.
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Sun L, Lin Z, Zhang J, Shen J, Wang X, Yang J. Genetic etiological analysis of auditory neuropathy spectrum disorder by next-generation sequencing. Front Neurol 2022; 13:1026695. [PMID: 36570450 PMCID: PMC9772003 DOI: 10.3389/fneur.2022.1026695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/14/2022] [Indexed: 12/12/2022] Open
Abstract
Objective Auditory neuropathy spectrum disease (ANSD) is caused by both environmental and genetic causes and is defined by a failure in peripheral auditory neural transmission but normal outer hair cells function. To date, 13 genes identified as potentially causing ANSD have been documented. To study the etiology of ANSD, we collected 9 probands with ANSD diagnosed in the clinic and performed targeted next-generation sequencing. Methods Nine probands have been identified as ANSD based on the results of the ABR tests and DPOAE/CMs. Genomic DNA extracted from their peripheral blood was examined by next-generation sequencing (NGS) for a gene panel to identify any potential causal variations. For candidate pathogenic genes, we performed co-segregation among all family members of the pedigrees. Subsequently, using a mini-gene assay, we examined the function of a novel splice site mutant of OTOF. Results We analyzed nine cases of patients with ANSD with normal CMs/DPOAE and abnormal ABR, discovered three novel mutants of the OTOF gene that are known to cause ANSD, and six cases of other gene mutations including TBC1D24, LARS2, TIMM8A, MITF, and WFS1. Conclusion Our results extend the mutation spectrum of the OTOF gene and indicate that the genetic etiology of ANSD may be related to gene mutations of TBC1D24, LARS2, TIMM8A, MITF, and WFS1.
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Affiliation(s)
- Lianhua Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China,*Correspondence: Lianhua Sun
| | - Zhengyu Lin
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Jifang Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Jiali Shen
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Xiaowen Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Jun Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China,Shanghai Jiao Tong University School of Medicine Ear Institute, Shanghai, China,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China,Jun Yang
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Riggs WJ, Fontenot TE, Hiss MM, Varadarajan V, Moberly AC, Adunka OF, Fitzpatrick DC. Lack of neural contributions to the summating potential in humans with Meniere's disease. Front Neurosci 2022; 16:1039986. [PMID: 36570833 PMCID: PMC9768452 DOI: 10.3389/fnins.2022.1039986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
Objective To investigate the electrophysiology of the cochlear summating potential (SP) in patients with Meniere's disease (MD). Although long considered a purely hair cell potential, recent studies show a neural contribution to the SP. Patients with MD have an enhanced SP compared to those without the disease. Consequently, this study was to determine if the enhancement of the SP was in whole or part due to neural dysfunction. Design Study participants included 41 adults with MD and 53 subjects with auditory neuropathy spectrum disorder (ANSD), undergoing surgery where the round window was accessible. ANSD is a condition with known neural dysfunction, and thus represents a control group for the study. The ANSD subjects and 17 of the MD subjects were undergoing cochlear implantation (CI) surgery; the remaining MD subjects were undergoing either endolymphatic sac decompression or labyrinthectomy to alleviate the symptoms of MD. Electrocochleography was recorded from the round window using high intensity (90 dB nHL) tone bursts. The SP and compound action potential (CAP) were measured to high frequencies (> = 2 kHz) and the SP, cochlear microphonic (CM) and auditory nerve neurophonic (ANN) to low frequencies. Linear mixed models were used to assess differences between MD and ANSD subjects. Results Across frequencies, the MD subjects had smaller alternating current (AC) response than the ANSD subjects (F = 31.61,534, p < 0.001), but the SP magnitudes were larger (F = 94.31,534, p < 0.001). For frequencies less than 4 kHz the SP magnitude in the MD group was significantly correlated with the magnitude of the CM (p's < 0.001) but not in the ANSD group (p's > 0.05). Finally, the relative proportions of both ANN and CAP were greater in MD compared to ANSD subjects. The shapes of the waveforms in the MD subjects showed the presence of multiple components contributing to the SP, including outer and inner hair cells and neural activity. Conclusion The results support the view that the increased negative polarity SP in MD subjects is due to a change in the operating point of hair cells rather than a loss of neural contribution. The steady-state SP to tones in human subjects is a mixture of different sources with different polarities.
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Affiliation(s)
- William J. Riggs
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
- Department of Audiology, Nationwide Children’s Hospital, Columbus, OH, United States
| | - Tatyana E. Fontenot
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Meghan M. Hiss
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
| | - Varun Varadarajan
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
| | - Aaron C. Moberly
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
| | - Oliver F. Adunka
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
- Department of Audiology, Nationwide Children’s Hospital, Columbus, OH, United States
| | - Douglas C. Fitzpatrick
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Robot-Assisted Electrode Insertion in Cochlear Implantation Controlled by Intraoperative Electrocochleography-A Pilot Study. J Clin Med 2022; 11:jcm11237045. [PMID: 36498620 PMCID: PMC9737018 DOI: 10.3390/jcm11237045] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022] Open
Abstract
Robotics in otology has been developing in many directions for more than two decades. Current clinical trials focus on more accurate stapes surgery, minimally invasive access to the cochlea and less traumatic insertion of cochlear implant (CI) electrode arrays. In this study we evaluated the use of the RobOtol® (Collin, Bagneux, France) otologic robot to insert CI electrodes into the inner ear with intraoperative ECochG analysis. This prospective, pilot study included two adult patients implanted with Advanced Bionics (Westinghouse PI, CA, USA) cochlear implant, with HiFocus™ Mid-Scala electrode array. The standard surgical approach was used. For both subjects, who had residual hearing in the implanted ear, intraoperative and postoperative ECochG was performed with the AIMTM system. The surgeries were uneventful. A credible ECochG response was obtained after complete electrode insertion in both cases. Preoperative BC thresholds compared to intraoperative estimated ECochG thresholds and 2-day postoperative BC thresholds had similar values at frequencies where all thresholds were measurable. The results of the ECochG performed one month after the surgery showed that in both patients the hearing residues were preserved for the selected frequencies. The RobOtol® surgical robot allows for the correct, safe and gentle insertion of the cochlear implant electrode inside the cochlea. The use of electrocochleography measurements during robotic cochlear implantation offers an additional opportunity to evaluate and modify the electrode array insertion on an ongoing basis, which may contribute to the preservation of residual hearing.
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Round Window Electrocochleography to Low Frequency Tones in Pediatric Cochlear Implant Recipients with and Without Auditory Neuropathy Spectrum Disorder: Separating Hair Cell and Neural Contributions Using a Computational Model. Otol Neurotol 2022; 43:781-788. [PMID: 35763496 PMCID: PMC9329248 DOI: 10.1097/mao.0000000000003568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS Characterize the contribution of the auditory nerve neurophonic (ANN) to electrocochleography (ECochG) of pediatric cochlear implant (CI) recipients with and without auditory nerve spectrum disorder (ANSD). BACKGROUND ECochG is an emerging technique for predicting outcomes in CI recipients. Its utility may be increased by separating the cochlear microphonic (CM), produced by hair cells, from the ANN, the evoked potential correlate of neural phase-locking, which are mixed in the ongoing portion of the response to low frequency tone bursts. METHODS Responses to tone bursts of different frequency and intensities were recorded from the round window of pediatric CI recipients. Separation of the CM and ANN was performed using a model of the underlying processes that lead to the shapes of the observed waveforms. RESULTS Preoperative mean pure tone amplitudes of the included ANSD (n = 36) and non-ANSD subjects (n = 123), were similar (89.5 and 93.5, p = 0.1). Total of 1,024 ECochG responses to frequency and intensity series were recorded. The mean correlation (r) between the input and the modeled signals was 0.973 ± 0.056 (standard deviation). The ANN magnitudes were higher in the ANSD group (ANOVAs, F = 26.5 for frequency and 21.9 for intensity, df's = 1, p's < 0.001). However, its relative contribution to the overall signal was lower (ANOVAs, F = 25.8 and 12.1, df = 1, p's < 0.001). CONCLUSIONS ANN was detected in low frequency ECochG responses but not high frequency responses in both ANSD and non-ANSD subjects. ANSD subjects, evidence of neural contribution in responses to low frequency stimuli was highly variable and often comparable to signals recorded in non-ANSD subjects. The computational model revealed that on average the ANN comprised a lower proportion of the overall signal than in non-ANSD subjects.
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Lutz BT, Hutson KA, Trecca EMC, Hamby M, Fitzpatrick DC. Neural Contributions to the Cochlear Summating Potential: Spiking and Dendritic Components. J Assoc Res Otolaryngol 2022; 23:351-363. [PMID: 35254541 DOI: 10.1007/s10162-022-00842-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/21/2022] [Indexed: 11/30/2022] Open
Abstract
Using electrocochleography, the summating potential (SP) is a deflection from baseline to tones and an early rise in the response to clicks. Here, we use normal hearing gerbils and gerbils with outer hair cells removed with a combination of furosemide and kanamycin to investigate cellular origins of the SP. Round window electrocochleography to tones and clicks was performed before and after application of tetrodotoxin to prevent action potentials, and then again after kainic acid to prevent generation of an EPSP. With appropriate subtractions of the response curves from the different conditions, the contributions to the SP from outer hair cells, inner hair cell, and neural "spiking" and "dendritic" responses were isolated. Like hair cells, the spiking and dendritic components had opposite polarities to tones - the dendritic component had negative polarity and the spiking component had positive polarity. The magnitude of the spiking component was larger than the dendritic across frequencies and intensities. The onset to tones and to clicks followed a similar sequence; the outer hair cells responded first, then inner hair cells, then the dendritic component, and then the compound action potential of the spiking response. These results show the sources of the SP include at least the four components studied, and that these have a mixture of polarities and magnitudes that vary across frequency and intensity. Thus, multiple possible interactions must be considered when interpreting the SP for clinical uses.
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Affiliation(s)
- Brendan T Lutz
- The University of North Carolina at Chapel Hill, Department of Otolaryngology - Head & Neck Surgery, 101 Mason Farm Rd, CB#7546, Chapel Hill, NC, USA
| | - Kendall A Hutson
- The University of North Carolina at Chapel Hill, Department of Otolaryngology - Head & Neck Surgery, 101 Mason Farm Rd, CB#7546, Chapel Hill, NC, USA
| | - Eleonora M C Trecca
- IRCCS Casa Sollievo Della Sofferenza, Department of Maxillofacial Surgery and Otolaryngology, San Giovanni Rotondo (Foggia), Italy.,University Hospital of Foggia, Department of Otolaryngology- Head and Neck Surgery, Foggia, Italy
| | - Meredith Hamby
- The University of North Carolina at Chapel Hill, Department of Otolaryngology - Head & Neck Surgery, 101 Mason Farm Rd, CB#7546, Chapel Hill, NC, USA
| | - Douglas C Fitzpatrick
- The University of North Carolina at Chapel Hill, Department of Otolaryngology - Head & Neck Surgery, 101 Mason Farm Rd, CB#7546, Chapel Hill, NC, USA.
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Intraoperative Electrocochleography in Subjects Affected by Vestibular Schwannoma and Ménière's Disease: Comparison of Results. Ear Hear 2021; 43:874-882. [PMID: 34582395 DOI: 10.1097/aud.0000000000001133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Histologic reports of temporal bones of ears with vestibular schwannomas (VSs) have indicated findings of endolymphatic hydrops (ELH) in some cases. The main goal of this investigation was to test ears with VSs to determine if they exhibit electrophysiological characteristics similar to those of ears expected to experience ELH. DESIGN Fifty-three subjects with surgically confirmed VS aged ≥18 and with normal middle ear status were included in this study. In addition, a second group of adult subjects (n = 24) undergoing labyrinthectomy (n = 6) or endolymphatic sac decompression and shunt (ELS) placement (n = 18) for poorly controlled vestibular symptoms associated with Meniere's disease (MD) participated in this research. Intraoperative electrocochleography (ECochG) from the round window was performed using tone burst stimuli. Audiometric testing and word recognition scores (WRS) were performed preoperatively. ECochG amplitudes, cochlear microphonic/auditory nerve neurophonic (ANN) in the form of the "ongoing" response and summation potential, were analyzed and compared between the two groups of subjects. In addition, to evaluate any effect of auditory nerve function, the auditory nerve score was calculated for each subject. Pure-tone averages were obtained using the average air conduction thresholds at 0.5, 1, and 2 kHz while WRS was assessed using Northwestern University Auditory Test No. 6 word lists. RESULTS In the VS group the average pure-tone averages and WRS were 59.6 dB HL and 44.8%, respectively, while in the MD group they were 52.3 dB HL and 73.8%. ECochG findings in both groups revealed a reduced trend in amplitude of the ongoing response with increased stimulus frequency. The summation potential amplitudes of subjects with VS were found to be less negative than the MD subjects for nearly all test frequencies. Finally, the VS group exhibited poorer amounts of auditory nerve function compared to the MD group. CONCLUSIONS The current findings suggest cochlear pathology (e.g., hair cell loss) in both groups but do not support the hypothesis that VSs cause ELH.
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Clinical Utility of Intraoperative Electrocochleography (ECochG) During Cochlear Implantation: A Systematic Review and Quantitative Analysis. Otol Neurotol 2021; 42:363-371. [PMID: 33347054 DOI: 10.1097/mao.0000000000002996] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the utility of intraoperative electrocochleography (ECochG) as a predictive tool for preservation of residual acoustic hearing after cochlear implantation. DATA SOURCES A systematic review employing a multi-database search strategy (Ovid MEDLINE, Embase, EBM Cochrane, and Scopus) was conducted from inception to August 1, 2019. English language studies in humans were included. STUDY SELECTION All articles were independently reviewed by two authors according to Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines. Studies without intraoperative ECochG obtained during cochlear implantation were excluded. DATA EXTRACTION Extracted variables included number of patients, ECochG recording technique, success rate of obtaining ECochG potentials, intraoperative changes in ECochG signal, and postoperative hearing preservation outcomes. DATA SYNTHESIS Among 537 eligible articles, 22 met inclusion criteria encompassing 498 unique patients. Ten studies featured extracochlear measurements, eight featured intracochlear measurements, and four featured both. Extracochlear ECochG had an average (SD) recording success rate of 94.9% (12.7%) while intracochlear ECochG had an average (SD) recording success rate of 91.8% (9.8%). One hundred forty five unique patients from six studies had complete intraoperative ECochG data with postoperative behavioral audiometry. After accounting for study-specific definitions of ECochG signal disturbance, worsening changes in intraoperative ECochG signal predicted postoperative hearing loss with limited sensitivity and specificity and notable heterogeneity across studies. CONCLUSIONS Intraoperative ECochG recordings can be obtained in over 90% of patients, but accuracy in predicting postoperative hearing loss remains limited. Standardization of intraoperative ECochG monitoring technique and data interpretation are necessary to more robustly investigate outcomes and refine technique.
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Real Time Monitoring During Cochlear Implantation: Increasing the Accuracy of Predicting Residual Hearing Outcomes. Otol Neurotol 2021; 42:e1030-e1036. [PMID: 33859138 DOI: 10.1097/mao.0000000000003177] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Real-time electrocochleography (rt-ECochG) is a method to detect intracochlear potential changes during cochlear implantation (CI). Steep amplitude drops of the cochlear microphonic (CM) signal (so called "ECochG events") have been correlated with worse residual hearing outcomes. However, the sensitivity and specificity of monitoring CM amplitude on its own are too low to use it as a biomarker. The aim of this article was to establish if additional signal components would help to better predict postoperative hearing outcomes. DESIGN AND SETTING Single-center, prospective cohort study at a tertiary referral hospital. PARTICIPANTS AND INTERVENTIONS Between 2017 and 2020, we included 73 adult patients receiving a lateral wall cochlear implant electrode. During electrode insertion, rt-ECochG measurements were performed. MAIN OUTCOMES We calculated a multiple regression analysis for patients with one ECochG event. The dependant variable was the relative acoustic hearing result 4 weeks after surgery. Independent variables were CM latency, a ratio of the auditory nerve neurophonic to the CM (the ANN/CM index) as well as CM signal recovery. RESULTS The change of the ANN/CM index linearly correlated with acoustic hearing outcomes 4 weeks after surgery. Adding this factor led to a statistically significant increase in the variance accounted for by the regression model. CONCLUSIONS When monitoring the implantation process with rt-ECochG, prediction of postoperative hearing thresholds is improved by addition of the ANN/CM index to a model that includes CM amplitude fluctuation.
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Abstract
OBJECTIVE Given the heterogeneity of papers about electrocochleography (ECochG) and cochlear implantation (CI) and the absence of a systematic review in the current literature, the aim of this work was to analyze the uses of ECochG in the different stages of CI. DATA SOURCES A search of PubMed from inception to December 8, 2019, with cross-references, was executed. Keywords were: "Cochlear Implant" OR "Cochlear Implantation" AND "Electrocochleography" OR "ECochG." The main eligibility criteria were English-language articles, investigating the use of ECochG in the different phases of CI. STUDY SELECTION Literature reviews, editorials, case reports, conference papers were excluded, as were papers in which ECochG was just sporadically executed. DATA EXTRACTION The quality of the included studies was assessed using "The Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) Statement. DATA SYNTHESIS A total of 95 articles were identified and 60 papers were included. The included articles covered a timeframe from 2003 to 2019. Of the 60 papers, 46 were human studies, 12 animal studies, and two involved more data sets. Eleven related to the diagnostic phase, 43 described intraoperative monitoring, and 10 were regarding follow-up testing. Hearing preservation was the most discussed topic with 25 included articles. CONCLUSIONS AND RELEVANCE ECochG measurements appeared to be useful in many aspects of CI, such as hearing preservation. Our review is the first that shows the evolution of the technique and how much has been achieved from the earliest experiments to the most recent signal process refinements and device implementation in CI.
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Trecca EMC, Adunka OF, Mattingly JK, Hiss MM, Cassano M, Malhotra PS, Riggs WJ. Electrocochleography Observations in a Series of Cochlear Implant Electrode Tip Fold-Overs. Otol Neurotol 2021; 42:e433-e437. [PMID: 33196531 DOI: 10.1097/mao.0000000000003008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Tip fold-over is a rare but serious complication of cochlear implant (CI) surgery. The purpose of this study was to present intraoperative electrocochleography (ECochG) observations in a series of CI electrode tip fold-overs. PATIENTS Five pediatric subjects undergoing CI surgery through a round window (RW) approach with a perimodiolar electrode array, who were diagnosed with either auditory neuropathy spectrum disorder or enlarged vestibular aqueduct. INTERVENTIONS Intraoperative RW ECochG during CI surgery: tone burst stimuli were presented from 95 to 110 dB SPL. MAIN OUTCOME MEASURES Magnitude and phase characteristics of ECochG responses obtained intraoperatively before and immediately after electrode insertion were examined for patients with and without tip fold-over. RESULTS Three subjects presented with tip fold-over and two formed the control group. Among fold-over cases, one participant exhibited an inversion in the starting phase of the cochlear microphonic response and a decrease in spectral magnitude from pre- to postinsertion. Both subjects who did not exhibit a change in phase had an increase in the ECochG-total response (ECochG-TR) magnitude. No case in the control group exhibited a change in starting phase. In regard to the ECochG-TR, all controls showed a decrease in the magnitude. CONCLUSIONS Despite the small number of patients, heterogeneous ECochG response patterns were observed within the fold-over group. Though these results are not conclusive, they can serve as a framework to begin to understand ECochG's utility in detecting intraoperative tip fold-over.
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Affiliation(s)
- Eleonora M C Trecca
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Otolaryngology - Head and Neck Surgery, University Hospital of Foggia, Foggia, Italy
| | - Oliver F Adunka
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jameson K Mattingly
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Meghan M Hiss
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Michele Cassano
- Department of Otolaryngology - Head and Neck Surgery, University Hospital of Foggia, Foggia, Italy
| | - Prashant S Malhotra
- Department of Otolaryngology - Head and Neck Surgery, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - William J Riggs
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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Zhan KY, Adunka OF, Eshraghi A, Riggs WJ, Prentiss SM, Yan D, Telischi FF, Liu X, He S. Electrophysiology and genetic testing in the precision medicine of congenital deafness: A review. J Otol 2021; 16:40-46. [PMID: 33505449 PMCID: PMC7814082 DOI: 10.1016/j.joto.2020.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/11/2020] [Accepted: 07/21/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Congenital hearing loss is remarkably heterogeneous, with over 130 deafness genes and thousands of variants, making for innumerable genotype/phenotype combinations. Understanding both the pathophysiology of hearing loss and molecular site of lesion along the auditory pathway permits for significantly individualized counseling. Electrophysiologic techniques such as electrocochleography (ECochG) and electrically-evoked compound action potentials (eCAP) are being studied to localize pathology and estimate residual cochlear vs. neural health. This review describes the expanding roles of genetic and electrophysiologic evaluation in the precision medicine of congenital hearing loss.The basics of genetic mutations in hearing loss and electrophysiologic testing (ECochG and eCAP) are reviewed, and how they complement each other in the diagnostics and prognostication of hearing outcomes. Used together, these measures improve the understanding of insults to the auditory system, allowing for individualized counseling for CI candidacy/outcomes or other habilitation strategies. CONCLUSION Despite tremendous discovery in deafness genes, the effects of individual genes on neural function remain poorly understood. Bridging the understanding between molecular genotype and neural and functional phenotype is paramount to interpreting genetic results in clinical practice. The future hearing healthcare provider must consolidate an ever-increasing amount of genetic and phenotypic information in the precision medicine of hearing loss.
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Affiliation(s)
- Kevin Y. Zhan
- Department of Otolaryngology – Head & Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Oliver F. Adunka
- Department of Otolaryngology – Head & Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Audiology, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Adrien Eshraghi
- Department of Otolaryngology – Head & Neck Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - William J. Riggs
- Department of Otolaryngology – Head & Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Audiology, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Sandra M. Prentiss
- Department of Otolaryngology – Head & Neck Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Denise Yan
- Department of Otolaryngology – Head & Neck Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Fred F. Telischi
- Department of Otolaryngology – Head & Neck Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Xuezhong Liu
- Department of Otolaryngology – Head & Neck Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Dr. John T. MacDonald Foundation, Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Shuman He
- Department of Otolaryngology – Head & Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Audiology, Nationwide Children’s Hospital, Columbus, OH, USA
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Hutson KA, Pulver SH, Ariel P, Naso C, Fitzpatrick DC. Light sheet microscopy of the gerbil cochlea. J Comp Neurol 2020; 529:757-785. [PMID: 32632959 DOI: 10.1002/cne.24977] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 05/13/2020] [Accepted: 06/21/2020] [Indexed: 01/19/2023]
Abstract
Light sheet fluorescence microscopy (LSFM) provides a rapid and complete three-dimensional image of the cochlea. The method retains anatomical relationships-on a micrometer scale-between internal structures such as hair cells, basilar membrane (BM), and modiolus with external surface structures such as the round and oval windows. Immunolabeled hair cells were used to visualize the spiraling BM in the intact cochlea without time intensive dissections or additional histological processing; yet material prepared for LSFM could be rehydrated, the BM dissected out and reimaged at higher resolution with the confocal microscope. In immersion-fixed material, details of the cochlear vasculature were seen throughout the cochlea. Hair cell counts (both inner and outer) as well as frequency maps of the BM were comparable to those obtained by other methods, but with the added dimension of depth. The material provided measures of angular, linear, and vector distance between characteristic frequency regions along the BM. Thus, LSFM provides a unique ability to rapidly image the entire cochlea in a manner applicable to model and interpret physiological results. Furthermore, the three-dimensional organization of the cochlea can be studied at the organ and cellular level with LSFM, and this same material can be taken to the confocal microscope for detailed analysis at the subcellular level.
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Affiliation(s)
- Kendall A Hutson
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Stephen H Pulver
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Pablo Ariel
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Caroline Naso
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Douglas C Fitzpatrick
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Riggs WJ, Hiss MM, Varadarajan VV, Mattingly JK, Adunka OF. Enlarged vestibular aqueduct: Intraoperative electrocochleography findings during cochlear implantation. Int J Pediatr Otorhinolaryngol 2020; 134:110065. [PMID: 32361253 DOI: 10.1016/j.ijporl.2020.110065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/21/2020] [Accepted: 04/21/2020] [Indexed: 10/24/2022]
Abstract
Enlarged vestibular aqueduct (EVA) is the most frequent inner ear abnormality found on computed tomography in children with sensorineural hearing loss. The effects EVA abnormalities have on electrocochleography (ECochG) are unknown. Positive deflections in summation potential evoked by tone bursts were observed in 3/5 subjects, while a large negative deflection, similar to endolymphatic hydrops (EH), was observed for 2/5 subjects. The presence of an enlarged summation potential, with and without a compound action potential, was observed in response to a broadband click stimulus. Results suggest likely effects of a third window on ECochG responses and presence of EH in EVA.
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Affiliation(s)
- William J Riggs
- The Ohio State University, College of Medicine, Department of Otolaryngology- Head and Neck Surgery, Columbus, OH, USA; Nationwide Children's Hospital, Department of Audiology, Columbus, OH, USA.
| | - Meghan M Hiss
- The Ohio State University, College of Medicine, Department of Otolaryngology- Head and Neck Surgery, Columbus, OH, USA
| | - Varun V Varadarajan
- The Ohio State University, College of Medicine, Department of Otolaryngology- Head and Neck Surgery, Columbus, OH, USA
| | - Jameson K Mattingly
- The Ohio State University, College of Medicine, Department of Otolaryngology- Head and Neck Surgery, Columbus, OH, USA
| | - Oliver F Adunka
- The Ohio State University, College of Medicine, Department of Otolaryngology- Head and Neck Surgery, Columbus, OH, USA; Nationwide Children's Hospital, Department of Otolaryngology-Head and Neck Surgery, Columbus, OH, USA
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24
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Barnes JH, Yin LX, Saoji AA, Carlson ML. Electrocochleography in cochlear implantation: Development, applications, and future directions. World J Otorhinolaryngol Head Neck Surg 2020; 7:94-100. [PMID: 33997718 PMCID: PMC8103527 DOI: 10.1016/j.wjorl.2020.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 04/02/2020] [Accepted: 04/13/2020] [Indexed: 11/26/2022] Open
Affiliation(s)
- Jason H Barnes
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA
| | - Linda X Yin
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA
| | - Aniket A Saoji
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA
| | - Matthew L Carlson
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN, USA
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25
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Auditory Neuropathy Spectrum Disorders: From Diagnosis to Treatment: Literature Review and Case Reports. J Clin Med 2020; 9:jcm9041074. [PMID: 32290039 PMCID: PMC7230308 DOI: 10.3390/jcm9041074] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/21/2020] [Accepted: 04/01/2020] [Indexed: 12/21/2022] Open
Abstract
Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by deteriorated speech perception, despite relatively preserved pure-tone detection thresholds. Affected individuals usually present with abnormal auditory brainstem responses (ABRs), but normal otoacoustic emissions (OAEs). These electrophysiological characteristics have led to the hypothesis that ANSD may be caused by various dysfunctions at the cochlear inner hair cell (IHC) and spiral ganglion neuron (SGN) levels, while the activity of outer hair cells (OHCs) is preserved, resulting in discrepancies between pure-tone and speech comprehension thresholds. The exact prevalence of ANSD remains unknown; clinical findings show a large variability among subjects with hearing impairment ranging from mild to profound hearing loss. A wide range of prenatal and postnatal etiologies have been proposed. The study of genetics and of the implicated sites of lesion correlated with clinical findings have also led to a better understanding of the molecular mechanisms underlying the various forms of ANSD, and may guide clinicians in better screening, assessment and treatment of ANSD patients. Besides OAEs and ABRs, audiological assessment includes stapedial reflex measurements, supraliminal psychoacoustic tests, electrocochleography (ECochG), auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs). Hearing aids are indicated in the treatment of ANSD with mild to moderate hearing loss, whereas cochlear implantation is the first choice of treatment in case of profound hearing loss, especially in case of IHC presynaptic disorders, or in case of poor auditory outcomes with conventional hearing aids.
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Electrocochleography During Translabyrinthine Approach for Vestibular Schwannoma Removal. Otol Neurotol 2020; 41:e369-e377. [DOI: 10.1097/mao.0000000000002543] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Riggs WJ, Hiss MM, Skidmore J, Varadarajan VV, Mattingly JK, Moberly AC, Adunka OF. Utilizing Electrocochleography as a Microphone for Fully Implantable Cochlear Implants. Sci Rep 2020; 10:3714. [PMID: 32111954 PMCID: PMC7048783 DOI: 10.1038/s41598-020-60694-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 02/13/2020] [Indexed: 11/09/2022] Open
Abstract
Current cochlear implants (CIs) are semi-implantable devices with an externally worn sound processor that hosts the microphone and sound processor. A fully implantable device, however, would ultimately be desirable as it would be of great benefit to recipients. While some prototypes have been designed and used in a few select cases, one main stumbling block is the sound input. Specifically, subdermal implantable microphone technology has been poised with physiologic issues such as sound distortion and signal attenuation under the skin. Here we propose an alternative method that utilizes a physiologic response composed of an electrical field generated by the sensory cells of the inner ear to serve as a sound source microphone for fully implantable hearing technology such as CIs. Electrophysiological results obtained from 14 participants (adult and pediatric) document the feasibility of capturing speech properties within the electrocochleography (ECochG) response. Degradation of formant properties of the stimuli /da/ and /ba/ are evaluated across various degrees of hearing loss. Preliminary results suggest proof-of-concept of using the ECochG response as a microphone is feasible to capture vital properties of speech. However, further signal processing refinement is needed in addition to utilization of an intracochlear recording location to likely improve signal fidelity.
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Affiliation(s)
- William Jason Riggs
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Meghan M Hiss
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jeffrey Skidmore
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Varun V Varadarajan
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jameson K Mattingly
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Aaron C Moberly
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Oliver F Adunka
- Department of Otolaryngology, Head & Neck Surgery, The Ohio State University College of Medicine, Columbus, OH, USA.
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Intracochlear Electrocochleography: Response Patterns During Cochlear Implantation and Hearing Preservation. Ear Hear 2020; 40:833-848. [PMID: 30335669 DOI: 10.1097/aud.0000000000000659] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Electrocochleography (ECochG) obtained through a cochlear implant (CI) is increasingly being tested as an intraoperative monitor during implantation with the goal of reducing surgical trauma. Reducing trauma should aid in preserving residual hearing and improve speech perception overall. The purpose of this study was to characterize intracochlear ECochG responses throughout insertion in a range of array types and, when applicable, relate these measures to hearing preservation. The ECochG signal in cochlear implant subjects is complex, consisting of hair cell and neural generators with differing distributions depending on the etiology and history of hearing loss. Consequently, a focus was to observe and characterize response changes as an electrode advances. DESIGN In 36 human subjects, responses to 90 dB nHL tone bursts were recorded both at the round window (RW) and then through the apical contact of the CI as the array advanced into the cochlea. The specific setup used a sterile clip in the surgical field, attached to the ground of the implant with a software-controlled short to the apical contact. The end of the clip was then connected to standard audiometric recording equipment. The stimuli were 500 Hz tone bursts at 90 dB nHL. Audiometry for cases with intended hearing preservation (12/36 subjects) was correlated with intraoperative recordings. RESULTS Successful intracochlear recordings were obtained in 28 subjects. For the eight unsuccessful cases, the clip introduced excessive line noise, which saturated the amplifier. Among the successful subjects, the initial intracochlear response was a median 5.8 dB larger than the response at the RW. Throughout insertion, modiolar arrays showed median response drops after stylet removal while in lateral wall arrays the maximal median response magnitude was typically at the deepest insertion depth. Four main patterns of response magnitude were seen: increases > 5 dB (12/28), steady responses within 5 dB (4/28), drops > 5 dB (from the initial response) at shallow insertion depths (< 15 mm deep, 7/28), or drops > 5 dB occurring at deeper depths (5/28). Hearing preservation, defined as < 80 dB threshold at 250 Hz, was successful in 9/12 subjects. In these subjects, an intracochlear loss of response magnitude afforded a prediction model with poor sensitivity and specificity, which improved when phase, latency, and proportion of neural components was considered. The change in hearing thresholds across cases was significantly correlated with various measures of the absolute magnitudes of response, including RW response, starting response, maximal response, and final responses (p's < 0.05, minimum of 0.0001 for the maximal response, r's > 0.57, maximum of 0.80 for the maximal response). CONCLUSIONS Monitoring the cochlea with intracochlear ECochG during cochlear implantation is feasible, and patterns of response vary by device type. Changes in magnitude alone did not account for hearing preservation rates, but considerations of phase, latency, and neural contribution can help to interpret the changes seen and improve sensitivity and specificity. The correlation between the absolute magnitude obtained either before or during insertion of the ECochG and the hearing threshold changes suggest that cochlear health, which varies by subject, plays an important role.
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Shapiro SM, Riordan SM. Review of bilirubin neurotoxicity II: preventing and treating acute bilirubin encephalopathy and kernicterus spectrum disorders. Pediatr Res 2020; 87:332-337. [PMID: 31581172 DOI: 10.1038/s41390-019-0603-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 09/09/2019] [Indexed: 11/09/2022]
Abstract
Previously in Part I of this two-part review, we discussed the current and recent advances in the understanding of the molecular biology and neuropathology of bilirubin neurotoxicity (BNTx). Here in Part II, we summarize current treatment options available to treat the severely jaundiced infants to prevent significant brain damage and improve clinical outcomes. In addition, we review potential novel therapies that are in various stages of research and development. We will emphasize treatments for both prevention and treatment of both acute bilirubin encephalopathy (ABE) and kernicterus spectrum disorders (KSDs), highlighting the treatment of the most disabling neurological sequelae of children with mild-to-severe KSDs whose "rare disease" status often means they are overlooked by the clinical research community at large. As with other secondary dystonias, treatment of the dystonic motor symptoms in kernicterus is the greatest clinical challenge.
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Affiliation(s)
- Steven M Shapiro
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA. .,Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA. .,Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA. .,Department of Pediatrics, University of Missouri-Kansas City, Kansas City, MO, USA.
| | - Sean M Riordan
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA.,Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA.,Department of Pediatrics, University of Missouri-Kansas City, Kansas City, MO, USA
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30
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Residual Cochlear Function in Adults and Children Receiving Cochlear Implants: Correlations With Speech Perception Outcomes. Ear Hear 2019; 40:577-591. [PMID: 30169463 DOI: 10.1097/aud.0000000000000630] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Variability in speech perception outcomes with cochlear implants remains largely unexplained. Recently, electrocochleography, or measurements of cochlear potentials in response to sound, has been used to assess residual cochlear function at the time of implantation. Our objective was to characterize the potentials recorded preimplantation in subjects of all ages, and evaluate the relationship between the responses, including a subjective estimate of neural activity, and speech perception outcomes. DESIGN Electrocochleography was recorded in a prospective cohort of 284 candidates for cochlear implant at University of North Carolina (10 months to 88 years of ages). Measurement of residual cochlear function called the "total response" (TR), which is the sum of magnitudes of spectral components in response to tones of different stimulus frequencies, was obtained for each subject. The TR was then related to results on age-appropriate monosyllabic word score tests presented in quiet. In addition to the TR, the electrocochleography results were also assessed for neural activity in the forms of the compound action potential and auditory nerve neurophonic. RESULTS The TR magnitude ranged from a barely detectable response of about 0.02 µV to more than 100 µV. In adults (18 to 79 years old), the TR accounted for 46% of variability in speech perception outcome by linear regression (r = 0.46; p < 0.001). In children between 6 and 17 years old, the variability accounted for was 36% (p < 0.001). In younger children, the TR accounted for less of the variability, 15% (p = 0.012). Subjects over 80 years old tended to perform worse for a given TR than younger adults at the 6-month testing interval. The subjectively assessed neural activity did not increase the information compared with the TR alone, which is primarily composed of the cochlear microphonic produced by hair cells. CONCLUSIONS The status of the auditory periphery, particularly of hair cells rather than neural activity, accounts for a large fraction of variability in speech perception outcomes in adults and older children. In younger children, the relationship is weaker, and the elderly differ from other adults. This simple measurement can be applied with high throughput so that peripheral status can be assessed to help manage patient expectations, create individually-tailored treatment plans, and identify subjects performing below expectations based on residual cochlear function.
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31
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Pappa AK, Hutson KA, Scott WC, Wilson JD, Fox KE, Masood MM, Giardina CK, Pulver SH, Grana GD, Askew C, Fitzpatrick DC. Hair cell and neural contributions to the cochlear summating potential. J Neurophysiol 2019; 121:2163-2180. [PMID: 30943095 DOI: 10.1152/jn.00006.2019] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The cochlear summating potential (SP) to a tone is a baseline shift that persists for the duration of the burst. It is often considered the most enigmatic of cochlear potentials because its magnitude and polarity vary across frequency and level and its origins are uncertain. In this study, we used pharmacology to isolate sources of the SP originating from the gerbil cochlea. Animals either had the full complement of outer and inner hair cells (OHCs and IHCs) and an intact auditory nerve or had systemic treatment with furosemide and kanamycin (FK) to remove the outer hair cells. Responses to tone bursts were recorded from the round window before and after the neurotoxin kainic acid (KA) was applied. IHC responses were then isolated from the post-KA responses in FK animals, neural responses were isolated from the subtraction of post-KA from pre-KA responses in NH animals, and OHC responses were isolated by subtraction of post-KA responses in FK animals from post-KA responses in normal hearing (NH) animals. All three sources contributed to the SP; OHCs with a negative polarity and IHCs and the auditory nerve with positive polarity. Thus the recorded SP in NH animals is a sum of contributions from different sources, contributing to the variety of magnitudes and polarities seen across frequency and intensity. When this information was applied to observations of the SP recorded from the round window in human cochlear implant subjects, a strong neural contribution to the SP was confirmed in humans as well as gerbils. NEW & NOTEWORTHY Of the various potentials produced by the cochlea, the summating potential (SP) is typically described as the most enigmatic. Using combinations of ototoxins and neurotoxins, we show contributions to the SP from the auditory nerve and from inner and outer hair cells, which differ in polarity and vary in size across frequency and level. This complexity of sources helps to explain the enigmatic nature of the SP.
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Affiliation(s)
- Andrew K Pappa
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Kendall A Hutson
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - William C Scott
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - J David Wilson
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Kevin E Fox
- Campbell University School of Osteopathic Medicine, Lillington, North Carolina
| | - Maheer M Masood
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Christopher K Giardina
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Stephen H Pulver
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Gilberto D Grana
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Charles Askew
- Gene Therapy Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Douglas C Fitzpatrick
- Department of Otolaryngology and Head and Neck Surgery, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
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Response Changes During Insertion of a Cochlear Implant Using Extracochlear Electrocochleography. Ear Hear 2019; 39:1146-1156. [PMID: 29554036 DOI: 10.1097/aud.0000000000000571] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Electrocochleography is increasingly being utilized as an intraoperative monitor of cochlear function during cochlear implantation (CI). Intracochlear recordings from the advancing electrode can be obtained through the device by on-board capabilities. However, such recordings may not be ideal as a monitor because the recording electrode moves in relation to the neural and hair cell generators producing the responses. The purposes of this study were to compare two extracochlear recording locations in terms of signal strength and feasibility as intraoperative monitoring sites and to characterize changes in cochlear physiology during CI insertion. DESIGN In 83 human subjects, responses to 90 dB nHL tone bursts were recorded both at the round window (RW) and then at an extracochlear position-either adjacent to the stapes or on the promontory just superior to the RW. Recording from the fixed, extracochlear position continued during insertion of the CI in 63 cases. RESULTS Before CI insertion, responses to low-frequency tones at the RW were roughly 6 dB larger than when recording at either extracochlear site, but the two extracochlear sites did not differ from one another. During CI insertion, response losses from the promontory or adjacent to the stapes stayed within 5 dB in ≈61% (38/63) of cases, presumably indicating atraumatic insertions. Among responses which dropped more than 5 dB at any time during CI insertion, 12 subjects showed no response recovery, while in 13, the drop was followed by partial or complete response recovery by the end of CI insertion. In cases with recovery, the drop in response occurred relatively early (<15 mm insertion) compared to those where there was no recovery. Changes in response phase during the insertion occurred in some cases; these may indicate a change in the distributions of generators contributing to the response. CONCLUSIONS Monitoring the electrocochleography during CI insertion from an extracochlear site reveals insertions that are potentially atraumatic, show interaction with cochlear structures followed by response recovery, or show interactions such that response losses persist to the end of recording.
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Patterns Seen During Electrode Insertion Using Intracochlear Electrocochleography Obtained Directly Through a Cochlear Implant. Otol Neurotol 2018; 38:1415-1420. [PMID: 28953607 DOI: 10.1097/mao.0000000000001559] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
HYPOTHESIS Intraoperative, intracochlear electrocochleography (ECochG) will provide a means to monitor cochlear hair cell and neural response during cochlear implant (CI) electrode insertion. Distinct patterns in the insertion track can be characterized. BACKGROUND Conventional CI surgery is performed without a means of actively monitoring cochlear hair cell and neural responses. Intracochlear ECochG obtained directly through the CI may be a source of such feedback. Understanding the patterns observed in the "insertion track" is an essential step toward refining intracochlear ECochG as a tool that can be used to assist in intraoperative decision making and prognostication of hearing preservation. METHODS Intracochlear ECochG was performed in 17 patients. During electrode insertion, a 50-ms tone burst acoustic stimulus was delivered with a frequency of 500 Hz at 110 dB SPL. The ECochG response was monitored from the apical-most electrode. The amplitude of the first harmonic was plotted and monitored in near real time by the audiologist-surgeon team during CI electrode insertion. RESULTS Three distinct patterns in first harmonic amplitude change were observed across subjects during insertion: Type A (52%), overall increase in amplitude from the beginning of insertion until completion; Type B (11%), a maximum amplitude at the beginning of insertion, with a decrease in amplitude as insertion progressed to completion; and Type C (35%), comparable amplitudes at the beginning and completion of the insertion with the maximum amplitude mid-insertion. CONCLUSION Three ECochG patterns were observed during electrode advancement into the cochlea. Ongoing and future work will broaden our scope of knowledge regarding the relationship among these patterns, the presence of cochlear trauma, and functional outcomes related to hearing preservation.
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34
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Fontenot TE, Giardina CK, Fitzpatrick DC. A Model-Based Approach for Separating the Cochlear Microphonic from the Auditory Nerve Neurophonic in the Ongoing Response Using Electrocochleography. Front Neurosci 2017; 11:592. [PMID: 29123468 PMCID: PMC5662900 DOI: 10.3389/fnins.2017.00592] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 10/09/2017] [Indexed: 12/02/2022] Open
Abstract
Electrocochleography (ECochG) is a potential clinically valuable technique for predicting speech perception outcomes in cochlear implant (CI) recipients, among other uses. Current analysis is limited by an inability to quantify hair cell and neural contributions which are mixed in the ongoing part of the response to low frequency tones. Here, we used a model based on source properties to account for recorded waveform shapes and to separate the combined signal into its components. The model for the cochlear microphonic (CM) was a sinusoid with parameters for independent saturation of the peaks and the troughs of the responses. The model for the auditory nerve neurophonic (ANN) was the convolution of a unit potential and population cycle histogram with a parameter for spread of excitation. Phases of the ANN and CM were additional parameters. The average cycle from the ongoing response was the input, and adaptive fitting identified CM and ANN parameters that best reproduced the waveform shape. Test datasets were responses recorded from the round windows of CI recipients, from the round window of gerbils before and after application of neurotoxins, and with simulated signals where each parameter could be manipulated in isolation. Waveforms recorded from 284 CI recipients had a variety of morphologies that the model fit with an average r2 of 0.97 ± 0.058 (standard deviation). With simulated signals, small systematic differences between outputs and inputs were seen with some variable combinations, but in general there were limited interactions among the parameters. In gerbils, the CM reported was relatively unaffected by the neurotoxins. In contrast, the ANN was strongly reduced and the reduction was limited to frequencies of 1,000 Hz and lower, consistent with the range of strong neural phase-locking. Across human CI subjects, the ANN contribution was variable, ranging from nearly none to larger than the CM. Development of this model could provide a means to isolate hair cell and neural activity that are mixed in the ongoing response to low-frequency tones. This tool can help characterize the residual physiology across CI subjects, and can be useful in other clinical settings where a description of the cochlear physiology is desirable.
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Affiliation(s)
- Tatyana E Fontenot
- Otolaryngology-Head and Neck Surgery, University of North Carolina, Chapel Hill, NC, United States
| | | | - Douglas C Fitzpatrick
- Otolaryngology-Head and Neck Surgery, University of North Carolina, Chapel Hill, NC, United States.,School of Medicine, University of North Carolina, Chapel Hill, NC, United States
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35
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Fontenot TE, Giardina CK, Teagle HF, Park LR, Adunka OF, Buchman CA, Brown KD, Fitzpatrick DC. Clinical role of electrocochleography in children with auditory neuropathy spectrum disorder. Int J Pediatr Otorhinolaryngol 2017; 99:120-127. [PMID: 28688553 PMCID: PMC5538887 DOI: 10.1016/j.ijporl.2017.05.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/26/2017] [Accepted: 05/31/2017] [Indexed: 01/21/2023]
Abstract
OBJECTIVES To assess electrocochleography (ECochG) to tones as an instrument to account for CI speech perception outcomes in children with auditory neuropathy spectrum disorder (ANSD). MATERIALS & METHODS Children (<18 years) receiving CIs for ANSD (n = 30) and non-ANSD (n = 74) etiologies of hearing loss were evaluated with ECochG using tone bursts (0.25-4 kHz). The total response (TR) is the sum of spectral peaks of responses across frequencies. The compound action potential (CAP) and the auditory nerve neurophonic (ANN) in ECochG waveforms were used to estimate nerve activity and calculate nerve score. Performance on open-set monosyllabic word tests was the outcome measure. Standard statistical methods were applied. RESULTS On average, TR was larger in ANSD than in non-ANSD subjects. Most ANSD (73.3%) and non-ANSD (87.8%) subjects achieved open-set speech perception; TR accounted for 33% and 20% of variability in the outcomes, respectively. In the ANSD group, the PTA accounted for 69.3% of the variability, but there was no relationship with outcomes in the non-ANSD group. In both populations, nerve score was sensitive in identifying subjects at risk for not acquiring open-set speech perception, while the CAP and the ANN were more specific. CONCLUSION In both subject groups, the TRs correlated with outcomes but these measures were notably larger in the ANSD group. There was also strong correlation between PTA and speech perception outcome in ANSD group. In both subject populations, weaker evidence of neural activity was related to failure to achieve open-set speech perception.
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Affiliation(s)
- Tatyana E Fontenot
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States.
| | - Christopher K Giardina
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States; University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Holly F Teagle
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States
| | - Lisa R Park
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States
| | - Oliver F Adunka
- The Ohio State University, Department of Otolaryngology, Columbus, OH, United States
| | - Craig A Buchman
- Washington University in St. Louis, Department of Otolaryngology, St. Louis, MO, United States
| | - Kevin D Brown
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States
| | - Douglas C Fitzpatrick
- University of North Carolina at Chapel Hill, Department of Otolaryngology, Chapel Hill, NC, United States; University of North Carolina School of Medicine, Chapel Hill, NC, United States
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