Multi-mode grounding stimulation with anodic monophasic pulses to treat/prevent anomalous facial nerve stimulation in cochlear implant: case report

Multi-mode grounding stimulation with anodic monophasic pulses to treat/prevent anomalous facial nerve stimulation in cochlear implant: case report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Multi-mode grounding stimulation with anodic monophasic pulses to treat/prevent anomalous facial nerve stimulation in cochlear implant: case report Leonardo Elías Ordóñez Ordóñez, Paola Medina Bravo, Jogeiri Núñez Rivera, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6166597/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Background: Cochlear implants (CIs) are a well-established treatment for individuals with severe-to-profound sensorineural hearing loss, benefiting both children and adults. However, a subset of CI users may experience unintended stimulation of non-cochlear nerves, particularly the facial nerve, resulting in involuntary facial movements triggered by sound. This phenomenon, termed anomalous facial nerve stimulation (AFNS), has a reported incidence of 5.6% (range: 0.68–43%) according to a systematic review. Risk factors for AFNS include otosclerosis, cochlear or inner ear malformations, facial nerve dehiscence, and cochlear ossification or obliteration. Device-related contributors such as lateral wall electrodes and high stimulation levels also play a role. Management typically begins with conservative programming adjustments to minimize current levels and off-cochlea dispersion. If these measures fail, deactivating specific electrodes responsible for AFNS is considered. While such interventions often preserve auditory function, performance may decline in certain cases, leading some individuals to discontinue CI use. In severe scenarios, explantation, with or without reimplantation, has been documented. Case presentation: Two clinical cases of CI users with severe-to-profound sensorineural hearing loss are described. The first case, a 57-year-old woman suffering chronic otitis media since childhood, required explantation because of severe AFNS and reimplantation with a device delivering using multi-mode grounding (MMG) stimulation with anodic monophasic pulses (AMP). The AFNS was controlled and she return to use CI with acceptable functional gain. The second case, a 27-year-old woman with bilateral otospongiosis, exhibited intraoperative facial nerve stimulation during bipolar monophasic testing, but this was prevented postoperatively using MMG + AMP. Conclusions: For CI users at risk of facial nerve stimulation (e.g., otosclerosis, cochlear malformations, facial nerve canal dehiscence, or cochlear ossification), careful device selection and programming strategies are essential to minimize current spread. CI systems with MMG and AMP can effectively manage FNS when conservative methods fail. In severe cases, explantation and reimplantation using this technology may be the better therapeutic approach. Cochlear implant. Facial nerve. Facial nerve stimulation. Facial nerve stimulation cochlear implant. Case Report Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Cochlear implants (CI) rehabilitate patients with severe-to-profound sensorineural hearing loss (SNHL) and are well-established treatment for children and adults[ 1 ]. Some CI users experience unintended stimulation of non-cochlear nerves, such as the facial nerve (FN)[ 1 , 2 ], leading to involuntary facial muscle movements with sound exposure. A systematic review reported this in 5.6% of users (range = 0.68-43%)[ 2 ]. Risk factors for anomalous facial nerve stimulation (AFNS) include otosclerosis[ 2 , 3 ], cochlear/internal ear malformations[ 2 ], FN dehiscence[ 4 ], and cochlear obliteration/ossification[ 5 ]. Device-related factors include lateral wall electrodes[ 2 , 6 ] and high stimulation levels[ 5 , 6 ]. To control AFNS, conservative CI programming adjustments aim to reduce current levels and dispersion outside the cochlea[ 1 , 3 , 5 – 13 ]. If ineffective, deactivating AFNS-causing electrodes is attempted[ 1 , 2 , 5 , 12 ]. While AFNS can often be managed while maintaining auditory stimulation, in some cases, performance declines, leading individuals to discontinue CI use[ 1 , 2 , 5 , 10 , 12 ]. In such cases, some authors report CI explantation with or without reimplantation[ 9 , 10 ]. To describe a management/prevention option for AFNS in CI patients, we present this clinical case report, following the CARE guidelines[ 14 ]. No patient-identifying data were recorded, ensuring confidentiality per national regulations. This report meets the ethical standards of the Helsinki declaration[ 15 ] and Colombian resolution 8430 of 1993[ 16 ]. Approval was obtained from the Institutional Ethics and Research Committee (CEIFUS 229 − 25 act No. 003–25). Case Presentation Clinical Case 1 A 57-year-old woman suffering chronic otitis media (COM) since childhood, leading to bilateral severe-to-profound SNHL. She received bilateral CIs (right 6y, left 2y ago), both Synchrony Flex28 devices (MED-EL). Prior to implantation, she underwent tympanomastoid surgeries, including bilateral subtotal petrosectomies. Her CI performance was good, with speech discrimination scores (SDS)=70% (left) and 80% (right). Over 12 months, she developed bilateral AFNS triggered by sound, more intense on the left. It worsened, severely affecting the left hemiface. Step-by-step audiological adjustments controlled right-side AFNS but not left. Changing the speech coding strategy to High-Definition Continuous Interleaved Sampling and deactivating electrodes 1-3,10-12 controlled AFNS but degraded speech perception (SDS=20%), leading to left CI discontinuation. A CT scan confirmed proper electrode placement but showed FN dehiscence, Figure 1a,b . Device integrity testing was normal. The treating team recommended left CI removal and reimplantation with a NeuroZti CI (Oticon Medical) to improve auditory performance while reducing AFNS [9,10]. Surgery was uneventful, achieving full electrode insertion, Figure 1d . The initial fitting used Multi-mode grounding (MMG) stimulation and anodic monophasic pulses (AMP). Follow-up showed AFNS with electrodes 1-3 and 13-16 at low thresholds (20-24nC/phase), leading to deactivation. A single map adjusted pulse amplitude to 17SA (1SA=1/45 mA), reaching 40-45nC/phase with Crystalis CAP strategy. The new map eliminated AFNS, yielding PTA(0.5Hz-3KHz)=36.6dB and SDS=50% at 8 months of follow-up Figure 2 . The patient reported satisfactory auditory and communicative performance and continued using both CIs. Clinical Case 2 A 27-year-old woman with severe-to-profound SNHL experienced progressive hearing loss since age 11, worsening until she used bilateral hearing aids at 21. Due to poor performance, she was evaluated for cochlear implantation. A CT scan revealed bilateral cochlear otospongiosis, Figure 3. Audiometry confirmed severe-to-profound hearing loss and free-field speech audiometry showed aided SDS=20%. She was ineligible for stapedotomy due to poor cochlear reserve, and bilateral CIs with NeuroZti devices (Oticon Medical) was recommended. During surgery, full electrode insertion was achieved, Figure 3c . Electrically evoked compound action potential testing with monopolar biphasic stimulation (Stimulus MB) detected FN stimulation (FNS) bilaterally via FN monitoring (Medtronic, NIM 3.0; threshold=30µVolts). Left-side FNS occurred on electrodes 1,5,16,20 (4/20); right-side on 20,13 (2/20). At fitting (four weeks post-op), a single map used MMG stimulation with AMP pulses. Amplitude was set at 20SA, reaching up to 32nC/phase. No AFNS occurred in response to electrode stimulation or sound. At 24-month follow-up, routine programming adjustments were made, and the patient never reported AFNS, with excellent performance, Figure 4 . Discussion and Conclusions Case 1 illustrates AFNS complexity, requiring explantation and reimplantation with a different device. Van Horn et al[2] reported 4/3015 (0.13%) AFNS cases requiring explantation. AFNS occurs when an electrode’s electric field extends beyond the cochlea, stimulating the FN, especially labyrinthine/tympanic segments[1,3,6,7]. AFNS can worsen, involving more channels and lowering charge thresholds[1]. Case 1 had FN dehiscence, Figure 1a,b , a known AFNS risk factor[4]. Case 2 involved cochlear otosclerosis, another AFNS risk factor[2,3,6], with a strong association (OR=13.73, 95%CI=3.57-52.78), reported in 26% of cases (range=6.25-75%)[2]. Initial AFNS management involves adjusting parameters[1,3,5-13]: 1. Increasing pulse duration. 2. Reducing pulse amplitude/MCL. 3. Using triphasic, anodic monophasic, or MMG stimulation modes (CI brand-dependent). 4. Deactivating AFNS-causing electrodes: effective when few electrodes are involved but degrades speech if multiple electrodes are affected (Case 1). If conservative measures fail, switching to a device with lower extracochlear energy dispersion and MMG stimulation with AMP may be necessary, as reported by Zellhuber et al.[9], Hyppolito et al.[10], and Eitutis et al.[17]. MMG with AMP uses extracochlear and all intracochlear electrodes as references, except the stimulating electrode [9,10,18], allowing up to 80% of current discharge within the cochlea, reducing peripheral spread, including FN[18]. Loudness is adjusted by pulse duration instead of amplitude. The anodic monophasic pulse is followed by a non-stimulating cathodic phase, reducing power needs and minimizing AFNS risk compared to biphasic/triphasic pulses[17-19]. This was evidenced in Case 2, where intraoperative FNS (Stimulus MB) was absent during routine use (Stimulus MMG). Further research employing a prospective design and encompassing a larger sample size is essential to validate the findings presented in this case report. As conclusions, for CI candidates with AFNS risk factors (otosclerosis, inner ear malformations, FN dehiscence, cochlear obliteration/ossification), these must be considered in device selection. Stimulation modes minimizing AFNS should be used. In severe AFNS cases where auditory performance cannot be balanced with conservative measures, explantation and reimplantation with MMG-AMP-compatible devices may be the best therapeutic option. Abbreviations • AFNS • anomalous facial nerve stimulation • AMP • anodic monophasic pulses • CI • cochlear implant • COM • chronic otitis media • CT • computed tomography • FN • facial nerve • FNS • facial nerve stimulation • MMG • multi-mode grounding • PTA • pure tone average • SDS • speech discrimination score • SNHL • sensorineural hearing loss • Stimulus MB • monopolar biphasic stimulation Declarations Ethics approval and consent to participate: The study was approved by the institutional review board, CEIFUS, with de reference CEIFUS 229 − 25 (act No. 003–25).This study complies with the ethical standards established by the Declaration of Helsinki and the Colombian resolution 8430 of 1993 for studies in human beings. The patients signed a consent to participate in this study. Funding Funding was received from Fundación Universitaria Sanitas (Unisanitas, Bogotá, Colombia) for design of the study, data collection, analysis, interpretation of data and in writing the manuscript. Competing Interests JN, PMB, ESFA and ECH have no competing interests to declare. LEOO has consultant agreements and research projects with Advanced Bionics, LLC and Cochlear Corporation. FD works in the Clinical Department of Oticon Medical in São Paulo, Brazil. Author Contribution Study conception and design: LEEO and JN. Data collection: JN, PMB and ECH. Material preparation and first draft writing: LEEO, JN and PMB. Writing, reviewing and editing of the manuscript: LEOO, ESAM, JN, PMB, ECH and FD. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Acknowledgement To our patients for their willingness to provide information for this report. Data Availability The authors stated that all information provided in this article could be shared and the raw data can be requested by email to the corresponding author. References Alzhrani F, Halawani R, Basodan S, Hudeib R (2020) Investigating facial nerve stimulation after cochlear implantation in adult and pediatric recipients. Laryngoscope 131:374–379. https://doi.org/10.1002/lary.28632 Van Horn A, Hayden C, Mahairas AD, Leader P, Bush ML (2020) Factors Influencing aberrant facial nerve stimulation following cochlear implantation: a systematic review and meta-analysis. Otol Neurotol 41:1050–1059. https://doi.org/10.1097/MAO.0000000000002693 Seyyedi M, Herrmann BS, Eddington DK, Nadol JB (2013) The pathologic basis of facial nerve stimulation in otosclerosis and multi-channel cochlear implantation. Otol Neurotol 34:1603–1609. https://doi.org/10.1097/MAO.0b013e3182979398 Chen J, Chen B, Zhang L, Li Y (2021) Severe and persistent facial nerve stimulation after cochlear implantation in a patient with cochlear-facial dehiscence: a case report. J Int Med Res 49:3000605211057823. 10.1177/03000605211057823 Berrettini S, Vito de A, Bruschini L, Passetti S, Forli F (2011) Facial nerve stimulation after cochlear implantation: our experience. Acta Otorhinolaryngol Ital 31:11–16 Frijns JH, Kalkman RK, Briaire JJ (2009) Stimulation of the facial nerve by intracochlear electrodes in otosclerosis: a computer modeling study. Otol Neurotol 30:1168–1174. https://doi.org/10.1097/MAO.0b013e3181b12115 Aljazeeri IA, Khurayzi T, Al-Amro M, Alzhrani F, Alsanosi A (2021) Evaluation of computed tomography parameters in patients with facial nerve stimulation post-cochlear implantation. Eur Arch Otorhinolaryngol 278:3789–3794. https://doi.org/10.1007/s00405-020-06486-7 Alhabib S, Abdelsamad Y, Yousef M, Alzhrani F (2021) Performance of cochlear implant recipients fitted with triphasic pulse patterns. Eur Arch Otorhinolaryngol 278:3211–3216. https://doi.org/10.1007/s00405-020-06382-0 Zellhuber N, Helbig R, James P, Bloching M, Lyutenski S (2022) Multi-mode grounding and monophasic passive discharge stimulation avoid aberrant facial nerve stimulation following cochlear implantation. Clin Case Rep 10:e05360. 10.1002/ccr3.5360 Hyppolito MA, Barbosa Reis ACM, Danieli F, Hussain R, Le Goff N (2023) Cochlear re-implantation with the use of multi-mode grounding associated with anodic monophasic pulses to manage abnormal facial nerve stimulation. Cochlear Implants Int 24:55–64. 10.1080/14670100.2022.2157077 Bahmer A, Adel Y, Baumann U (2017) Preventing Facial Nerve Stimulation by Triphasic Pulse Stimulation in Cochlear Implant Users: Intraoperative Recordings. Otol Neurotol 38:e438–e444. https://doi.org/10.1097/MAO.0000000000001603 Pires JS, Melo AS, Caiado R, Martins JH, Elói Moura J, Silva LF (2018) Facial nerve stimulation after cochlear implantation: Our experience in 448 adult patients. Cochlear Implants Int 19(4):193–197. https://doi.org/10.1080/14670100.2018.1452561 van der Westhuizen J, Hanekom T, Hanekom JJ (2022) Apical Reference Stimulation: A Possible Solution to Facial Nerve Stimulation. Ear Hear 43:1189–1197. https://doi.org/10.1097/AUD.0000000000001170 Riley DS, Barber MS, Kienle GS, Aronson JK, von Schoen-Angerer T, Tugwell P et al (2017) CARE guidelines for case reports: explanation and elaboration document. J Clin Epidemiol 89:218–235. 10.1016/j.jclinepi.2017.04.026 World Medical Association (2013) World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA 310:2191–2194. 10.1001/jama.2013.281053 Ministerio De Salud y Protección Social (2024) Resolución Número 8430 de 1993. Available from: https://www.minsalud.gov.co/sites/rid/Lists/BibliotecaDigital/RIDE/DE/DIJ/RESOLUCION-8430-DE-1993.PDF . Accessed 10th October Eitutis ST, Carlyon RP, Tam YC, Salorio-Corbetto M, Vanat Z, Tebbutt K et al (2022) Management of Severe Facial Nerve Cross Stimulation by Cochlear Implant Replacement to Change Pulse Shape and Grounding Configuration: A Case-series. Otol Neurotol 43:452–459. https://doi.org/10.1097/MAO.0000000000003493 Danieli F, Hyppolito MA, Hussain R, Hoen M, Karoui C, Reis ACMB (2023) The Effects of Multi-Mode Monophasic Stimulation with Capacitive Discharge on the Facial Nerve Stimulation Reduction in Young Children with Cochlear Implants: Intraoperative Recordings. J Clin Med 12:534. 10.3390/jcm12020534 Dang K (2017) Electrical conduction models for cochlear implant stimulation. COMUE Université Côte d'Azur (2015–2019). Available from: https://hal.science/tel-01562277/ . Accessed 26 October 2024 Additional Declarations Competing interest reported. JN, PMB, ESFA and ECH have no competing interests to declare. LEOO has consultant agreements and research projects with Advanced Bionics, LLC and Cochlear Corporation. FD works in the Clinical Department of Oticon Medical in São Paulo, Brazil. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 21 Sep, 2025 Reviews received at journal 21 Sep, 2025 Reviewers agreed at journal 16 Sep, 2025 Reviews received at journal 13 Jun, 2025 Reviewers agreed at journal 30 May, 2025 Reviewers invited by journal 23 Mar, 2025 Editor assigned by journal 19 Mar, 2025 Submission checks completed at journal 19 Mar, 2025 First submitted to journal 05 Mar, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6166597","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":432796668,"identity":"e201e73b-a12f-4f83-9738-33876ae31b4a","order_by":0,"name":"Leonardo Elías Ordóñez Ordóñez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAv0lEQVRIiWNgGAWjYHACxgNAQg7EOvCAKA1sQJVAyhisJYEULYkNIA5RWvjlmw8c+FBxL31+2OGHQFvs5HQbCGiRbGNLODjjTHHuxttpBkAtycZmBwhoMTjGY3CYty0hd+PsBJCWA4nbiNLyty0h3XB2+gcStDC2JSTIS+cQaYtkW1rCwZ4zCYYbpHMKDiQYEOEXfubDBx/8qEiQl5+dvvnDhwo7OYJaEC4EqzQgVjkIyDeQonoUjIJRMApGFAAAW2FIFvGcP6wAAAAASUVORK5CYII=","orcid":"","institution":"Clínica Universitaria Colombia","correspondingAuthor":true,"prefix":"","firstName":"Leonardo","middleName":"Elías Ordóñez","lastName":"Ordóñez","suffix":""},{"id":432796669,"identity":"ff25f8bf-790f-4d4e-bbb8-09cfdf469510","order_by":1,"name":"Paola Medina Bravo","email":"","orcid":"","institution":"Fundación Universitaria Sanitas","correspondingAuthor":false,"prefix":"","firstName":"Paola","middleName":"Medina","lastName":"Bravo","suffix":""},{"id":432796670,"identity":"3ef40bea-beac-4c37-abb6-9af9e3ee0ceb","order_by":2,"name":"Jogeiri Núñez Rivera","email":"","orcid":"","institution":"Hospital General de la Plaza de la Salud","correspondingAuthor":false,"prefix":"","firstName":"Jogeiri","middleName":"Núñez","lastName":"Rivera","suffix":""},{"id":432796671,"identity":"77847b63-bf3e-4739-b608-b1af317361f4","order_by":3,"name":"Estefany Catherine Hernández","email":"","orcid":"","institution":"Clínica Universitaria Colombia","correspondingAuthor":false,"prefix":"","firstName":"Estefany","middleName":"Catherine","lastName":"Hernández","suffix":""},{"id":432796672,"identity":"a26f3b1f-e257-42d0-9673-cb2aa933dbaf","order_by":4,"name":"Fabiana Danieli","email":"","orcid":"","institution":"Universidade de São Paulo","correspondingAuthor":false,"prefix":"","firstName":"Fabiana","middleName":"","lastName":"Danieli","suffix":""},{"id":432796673,"identity":"c3ea6940-4db5-4792-8189-b8ea2f614f81","order_by":5,"name":"Esther Sofía Angulo Martínez","email":"","orcid":"","institution":"Anaboleas Research Team","correspondingAuthor":false,"prefix":"","firstName":"Esther","middleName":"Sofía Angulo","lastName":"Martínez","suffix":""}],"badges":[],"createdAt":"2025-03-06 03:23:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6166597/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6166597/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":79673523,"identity":"4ce5420a-062c-4d51-a5a3-ca7ad216d5d3","added_by":"auto","created_at":"2025-04-01 11:48:36","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":132005,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eImages of the previous and new implanted electrode arrays in Case\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe CT scan shows the fully inserted electrode array (Flex28) and the obliterated mastoid cavity (a,b,c). The arrows indicate the dehiscence of the labyrinthine (white) and tympanic (black) portions of the FN, near the electrode array. The CI was explanted, and during the same surgery, a new device (Neuro Zti, classic electrode array) was implanted. The X-ray confirms the proper placement and full insertion of the new electrode array (d).\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6166597/v1/52b8fa65dcf0008c6fd8fe1c.jpeg"},{"id":79673526,"identity":"73e27f87-ee14-4836-a73e-6ef09e1fa862","added_by":"auto","created_at":"2025-04-01 11:48:37","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":286017,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFree-field audiological outcomes of Case 1 with her left CI\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSDS was measured using a disyllabic word list (Spanish) with Neuro ZTi/Neuro 2 CI (Oticon Medical).\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6166597/v1/e4079318e460e963b846d1b7.jpeg"},{"id":79675413,"identity":"eb8e985c-72ab-4f94-b06d-8da3b2865ef0","added_by":"auto","created_at":"2025-04-01 12:04:36","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":122413,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePreoperative and intraoperative images of Case 2.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe preoperative CT scan (a,b) shows an otospongiotic focus (arrows), which generates lower electrical impedance and constitutes a risk factor for AFNS. The intraoperative X-ray confirms the proper placement and full insertion of the electrode array (Neuro Zti, classic electrode array) on both sides (c).\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6166597/v1/172b079fa6b3251fb10b1349.jpeg"},{"id":79674891,"identity":"e29efdeb-7afc-4b73-8f9c-2c976c3f0f13","added_by":"auto","created_at":"2025-04-01 11:56:37","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":263803,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFree-field audiological outcomes of Case 2 with bilateral CIs.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe SDS was measured using a disyllabic word list (Spanish). Blue=left CI, Red=right CI and Green=both CIs\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6166597/v1/9fa423546733e8d8cfa11cd3.jpeg"},{"id":79675415,"identity":"fd1f0882-63c1-4c23-be41-183f9b38d47b","added_by":"auto","created_at":"2025-04-01 12:04:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1391515,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6166597/v1/3b2b3a0e-aa68-4437-8720-f0734a7c3527.pdf"}],"financialInterests":"Competing interest reported. JN, PMB, ESFA and ECH have no competing interests to declare. \nLEOO has consultant agreements and research projects with Advanced Bionics, LLC and Cochlear Corporation. \nFD works in the Clinical Department of Oticon Medical in São Paulo, Brazil.","formattedTitle":"Multi-mode grounding stimulation with anodic monophasic pulses to treat/prevent anomalous facial nerve stimulation in cochlear implant: case report","fulltext":[{"header":"Background","content":"\u003cp\u003eCochlear implants (CI) rehabilitate patients with severe-to-profound sensorineural hearing loss (SNHL) and are well-established treatment for children and adults[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Some CI users experience unintended stimulation of non-cochlear nerves, such as the facial nerve (FN)[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], leading to involuntary facial muscle movements with sound exposure. A systematic review reported this in 5.6% of users (range\u0026thinsp;=\u0026thinsp;0.68-43%)[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Risk factors for anomalous facial nerve stimulation (AFNS) include otosclerosis[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], cochlear/internal ear malformations[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], FN dehiscence[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], and cochlear obliteration/ossification[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Device-related factors include lateral wall electrodes[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] and high stimulation levels[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo control AFNS, conservative CI programming adjustments aim to reduce current levels and dispersion outside the cochlea[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan additionalcitationids=\"CR6 CR7 CR8 CR9 CR10 CR11 CR12\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. If ineffective, deactivating AFNS-causing electrodes is attempted[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. While AFNS can often be managed while maintaining auditory stimulation, in some cases, performance declines, leading individuals to discontinue CI use[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. In such cases, some authors report CI explantation with or without reimplantation[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo describe a management/prevention option for AFNS in CI patients, we present this clinical case report, following the CARE guidelines[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. No patient-identifying data were recorded, ensuring confidentiality per national regulations. This report meets the ethical standards of the Helsinki declaration[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and Colombian resolution 8430 of 1993[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Approval was obtained from the Institutional Ethics and Research Committee (CEIFUS 229\u0026thinsp;\u0026minus;\u0026thinsp;25 act No. 003\u0026ndash;25).\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003e\u003cstrong\u003eClinical Case 1\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 57-year-old woman suffering chronic otitis media (COM) since childhood, leading to bilateral severe-to-profound SNHL. She received bilateral CIs (right 6y, left 2y ago), both Synchrony Flex28 devices (MED-EL). Prior to implantation, she underwent tympanomastoid surgeries, including bilateral subtotal petrosectomies. Her CI performance was good, with speech discrimination scores (SDS)=70% (left) and 80% (right). Over 12 months, she developed bilateral AFNS triggered by sound, more intense on the left. It worsened, severely affecting the left hemiface.\u003c/p\u003e\n\u003cp\u003eStep-by-step audiological adjustments controlled right-side AFNS but not left. Changing the speech coding strategy to High-Definition Continuous Interleaved Sampling and deactivating electrodes 1-3,10-12 controlled AFNS but degraded speech perception (SDS=20%), leading to left CI discontinuation. A CT scan confirmed proper electrode placement but showed FN dehiscence, \u003cstrong\u003eFigure 1a,b\u003c/strong\u003e. Device integrity testing was normal.\u003c/p\u003e\n\u003cp\u003eThe treating team recommended left CI removal and reimplantation with a NeuroZti CI (Oticon Medical) to improve auditory performance while reducing AFNS [9,10]. Surgery was uneventful, achieving full electrode insertion, \u003cstrong\u003eFigure 1d\u003c/strong\u003e. The initial fitting used Multi-mode grounding (MMG) stimulation and anodic monophasic pulses (AMP). Follow-up showed AFNS with electrodes 1-3 and 13-16 at low thresholds (20-24nC/phase), leading to deactivation. A single map adjusted pulse amplitude to 17SA (1SA=1/45 mA), reaching 40-45nC/phase with Crystalis CAP strategy. The new map eliminated AFNS, yielding PTA(0.5Hz-3KHz)=36.6dB and SDS=50% at 8 months of follow-up \u003cstrong\u003eFigure 2\u003c/strong\u003e. The patient reported satisfactory auditory and communicative performance and continued using both CIs.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Case 2\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 27-year-old woman with severe-to-profound SNHL experienced progressive hearing loss since age 11, worsening until she used bilateral hearing aids at 21. Due to poor performance, she was evaluated for cochlear implantation. A CT scan revealed bilateral cochlear otospongiosis, \u003cstrong\u003eFigure 3.\u0026nbsp;\u003c/strong\u003eAudiometry confirmed severe-to-profound hearing loss and free-field speech audiometry showed aided SDS=20%. She was ineligible for stapedotomy due to poor cochlear reserve, and bilateral CIs with NeuroZti devices (Oticon Medical) was recommended.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDuring surgery, full electrode insertion was achieved, \u003cstrong\u003eFigure 3c\u003c/strong\u003e. Electrically evoked compound action potential testing with monopolar biphasic stimulation (Stimulus MB) detected FN stimulation (FNS) bilaterally via FN monitoring (Medtronic, NIM 3.0; threshold=30\u0026micro;Volts). Left-side FNS occurred on electrodes 1,5,16,20 (4/20); right-side on 20,13 (2/20).\u003c/p\u003e\n\u003cp\u003eAt fitting (four weeks post-op), a single map used MMG stimulation with AMP pulses. Amplitude was set at 20SA, reaching up to 32nC/phase. No AFNS occurred in response to electrode stimulation or sound. At 24-month follow-up, routine programming adjustments were made, and the patient never reported AFNS, with excellent performance, \u003cstrong\u003eFigure 4\u003c/strong\u003e.\u003c/p\u003e"},{"header":"Discussion and Conclusions","content":"\u003cp\u003eCase 1 illustrates AFNS complexity, requiring explantation and reimplantation with a different device. Van Horn et al[2] reported 4/3015 (0.13%) AFNS cases requiring explantation. AFNS occurs when an electrode’s electric field extends beyond the cochlea, stimulating the FN, especially labyrinthine/tympanic segments[1,3,6,7]. AFNS can worsen, involving more channels and lowering charge thresholds[1]. Case 1 had FN dehiscence, \u003cstrong\u003eFigure 1a,b\u003c/strong\u003e, a known AFNS risk factor[4]. Case 2 involved cochlear otosclerosis, another AFNS risk factor[2,3,6], with a strong association (OR=13.73, 95%CI=3.57-52.78), reported in 26% of cases (range=6.25-75%)[2].\u003c/p\u003e\n\u003cp\u003eInitial AFNS management involves adjusting parameters[1,3,5-13]: 1. Increasing pulse duration. 2. Reducing pulse amplitude/MCL. 3. Using triphasic, anodic monophasic, or MMG stimulation modes (CI brand-dependent). 4. Deactivating AFNS-causing electrodes: effective when few electrodes are involved but degrades speech if multiple electrodes are affected (Case 1). If conservative measures fail, switching to a device with lower extracochlear energy dispersion and MMG stimulation with AMP may be necessary, as reported by Zellhuber et al.[9], Hyppolito et al.[10], and Eitutis et al.[17].\u003c/p\u003e\n\u003cp\u003eMMG with AMP uses extracochlear and all intracochlear electrodes as references, except the stimulating electrode [9,10,18], allowing up to 80% of current discharge within the cochlea, reducing peripheral spread, including FN[18]. Loudness is adjusted by pulse duration instead of amplitude. The anodic monophasic pulse is followed by a non-stimulating cathodic phase, reducing power needs and minimizing AFNS risk compared to biphasic/triphasic pulses[17-19]. This was evidenced in Case 2, where intraoperative FNS (Stimulus MB) was absent during routine use (Stimulus MMG).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFurther research employing a prospective design and encompassing a larger sample size is essential to validate the findings presented in this case report.\u003c/p\u003e\n\u003cp\u003eAs conclusions, for CI candidates with AFNS risk factors (otosclerosis, inner ear malformations, FN dehiscence, cochlear obliteration/ossification), these must be considered in device selection. Stimulation modes minimizing AFNS should be used. In severe AFNS cases where auditory performance cannot be balanced with conservative measures, explantation and reimplantation with MMG-AMP-compatible devices may be the best therapeutic option.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eAFNS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; anomalous facial nerve stimulation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eAMP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; anodic monophasic pulses\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eCI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; cochlear implant\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eCOM\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; chronic otitis media\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eCT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; computed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eFN\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; facial nerve\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eFNS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; facial nerve stimulation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eMMG\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; multi-mode grounding\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003ePTA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; pure tone average\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eSDS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; speech discrimination score\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eSNHL\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; sensorineural hearing loss\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u0026bull; \u003cb\u003eStimulus MB\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e\u0026bull; monopolar biphasic stimulation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics approval and consent to participate:\u003c/h2\u003e\n\u003cp\u003eThe study was approved by the institutional review board, CEIFUS, with de reference CEIFUS 229\u0026thinsp;\u0026minus;\u0026thinsp;25 (act No. 003\u0026ndash;25).This study complies with the ethical standards established by the Declaration of Helsinki and the Colombian resolution 8430 of 1993 for studies in human beings. The patients signed a consent to participate in this study.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eFunding was received from Fundaci\u0026oacute;n Universitaria Sanitas (Unisanitas, Bogot\u0026aacute;, Colombia) for design of the study, data collection, analysis, interpretation of data and in writing the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJN, PMB, ESFA and ECH have no competing interests to declare. LEOO has consultant agreements and research projects with Advanced Bionics, LLC and Cochlear Corporation. FD works in the Clinical Department of Oticon Medical in S\u0026atilde;o Paulo, Brazil.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eStudy conception and design: LEEO and JN. Data collection: JN, PMB and ECH. Material preparation and first draft writing: LEEO, JN and PMB. Writing, reviewing and editing of the manuscript: LEOO, ESAM, JN, PMB, ECH and FD. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003ch2\u003eAcknowledgement\u003c/h2\u003e\n\u003cp\u003eTo our patients for their willingness to provide information for this report.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe authors stated that all information provided in this article could be shared and the raw data can be requested by email to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAlzhrani F, Halawani R, Basodan S, Hudeib R (2020) Investigating facial nerve stimulation after cochlear implantation in adult and pediatric recipients. 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Accessed 26 October 2024\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-egyptian-journal-of-otolaryngology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [The Egyptian Journal of Otolaryngology](https://ejo.springeropen.com/)","snPcode":"43163","submissionUrl":"https://submission.springernature.com/new-submission/43163/3","title":"The Egyptian Journal of Otolaryngology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Cochlear implant. Facial nerve. Facial nerve stimulation. Facial nerve stimulation cochlear implant. Case Report","lastPublishedDoi":"10.21203/rs.3.rs-6166597/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6166597/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Cochlear implants (CIs) are a well-established treatment for individuals with severe-to-profound sensorineural hearing loss, benefiting both children and adults. However, a subset of CI users may experience unintended stimulation of non-cochlear nerves, particularly the facial nerve, resulting in involuntary facial movements triggered by sound. This phenomenon, termed anomalous facial nerve stimulation (AFNS), has a reported incidence of 5.6% (range: 0.68–43%) according to a systematic review.\u003c/p\u003e\n\u003cp\u003eRisk factors for AFNS include otosclerosis, cochlear or inner ear malformations, facial nerve dehiscence, and cochlear ossification or obliteration. Device-related contributors such as lateral wall electrodes and high stimulation levels also play a role. Management typically begins with conservative programming adjustments to minimize current levels and off-cochlea dispersion. If these measures fail, deactivating specific electrodes responsible for AFNS is considered. While such interventions often preserve auditory function, performance may decline in certain cases, leading some individuals to discontinue CI use. In severe scenarios, explantation, with or without reimplantation, has been documented.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase presentation:\u003c/strong\u003e Two clinical cases of CI users with severe-to-profound sensorineural hearing loss are described. The first case, a 57-year-old woman suffering chronic otitis media since childhood, required explantation because of severe AFNS and reimplantation with a device delivering using multi-mode grounding (MMG) stimulation with anodic monophasic pulses (AMP). The AFNS was controlled and she return to use CI with acceptable functional gain. The second case, a 27-year-old woman with bilateral otospongiosis, exhibited intraoperative facial nerve stimulation during bipolar monophasic testing, but this was prevented postoperatively using MMG + AMP.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e For CI users at risk of facial nerve stimulation (e.g., otosclerosis, cochlear malformations, facial nerve canal dehiscence, or cochlear ossification), careful device selection and programming strategies are essential to minimize current spread. CI systems with MMG and AMP can effectively manage FNS when conservative methods fail. In severe cases, explantation and reimplantation using this technology may be the better therapeutic approach.\u003c/p\u003e","manuscriptTitle":"Multi-mode grounding stimulation with anodic monophasic pulses to treat/prevent anomalous facial nerve stimulation in cochlear implant: case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-01 11:48:32","doi":"10.21203/rs.3.rs-6166597/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-21T20:25:26+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-21T19:06:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"84409750333024708925115565467467828596","date":"2025-09-16T15:56:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-13T13:04:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232991194758850912426308951401874487576","date":"2025-05-30T04:37:28+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-03-23T21:09:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-03-19T04:20:47+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-03-19T04:19:30+00:00","index":"","fulltext":""},{"type":"submitted","content":"The Egyptian Journal of Otolaryngology","date":"2025-03-06T03:11:19+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-egyptian-journal-of-otolaryngology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [The Egyptian Journal of Otolaryngology](https://ejo.springeropen.com/)","snPcode":"43163","submissionUrl":"https://submission.springernature.com/new-submission/43163/3","title":"The Egyptian Journal of Otolaryngology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"07cf16bb-f748-4e0a-a742-9ca69f128416","owner":[],"postedDate":"April 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-10-17T11:38:37+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-01 11:48:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6166597","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6166597","identity":"rs-6166597","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}