J Neuroscience and Neurological Surgery Copy rights@ Sheila Veronese et.al. Auctores Publishing – Volume 9(5)-203 www.auctoresonline.org ISSN: 2578-8868 Page 1 of 7 New Protocol for Auditory Brainstem Implant Positioning Sheila Veronese*, Marco Cambiaghi, Andrea Sbarbati Department of Neuroscience, Biomedicine and Movement Sciences - Verona University, Verona, Italy *Corresponding Author: Sheila Veronese, Department of Neurosciences, Biomedicine and Movement Sciences, Verona University – 10 Sq. A.Stefani, Verona 37134, Italy Received date: August 20, 2021; Accepted date: October 29, 2021; Published date: November 12, 2021 Citation: Sheila Veronese, Marco Cambiaghi, Andrea Sbarbati (2021) New Protocol for Auditory Brainstem Implant Positioning. J. Neuroscience and Neurological Surgery. 9(5); DOI:10.31579/2578-8868/203 Copyright: © 2021 Sheila Veronese, This is an open-access article distributed under the terms of The Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Abstract Background: Surgery for applying the auditory brainstem implant is an otoneurosurgery that requires careful intraoperative monitoring to optimize the placement of the electrode paddle. This study aimed to validate a new method capable of increasing the accuracy of electrode array placement, reducing channel interaction, electrical artefacts, and saturation effects, and providing the largest number of electrodes that can be activated with the lowest possible electric charge. Materials and methods: Thirty-six subjects aged between 1.42 and 69.92 years were tested during surgery for auditory brainstem implantation. We recorded auditory electrical responses of the brainstem using the implant supplier's suggested stimulation protocol and the new protocol. Results: Saturations effects and electric artefacts were noticed respectively in 81.85% and 53.25% of recordings using implant supplier's method, while in 70.34% and 24.75% of recordings using the new method, with a percentage variation of 11.51% and 28.50%. Considering the amount of charge required to activate the electrodes, with the implant supplier's method an average charge of 14 nC was needed, while with the new protocol an average charge of 8 nC was necessary. Conclusions: The new method improves the coupling between the auditory brainstem implant and the surface of the cochlear nucleus. Keywords: ABI; EABR; intraoperative monitoring; electrodes positioning Introduction The auditory brainstem implant (ABI) represents a device that effectively restores auditory sensations in patients with NF2 and acoustic neuromas. Its application was extended to children and adults with injuries or malformations of the cochlea and cochlear nerve, who are not eligible for a cochlear implant [1], [2]. The use of electrophysiology, in particular of the electrical auditory brainstem responses (EABR), is known to facilitate electrode plate placement during ABI implant surgery [3], [4], [5]. Waring optimized pacing and recording parameters to achieve efficient EABR monitoring during surgery [6], [7]. Achieving efficient monitoring means being able to recognize the waveforms of auditory responses and distinguish them from the current of stimulation and other evoked potentials that could result from stimulation of nearby non-auditory anatomical structures. Many authors have tried to define the optimum EABR monitoring procedure and to correlate its results with the auditory outcomes [8], [9], [10], [11], [12], [13]. Nevison et al. [8] demonstrated that achieving good intraoperative EABRs is not related to the performance of implanted patients, but subjects who achieve good EABRs also have postoperative auditory sensations. Furthermore, they reported the presence of non-auditory sensations during ABI programming in 92.3% of cases. This means that the number of usable electrodes varies significantly between subjects, and that an imperfect coupling of the electrodes with the cochlear nuclei can more easily induce the excitation of non-auditory stimulations. This study aimed to validate a new method capable of increasing the accuracy of electrode array placement, reducing channel interaction, electrical artefacts, and saturation effects, and providing the largest number of electrodes that can be activated with the lowest possible electric charge. Open Access Review Article Journal of Neuroscience and Neurological Surgery Sheila Veronese * AUCTORES Globalize your Research