Would an endosteal CI-electrode make sense? Comparison of the auditory nerve excitability from different stimulation sites using ESRT measurements and mathematical models

Abstract

N/A.

Cochlear promontory anatomy relevant to development of subendosteal and transpromontory electrodes using 192‐section ultra‐high resolution temporal bone CT imaging

“…Several investigations surrounding the expansion of existing electrode placement techniques for cochlear implantation have surfaced in recent years. 1 , 2 , 3 , 4 Successful implementation of subendosteal electrode placement requires understanding of normal anatomic ranges of cochlear promontory thickness as differing electrode designs and extent of surgical drilling may be required. A similar rationale can be applied to emerging data regarding transpromontory electrical stimulation of the cochlea for chronic disabling nonpulsatile tinnitus.…”

“…Characterization of clinically relevant cochlear anatomy is necessary for expansion of surgical intervention options to rehabilitate neurotologic disorders. A growing emphasis has been placed in recent years on the potential use of subendosteal and transpromontory electrodes for rehabilitation of sensorineural hearing loss with cochlear implantation 1–4 . These implantation strategies may be particularly useful in scenarios where significant cochlear ossification precludes conventional intracochlear electrode placement; as a strategy to access apical regions of the cochlea with a separate electrode; or, as a means to atraumatically stimulate the cochlea without intracochlear electrode placement in patients with substantial residual hearing 2 .…”

“…A growing emphasis has been placed in recent years on the potential use of subendosteal and transpromontory electrodes for rehabilitation of sensorineural hearing loss with cochlear implantation. 1 , 2 , 3 , 4 These implantation strategies may be particularly useful in scenarios where significant cochlear ossification precludes conventional intracochlear electrode placement; as a strategy to access apical regions of the cochlea with a separate electrode; or, as a means to atraumatically stimulate the cochlea without intracochlear electrode placement in patients with substantial residual hearing. 2 Similarly, investigation towards subendosteal electrode placement for the treatment of chronic tinnitus has received attention.…”

Automated detection of electrically evoked stapedius reflexes (eSR) during cochlear implantation

“…Further, stapedius reflexes showed to be a useful research tool investigating the auditory pathway. Reported applications include the determination of the correct cochlear implant electrode position inside the cochlea or the assessment of the cochlear implant integrity [5][6][7]. Preliminary attempts to measure eSR and to determine the electrically elicited stapedius reflex threshold (eSRT) intraoperatively were performed by means of tympanometry of the contralateral side [8] and using electromyography recordings of the stapedius muscle [9,10].…”

Stimulation strategies and electrode design in computational models of the electrically stimulated cochlea: An overview of existing literature

“…with rotationally symmetric geometries ( Figure 3), and finally as increasingly realistic spiraling structures ( Figure 4) (Finley et al 1990;Frijns et al 1995;Briaire and Frijns 2000;Frijns et al 2001;Hanekom 2001;Rattay et al 2001b;Choi et al 2004;Choi et al 2005;Choi et al 2006;Tognola et al 2007;Whiten 2007;Nogueira et al 2014;Pau et al 2014;Kalkman et al 2015;Malherbe et al 2015b;Wong et al 2016). Despite this tendency to move to more detailed cochlear geometries, simpler mathematical models of unrolled cochleae have retained their usefulness and are still employed in specific situations (Litvak et al 2007;Bonham and Litvak 2008;Goldwyn et al 2010).…”