LA-TT-EALR / PromCERA: Comparison of preoperatively performed electrically evoked auditory potentials at the brainstem and cortical level during local anesthesia

Abstract Introduction: In the past years, some groups established methods to use promontory stimulation and subjective responses as a tool for preoperative of cochlea before cochlear implant (CI) surgery by temporary transtympanic needle placed on middle ear. Our research group tested CI candidates when presence auditory nerve could not be confirmed other pre-operative tests analyzed objective results electrical brainstem response recorded with trans-tympanic in local anesthesia (LA-TT-EABR) “golfclub” electrode round window niche (Polterauer et al. 2018). However, EABR recording suffers from an artifact focuses excitability solely nerve. We hypothesize that late evoked potential (EALR) can used assessment pathway up cortical area less interference. Methods: The electrically (LA-TT-EALR) was added our protocol right after LA-TT-EABR unique session. this study, we investigated feasibility LA-TT-EALR using MED-EL hardware software. These two measurements, LATT- LA-TT-EALR, were compared. Results: total n=18 subjects, it possible record 10 13. contrast fact acoustically are often hard detect, heavily affects LA-TT-EABR, did experience these problems recordings. matching between measurements present 67% cases. Conclusion: may complement existing state-of-the-art implantation offering information about pathways cortex small increase time. equivalency is encouraging.