Peri-operative electrically evoked auditory brainstem response assessment of facial nerve/cochlea interaction at cochlear implantation. (2nd November 2018)

• Record Type: Journal Article
• Authors: Schart-Morén, Nadine; Hallin, Karin; Agrawal, Sumit K.; Ladak, Hanif M.; Eriksson, Per-Olof; Li, Hao; Rask-Andersen, Helge
• Is Part Of: Cochlear implants international. Volume 19:Number 6(2018)
• Page Start: 324
• Page End: 329
• Publication Date: 2018-11-02
• Subjects: Dehiscence -- Cochlear implantation -- Facial nerve stimulation -- Cochlea; Cochlear implants -- Periodicals; 617.882
• DOI: 10.1080/14670100.2018.1481179
• Languages: English
• ISSNs: 1467-0100

Abstract

Abstract : Objectives: Dehiscence between the cochlear otic capsule and the facial nerve canal is a rare and relatively newly described pathology. In cochlear implantation (CI), this dehiscence may lead to adverse electric facial nerve stimulation (FNS) already at low levels, rendering its use impossible. Here, we describe an assessment technique to foresee this complication. Methods: Pre- and postoperative computed tomography (CT) scans and intraoperative electrically evoked auditory brainstem response (e-ABR) measurements were analyzed in two patients with cochlear-facial dehiscence (CFD). Results: Because of the relatively low resolution, the confirmation of CFD with a clinical CT was difficult. The e-ABR displayed a large potential with 6 and 7.5 ms latency, respectively, which did not occur otherwise. Discussion: Potential strategies to resolve and manage FNS are described. Conclusion: Prediction of FNS by assessing the distance between the labyrinthine portion of the facial nerve and the cochlea is difficult using conventional CT scans. A large evoked late myogenic potential at low stimulation levels during intraoperative e-ABR measurement may foresee FNS at CI activation.