Intra-Cochlear Electrocochleography During Cochear Implant Electrode Insertion Is Predictive of Final Scalar Location. Otol Neurotol 2018 Sep;39(8):e654-e659
Date
08/17/2018Pubmed ID
30113557Pubmed Central ID
PMC6097527DOI
10.1097/MAO.0000000000001906Scopus ID
2-s2.0-85059314278 (requires institutional sign-in at Scopus site) 40 CitationsAbstract
HYPOTHESIS: Electrocochleography (ECochG) patterns observed during cochlear implant (CI) electrode insertion may provide information about scalar location of the electrode array.
BACKGROUND: Conventional CI surgery is performed without actively monitoring auditory function and potential damage to intracochlear structures. The central hypothesis of this study was that ECochG obtained directly through the CI may be used to estimate intracochlear electrode position and, ultimately, residual hearing preservation.
METHODS: Intracochlear ECochG was performed on 32 patients across 3 different implant centers. During electrode insertion, a 50-ms tone burst stimulus (500 Hz) was delivered at 110 dB SPL. The ECochG response was monitored from the apical-most electrode. The amplitude and phase changes of the first harmonic were imported into an algorithm in an attempt to predict the intracochlear electrode location (scala tympani [ST], translocation from ST to scala vestibuli [SV], or interaction with basilar membrane). Anatomic electrode position was verified using postoperative computed tomography (CT) with image processing.
RESULTS: CT analysis confirmed 25 electrodes with ST position and 7 electrode arrays translocating from ST into SV. The ECochG algorithm correctly estimated electrode position in 26 (82%) of 32 subjects while 6 (18%) electrodes were wrongly identified as translocated (sensitivity = 100%, specificity = 77%, positive predictive value = 54%, and a negative predictive value = 100%). Greater hearing loss was observed postoperatively in participants with translocated electrode arrays (36 ± 15 dB) when compared with isolated ST insertions (28 ± 20 dB HL). This result, however, was not significant (p = 0.789).
CONCLUSION: Intracochlear ECochG may provide information about CI electrode location and hearing preservation.
Author List
Koka K, Riggs WJ, Dwyer R, Holder JT, Noble JH, Dawant BM, Ortmann A, Valenzuela CV, Mattingly JK, Harris MM, O'Connell BP, Litvak LM, Adunka OF, Buchman CA, Labadie RFAuthor
Michael S. Harris MD Associate Professor in the Otolaryngology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAudiometry, Evoked Response
Cochlea
Cochlear Implantation
Cochlear Implants
Female
Humans
Intraoperative Neurophysiological Monitoring
Male
