Estimating Performance Using Tonotopic Measurements of Intracochlear Electrocochleography: Comparison of Lateral Wall and Perimodiolar Arrays

Saturday, October 11, 2025

9:36 AM - 9:42 AM EDT

Location: 239

Disclosure(s):

Jordan J. Varghese, MD, MSCI:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Matthew A. Shew, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Cameron C. Wick, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Limitations in estimating cochlear implant (CI) performance remains a critical barrier to dissemination and implementation. A tonotopic-based approach to intracochlear electrocochleography (ECochG) during implantation can estimate speech-perception performance for perimodiolar arrays and the primary aim of this study was to assess this relationship for both lateral wall and perimodiolar arrays.

Methods: From December 2021 to June 2024, intracochlear ECochG was measured for adults at a tertiary academic center using the Active Insertion Monitoring (AIM) system by Advanced Bionics. After insertion, multifrequency tone bursts were delivered through the ear canal via a sound tube from 250 Hz to 2 kHz at 95 to 105 dB HL and recordings were made at all 16 internal electrode contacts. Using spectral analysis, the best frequency (BF) electrode was identified to have the largest magnitude response to a given stimulus frequency. BF-ECochG electrode responses at each test frequency were summed into a single value called the total response (BF-ECochG-TR). Postoperative CI performance was routinely monitored. Pearson correlation was utilized after confirming normally with the Shapiro-Wilk test.

Results: Of 57 participants with intracochlear ECochG there were 43 (age [in years]; mean 69, SD 14) who completed open-set testing through six-month follow-up. Of the CIs, 23 were perimodiolar (Mid-Scala [MS]) and 20 were lateral wall (SlimJ [SJ]). BF-ECochG-TR had a strong positive correlation to six-month consonant-nucleus-consonant (CNC) word scores for MS cases (r = 0.73, 95% CI [0.46 to 0.88]), but showed no significant correlation for SJ cases (r = 0.04, 95% CI [-0.41 to 0.47]).

Conclusions: While ECochG recorded on the round window and promontory has demonstrated value for estimating performance for all CIs, the utility of intracochlear BF-ECochG-TR may be limited to perimodiolar devices. This can be explained by the tendency of lateral wall arrays to contact the basilar membrane which leads to atypical ECochG signal. Future work will continue to explore clinical outcomes for intracochlear ECochG with other CI arrays.

Presenting Author(s)

Jordan J. Varghese, MD, MSCI

Resident Physician & Post-Doctoral Fellow
Washington University in St. Louis
Saint Louis, MO, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Co-Author(s)

Matthew A. Shew, MD

Assistant Professor
Washington University School of MedicineDepartment of Otolaryngology
St. Louis, MO, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
AW

Amit Walia, MD

Neurotology Fellow
Washington University in St. Louis
St. Louis, MO, United States

Disclosure information not submitted.
SL

Shannon M. Lefler, AuD

Washington University School of Medicine, United States

Disclosure information not submitted.
AO

Amanda J. Ortmann, PhD

Washington University School of Medicine, United States

Disclosure information not submitted.
ND

Nedim Durakovic, MD

Assistant Professor
Washington University in St. Louis
Saint Louis, MO, United States

Disclosure information not submitted.
Cameron C. Wick, MD

Associate Professor
University Hospitals of Cleveland
Cleveland, OH, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
JH

Jacques A. Herzog, MD

Chief Division of Otology and Neurotology, Professor
Washington University School of Medicine
Creve Couer, MO, United States

Disclosure information not submitted.

Senior Author(s)

Craig A. Buchman, MD

Lindburg Professor and Head, Otolaryngology - Head & Neck Surgery
Washington University in St. Louis
St. Louis, MO, United States

Disclosure information not submitted.