Objective physiologic changes measured using electrocochleography at the round window (ECOGRW) are observable during endolymphatic sac decompression and shunt surgery (ELS).
Limited effective treatment options are available to patients with Menière's disease (MD) who have failed conservative management, experience persistent vertigo symptoms, and have substantial residual hearing. ELS is a feasible therapeutic option for these patients. However, the efficacy of this procedure has been questioned, and objective measures assessing inner ear physiologic alterations are lacking.
ECOGRW was measured in patients with MD undergoing ELS. Stimuli consisted of tone bursts (250, 500, 1000, 2000, 4000 Hz) and 100 μs broadband clicks at various intensities (60–90 dB nHL). Cochlear microphonic (CM), summation potential (SP), compound action potential (AP), SP:AP ratio, and CM harmonic distortions were measured.
ECOGRW was completed in 18 patients. The mean SP magnitude at 500 Hz changed significantly from −7.1 μV before to −5.1 μV after ELS (p < 0.05). However, the mean SP:AP ratio in those tested (n = 13) did not significantly change after ELS. CM harmonic magnitudes remained unchanged from pre- to post-ELS (n = 12) across all frequencies.
ECOGRW allows detection of acute electrophysiological changes in the cochlea. However, our results indicate only small objective changes in the low-frequency SP magnitude (500 Hz) immediately after ELS, but not in other frequencies or measures tested (CM, SP:AP, CM harmonic distortions). These results suggest minimal electrophysiological changes occur in the cochlea as a result of ELS.
*Department of Otolaryngology – Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
†Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin
Address correspondence and reprint requests to Jameson K. Mattingly, M.D., Department of Otolaryngology – Head and Neck Surgery, The Ohio State University Wexner Medical Center, 915 Olentangy River Road, Suite 4000, Columbus, OH 43212; E-mail: firstname.lastname@example.org
O.F.A. is consultant for MED-EL and Advanced Bionics Corporations and receives research support from Cochlear, MED-EL, and Advanced Bionics Corporations. O.F.A. is the president of Advanced Cochlear Diagnostics.
A.C.M. received grant support through the American Otology Society Clinician-Scientist Award and the National Institutes of Health, National Institute on Deafness and Other Communication Disorders (NIDCD) Career Development Award 5K23DC015539-02 that are unrelated to this project. He also received research support from Cochlear Americas for an unrelated investigator-initiated project.
No funding was provided for the work related to this manuscript.
The authors disclose no conflicts of interest.