Cochlear monitoring during and after CI-Insertion using intracochlearly recorded Electrocochleography

Introduction To preserve residual hearing during CI insertion it is desirable to use intraoperative monitoring of the cochlea. A promising approach is the recording of cochlear microphonics using Electrocochleography (ECochG).

Methods During the insertion of hearing preservation CI electrodes the potentials were recorded using the CI electrode at contact 1. After insertion the recording was done at different electrode contacts. The stimulation was done acoustically using 500 Hz tone bursts. For recording the clinical CI software (Maestro, Medel) was used. After 6 months the recording at different contacts was repeated. The location of the electrode in the cochlea during insertion was estimated using preoperative radio imaging (CT scan) and mathematical modelling, the postoperative location was measured using postoperative radio imaging (cone beam CT scan). Up to now 6 patients were included.

Results In most of the cases the signal amplitude rose during the insertion. In patients with good residual hearing the largest amplitudes were recorded at electrode contacts which lay closest to the generators of the stimulation frequency.

Conclusion The intracochlear ECochG during and after CI insertion is very good possible and seems to yield consistent results to the location of the electrode in the cochlea.

Poster-PDF A-1419.pdf

Publication History

Article published online:
13 May 2021