Intraoperative recording of eABR using intracochlear stimulation

Introduction 

In some cases it is desirable to determine intraoperatively whether a patient can get an adequate hearing impression with a cochlear implant (CI) without opening a full implant. There are special electrodes for intracochlear stimulation that are connected to the regular CI measurement setup. In order to be able to make a decision for or against a CI on the basis of these measurements, however, the results must be highly reliable.

Methods:

In the context of CI operations and translabyrinthine acoustic neuroma removals, intracochlear stimulation was carried out with the ANTS system (Auditory Nerve Test System, MED-EL) and E-ABR was measured. In CI operations, the measurement was repeated with stimulation via the CI. 6 patients were currently included in the study (2 children, 4 adults, 5x CI, 1x AKN).

Results 

In most cases, it was possible to measure stimulus responses via both ANTS and CI stimulation, which disappeared at lower stimulation intensities. The morphology of the curves did not always have the typical shape of an E-ABR, but was similar for ANTS and CI stimulation. The connections to later hearing success with CI need to be further investigated.

Conclusion 

Basically, the E-ABR measurement seems to work with the intracochlear stimulator, but for further conclusions the patient groups must be significantly enlarged.

Publication History

Article published online:
24 May 2022