Electrically evoked auditory brainstem response in cochlear implantation: what you need to know (short review)

Abstract

Background: Electrically evoked auditory brainstem response (E-ABR) is an evoked potential recorded from the auditory nerve in response to electric stimulation. It is considered a short latency evoked potential. It plays a vital role, especially after the increased number of cochlear implant receivers. Body of abstract: E-ABR is characterized by three positive peaks (eII, eIII, and eV) generated from the auditory nerve, cochlear nucleus, and perhaps from neurons in the lateral lemniscus or inferior colliculus. The largest is corresponding to wave V of the acoustic one. There are differences between both acoustic auditory brainstem response (A-ABR) and E-ABR. E-ABR is characterized by larger amplitudes and shorter latencies than the acoustic, and it has a steeper latency-intensity function. There are many variables affecting the E-ABR waveform, including recording-related variables, stimulus-related variables, and subject-related variables. E-ABR has potential clinical applications in cochlear implants (pre, inter, and postoperative). Conclusion: After the increase in the number of cochlear implant receivers, E-ABR provides a promising new tool that can be used to evaluate auditory nerve functions. A lot of factors affect its waveform, including recording-related factors and stimulus-related and subject-related variables. E-ABR has many clinical applications, not only in post-implantation situations but also in preimplantation.