EABR comparison study
Research type
Research Study
Full title
A comparison of intracochlear and extracochlear EABR recordings in profoundly deaf adults.
IRAS ID
127209
Contact name
Martin O'Driscoll
Contact email
Sponsor organisation
Manchester University NHS Foundation Trust
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Cochlear Implants (CI) are inserted into the inner ear of profoundly deaf people where they electrically stimulate the auditory nerve. In response to the electrical stimulation by the CI, the auditory nerve sends nerve impulses along the hearing pathway through the brainstem to the auditory cortex where is is heard. With working CIs, the signal starts at auditory nerve and travels through the brainstem to the cortex; where is it heard. A working auditory nerve is needed to be able to hear the CI. Electrically Evoked Auditory Brainstem Responses (EABRs) are measured to test auditory nerve function of patients about to receive CIs. EABRs are signals a recorded from the auditory part of the brainstem, using needle electrodes. The inner ear is electrically stimulated to generate the EABR. A present EABR indicates good nerve function as the signal needs to travel through the auditory nerve to be recorded. Present EABRs are more likely to result in successful CI.
In peri-operative EABR (performed before cochlear implantation) the inner ear is stimulated using a removable electrode. In post-operative EABR (performed after cochlear implantation) the inner ear is stimulated using an electrode form the cochlear implant itself. The clinical usefulness of post-operative EABR has been widely investigated, and normative data for the response have been published. Peri-operative EABR is comparatively under-researched. There are two ways it can be generated: using an intracochlear test electrode (surgically inserted into the cochlea of the inner ear) or an extracochlear electrode surgically placed at the entrance; (promontory of the inner ear). There is little normative data for extracochlear EABR, and no published data for the newer intracochlear test electrode EABR method. Furthermore, there are no known published data comparing the three methods.
Participants will be adult CI patients from Manchester Royal Infirmary (CMFT) who are receiving cochlear implants. We plan to measure and compare the three EABR methods for each participant during the same surgery. The study will last for approximately 2 years and is part of an MSc in Clinical Science.
REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
17/NW/0151
Date of REC Opinion
10 Mar 2017
REC opinion
Favourable Opinion