Minimizing Facial Nerve Stimulation in Cochlear Implants
Cochlear Hearing Loss, Hearing Loss, Sensorineural, Hearing Loss
About this trial
This is an interventional diagnostic trial for Cochlear Hearing Loss
Eligibility Criteria
Inclusion Criteria:
Participant is willing and able to give informed consent for participation in the study.
- Male or Female, aged 18 years or above.
- Unilateral user of a cochlear implant or at least 6 months (post-operative group), or prospective CI user, meeting NICE criteria for implantation (intra-operative group).
- First language English or sufficiently fluent in English to understand the consenting process
- Post-lingual onset of severe to profound hearing loss
- No other handicaps that would interfere with participation in the study in the opinion of the Principal Investigator
Exclusion Criteria:
Unstable cochlear implant or hearing aid fitting
- Using medication in an intermittent manner that might influence hearing levels
- Cognitive or psychological challenges that might lead to variations in attention
Sites / Locations
- Addenbrookes Hospital
Arms of the Study
Arm 1
Arm 2
Experimental
Experimental
IntraOperative Group
PostOperative Group
The intra-operative group consists of patients who have met criteria for cochlear implants. We monitor the facial nerve EMG intraoperatively in all patients, and often get some facial nerve activation when we are testing the implant intraoperatively when we are looking to see if we are getting any hearing nerve responses from electrical stimulation of the implant. We will also measure the facial nerve responses for some other charge-balanced pulse shapes, which are asymmetric and in which either the positive or negative charge is expected to stimulate the nerve. We will only measure these for two electrodes, not for all 12-22 electrodes They will be then invited back post operatively for a second testing during a standard of care visit post switch on for other pulse shapes.
The post-operative group, are patients who are actually having facial nerve stimulation on one or more electrodes, and for whom these electrodes are turned down so much they can't hear very well, or are actually turned off because of the facial nerve stimulation. For these patients, we will slowly increase the current levels on the offending electrodes (maximum of two) until they get some facial nerve twitching, and then turn down the current until they do not have stimulation any more. We will do this for all pulse shapes and determine which shape produces the greatest loudness without stimulating the facial nerve. This will be the only testing session for the second group.