Minimizing Facial Nerve Stimulation in Cochlear Implants

NCT04161261 | Unknown

• 1 other identifier: 272538
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to understand how to manipulate the electrical stimulation from the cochlear implant to maximize hearing stimulation and minimize facial stimulation. It is know from animal data that the hearing and facial nerves have different sensitivities to things like electrical pulse shape, its pattern, and its duration. It is very unclear however if this applies to human cochlear implant patients, and what the optimal parameters are to selectively stimulate the hearing nerve in humans. The outcomes of this study will be used to more selectively program some patients with severe facial nerve cross stimulation and to inform the development of new types of implant stimulation.

Conditions

Cochlear Hearing Loss; Hearing Loss, Sensorineural; Hearing Loss; Facial Nerve Injury; Nerve Disorders

Outcome Measures

Primary Outcomes (1)

• To identify stimulus parameters for cochlear implant stimulation that achieve sufficient loudness for hearing, while minimizing stimulation of the facial nerve.

  The loudness level, or auditory nerve response at which facial nerve stimulation occurs for different stimulation pulse shapes will be measured for all 24 patients on both groups and help to identify different optimal stimulus parameters. By comparing the amount of electrical current required to initiate a facial nerve response for each pulse shape this will determine if there is an optimal type of stimulation to use, to reduce facial nerve stimulation.

  18 months

Secondary Outcomes (1)

• To increase scientific understanding of the biology of the auditory and facial nerve's responses to stimulation.

  18 months

Study Arms (2)

IntraOperative Group

EXPERIMENTAL

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.

Procedure: Electrical Stimulation

PostOperative Group

EXPERIMENTAL

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.

Procedure: Electrical Stimulation

Interventions

Electrical Stimulation PROCEDURE

To measure the facial nerve stimulation threshold for one mid-array and one apical electrode of the implant using the pulse-train stimuli

IntraOperative Group; PostOperative Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Cambridge University Hospitals NHS Foundation Trust: lead
• University of Cambridge: collaborator
• Medical Research Council Cognition and Brain Sciences Unit: collaborator

Study Sites (1)

Addenbrookes Hospital

Cambridge, United Kingdom

Location

MeSH Terms

Conditions

Hearing Loss, Sensorineural; Hearing Loss; Facial Nerve Injuries

Interventions

Electric Stimulation

Condition Hierarchy (Ancestors)

Hearing Disorders; Ear Diseases; Otorhinolaryngologic Diseases; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Facial Nerve Diseases; Mouth Diseases; Stomatognathic Diseases; Cranial Nerve Injuries; Cranial Nerve Diseases; Craniocerebral Trauma; Trauma, Nervous System; Wounds and Injuries

Intervention Hierarchy (Ancestors)

Physical Stimulation; Investigative Techniques

Study Officials

• Manohar L Bance, Professor

  Cambridge University Hospitals NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: /Chief Investigator Professor Manohar Bance

Model Details: We will have 2 groups of patients. An Intraoperative group (undergoing cochlear implantation) and a post operative group (with pre existing facial nerve stimulation). The study compares the effectiveness of different pulse shapes within each group, rather than performing a between-group comparison

Study Record Dates

• First Submitted: November 5, 2019
• First Posted: November 13, 2019
• Study Start: December 13, 2019
• Primary Completion: May 3, 2022
• Study Completion: November 1, 2022
• Last Updated: July 29, 2021

Record last verified: 2021-07

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)