ECochG: Electrocochleography Function for Monitoring Residual Hearing
Study Details
Study Description
Brief Summary
This trial is a pilot study to assess the feasibility of using Electrocochleography recorded from a cochlear implant intra-operatively in real time to monitor the progress of its insertion. Correlation between:
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Observed changes in this signal during surgery and residual hearing loss post-operatively and
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Recordings of this signal post-operatively and actual pure tone audiometry results will also be assessed.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
Cochlear Implants (CIs) can provide deaf individuals the ability to hear. CIs are electronics packages inserted into the cochlea (hearing organ). An external processor digitises sound and transmits it to the implant. An electric stimulus from the implant mimics the change in electrical potential normally caused by the movement of stereocilia in the cochlea when a sound occurs. This change generates an impulse along the auditory nerve to the brain resulting in perception of sound.
CIs are available in the UK to people who have profound hearing loss. The improvement of CI technology means individuals with less significant losses, or profound losses at only some pitches may now benefit from a CI over a hearing aid. Patients having useful residual hearing has led to interest in better preserving that hearing during surgery. Thus allowing benefit from traditional acoustic amplification in addition to electrical stimulation from the implant.
The investigators propose recording a measurement via the implant during surgery and at audiology appointments called a cochlear microphonic using a technique called electrocochleography (ECochG). This is essentially recording the electrical signal generated by the movement of hair cells in the cochlea in response to a sound. It is hypothesised that reduction of this signal during implantation may correspond to cochlea damage occurring and that with development this signal might be useful feedback for surgeons. The signal is known to be correlated to actual hearing ability so a better understanding of this may allow us to fit the acoustic amplification portion of implants in individuals who are unable to respond reliably to a normal hearing test.
The purpose of this study is a pilot to assess the correlation between observed changes in this signal during surgery and residual hearing loss post-operatively and the degree correlation between recordings of this signal post-operatively and actual hearing test results.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Pilot Group Intra and Post-operative Electrocochleography |
Procedure: Electrocochleography
Electrocochleography measurement Intra-operatively and Post-operatively at follow-up appointments along with correlative measurements (Impedance, eCAP, PTA, Speech)
|
Outcome Measures
Primary Outcome Measures
- Cochlear Microphonic Amplitude (micro volts) via Electrocochleography during Cochlear Implant Insertion [1 Year]
Cochlear Microphonic amplitude from real time electrocochleography using the apical cochlear implant electrode during implant insertion.
- Cochlear Microphonic Amplitude (micro volts) via Electrocochleography during post-operative audiological appointments [1 Year]
Cochlear Microphonic amplitude recorded from varying electrodes and at varying frequencies post-insertion during each follow-up appointment for the first year.
Secondary Outcome Measures
- ECochG Correlations [1 Year]
Correlations between Intra and Post-operative cochlear microphonic amplitudes and other normal clinical measures (Impedance, eCAP, PTA, Speech)
Eligibility Criteria
Criteria
Inclusion Criteria:
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Meets normal candidacy requirements for cochlear implantation
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At least 1 year of age at time of consent being given
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Patent cochlea as verified by CT or MRI scan
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No cochlear abnormality that might prevent insertion of the electrode array
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Measurable residual hearing in the ear to be implanted
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No additional complex needs that would prevent study procedures or normal clinical follow-up protocol being followed
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AB Implant selected by patient or MDT
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Written informed consent obtained
Exclusion Criteria:
- Medically complex cases where minimal duration of surgery is required
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Hearing Implant Centre, Guy's and St Thomas' NHS Foundation Trust | London | United Kingdom | SE1 7EH |
Sponsors and Collaborators
- Guy's and St Thomas' NHS Foundation Trust
Investigators
- Principal Investigator: Terry B Nunn, MSc, Head of Audiology and Consultant Clinical Scientist
- Study Chair: Dan Jiang, PhD FRCS, Professor of Otology and Auditory Implantation Surgery.
Study Documents (Full-Text)
None provided.More Information
Publications
- Dalbert A, Pfiffner F, Hoesli M, Koka K, Veraguth D, Roosli C, Huber A. Assessment of Cochlear Function during Cochlear Implantation by Extra- and Intracochlear Electrocochleography. Front Neurosci. 2018 Jan 26;12:18. doi: 10.3389/fnins.2018.00018. eCollection 2018.
- Koka K, Saoji AA, Litvak LM. Electrocochleography in Cochlear Implant Recipients With Residual Hearing: Comparison With Audiometric Thresholds. Ear Hear. 2017 May/Jun;38(3):e161-e167. doi: 10.1097/AUD.0000000000000385.
- Mandalà M, Colletti L, Tonoli G, Colletti V. Electrocochleography during cochlear implantation for hearing preservation. Otolaryngol Head Neck Surg. 2012 May;146(5):774-81. doi: 10.1177/0194599811435895. Epub 2012 Jan 30.
- O'Connell BP, Holder JT, Dwyer RT, Gifford RH, Noble JH, Bennett ML, Rivas A, Wanna GB, Haynes DS, Labadie RF. Intra- and Postoperative Electrocochleography May Be Predictive of Final Electrode Position and Postoperative Hearing Preservation. Front Neurosci. 2017 May 29;11:291. doi: 10.3389/fnins.2017.00291. eCollection 2017.
- Pienkowski M, Adunka OF, Lichtenhan JT. Editorial: New Advances in Electrocochleography for Clinical and Basic Investigation. Front Neurosci. 2018 May 8;12:310. doi: 10.3389/fnins.2018.00310. eCollection 2018.
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