Study of the Fine Structure and Temporal Envelope of the Human Cochlea in Response to Human Vocalizations
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In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: near field recording of human auditory nerve activity during retro sigmoid approach with contact electrode.
- Who it may be relevant to
- Registry conditions: Structure Cochlea, Temporal Envelope Cochlea. Basic parameters: 18 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Functional Role of Cochlear Synaptopathy for Speech Coding in the Brain
Overview
In humans, surface electrophysiological recordings of the cochlear nerve in response to a sound stimulus provide information about the cochlear's ability to encode sound. Depending on the stimulus, the fine structure and temporal envelope of the signal will vary, allowing us to determine its characteristics. By phenotyping patients before surgery using subjective and objective audiometric tests, it will be possible to isolate for each patient the moment when the fine structure disappears and when the temporal envelope is effective.
Detailed description
During functional cerebellopontine angle surgery, a spherical electrode is placed on the human cochlear nerve to monitor hearing. Once the electrode is in place, clicks and speech signals with and without noise are delivered to analyze the cochlear electrophysiological signal produced. Depending on the characteristics recorded, this signal can be used to determine how fine structure and temporal envelope are encoded by the cochlea. Prior to surgery, each patient is evaluated by an audiologist to determine quiet and noise thresholds, tone and speech, electrocochleography, distortion testing, tympanometry, ABR and psychoacoustic testing.
Interventions
- Procedure near field recording of human auditory nerve activity during retro sigmoid approach with contact electrode
During surgery using a retro-sigmoid approach in the cerebellopontine angle (microvascular decompression), near-field recording of human auditory nerve activity using a contact electrode is performed on patients with normal or impaired hearing threshold. Each patient is explored preoperatively by hearing tests. During the surgery, stimuli are delivered.
Primary outcome measures
- To compare the amplitude of coding of complex and ecological sounds [Time frame: At 48 months]
- To compare the spectrum of coding of complex and ecological sounds [Time frame: At 48 months]
Secondary outcome measures (4)
- The spectrum of the temporal envelope of the signal [Time frame: At 48 months]
- The amplitude of the temporal envelope of the [Time frame: at 48 months]
- The spectrum of the fine structure of the signal [Time frame: at 48 months]
- The amplitude of the fine structure of the signal [Time frame: at 48 months]
Eligibility criteria
Inclusion criteria
- The following will be included as hearing-impaired patients:
- Male or female
- Over 18 and up to 80 years of age
- Normal otoscopic examination
- Scheduled for surgery on the cerebellopontine angle (microvascular decompression)
- With sensorineural hearing loss defined by average hearing thresholds between 21 dB HL and 40 dB HL at 0.5, 1, 2 and 4 kHz
- Affiliated to a social security scheme
- Having read the information note describing the study and having agreed in writing to participate by signing the informed consent form
- Will be included as normal-hearing patients:
- Male or female
- Over 18 and up to 80 years of age
- Normal otoscopic examination
- Scheduled for surgery on the cerebellopontine angle (microvascular decompression)
- Free of sensorineural hearing loss, defined by average hearing thresholds of less than or equal to 20 dB HL in tonal air conduction audiometry, bilaterally on the side of the ear undergoing surgery and on the side not undergoing surgery, at 0.5, 1, 2 and 4 kHz
- Affiliated to a social security scheme
- Having read the information note describing the study and having agreed in writing to participate by signing the informed consent form
Exclusion criteria: patients will be excluded from the study if the auditory nerve is not accessible during surgery:
- Notably because of complete tumor invasion of the cochlear nerve (stage III and IV neuroma, advanced meningioma) ;
- Or because of a particular anatomical feature not identified during the preoperative examination, making its exposure for recordings impossible (protrusion of the posterior face of the rock).
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
France · 1 center
- Damien JOLLY — Reims
Identifiers
NCT: NCT06499584 · PO23102