Cochlear Implant and Vestibular Function.

Study Overview
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Brief Summary
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This study investigate weather one type of cochlear implant (CI) surgery (insertion of the electrode via paracentesis of the round window (RWA)) leads to less vertigo than another type of CI surgery (cochleostomy). The participants will be randomized into 2 groups: RWA or cochleostomy. They will be examined with a video head impulse test (vHIT) before and after CI surgery to clarify their vestibular function.

Detailed Description
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Cochlear implant is an advanced type of hearing advice. It consists of an outer microphone, which picks up sound and sends it through an electrode into the cochlear. With a cochlear implant people, that are profoundly deaf or have severe hearing loss, can get their hearing back. Vertigo is one of the most common side effects to cochlear implant surgery. In this study we will investigate if one type of CI surgery (insertion of the electrode via paracentesis of the round window) leads to less vertigo than another type of CI surgery (cochleostomy). In the randomization there will be stratified according to age (60+/-), residual hearing (yes/no) and gain before surgery (+/-0,68). Three different surgeons will do the surgeries. All technical aspect of the surgery, other than the insertion of the electrode into cochlea, is being done identically. Electrodes from Cochlear, MEDEL and AB is being used. We will compare the findings from the vHIT examination with the subject dizziness perceived of the patient. The patients will be examined before surgery, the day after their surgery and one month after their surgery. The same examinator will perform all the vHIT tests. The test will be performed in continuation of the patient's other visits at the Department of Audiology and Department of Otorhinolaryngology -Head and Neck Surgery.

Official Title
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Vestibular Function Evaluated by the Video Head Impulse Test (vHIT) and Vertigo Perceived by the Patients Before and After Cochlear Implant Surgery.

Conditions
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Sensorineural Hearing Loss, Deafness, Hearing Loss

Intervention / Treatment
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* Procedure: Round window approach
* Procedure: Cochleostomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: deaf or severe hard of hearing normal or slightly affected vestibular function (gain >0,50) Exclusion Criteria: subjects with otosclerosis subject who will have the CI surgery for preservation of the residual hearing

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Cochleostomy<br>In this group the insertion of the electrode into cochlea will be performed by drilling a hole in cochlea (cochleostomy). | Procedure: Cochleostomy<br>* In this group the insertion of the electrode into cochlea will be performed by drilling a hole in cochlea (cochleostomy).<br>|
| Active Comparator: Round window approach<br>In this group the insertion of the electrode into cochlea will be performed through an incision in the membrane (paracentesis) of the round window (round window approach = RWA) | Procedure: Round window approach<br>* In this group the insertion of the electrode into cochlea will be performed through an incision in the membrane (paracentesis) of the round window (round window approach = RWA).<br>* Other names: RWA;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vestibular function | Measured by video head impulse test one month after CI surgery in connection with consultation for CI activation | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective dizziness | Measured by Dizziness Handicap Inventory Score (DHI). | 1 month | 
| Dizziness | Measured by a visuel analog scale (VAS) the day after cochlear implant surgery. | 1 day | 
| Dizziness | Measured by a visuel analog scale (VAS) in connection with consultation for CI activation. | 1 month | 
| T level | T level is a electropsysiological value. It is the minimum electrical signal in the electrode required for the patient to sense sound. | 1 month | 
| C level | C level is the maximum electrical signal in the electrode that is acceptable for the patient to tolerate the sound. | 1 month | 
| NRT level | Neural response telemetry, is an electrical response of the auditory nerve, when stimulated electrically. | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hearing loss, Cochlear implant