Electro-physiological Findings and Symptoms Severity in Superior Canal Dehiscence

Study Overview
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Brief Summary
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This research aims at assessing the validity of three different electro-physiological tests (Vestibular Evoked Myogenic Potentials, WideBand Tympanometry, Electrocochleography) used in the investigation of the symptoms severity in the case of superior semi-circular canal dehiscence syndrome.

Detailed Description
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Superior semi-circular canal dehiscence (SCD) syndrome can associate several cochlear and vestibular symptoms. Recent systematic reviews identified pulsatile tinnitus, autophony, sound-induced and pressure-induced vertigo as most specific signs of SCD. These signs are rarely all present and the symptomatology remains highly variable from a patient to another, with frequent though less evocative symptoms such as dizziness or ear pressure. A surgical treatment may be proposed when the symptoms become significantly incapacitating. Unfortunately to date, there is no objective marker of this severity and all surgical decisions rely on the importance of patients' complaints. High Resolution Computed Tomography (HRCT) of the temporal bone can confirm the diagnosis. Electro-physiological investigations such as Vestibular Evoked Myogenic potentials (VEMPs) have also been extensively described in the diagnosis of SCD but they have been reported as independent from the symptoms severity. Wideband tympanometry (WBT) and Electrocochleography (EcoG) have only been studied in few reports but the latter appears as a promising tool in the assessment of the symptoms because it explores inner ear biomechanics, directly involved in the pathophysiology of this condition.

Official Title
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Interest of Electro-physiological Findings in the Assessment of Symptoms Severity in Superior Semi-circular Canal Dehiscence Syndrome

Conditions
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Superior Semicircular Canal Dehiscence

Intervention / Treatment
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* Diagnostic Test: Wideband tympanometry
* Diagnostic Test: Electrocochleography
* Diagnostic Test: Vestibular Evoked Myogenic potentials


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: confirmed unilateral SCD (using specific HRCT settings and reconstructions) with or without SCD symptoms if present, SCD symptoms should be stable patients understanding and reading french affiliated to social security. Exclusion Criteria: bilateral confirmed SCD doubtful SCD other otologic or neurotologic condition that might mimick SCD symptomatology : middle ear conditions, Meniere disease, vestibular migraine

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Interventional<br>Electrophysiological tests | Diagnostic Test: Wideband tympanometry<br>* Wideband tympanometry<br>Diagnostic Test: Electrocochleography<br>* Electrocochleography<br>Diagnostic Test: Vestibular Evoked Myogenic potentials<br>* Vestibular Evoked Myogenic potentials<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| EcoG validity - pulsatile tinnitus | the validity of EcoG will be assessed by the correlation between the alteration of the summating potential/action potential ratio and symptom severity (pulsatile tinnitus) assessed by a visual analogue scale (0 to 10) | 30 day | 
| EcoG validity - autophony | the validity of EcoG will be assessed by the correlation between the alteration of the summating potential/action potential ratio and symptom severity (autophony) assessed by a visual analogue scale (0 to 10) | 30 day | 
| EcoG validity - dizziness induced by loud sounds | the validity of EcoG will be assessed by the correlation between the alteration of the summating potential/action potential ratio and symptom severity (dizziness induced by loud sounds) assessed by a visual analogue scale (0 to 10) | 30 day | 
| EcoG validity - dizziness induced by pressure changes | the validity of EcoG will be assessed by the correlation between the alteration of the summating potential/action potential ratio and symptom severity (dizziness induced by pressure changes) assessed by a visual analogue scale (0 to 10) | 30 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Superior semi-circular canal dehiscence, Minor syndrome, Pulsatile tinnitus, Autophony Tullio phenomenon