Gentamicin Treatment Prior to Schwannoma Surgery - No Residual Function

Study Overview
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Brief Summary
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The purpose of the study is to determine whether vestibular and postural compensation following schwannoma surgery is improved by ablating vestibular function prior to surgery, even if vestibular function is absent according to modern assessment techniques

Detailed Description
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Patients subjected to vestibular schwannoma surgery most often suffer from vertigo after surgery, even if no vestibular function can be found in pre-surgical assessment. According to retrospective data about 33% of patients scheduled for surgery do not have any measurable vestibular function. Even the occurrence of spontaneous nystagmus has been recorded in patients with no or very little function prior to surgery (Parietti-Winkler et al. 2008 JNNP). This indicates that despite new methods of measuring vestibular function, remaining vestibular function can be present and patients might benefit from pre-treatment of gentamicin (Tjernström et al. 2009 JNNP)

Official Title
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Gentamicin Treatment Prior to Vestibular Schwannoma Surgery in Patients With no Measurable Remaining Vestibular Function

Conditions
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Vestibular Schwannoma

Intervention / Treatment
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* Drug: Gentamicin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Vestibular schwannoma advised to surgical treatment No measurable remaining vestibular function Exclusion Criteria: impaired decision making neurofibromatosis signs for central dysfunction remaining vestibular function Patients are advised not to participate in the gentamicin arm if hearing is better than 30 deciBel (dB) in pure tone average (500, 1000, 2000, 3-4000 Hz) and speech discrimination better than 70% the neurosurgeon aim at hearing preservation surgery and do not want to risk gentamicin associated hearing loss

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Gentamicin treated<br>Installation of gentamicin in the middle ear 6 weeks prior to surgery + rehabilitation exercises before and after both treatment and surgery. Rehabilitation exercises are not considered to be an intervention since their benign impact on vestibular/postural compensation is well documented and exclusion from exercises would not be approved by the ethical board | Drug: Gentamicin<br>* Intratympanic installation of gentamicin 2-4 times depending on the efficacy of vestibular deafferentation<br>* Other names: prehabituation;|
| No Intervention: Non-gentamicin<br>Rehabilitation exercises before and after both treatment and surgery Rehabilitation exercises are not considered to be an intervention since their benign impact on vestibular/postural compensation is well documented and exclusion from exercises would not be approved by the ethical board | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences and changes of postural control following surgery, compared to before surgery | Postural control assessed with posturography during a sensory conflict | At first vestibular assessment at the time for inclusion and 6 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrence of spontaneous nystagmus after surgery | To measure spontaneous nystagmus and its direction after surgery as a sign of vestibular deafferentation or central nervous damage | Day 1 after surgery and for the duration of either spontaneous nystagmus or hospital stay (up to 2 weeks) | 
| Change of hearing levels | Measuring hearing levels (pure tone average and speech discrimination) before and after gentamicin treatment to determine possible detrimental effects on hearing | At first vestibular assessment and 4weeks after gentamicin installation | 
| Differences in the level of stress after surgery | Measuring cortisol in the saliva after surgery during the time patients are admitted to the hospital | Daily after surgery for the duration of the hospital stay, up to 2 weeks | 
| Differences of subjective well being after surgery | Daily subjective assessment of perceived vertigo/dizziness after surgery | Immediate time after surgery (2weeks) | 
| Differences of duration of hospital stay | Length of hospital stay required before patients can be discharged | After surgery for the duration of the hospital stay up to 2 weeks | 
| Differences of subjective well being after gentamicin treatment | Daily subjective assessment of perceived vertigo/dizziness after gentamicin treatment | Immediate time after gentamicin treatment (2weeks) | 
| Differences of perceived dizziness after surgery | Measurement of level of dizziness in daily life, questionnaire Dizziness Handicap Inventory (DHI) | 6 months after surgery | 
| Differences of perceived anxiety/depression after surgery | Measurement of level of anxiety/depression in daily life, questionnaire Hospital Anxiety and Depression Scale (HADS) | 6 months after surgery | 
| Change of level of perceived dizziness after surgery as compared to before surgery | Measurement of level of dizziness in daily life, questionnaire Dizziness Handicap Inventory (DHI) | At first vestibular assessment (inclusion) and 6 months after surgery | 
| Change of level of perceived anxiety/depression after surgery as compared to before surgery | Measurement of level of anxiety/depression in daily life, questionnaire Hospital Anxiety and Depression Scale (HADS) | At first vestibular assessment (inclusion) and 6 months after surgery | 
| Differences in vestibular compensation after surgery | Vestibular function tests; v-HIT (head impulse test), calorics and otolith tests to determine compensation and function after surgery | 6 months after surgery | 
| Change of vestibular function after gentamicin treatment | Vestibular function tests; v-HIT (head impulse test), calorics and otolith tests to determine compensation and function after gentamicin treatment | 6 weeks after gentamicin treatment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vestibular schwannoma, acoustic neuroma, cerebellopontine angle tumour, gentamicin, rehabilitation, postural balance