Back to resultsOVEMP in Myasthenia
Primary Purpose
Myasthenia Gravis, Ocular
Status
Completed
Phase
Not Applicable
Locations
Switzerland
Study Type
Interventional
Intervention
Ocular vestibular evoced myogenic potentials
Sponsored by
About this trial
This is an interventional diagnostic trial for Myasthenia Gravis, Ocular focused on measuring Ocular Vestibular Evoked Myogenic Potentials
Eligibility Criteria
Inclusion Criteria:
- Informed Consent as documented by signature
- Patients with diplopia and/or ptosis suspicious for myasthenia gravis.
Exclusion Criteria:
- Vestibular disorders
- Significant systemic myasthenia symptoms (respiration or swallowing difficulties) unable to undergo oVEMP testing.
- Patients with significant cardiac or respiratory disease will be excluded from the Tensilon test as part of the reference standard.
- Women who are pregnant or breast feeding.
Sites / Locations
- University Hospital Zurich, Ophthalmology/Neurology Department
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
Patients with clinical suspicion of ocular myasthenia gravis
Arm Description
Outcomes
Primary Outcome Measures
Decrement (as quantified in %) of repetitive 20 Hz ocular vestibular-evoked myogenic potentials (oVEMP)
oVEMP have been established as a standard clinical test of otolith function. Based on this technique, repetitive oVEMP stimulation, as a novel method for detecting ocular myasthenia gravis, was recently developed. Using this method, a response decrement in extraocular muscles can be quantified. The method is based on the conventional oVEMP montage with surface electrodes placed below the eyes. In order to elicit a response decrement, trains of ten bone-conducted vibration bursts at repetition rates of 20Hz will be applied with a hand-held 'minishaker' to the forehead. The oVEMP in response to these repetitive vibration stimuli will be measured in sustained upgaze from both inferior oblique muscles via surface electrodes. The magnitude of the decrement will be calculated as the difference between the amplitude of the second stimulus repetition and the mean amplitude of the fifth to ninth stimulus repetition. For further Information see: Valko et al. 2016 PMID:26791146
Secondary Outcome Measures
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT03049956
Brief Title
OVEMP in Myasthenia
Official Title
Diagnostic Accuracy of Repetitive Ocular Vestibular Evoked Myogenic Potentials in Myasthenia Gravis (OMG Study)
Study Type
Interventional
2. Study Status
Record Verification Date
January 2021
Overall Recruitment Status
Completed
Study Start Date
November 1, 2016 (Actual)
Primary Completion Date
December 31, 2020 (Actual)
Study Completion Date
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3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
University of Zurich
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief Summary
Myasthenia gravis is an autoimmune disorder of neuromuscular transmission, characterized by fluctuating muscle weakness and fatigability. In isolated ocular myasthenia, when only the extraocular muscles are involved, most common ancillary tests, such as acetylcholine receptor autoantibodies and repetitive nerve stimulation, are often negative.
A simple, quick and non-invasive test for ocular myasthenia based on ocular vestibular evoked myogenic potentials (oVEMP) was recently developed.
The main goal of the study is to validate repetitive oVEMP stimulation in a blinded diagnostic accuracy study in order to facilitate early and accurate diagnosis of ocular myasthenia.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Myasthenia Gravis, Ocular
Keywords
Ocular Vestibular Evoked Myogenic Potentials
7. Study Design
Primary Purpose
Diagnostic
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking Description
Blinded diagnostic accuracy study (index test vs. reference standard).
Allocation
N/A
Enrollment
96 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Patients with clinical suspicion of ocular myasthenia gravis
Arm Type
Experimental
Intervention Type
Diagnostic Test
Intervention Name(s)
Ocular vestibular evoced myogenic potentials
Intervention Description
The oVEMP technique is an accepted standard for testing otolith function in vestibular patients. It represents a quick, simple and non-invasive technique utilizing repetitive stimulation of the otolith organs with bone-conducted vibration to elicit an extraocular muscle response. Repetitive oVEMP stimulation leads to a characteristic decrement in patients with myasthenia, which can be quantified with surface electromyography from the inferior oblique muscle underneath the eye.
Primary Outcome Measure Information:
Title
Decrement (as quantified in %) of repetitive 20 Hz ocular vestibular-evoked myogenic potentials (oVEMP)
Description
oVEMP have been established as a standard clinical test of otolith function. Based on this technique, repetitive oVEMP stimulation, as a novel method for detecting ocular myasthenia gravis, was recently developed. Using this method, a response decrement in extraocular muscles can be quantified. The method is based on the conventional oVEMP montage with surface electrodes placed below the eyes. In order to elicit a response decrement, trains of ten bone-conducted vibration bursts at repetition rates of 20Hz will be applied with a hand-held 'minishaker' to the forehead. The oVEMP in response to these repetitive vibration stimuli will be measured in sustained upgaze from both inferior oblique muscles via surface electrodes. The magnitude of the decrement will be calculated as the difference between the amplitude of the second stimulus repetition and the mean amplitude of the fifth to ninth stimulus repetition. For further Information see: Valko et al. 2016 PMID:26791146
Time Frame
The primary outcome measure (index test oVEMP) will be assessed at baseline, in conjunction with reference standard/standard clinical workup (including blood analysis, neurological exam, edrophonium test, electromyography, single-fiber electromyography).
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Informed Consent as documented by signature
Patients with diplopia and/or ptosis suspicious for myasthenia gravis.
Exclusion Criteria:
Vestibular disorders
Significant systemic myasthenia symptoms (respiration or swallowing difficulties) unable to undergo oVEMP testing.
Patients with significant cardiac or respiratory disease will be excluded from the Tensilon test as part of the reference standard.
Women who are pregnant or breast feeding.
Facility Information:
Facility Name
University Hospital Zurich, Ophthalmology/Neurology Department
City
Zurich
ZIP/Postal Code
8091
Country
Switzerland
12. IPD Sharing Statement
Plan to Share IPD
No
Citations:
PubMed Identifier
26791146
Citation
Valko Y, Rosengren SM, Jung HH, Straumann D, Landau K, Weber KP. Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis. Neurology. 2016 Feb 16;86(7):660-8. doi: 10.1212/WNL.0000000000002383. Epub 2016 Jan 20.
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OVEMP in Myasthenia
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