OVEMP in Myasthenia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03049956
Recruitment Status : Recruiting
First Posted : February 10, 2017
Last Update Posted : October 11, 2018
Information provided by (Responsible Party):
Konrad Peter Weber, University of Zurich

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.

Condition or disease Intervention/treatment Phase
Myasthenia Gravis, Ocular Diagnostic Test: Ocular vestibular evoced myogenic potentials Not Applicable

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 200 participants
Intervention Model: Single Group Assignment
Masking Description: Blinded diagnostic accuracy study (index test vs. reference standard).
Primary Purpose: Diagnostic
Official Title: Diagnostic Accuracy of Repetitive Ocular Vestibular Evoked Myogenic Potentials in Myasthenia Gravis (OMG Study)
Actual Study Start Date : November 1, 2016
Estimated Primary Completion Date : December 31, 2019
Estimated Study Completion Date : December 31, 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Patients with clinical suspicion of ocular myasthenia gravis Diagnostic Test: Ocular vestibular evoced myogenic potentials
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 Measures :
  1. Decrement (as quantified in %) of repetitive 20 Hz ocular vestibular-evoked myogenic potentials (oVEMP) [ 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). ]
    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

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03049956

Contact: Konrad P Weber, PD, MD

University Hospital Zurich, Ophthalmology/Neurology Department Recruiting
Zurich, Switzerland, 8091
Contact: Konrad P Weber, PD, MD         
Sponsors and Collaborators
University of Zurich

Responsible Party: Konrad Peter Weber, PD, University of Zurich Identifier: NCT03049956     History of Changes
Other Study ID Numbers: 2016-01109
First Posted: February 10, 2017    Key Record Dates
Last Update Posted: October 11, 2018
Last Verified: October 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Konrad Peter Weber, University of Zurich:
Ocular Vestibular Evoked Myogenic Potentials

Additional relevant MeSH terms:
Myasthenia Gravis
Muscle Weakness
Muscular Diseases
Musculoskeletal Diseases
Neuromuscular Manifestations
Neurologic Manifestations
Nervous System Diseases
Pathologic Processes
Signs and Symptoms
Autoimmune Diseases of the Nervous System
Neuromuscular Junction Diseases
Neuromuscular Diseases
Autoimmune Diseases
Immune System Diseases