Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis.
- Valko Y From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia.
- Rosengren SM From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia.
- Jung HH From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia.
- Straumann D From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia.
- Landau K From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia.
- Weber KP From the Departments of Ophthalmology (Y.V., K.L., K.P.W.) and Neurology (Y.V., H.H.J., D.S., K.P.W.), University Hospital Zurich, University of Zurich, Switzerland; Department of Neurology (S.M.R.), Royal Prince Alfred Hospital, Sydney; and the Central Clinical School (S.M.R.), University of Sydney, Australia. konrad.weber@usz.ch.
- 2016-01-22
Published in:
- Neurology. - 2016
Adult
Aged
Aged, 80 and over
Electromyography
Evoked Potentials
Female
Humans
Male
Middle Aged
Myasthenia Gravis
Oculomotor Muscles
Physical Stimulation
Prospective Studies
ROC Curve
Sensitivity and Specificity
Vibration
Young Adult
English
OBJECTIVE
To explore whether ocular vestibular evoked myogenic potentials (oVEMP) can be used to detect a decrement in the extraocular muscle activity of patients with myasthenia gravis (MG).
METHODS
Twenty-seven patients with MG, including 13 with isolated ocular and 14 with generalized MG, and 28 healthy controls participated. We applied repetitive vibration stimuli to the forehead and recorded the activity of the inferior oblique muscle with 2 surface electrodes placed beneath the eyes. To identify the oVEMP parameters with the highest sensitivity and specificity, we evaluated the decrement over 10 stimulus repetitions at 3 different repetition rates (3 Hz, 10 Hz, and 20 Hz).
RESULTS
Repetitive stimulation at 20 Hz yielded the best differentiation between patients with MG and controls with a sensitivity of 89% and a specificity of 64% when using a unilateral decrement of ≥15.2% as cutoff. When using a bilateral decrement of ≥20.4% instead, oVEMP allowed differentiation of MG from healthy controls with 100% specificity, but slightly reduced sensitivity of 63%. For both cutoffs, sensitivity was similar in isolated ocular and generalized MG.
CONCLUSION
Our study demonstrates that the presence of an oVEMP decrement is a sensitive and specific marker for MG. This test allows direct and noninvasive examination of extraocular muscle activity, with similarly good diagnostic accuracy in ocular and generalized MG. Thus, oVEMP represents a promising diagnostic tool for MG.
CLASSIFICATION OF EVIDENCE
This study provides Class III evidence that oVEMP testing accurately identifies patients with MG with ocular symptoms (sensitivity 89%, specificity 64%).
To explore whether ocular vestibular evoked myogenic potentials (oVEMP) can be used to detect a decrement in the extraocular muscle activity of patients with myasthenia gravis (MG).
METHODS
Twenty-seven patients with MG, including 13 with isolated ocular and 14 with generalized MG, and 28 healthy controls participated. We applied repetitive vibration stimuli to the forehead and recorded the activity of the inferior oblique muscle with 2 surface electrodes placed beneath the eyes. To identify the oVEMP parameters with the highest sensitivity and specificity, we evaluated the decrement over 10 stimulus repetitions at 3 different repetition rates (3 Hz, 10 Hz, and 20 Hz).
RESULTS
Repetitive stimulation at 20 Hz yielded the best differentiation between patients with MG and controls with a sensitivity of 89% and a specificity of 64% when using a unilateral decrement of ≥15.2% as cutoff. When using a bilateral decrement of ≥20.4% instead, oVEMP allowed differentiation of MG from healthy controls with 100% specificity, but slightly reduced sensitivity of 63%. For both cutoffs, sensitivity was similar in isolated ocular and generalized MG.
CONCLUSION
Our study demonstrates that the presence of an oVEMP decrement is a sensitive and specific marker for MG. This test allows direct and noninvasive examination of extraocular muscle activity, with similarly good diagnostic accuracy in ocular and generalized MG. Thus, oVEMP represents a promising diagnostic tool for MG.
CLASSIFICATION OF EVIDENCE
This study provides Class III evidence that oVEMP testing accurately identifies patients with MG with ocular symptoms (sensitivity 89%, specificity 64%).
- Language
-
- English
- Open access status
- green
- Identifiers
-
- DOI 10.1212/WNL.0000000000002383
- PMID 26791146
- Persistent URL
- https://sonar.ch/global/documents/166095
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