Repetitive ocular vestibular evoked myogenic potential stimulation for the diagnosis of myasthenia gravis: Optimization of stimulation parameters.

Autor: Wirth MA; Department of Ophthalmology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland., Valko Y; Department of Neurology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 26, 8091 Zurich, Switzerland., Rosengren SM; Department of Neurology, Royal Prince Alfred Hospital, Missenden Rd, Camperdown, NSW 2050, Australia., Schmückle-Meier T; Department of Ophthalmology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland., Bockisch CJ; Department of Ophthalmology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland; Department of Neurology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 26, 8091 Zurich, Switzerland; Department of Otorhinolaryngology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland., Straumann D; Department of Neurology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 26, 8091 Zurich, Switzerland., Landau K; Department of Ophthalmology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland., Weber KP; Department of Ophthalmology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, 8091 Zurich, Switzerland; Department of Neurology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 26, 8091 Zurich, Switzerland. Electronic address: konrad.weber@usz.ch.
Jazyk: angličtina
Zdroj: Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology [Clin Neurophysiol] 2019 Jul; Vol. 130 (7), pp. 1125-1134. Date of Electronic Publication: 2019 Apr 25.
DOI: 10.1016/j.clinph.2019.03.033
Abstrakt: Objective: To determine the most effective stimulation parameters for the diagnosis of ocular myasthenia gravis (MG) using repetitive ocular vestibular evoked myogenic potentials (oVEMP) for quantification of the extraocular muscle response decrement.
Methods: Repetitive bone-conducted oVEMPs were elicited in 18 MG patients and 20 healthy subjects. We compared four different stimulus repetition rates (20 Hz, 30 Hz, 40 Hz, 50 Hz) and 100 Hz continuous stimulation, as well as recordings from the inferior oblique muscles and the lateral rectus muscles to determine the most sensitive and specific oVEMP parameters for decrement detection.
Results: Repetitive stimulation at all tested repetition rates with recordings from inferior oblique muscles allowed for effective differentiation between MG patients and healthy subjects. Among all repetition rates, 30 Hz showed a trend towards superiority, with a sensitivity of 71% and a specificity of 94% (area under the curve (AUC) 0.88) when using the smaller decrement of the two eyes and -10% as cutoff. Considering the larger decrement for analysis (-9% as cutoff), sensitivity increased to 82%, but specificity decreased to 78% (AUC 0.81).
Conclusions: Our study demonstrates, that repetitive oVEMP stimulation elicits a robust decrement in the inferior oblique muscles of MG patients at repetition rates between 20 Hz and 50 Hz, with a probable optimum at 30 Hz.
Significance: Repetitive inferior oblique oVEMP stimulation with optimal stimulus parameters facilitates early and accurate diagnosis of ocular MG.
(Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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