Repetitive nerve stimulation in myasthenia gravis—relative sensitivity of different muscles

Costa, Jerome; Evangelista, Teresinha; Conceição, Isabel; Carvalho, Mamede de

doi:10.1016/j.clinph.2004.05.024

Cited by 100 publications

(93 citation statements)

References 22 publications

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“…24 In ocular MG, SFEMG is considered the diagnostic gold standard, as reflected by four studies reporting a high sensitivity of 92-97% [25][26][27][28] , although two other groups found lower sensitivities of 83% and 62%. 29,30 Comparison of different electromyographic tests in ocular MG demonstrated that the closer the measurement to the extraocular muscles, the higher the sensitivity.…”

Section: Ovemp In Mgmentioning

confidence: 99%

Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis

et al. 2016

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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%). Author contributions:Yulia Valko collected and analyzed the data and wrote the manuscript.Sally Rosengren contributed to the study design, data analysis and writing of the manuscript.Hans Jung contributed to the patient examination and review of the manuscript.Dominik Straumann contributed to the study design, data analysis and review of the manuscript.Klara Landau contributed to the study design, patient examination and review of the manuscript.Konrad Weber designed the study, contributed to data collection, data analysis and writing of the manuscript, and conducted the statistical analysis.Study funding: the study was supported by a research grant of the University of Zurich (Forschungskredit der Universität Zürich).Disclosure Agreement: All authors report no disclosures.Valko et al. 3 AbstractObjective: To explore whether ocular vestibular evoked myogenic potentials (oVEMP)can be used to detect a decrement in the extraocular muscle activity of myasthenia gravis (MG) patients.Methods: Twenty-seven MG patients, including 13 with isolated ocular and 14 with generalized MG and 28 healthy subjects participated. We applied repetitive vibration stimuli to the forehead and recorded the activity of the inferior oblique muscle with two surface electrodes placed beneath the eyes. To identify the oVEMP parameters with the highest sensitivity and specificity, we evaluated th...

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Section: Ovemp In Mgmentioning

confidence: 99%

Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis

et al. 2016

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“…Only a few studies have correlated RNS sensitivity with MG clinical subgroups [9,10,12,13]. The purpose of this study was to assess the utility of RNS in the O.O., nasalis and ADQ and to correlate the sensitivity of these muscles with the clinical subgroups of MG.…”

Section: Introductionmentioning

confidence: 99%

“…is the most frequently used facial muscle for RNS with a diagnostic yield of 75–85% in generalized MG [6,7]. The nasalis is also frequently used with a diagnostic yield of 52–67% [8,9,10]. On the other hand, the abductor digiti quinti (ADQ), which is usually tested because it is easy to test and stabilize the stimulating and recording electrodes, has low sensitivity with a diagnostic yield of 0–62% in ocular and oculobulbar MG [2,7,11,12,13].…”

Section: Introductionmentioning

confidence: 99%

Repetitive Nerve Stimulation of Facial and Hypothenar Muscles: Relative Sensitivity in Different Myasthenia Gravis Subgroups

Kokotis¹,

Karandreas²

2011

Eur Neurol

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Aim: To assess the utility of repetitive nerve stimulation (RNS) in facial and hypothenar muscles in the clinical groups of myasthenia gravis (MG). Patients and Methods: We performed RNS study in the orbicularis oculi (O.O.), nasalis and abductor digiti quinti (ADQ) in 115 consecutive myasthenic patients and classified them according to the classifications of the Myasthenia Gravis Foundation of America. Patients were classified into three groups: group 1, group 2 (IIa, IIIa and IVa) and group 3 (IIb, IIIb and IVb). Results: RNS was abnormal in 95 patients (82.6%): 78.3% in the O.O., 66.1% in the nasalis and 19.1% in the ADQ. Both facial muscles were statistically more sensitive than the ADQ in all groups of patients. RNS in the O.O. was more frequently abnormal than in the nasalis only in group 1. Sensitivity to acetylcholine antibodies in myasthenic patients was 84%. Acetylcholine receptor (AChR) and muscle-specific tyrosine kinase antibodies were present in 96.7% of the patients with abnormal RNS in both facial muscles. Single-fiber electromyogram (SFEMG) was abnormal in 91.3% of the tested patients. One of the three tests used for the diagnosis of MG (AChR antibodies, SFEMG, RNS) was abnormal in 99.1% of the patients. Discussion: O.O. is the most sensitive muscle in all groups of MG followed by nasalis, while the ADQ is the muscle with the lowest sensitivity. Facial muscles, especially the O.O., should be the first to be tested in MG. The negativity of all tests (RNS, AChR antibodies, SFEMG) should question the diagnosis of MG, even in the presence of symptoms consistent with MG.

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“…[15][16][17] Thus, tests using alae nasae, trapezius muscle, and anconeus (anatomically an extension of the triceps) are to be preferred. 18 In children, the major difficulties result from the discomfort of the test and the consequent movement that may occur. It is really not possible to use the muscles mentioned.…”

Section: Repetitive Nerve Stimulationmentioning

confidence: 99%

Neurophysiological strategies for the diagnosis of disorders of the neuromuscular junction in children

Pitt

2008

Develop Med Child Neuro

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The disorders of the neuromuscular junction seen in children, the congenital myasthenic syndromes and autoimmune myasthenia gravis, are very rare. Their clinical symptoms and signs may be variable, most notably in the neonate and infant. They should enter the differential diagnosis of many different clinical presentations, such as ‘floppy infant’ or attacks of episodic apnoea. Many molecular genetic abnormalities have been discovered in congenital myasthenic syndromes, but screening for these is impracticable without confirmation of a disorder of the neuromuscular junction. In this review, the different neurophysiological tests that can be used are discussed, with their merits and contraindications in children. After consideration of the acceptability of the different techniques, it has been found that stimulation single‐fibre electromyography (stimSFEMG) of orbicularis oculi seems to be the best choice in children. In most instances it can be performed on the conscious child and it has a good specificity and high sensitivity. A protocol for using stimSFEMG is described.

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Repetitive nerve stimulation in myasthenia gravis—relative sensitivity of different muscles

Cited by 100 publications

References 22 publications

Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis

Ocular vestibular evoked myogenic potentials as a test for myasthenia gravis

Repetitive Nerve Stimulation of Facial and Hypothenar Muscles: Relative Sensitivity in Different Myasthenia Gravis Subgroups

Neurophysiological strategies for the diagnosis of disorders of the neuromuscular junction in children

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