Sensitivity of Repetitive Nerve Stimulation Performed in Early and Later Stages of Myasthenia Gravis.

INTRODUCTION/AIMS: Repetitive nerve stimulation (RNS) is a valuable tool in the diagnostic evaluation of myasthenia gravis (MG). However, there are conflicting reports of its sensitivity when performed ≤ 30 days from symptom onset. We aim to compare the sensitivity of RNS performed in the early versus later stages of MG. METHODS: Data from patients with MG who underwent RNS testing from 2017 to 2021 at Cleveland Clinic and from 1975 to 2001 at Duke University Medical Center were reviewed. RESULTS: A total of 525 patients with MG underwent RNS testing. RNS was performed ≤ 30 days after symptom onset in 32 patients (Early RNS) and in 493 patients > 30 days after onset (Late RNS). RNS was abnormal in 56.3% of patients in the Early RNS group and 59.4% of those in the Late RNS group (p = 0.72). There was no difference in RNS positivity rates for either group between the institutions. DISCUSSION: We found no significant difference in the sensitivity of RNS performed within or after 30 days from the onset of MG. Our findings support the use and value of RNS in the diagnostic evaluation of MG in patients presenting both early and late.

Duke Scholars

Author Donald Benjamin Sanders Neurology, Neuromuscular Disease

Author Janice Munn Massey Neurology, Neuromuscular Disease

Author Vern Charles Juel Neurology, Neuromuscular Disease

Author Shruti Mukund Raja Neurology, Neuromuscular Disease