Correlation of Jitter Parameters and Acetylcholine Receptor Antibody Titers in Myasthenia Gravis

Abstract

Aim: Acetylcholine receptor (AChR) antibody test and single-fiber electromyography (SFEMG) are two important tests for the diagnosis of myasthenia gravis (MG). In this study, it was aimed to find out whether there is a relationship between AChR antibody titers and stimulated SFEMG (SSFEMG) parameter.Materials and Methods: Patients whose clinical findings, repetitive nerve stimulation (RNS), and AChR antibody test were compatible with MG were included in this retrospective cohort study. The patients had to be newly diagnosed. SSFEMG was applied to the patients and SSFEMG parameters were analyzed.Results: Sixteen patients (11 males, 5 females) were included in the study. The mean age of the patients was 54.1 ± 15.8 years. AChR antibody positivity, abnormality in RNS and SSFEMG parameters were found in 13 (81%), 9 (56%), 14 (88%) patients, respectively. A significant positive correlation was found between serum AChR antibody level and the percentage of apparent single-fiber action potential (ASFAP) pairs with increased jitter (p=0.019, r=0.639).Conclusion: This study showed a positive correlation between AChR antibody titers and the percentage of ASFAP pairs with increased jitter obtained by SSFEMG.

Keywords

• acetylcholine receptor antibody
• myasthenia gravis
• stimulated single-fiber electromyography