Clinical differences between early-and late-onset myasthenia

Abstract

Objective To explore the clinical differences between patients with early-onset myasthenia gravis(EOMG)and those with late-onset myasthenia gravis(LOMG). Methods This was a retrospective study enrolling 157 MG patients.Based on the age of onset, patients were divided into the EOMG group(n=85)and the LOMG group(n=72). The groups were compared on clinical characteristics, including clinical manifestations, MG classification, electrophysiological findings on repetitive nerve stimulation(RNS), single fiber electromyography(SFEMG), levels of antibody against acetylcholine receptors(Ach-R Ab), antibody to muscle-specific kinase(MuSK Ab), titin antibody(Titin Ab), ryanodine receptor antibody(RyR Ab), thyroid function, thymectomy, thymus pathology and responses to treatment. Results The mean ages of onset were markedly different〔(40.9±9.7)years vs.(62.0±12.2)years, P 0.05). Moreover, patients in the EOMG group were more likely to have abnormal thyroid function and higher percentages of receiving steroids, tacrolimus, plasma exchange therapy, and thymectomy(P<0.05). Conclusions The clinical profiles of LOMG are different from those of EOMG in clinical manifestations, thyroid function, thymectomy frequency, striational antibody levels and disease-modifying drug options. Key words: Myasthenia gravis; Recepors, cholinergic