Epidemiological profile of myasthenia gravis patients at the Neuromuscular Diseases Service of the Hospital de Clínicas of the Federal University of Paraná

Abstract

Background: Myasthenia Gravis (MG) is an autoimmune disease of the neuromuscular junction. In Brazil, epidemiological data regarding MG and its clinical aspects are limited. Objectives: The aim of this study was to describe the clinical and epidemiological profile of patients with MG at a referral center. Design and setting: Cross-sectional observational study performed on patients with Myasthenia Gravis age 18 years and older at Federal University of Paraná. Methods: Data were obtained through clinical evaluation and medical records. Results: The sample comprised 100 patients (67 females and 33 males). The median age at last appointment was 49.5 years (IQR 37-61). AntiAchR antibody was positive in 79 patients. Anti-MuSK antibody was positive in 6 positive patients. The Repetitive Nerve Stimulation (RNS) test presented abnormal result in 89 individuals. The main comorbidities reported were systemic arterial hypertension (SAH) (35%), mental health disorders (23%), diabetes mellitus (DM) (21%), dyslipidemia (18%), and hypothyroidism (13%). During the study period, the patients were on the following medications: pyridostigmine (88%), prednisone (42%), azathioprine (45%), cyclosporine (13%), and mycophenolate (6%). Thymectomy was performed in 30 patients, of whom 6 had a pathological diagnosis of thymoma, and five a pathological diagnosis of thymic hyperplasia. Conclusion: The patient profile as well as the prevalence of comorbidities in our MG sample were similar to previous studies. We also found that our sample presented a higher incidence of SAH, DM, mental health disorders and hypothyroidism compared with the general population.