Anti-striational antibodies detected in a patient with late-onset myasthenia gravis suffering from severe bradycardia.

Abstract

We report herein the case of a 79-year-old woman who experienced difficulties in swallowing, dysarthria, dropped head, and muscle weakness associated with diurnal and day-to-day variation. We made a diagnosis of generalized myasthenia gravis (MG) with anti-acetylcholine receptor antibodies. Contrast-enhanced computed tomography showed no sign of thymoma. As the MG worsened, the patient presented with severe bradycardia. Chest compressions were performed on days 6 and 7 after admission and she underwent implantation of a temporary pacemaker. The arrhythmia resolved after strong immunosuppressive treatment, and anti-striational antibodies, including anti-muscular voltagegated potassium channel-complex (Kv1.4) antibody and anti-titin antibody, were subsequently detected. This case implies the possible involvement of anti-striational antibodies in bradycardia.