Dilated cardiomyopathy in thyrotoxicosis and Moyamoya disease

A 37-year-old Korean woman was admitted at 31 weeks gestation with exertional dyspnea. Three years ago she was diagnosed as having Graves' disease. Thyrotoxicosis-induced dilated cardiomyopathy was diagnosed by echocardiography. During management, a first attack of seizure occurred. Brain MRI and MRA showed occlusion of both internal carotid arteries, which confirmed the diagnosis of Moyamoya disease. Coexistence of dilated cardiomyopathy in thyrotoxicosis and Moyamoya disease is rare and the pathogenic correlation is discussed.