SUN-567 Moyamoya and Autoimmune Graves' Disease

Introduction: Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis of large intracranial arteries and formation of collaterals called moyamoya vessels. Diagnosis of MMD is based on characteristic findings on angiography. The pathogenesis of moyamoya disease remains unknown. Coexistence of MMD and Graves’ disease has previously been reported and may suggest a clue to clarify the pathogenesis.Case: We present a case of a 25-year-old woman with MMD concurrent with Graves’ disease. The patient presented to the hospital with a history of numbness of her face, starting on the left side and spreading towards the right, followed by tingling and seizures. She had a history of a TIA two years prior to her presentation with seizures. MRI and MRA of the brain were consistent with MMD due to presence of complete occlusion of the supraclinoid portion of the R internal carotid artery and marked stenosis of L middle cerebral artery along with associated development of collateral vessels from anterior cerebral artery and vertebrobasilar system. During her hospitalization, the patient reported symptoms of hyperthyroidism and thyroid function studies were obtained. Laboratory results showed suppressed TSH and elevated freeT4 as well as positive titers of anti-TPO, TSI, and thyrotropin receptor antibodies. She also has positive titer for antinuclear antibody. Thyroid ultrasound revealed a right thyroid nodule. Medical treatment was started with methimazole as well as with atorvastatin and aspirin. She underwent a successful left encephalo-duro-arteriosynangiosis(EDAS). Discussion: Several factors are thought to be involved in the coincidental occurrence of these two diseases.Autoimmune and genetic factors may play important roles in the pathogenesisof both diseases. Further studies are required to define the probable common pathogenesis of MMD,especially in cases with concurrent conditions such as Graves’ disease.