A Case of Graves’ Disease Diagnosed in the Course of Bilateral Carotid Artery Stenoses (Moyamoya Disease); A Case Report and Review of the Literature

A 14-year-old boy was admitted to our hospital after being diagnosed at a local clinic with bilateral carotid artery stenoses (Moyamoya disease) and mild thyrotoxicosis. A blood examination showed suppressed TSH and elevated triiodothyronine and thyroxine levels; however, he was negative for anti-thyrotropin receptor antibody (TRAB) and thyroid stimulating antibody (TSAB). Concern about a possible thyroid crisis led us to administer thiamazole (MMI) and potassium iodide (KI), following which encephalo-duro-arterio-synangiosis (EDAS) of the left side was performed successfully. After about 1 mo, he became positive for TRAB and TSAB. He was thought to have Graves’ disease and Moyamoya disease coincidentally. Several factors are considered to be involved in the coincidental onset of these two diseases.