もやもや病と甲状腺疾患

Association between Moyamoya Disease and Autoimmune Thyroid Disorders

Point

・Graves病合併もやもや病では，甲状腺機能の正常化が虚血性脳卒中発症抑制のために必要である．

・もやもや病患者では，抗甲状腺自己抗体陽性を示すことが多い．

・もやもや病患者では，甲状腺機能および抗甲状腺自己抗体を測定することは重要である．

　Moyamoya disease（MMD） is a progressive cerebrovascular disorder characterized by stenosis or occlusion of the terminal portion of the internal carotid arteries and development of abnormal collateral vessels. Recent studies have suggested a clinical association between MMD and autoimmune thyroid disorders or antithyroid antibodies. In patients with concurrent Graves'disease, thyrotoxicosis may precipitate ischemic cerebrovascular events, and normalization of thyroid function is crucial before revascularization surgery. Notably, elevated levels of antithyroid autoantibodies, such as antithyroid peroxidase and anti-thyroglobulin, are frequently observed in patients with MMD, despite the absence of clinically overt thyroid dysfunction. Genetic susceptibility, including RNF213 variants and immunological factors, might contribute to the pathophysiology of MMD and autoimmune thyroid disorders. The presence of thyroid autoantibodies may be associated with the pathological extension and cerebrovascular events in MMD. However, the underlying mechanisms linking thyroid autoimmunity and moyamoya angiopathy remain unclear. Further investigation is warranted to elucidate these associations and establish appropriate diagnostic and therapeutic approaches.