Early vascular lesion tracking in moyamoya disease: A case report with serial findings.

Moyamoya disease (MMD) is characterized by progressive stenosis of the internal carotid arteries and the presence of abnormal collateral vessels. However, knowledge of the early stages of MMD is limited. This case report discusses a woman in her 30s who experienced unusual symptoms, such as hand dysfunction and severe headaches. Initial MRI revealed stenosis of the right middle cerebral artery, and vascular imaging demonstrated eccentric thickening of the vessel wall with contrast enhancement. The patient was initially suspected to have arterial dissection and was treated with antiplatelet therapy. During the subsequent clinical course, Graves' disease was diagnosed based on the serological evidence of autoimmune hyperthyroidism. After 2 and a half years, further arterial narrowing and the development of abnormal collateral vessels were observed, ultimately fulfilling the diagnostic criteria for MMD. The disease did not progress thereafter, and the patient is currently under observation. This case highlights the difficulty in distinguishing MMD from other conditions, such as vasculitis and arterial dissection, in its early stages and provides valuable insights into the longitudinal progression of MMD, particularly in the context of coexisting thyroid disease.