Moyamoya Disease Masquerading as a Transient Ischemic Attack: The Importance of Early Vascular Imaging

Moyamoya disease is a rare progressive occlusive cerebrovascular disorder characterized by stenosis of intracranial arteries and compensatory collateral formation.Adult presentations most commonly include ischemic or hemorrhagic stroke, while transient ischemic attack (TIA) is less frequently reported.A 35-yearold woman presented with transient dizziness, dysarthria, left-sided weakness, and numbness lasting approximately one minute.Initial CT and MRI were unremarkable.CT angiography revealed near occlusion of the proximal left M1 segment.Diagnostic cerebral angiography demonstrated characteristic collateral vessels consistent with unilateral moyamoya disease (Suzuki stage II).Incidental nonfunctional pituitary enlargement was also identified.The patient was managed conservatively with antiplatelet therapy and outpatient follow-up.This case highlights the importance of early vascular imaging in patients presenting with transient neurological symptoms and normal MRI findings.Moyamoya disease should remain in the differential diagnosis for young adults with suspected TIA.