Adult-onset moyamoya disease presenting with recurrent ischemic stroke: The role of CT Perfusion and digital subtraction angiography in bypass planning.

Moyamoya disease is a rare progressive cerebrovascular disorder characterized by stenosis of the terminal internal carotid arteries and compensatory development of fragile basal collateral vessels. We report a 32-year-old Filipino woman with poorly controlled hypertension who presented with abrupt right facial and upper limb weakness followed by recurrent left hemispheric ischemic events despite antiplatelet therapy, statin treatment, and blood pressure optimization. Magnetic resonance imaging showed recurrent left-sided watershed and cortical infarcts, while magnetic resonance angiography suggested bilateral terminal internal carotid artery stenosis with collateralization. Digital subtraction angiography confirmed bilateral distal internal carotid artery tapering, bilateral M1 involvement, and prominent collateral revascularization, consistent with moyamoya disease. CT perfusion demonstrated left hemispheric hemodynamic compromise with delayed perfusion and relatively preserved cerebral blood volume, supporting prioritization of left-sided superficial temporal artery-to-middle cerebral artery bypass, with staged contralateral reassessment planned after postoperative recovery. This case emphasizes that recurrent ischemic events in young adults should prompt evaluation for moyamoya disease and illustrates the complementary role of digital subtraction angiography and CT perfusion in diagnosis, mechanism clarification, and individualized bypass planning.