Development and Validation of Risk Prediction Models for Stroke and Cognitive Impairment in Moyamoya Disease and Moyamoya Syndrome

Inclusion Criteria 1. Age 12 to 70 years. 2. Diagnosis of moyamoya disease or moyamoya syndrome by DSA, CTA or MRA. 3. Ability to complete neurological and cognitive assessments. 4. Ability to complete at least 12 months of clinical follow-up and willingness, in principle, to complete 24 months of follow-up. 5. At least one analyzable baseline vascular imaging examination in original DICOM format, including CTA, MRA, or DSA. 6. Written informed consent provided by the participant and/or legally authorized representative. Exclusion Criteria 1. Refusal to participate or inability to complete follow-up. 2. Pregnancy or breastfeeding. 3. Coexisting cerebrovascular malformation, intracranial tumor, hydrocephalus, or another disorder that may independently affect stroke or cognitive outcomes. 4. Severe visual impairment, aphasia, impaired consciousness, psychiatric illness, or another disorder that prevents valid cognitive assessment, including Alzheimer's disease, Parkinson's disease, or frontotemporal dementia. 5. Cardiac conditions that may cause cardioembolic stroke, including atrial fibrillation, patent foramen ovale or other right-to-left shunting cardiac disease, intracardiac mural thrombus, or infective endocarditis; or severe hepatic or renal dysfunction, coagulation disorders, malignancy, or severe cardiopulmonary disease. 6. Receipt of an investigational drug or device within 30 days before screening, or current participation in another interventional clinical trial that may interfere with this study. 7. Previous cerebral revascularization surgery.