Moyamoya disease in pediatric Down syndrome: diagnostic challenges and management strategies: a case report.

Introduction and importance: Moyamoya is a rare disease of cerebrovascular incidence manifested as blockage of the terminal parts of the internal carotid artery bilaterally or progressive stenosis, leading to abnormal blood vessels in the brain. Presentation of case: The study presents a 7-year-old boy with Down syndrome who had recurrent transient ischemic attacks that presented as right-sided weakness and facial droop. Magentic Resonance Imaging (MRI) and Magentic Resonance Angiography (MRA) confirmed that the patient had multiple lacunar infarcts and near occlusion of bilateral Intracranial Athrosclerotic diseasaes (ICAs) with arterial collaterals. The diagnosis was confirmed by MRA, which shows the typical picture described as a "puff of smoke." Treatment was aimed at the surgical reconstruction of cerebral blood vessels. Clinical discussion: The usefulness of early identification of Moyamoya disease and referral to a specialized center became evident in the present case scenario, especially when children with comorbidities, including Down syndrome, are involved. Conclusion: It is a low-incidence cerebrovascular disease diagnosed by gradual narrowing or occlusion of the internal carotids and the development of new blood vessels. It is still essential to improve the early identification of patients destined to progress to stroke and decide about optimal revascularization interventions.