Moyamoya Disease Recommendations for Moyamoya Disease Referenced studies that support recommendations are summarized in online Data Supplement 30. COR LOE Recommendations In patients with moyamoya disease and a history of ischemic stroke or TIA, surgi- cal revascularization with direct or indirect extracranial-intracranial bypass can be beneficial for the prevention of ischemic stroke In patients with moyamoya disease and a his- tory of ischemic stroke or TIA, the use of anti- platelet therapy, typically aspirin monotherapy, for the prevention of ischemic stroke or TIA may be reasonable.393,394,397 401 Synopsis Moyamoya disease is an idiopathic rare steno-occlusive disease of the arteries of the circle of Willis, typically anterior circulation, with abnormal collateral development in lenticulostriate arteries, resulting in the characteristic angiographic puff of smoke appearance. Moyamoya disease may be more common in individuals of Asian descent, but non-Asian people can be affected.402 404 Moyamoya disease has a bimodal distribution, with a peak in childhood (more ischemic) and adulthood (isch- emic and hemorrhagic), and can be asymptomatic.404 Although a causal relationship is not well established, similar vascular changes also may be seen in association with prior radiation exposure, Down syndrome, sickle cell disease, neurofibromatosis, and atherosclerosis. This sit- uation is often referred to as moyamoya syndrome. Treat- ment focuses on preventing progression and reducing the risk of ischemic or hemorrhagic stroke. One prospec- tive RCT (JAM trial [Japan Adult Moyamoya]) examined the efficacy of surgical revascularization for preventing hemorrhagic stroke, but there are no similar prospective RCTs for ischemic stroke prevention.405 No prospective RCTs have studied medical management of either symp- tomatic or asymptomatic moyamoya disease. Although multiple case series and meta-analyses of varying sizes and quality exist, many include both patients with moy- amoya disease and those with moyamoya syndrome, as well as pediatric and adult patients. 