Management of moyamoya disease: a review of current and future therapeutic strategies

Moyamoya disease (MMD) is characterized by idiopathic, progressive stenosis of the circle of Willis and the terminal portion of the internal carotid arteries with the development of prominent small collateral vessels and a characteristic moyamoya or puff-of-smoke radiographic appearance. The incidence and prevalence of MMD varies by region, age, and sex, with higher rates in Asian and East Asian populations compared to North American or European populations. There is a bimodal distribution of patients diagnosed with MMD. Pediatric patients are more commonly diagnosed within the 1st decade of life, whereas adult patients present in the 5th or 6th decade of life. Overall, there is a nearly 2:1 female-to-male ratio. Ischemic symptoms are the most common presentation in pediatric and adult populations, but adult patients are nearly twice as likely to present with intracranial hemorrhage compared to their pediatric counterparts. Surgical revascularization is indicated in symptomatic cases, and antiplatelet therapy may be a useful adjunct to prevent recurrent symptoms. Direct and combined bypass procedures seem to be more effective in adults, whereas children respond well to indirect bypass. The identification of key genetic, molecular, and environmental factors including RNF213 and GUCY1A3 loss-of-function mutations, angiogenic growth factors, autoantibodies, CNS infections, and radiation exposure suggest multiple pathways for the development of moyamoya arteriopathy. Further research is needed to better understand the heterogeneity of pathogenetic mechanisms that lead to moyamoya and to identify novel therapeutic targets to prevent, stabilize, and treat MMD.