Development of Hemorrhage-prone Anastomoses in Asymptomatic Moyamoya Disease-A Comparative Study with Japan Adult Moyamoya Trial.

Present study was aimed to precisely evaluate the angio-architectures in patients with asymptomatic moyamoya disease (MMD) by comparing with those with hemorrhagic stroke.This study used the data set of cerebral angiography in Asymptomatic Moyamoya Registry (AMORE) Study and Japan Adult Moyamoya (JAM) Trial at enrollment. The development of 3 subtypes of collateral vessels, including lenticulostriate, thalamic, and choroidal anastomosis, was evaluated on cerebral angiography. Suzuki's angiographical stage and posterior cerebral artery (PCA) involvement were also assessed. These findings were compared between asymptomatic (AMORE) and hemorrhagic (JAM) groups.This study included 55 hemispheres of 35 patients in asymptomatic group and 75 hemispheres of 75 patients in hemorrhagic group. In asymptomatic group, thalamic anastomosis was less developed than in hemorrhagic group (P = .011), but there were no significant differences in the development of lenticulostriate and choroidal anastomosis between the 2 groups (P = .077 and P = .26, respectively). Suzuki's stage was more progressed and the prevalence of PCA involvement was significantly higher in hemorrhagic group than in asymptomatic group (P = .0033 and P = .016, respectively).This study reveals no significant differences in the development of choroidal anastomoses between asymptomatic and hemorrhagic-onset MMD. On the other hand, disease stage and PCA involvement were less advanced in asymptomatic MMD than in hemorrhagic-onset MMD. These findings strongly suggest a certain subgroup of asymptomatic patients with MMD is at potential risk for hemorrhagic stroke.