Moyamoya disease

Stage	Finding
1	Stenosis of suprasellar ICA, usually bilateral
2	Development of moyamoya vessels at base of brain. ACA, MCA, & PCA dilated
3	Increasing ICA stenosis & prominence of moyamoya vessels (most cases diagnosed at this stage). Maximal basal moyamoya
4	Entire circle of Willis and PCAs occluded, extracranial collaterals start to appear, moyamoya vessels begin to diminish
5	Further progression of stage 4 with intensification of ECA collaterals & reduction of moyamoya associated vessels
6	Total occlusion of ICA & major cerebral arteries and complete absence of moyamoya vessels