====== Suzuki staging ======

The [[staging]] system for [[moyamoya disease]] first described by Suzuki and Takaku in their seminal [[1969]] article 
((Suzuki J, Takaku A. Cerebrovascular "moyamoya" disease. Disease showing abnormal net-like vessels in base of brain. Arch Neurol. 1969 Mar;20(3):288-99. doi: 10.1001/archneur.1969.00480090076012. PMID: 5775283.))
is still in use today. Formally, the staging refers to findings on conventional angiography, although there are efforts to apply similar systems to [[MR angiography]]
((Houkin K, N Nakayama, S Kuroda, et al. Novel Magnetic Resonance Angiography Stage Grading for Moyamoya Disease. 2005;20 (5): 347–54. . doi:10.1159/000087935.)).

Suzuki stage appears to correlate with collateralization in children, but not in adults
((Suzuki J and N Kodama. Moyamoya disease--a review. 1983;14 (1): 104–9. . doi:10.1161/01.STR.14.1.104.)).

The vast majority of patients will progress through some or all of the Suzuki stages, although progression may occur at different rates 
((Scott RM, Smith ER. Moyamoya disease and [[moyamoya syndrome]]. N Engl J Med. 2009 Mar 19;360(12):1226-37. doi: 10.1056/NEJMra0804622. PMID: 19297575.)), 
and appears to occur more rapidly in children than in adolescents or adults 
((Houkin K, Yoshimoto T, Kuroda S, Ishikawa T, Takahashi A, Abe H. Angiographic analysis of moyamoya disease--how does moyamoya disease progress? Neurol Med Chir (Tokyo). 1996 Nov;36(11):783-7; discussion 788. doi: 10.2176/nmc.36.783. PMID: 9420429.))

The Suzuki stages are as follows:

stage I
"narrowing of the carotid fork" *
narrowed ICA bifurcation

stage II
"initiation of the moyamoya"
dilated ACA, MCA and narrowed ICA bifurcation with moyamoya change

stage III
"intensification of the moyamoya"
further increase in moyamoya change of the ICA bifurcation and narrowed ACA and MCA

stage IV
"minimization of the moyamoya"
moyamoya change reducing with occlusive changes in ICA and tenuous ACA and MCA

stage V
"reduction of the moyamoya"
further decrease in moyamoya change with occlusion of ICA, ACA and MCA

stage VI
"disappearance of the moyamoya"
ICA essentially disappeared with supply of brain from ECA

* the description in inverted commas (quotation marks) is that of Suzuki in the original paper.