Classification of the severity of steno-occlusive change in the posterior cerebral artery
| PCA Stage | Angiographic Findings |
|---|---|
| 1 | No occlusive changes in the PCA |
| 2 | Stenosis in the PCA with or without slightly developed PCA moyamoya |
| 3 | Severe stenosis or virtually complete occlusion of the PCA with well-developed PCA moyamoya |
| 4 | Occlusion of the PCA with decreased PCA moyamoya |
Note.—Classification is according to Mugikura et al (12). PCA indicates posterior cerebral artery.