Grade | CM |
---|---|
CM0 | Cerebellum is rounded with CSF between vermis and foramen magnum |
CM1 | Indentation of cerebellum by supraoccipital bone; CSF present between vermis and foramen magnum |
CM2 | Cerebellar vermis is impacted into or through the foramen magnum |
SM0 | No syrinx or central canal dilation |
SM1 | Central canal dilation with a diameter < 2 mm |
SM2 | Central canal dilation > 2 mm, separate syrinx, or pre-syrinx with or without central canal dilation |