D.D.Types of Chiari Malformation

1-Look first to the cerebellar tonsils( sagittal MRI image), if it is descent or not in the cervical canal.

2-If it is not seen in the cervical canal, no chiari malformation.

3-If it is descended, look to the fourth ventricle, if it is seen or not and if it is seen, it has a normal configuration or not.

4-If it is seen with normal configuration without stretching, this is type one chiari.

5-If it is completely non visualized or stretched, look immediately if there is a lumbar or cervical myelo-meningiocele.

6-If it is associated with lumbar myelomeningiocele, it is considered type 2 chiari.

7-But if it is associated with cervical or low posterior fossa myelomeningiocele, it is considered type 3 chiari.