I had a question about Chiari Malformation. My cerebellar tonsil extends 4 mm below the foramen magnum. I know for a CM diagnosis it must extend 5mm below, but I have a lot of CM symptoms including a syrinx in my spinal cord. I have constant headaches, neck & back pain & a lot of numbness in my hands, arms & feet. Could my cerebellar tonsil extend further over time? Is this something I should periodically monitor? Thank you so much for any input!