If the malformation is not producing symptoms, your condition may need only careful monitoring for changes.
If the malformation produces symptoms, the only treatment is an operation called a chiari decompression. This surgery removes part of the bone in the back of the skull to give the brain more room. We often remove the back part of the first cervical bone. After removal of the bone, many surgeons will then open up the dura (a thick membrane that hold the brain and spinal cord in place) and sew in a large patch to give the brain even more room. Some surgeons will even shrink the tonsils down.
There is debate among surgeons which method is the best method.