Hello, by reading your post and by what your MRI's have said, you should mention to your doctor a basilar invagination. It is not very well known but is more common than one might think. I was diagnosed with a basilar invagination along with an Arnold Chiari 1 malformation at the age of 13. By your list of symptoms this could very well be a possiblity. Hope all goes well and you get some answers.