Dion's head tremor

We are not sure what is wrong with Dion, but the blood work came back good. The vet is calling the neurologist to see what the recommend. Here is a video of her head tremor.

http://s5.photobucket.com/albums/y152/LSCKitty/?action=view&current=DION004.flv

Click on the link above. Or copy and paste the link above. It is a little dark, but hopefully you can see it.