Hey, Spudbro.
Lara PMed me about this thread, and I didn't see any mention of an MRI. If she hasn't had one, I would certainly get one, particularly since she's still having problems after all this time.
The condition Lara mentioned, Arnold-Chiari Malformation, which my son has, is usually a congenital malformation, and symptoms are often not present until an injury of some kind occurs. It's very common, for example, for it to be dx'ed after whiplash from a car accident. It can generally only be dx'ed from an MRI, so if she hasn't had one yet, that should be done to rule it out.
Good luck, and please let me know...
LIZARD