I can't give you an idea of what is wrong with him, however, baclofen is a drug used for spasm. Perhaps that can help. It seems that his problems with balance and the movement disordre could be related to brain dysfunction. Have they done MRIs of the brain? Has he had a recent PET scan?

Also, I hope they can start IVIG for him soon, as that may help. I get IVIG and have had no side effects from it.

I am so sorry that you and he are going thru such a difficult time.