...hmmmmm...some more rambling thoughts...

I read that in Tourette's it is believed that an abnormal metabolism of the neurotransmitters dopamine and serotonin are involved with the disorder. That would send me in the direction of Parkinson's research and depression research.

Also, I read that people with Tourette's are more likely to have:

Attention-Deficit/Hyperactivity Disorder (ADHD)
Difficulties with Impulse Control (disinhibition)
Obsessive-Compulsive Disorder (OCD)
Various Learning Disabilities (such as dyslexia)
Various Sleep Disorders

The learning disabilities would suggest looking at corpus collosum (split-brain) research. As jeffp said, music seems to help stutterers. Is that the right brain influence, or is it relaxation? I think I also read somewhere that Tourette folks benefit from relaxation. You might look at various types of relaxation/biofeedback etc.

There are probably studies about various types of music and the effect on learning/sleep/brain waves etc. (the Mozart effect)

This really is a big topic. A Tourette newsgroup or bulletin board would probably be one of your most helpful resources.

Mary