Upper Cervical Care has been shown to help many of the more complex neurological conditions that get minimal results under standard medical and chiropractic care. There has even been some research done regarding Tourettes. I would recommend looking into the research link below, and then visiting an Upper Cervical Office for a more comprehensive evaluation for your son.

Many of our offices have helped patients with dystonia as well. While this disorder, like many of the complex neurological disorders, have no known medical cause, we have found that relieving the pressure in the upper cervical spine drastically helps in the healing process. As mentioned above, a more complete prognosis could be given after a more thorough evaluation.
 
Here is the link to the Tourettes research/case study: http://www.erinelster.com/pdfs/tourette.pdf