K.S.
Have you had your son tested for ADHD? I have an 8 y/o that was diagnosed with tourettes as well it came shortly after his ADHD diagnosis. the violence can be a result of untreated ADHD and they have found that the two go hand in hand. A large percentage of kids diagnosed with tourettes have also been diagnosed ADHD. they use to think that the medication was causing tourettes but studies have shown that the treatments for ADHD can significantly reduce the number and severity of tics. I have finally found a medication for my son that seems to have made all of his tourette symptoms and tics go away. I expect them to return as he gets closer to puberty, but for now all we have are a few eye twitches. I would consult your neurologist and also a child psychiatrist.
Let me know if there is any way I can help. I am good at doing research.