Hi Christine-
I'm so sorry things are not improving. By any chance is there a support group in your area for Tourettes? I've forgotten your specific details, but are you seeing a nuerologist that specializes in Tourette's Syndrome because perhaps a neurologist would be able to offer more ideas.
My roommate in college had Tourette's Syndrome and she went through some pretty severe times, however the severe tics would pass and life would continue. She has used many different medications to reduce tics. Hopefully difficult child severe tics will lesson. Are there any major stressors going on in his life? Is homework causing increased anxiety? I would do all you could right now to reduce stress.
There are some good books out there for tourette. Some are written for kids as well.
I agree with the others regarding the stimulants. I know his attention is greatly impacted, however major tics can have more of an impact than decreased attention. I would stop the stimulants and see what happens.
Fingers crossed that things improve so he can be back out there playing hockey,
Sending hugs.