See http://bit.ly/saitwitch for the full info, and http://saizai.com/tic_cards.png for the summary info I carry with me in my wallet.
It's a non-Tourette's tic. I don't get vocal tics (other than air forced out by full upper torso spasm) or the like.
Most of the time I'm completely normal (neurologically at least); I only have symptoms during an episode. Those can last anywhere from 15 min to 8 hours and vary pretty widely in severity, from something you wouldn't even notice unless I pointed it out, to severe full body contractures, spasms, mutism, etc.
At the time of this video, I'm taking 0.25mg clonazepam 3/day. It helps significantly. It'll probably go up in dose; I've had negative side effects, so mainly just trying to figure out a good balance point.
This video is licensed CC by-nc-nd.
You're welcome to use it for medical demonstrations, so long as you email me info about your talk and credit the video to me. I can be reached at saizai.com.
I'm a grad student in social neuroscience, so ironically I find my own disorder a bit academically interesting.