wondering if my son may have tourette's

Hi, My son is 26 yrs old. He has aspergers syndrome. As of about three years ago he has been having anger outbursts out of the blue. These outbursts start out with him becoming fidgety, then he walks around and may punch a wall or the table, then he begins yelling out obsenities. and phrases about violent acts he wants to commit. He screams at the top of his lungs, and ussually runs outside and down the street. But most times we stop him from going out. He gets these outbursts about once week and they last for about 10 minutes, then he is calm again. SOmetimes he can control them, sometimes he cant. When we try to talk to him during one it makes it worse and he gets more angry. He also started cutting himself about 4 years ago, but that hasnt happened in quite awhile. He takes zoloft 100 mg day. When I told the doctor about the verbal obsentities he suggested tourettes and we talked about the drug holdol. I am concerned about the possible side effect of permanent twitches. Can anyone on here help me out. We are going to the dr this Friday to discuss it further. But I would like to know if it sounds like tourett syndrome to any of you. He does not have body twitches. its all verbal. he is not repetitive, he just yells out scary violent phrases, and he has never physically harmed anyone, except himself as I had mentioned. any responses would be greatly appreciated, thanks..