Freaking Out and ADHD/Asperger's

I have a son with Asperger's Syndrome. For those that don't know, it is an Autism Spectrum disorder. One of the signs of Asperger's is rigidity. People with Asperger's cannot handle when things do not happen just right. As an example, today my son wanted to make rock candy. We had bought unwaxed dental floss for this. Joseph put sugar water in a jar, tied a paper clip to the floss, and tried to hang the floss from a pencil, with the help of me and my wife. However, in his view the string was always too high or too low from where it should hang. He became very upset, stomping, screaming, going "waaaahhh!" out loud, even rolling around on the floor.

It is tough to console him when he gets like this. Telling him not to do it doesn't work, because he has little control over his emotions. Telling him to stop the experiment doesn't help either. I finally told him that I would do the experiment when I get home from class, and that, if I succeeded, I would then help him do it the way I did it. This calmed him down somewhat, but he was still upset.

I mention this because I identify with how he is feeling. In fact, I have had those feelings before. I remember one time as a kid when I went to a party. I got lost along the way (it was at night in an unfamiliar area) and I started freaking out. Every muscle in my body felt like it was exploding with energy needing to be released. I stopped at a house, sobbing my head off, crying about how I was lost. I ended up using their phone and getting directions, and I made it to the party, but I was embarrassed about how I lost control. Though I don't cry or thrash about anymore, I still have times where something is going wrong and I feel like I need to do so.

I'm pretty certain I don't have Asperger's Syndrome or an Autism Spectrum disorder. This leaves me wondering whether my son also has ADHD and this is an ADHD trait, or whether it's a trait both people with ADHD and people with Asperger's share. I also have yet to find discussions about this type of reaction. Any thoughts on the subject are welcome.