Sounds more like both to me. My friend has epilepsy with petit mals. She does many of the same things. She found out that she also has a learning disability, which is why she didn't get her high school diploma 'til she was a full grown adult and had already raised her son. She discovered that it is Dyslexia.
My brother has adult ADHD. Current understanding is that ADHD doesn't go away. He didn't learn about it 'til he was an adult and after his own kid was diagnosed with ADHD. They figure this kind of thing out by having people who know what he was like as a kid and comparing it to current issues. I don't think he takes anything for it, but he does see someone for cognitive therapy. He has to work hard to stay organized. Fortunately, his wife helps him out with some of that, too. And, since he wants very much to be a good role model for his own children, he really works hard at doing the things that help him stay focused as much as the ADHD will allow.
Both conditions are neurological from what I've learned. Maybe your son still has both but has been able to learn how to compensate for many of the ADHD issues, since he was diagnosed as a young child.