6 yr old w/involuntary muscle movements/jerks/twitches, Paroxysmal Dyskinesias? please help!

Hi! Does anyone have experience with a child having involuntary muscle movements in hands, feet, arms and legs? It's like a wave of motion/stiffness. We just met with a neuro, had an MRI which was normal except for a smaller hippocampus than normal? Regular, asleep EEG was normal. But we are waiting for the Digitrace/video 48 hour EEG results which should be more telling. In the meantime I thought I'd post.

 When he was a toddler, he often twirled his hands when excited. He also had a significant gross motor delay, speech delay, some stuttering on and off. My mother is epileptic (grand mal seizures) I am fine and no other family history. My son went through EI phys. therapy, speech and some sensory motor therapies - "graduated" from all, normal 6 year old otherwise, doing very well in school. But has these "spasms" while playing, walking - I don't count but I'd say close to 50 per day if not more. He does not do it when he sleeps. We were working with one doctor (sensory motor integration specialist) who felt this was some form of stimming but my son is not autistic, no longer delayed and he doesn't do it to self-soothe. He cannot control when the movements start, but we can "interrupt" or stop the movements by touching him, talking to him, etc. It is VERY frustrating. During the movements his hands twist, bend inward at wrist, stiffen - it looks like someone with MS perhaps...arms and legs move all over, his feet cross if he is standing and he has been stumbling. It's like he can't control his foot placement. Our neuro. is investigating possibly seizures, but I have also read about "chorea" and Paroxysmal Dyskinesias?? All of it frightens me. I am worried about him. I would say the movements come and go....there are times we don't notice them and then he has really bad days?! Interestingly when he is really "focused" (like at school) - it rarely happens.

I would love to hear about other experiences with this. I would think if it were seizures we wouldn't be able to "interrupt" the movements, however if they are very short ones, maybe they would be ending anyway around the time we try to stop them??

Would love any feedback! Thanks :)