This happens to me too. It's like sometimes my body won't cooperate with what my mind wants it to do and I have 'slow reactions'. It's one of my panic triggers because of course, I start thinking that something is wrong with me. What I've come to the conclusion of (for myself) is that there are so many other things going through my mind that I'm just overwhelmed at times. Once I get myself calmed down, I'm fine. If it were anything serious, I think the symptoms would persist. I've also been to a neurologist, etc. and was told I have a 'healthy brain' (yeah, and overactive one too). Have you ever done any research on restless leg syndrome? It's like having growing pains all the time. Just a thought.
Since m leg muscles have started to ache feel like I'm having really slow movements or reactions to tings. I'm almost telling myself I'm going to do a movement before I do it to make sure I will be able to do it. This is beginning to worry me, I don't know why I'm fixating on my leg muscles, they've hurt now on and off for 2-3 weeks so I don't think I've got anything other than anxiety but I can't make it go away! Has anyone else had this?