Hi Slashman, My name is Tim and I'm new here. I have PD and something just like you described. My doctor says it's called hypnic seizures. I described it as when I am about to get to sleep or in a relaxed state, an explosion would happen in my back (just one) that is very violent. He gave me some epileptic meds like Primidone (500 mg) and Clonazepam (3mg/day). I still get them, but less often and less violent. Hope this helps.