I sustained 2 concussions prior to diagnosis. The first was a motorcycle accident at age 20. The second was at work. I was a maintenance man. I walked into a solid steel back access door to a boiler while looking down to avoid tripping on some hoses in the way. I was knocked out. I was 38 then. I was diagnosed with PD at 40. Was the PD due to the concussions or other factors? I can't say but I'm sure they didn't help matters.