Is it possible that all neurological based diseases have a blood flow problem?
Here are two videos. One with Michael J Fox skating. The other a distonia patient running. May be the increase in heart rate, affecting the blood flow is the key?

http://www.oprah.com/health/Michael-J-Fox-Goes-Ice-Skating-with-Dr-Oz-Video

http://www.youtube.com/watch?v=URHhyP4lmQ4