Well, then why did Fox write it in his book?
"If you experience sudden INVOLUNTARY MOVEMENTS on the drug, you may need a LOWER dose."
http://www.usnews.com/usnews/health/brain/parkinsons/park.treat.drugs.dopreplace.htm
(I am living through Parkinson's with my mother. Her neurologist said spastic movements can get out of control with over-medication.)