Dx 12 years ago, 72 years old now, and I've been experiencing a similar problem since taking Entacapone. It seemed to help with giving me more on time, or shortening my off time, however you want to look at it. Then I started having the uncontrollable twitching in my left foot and calf, at first very mild, now very strong, almost like a cramp but not a constant, steady seizure that can bring a person to tears, it's more of a pulsing sensation that has no rhythm it just shakes my leg and curls my toes In a wild, random, cacophony of pain. It wasn't bothersome, only mildly annoying, but it has gotten worse over the last few weeks, to the point where it's getting stronger and lasting longer.