If your medicines for Parkinson's disease just don't seem to help, there's a possibility that you have a related but different ailment called manganism. If you were a welder, steel worker, or manganese miner, you should let your doctor know and have the diagnosis re-examined.
Did you know that Mirapex, a common drug used to treat Parkinson's disease, has been linked to compulsive behavior such as shopping and gambling? It's possible that you may be eligible for recompense if you've suffered these side effects, but you need to document everything very carefully.