At this time, there is no known cause of Parkinson's disease. However, researchers have discovered that people with the condition have a deficiency of a certain brain chemical, called dopamine, that is responsible for muscle activity. This deficiency causes many of the symptoms of Parkinson's disease, such as tremors and movement problems. While there is no cure, several treatment options are available that can significantly relieve symptoms. Some of these treatments include medications, lifestyle changes, and brain surgery.