Parkinson’s Disease Making a Difference Today Each year, about 50,000 Americans are diagnosed with Parkinson’s disease,joining the estimated 1 million people already living in the United Stateswith this serious and disabling brain disorder. Parkinson’s occurs whennerve cells become damaged or destroyed in the substantia nigra, an areaof the brain that is important for normal voluntary movement and coordi-nation. People with Parkinson’s experience trembling, muscle stiffness,and slowness of movement. They also often experience depression, anxi-ety, dementia, constipation, urinary difficulties, and sleep disturbances.Symptoms tend to worsen over time. In addition to its physical and emotional toll, Parkinson’s costs eachpatient an average of $4,000 a year for medications. The annual price tagfor the U.S. economy—visits to doctors, Social Security payments, nurs-ing home expenditures, and lost income—is estimated at more than $5.6billion.