Parkinson’s disease is caused by damage to cells in a part of the brain called the substantia nigra. These cells (called neurons) are essential for control of movements of the body. They do this by producing a chemical called dopamine that acts as a messenger to other parts of the brain. When these neurons are damaged or die, less dopamine is made. Eventually, as enough cells are lost, the motor symptoms of Parkinson’s disease appear.
As a neurodegenerative condition that affects the motor system, most of the symptoms of Parkinson’s disease are abnormal movements of the body. The classic motor symptoms are tremors, muscle rigidity, and slowness of movement. Other motor symptoms include an inability to maintain posture and balance, and changes in speech and facial expression.
There is no cure for Parkinson’s disease. Treatment is individualized for each patient in order to alleviate symptoms; it may include medication, surgery, and lifestyle modifications—particularly exercise.