Parkinson's disease (PD) is a degenerative disorder of the central nervous system that belongs to a group of conditions called movement disorders. It is both chronic, meaning it persists over a long period of time, and progressive, meaning its symptoms grow worse over time.D is the most common form of parkinsonism [1] , in which disorders of other causes produce features and symptoms that closely resemble Parkinson’s disease. While most forms of parkinsonism have no known cause, there are cases in which the cause is known or suspected or where the symptoms result from another disorder.