Parkinson's disease (PD) is a chronic, progressive neurological disorder characterized by both motor and non-motor symptoms. PD is the second most common neurodegenerative disorder after Alzheimer's disease and the most common movement disorder. PD has age-related pathology; it is present in 1-2% of the population over 60 years of age. The disease is characterized by a triad of disordered voluntary motor activity in the form of bradykinesia (slowness of movement) or even akinesia (absence of movement),rigidity and postural instability, and a resting tremor of the hands and less commonly the feet.