Parkinson's disease (PD) is a progressive neurodegenerative disease characterized typically by motor features of tremor, rigidity and bradykinesia due to depletion of dopaminergic nigrostriatal neurons. PD is increasingly recognized as a non-motor disorder since symptoms such as dementia, depression and falls emerge with disease progression to become dominant in the clinical picture. PD results in a significant decline in quality of life for both patients and family and contributes to significant economic and institutional costs on family and society. PD is uncommon before the age of 40 but affects approximately 1% of patients over the age of 60, with a rising incidence and prevalence thereafter to around 2% in the population over 80 years of age.