IntroductionParkinson's disease (PD) is a progressive neurodegenerative disease characterized mainly by physical and psychological disabilities. This disorder is named after James Parkinson, an English physician who first described it as tremor paralysis in 1817 (Goetz, Factr, & Weiner, 2002). Jean-Martin Charcot, a French neurologist, then progressed and refined the description of the disease and identified other clinical characteristics of PD (Goetz, Factr and Weiner, 2002). PD involves the loss of cells that produce the neurotransmitter dopamine in a part of the brainstem called substansia nigra, resulting in several signs and symptoms (Byrd, Marks, & Starr, 2000). It manifests clinically as tremor, rigidity, bradykinesia, hypokinesia and postural instability. PD is a common disorder that affects at least 1% of people aged 70 and is 1.5 times more common in men than in women (Hauser et al. 2010). Incidence has been estimated between 4.5 and 21 cases per 100,000 population per year, with most studies estimating a prevalence of approximately 120 per 100,000 (Hauser, et al. 2010).CausesPD is known to be idiopathic , however, many studies have found that a combination of genetic and environmental factors is associated with the development of PD. Environmental risk factors include pesticide use, living in a rural area, drinking well water, and proximity to industrial facilities or quarries. Genetic causes have also been studied and it was found that a genetic cause of the development of PD accounts for 5% of all cases (Hauser et al. 2010). Drugs that block dopamine receptors are also considered a cause of the development of Parkinson's disease. Int...... middle of article....... Differential effects of black versus green tea on risk of Parkinson's disease in the Singapore Chinese Health Study. Journal of Epidemiol. (2008) 167 (5): 553-560.15. Michael S. Gazzeniga, Richard B. Gerorge, Mangun R, 2008. Cognitive Neuroscience, 2nd edition.16. Michael J Zigmond, Robert E. Burk, 1998. Pathophysiology of Parkinson's disease. Neuropharmacology: the fifth generation of progress.17. Poewe Werner, Angelo Antonini, Jan CM Zijlmans, et al. 2010. Dovepress Journal Volume 2010: 5 Pages 229.18. Robert A Hauser, Rajesh Pahwa, Kelly E Lyons, Theresa McClain, 2010. Parkinson's disease. Medscape, Neurology.19. Thomas Aird, 2000. Functional anatomy of the basal ganglia. Journal of Neuroscience Nursing.20. U Ehrt, Dag Aarsland, 2005. Psychiatric aspects of Parkinson's disease. Norway Curr Opin Psychiatry;18(3):335-341 Lippincott Williams & Wilkins