No one knows what causes the disease but toxins, including manganese, carbon monoxide and pesticides are suspects.For more information:http://www.mayoclinicproceedings.com/http://www.ninds.nih.gov/disorders/parkinson...About the authorSherry Baker is a widely published writer whose work has appeared in Newsweek, Health, the Atlanta Journal and Constitution, Yoga Journal, Optometry, Atlanta, Arthri