Early onset Parkinson's disease in Saskatchewan--environmental considerations for etiology.

The cause of idiopathic Parkinson's Disease (PD) is not known but it is believed to be related to some environmental agent(s). Given a long preclinical interval and onset of symptomatology around age 60 years, it becomes impossible to identify and analyze all prior environmental factors satisfactorily. To circumvent these difficulties we evaluated the childhood environment in those PD patients whose symptoms began at age 40 years or earlier. Twenty-one such cases were born and raised in the province of Saskatchewan. Nineteen of these 21 patients spent the first 15 years of life exclusively in rural Saskatchewan. Detailed population analysis indicates a strong predisposition to early onset idiopathic Parkinson's Disease (EPD) in those raised in rural areas (p = 0.0154). All but one case utilized exclusively well water for the first 15 years of life--a trait significantly different from that expected in the provincial population. It is concluded that rural Saskatchewan environments contribute to EPD and that well water used in childhood should be considered as a potential vehicle for the etiological agent.