Color-coded counties of the US indicating prevalence of PD cases. Red = highest, dark green = lowest

Niagara, Chautauqua, Cattaraugus, Wyoming, Genesee, Livingston – Red; Erie, Orleans – Orange; Allegany – Yellow

A highly comprehensive study into the geographic and ethnic variations in incidences of Parkinson’s Disease has been completed. It was published in January 2010. Titled in part “Geographic and Ethnic Variation in Parkinson’s disease,” the study, each year, examined nearly 500,000 PD cases gleaned from the roles of US Medicare beneficiaries. Therefore, subjects were 65 years of age or older. The years encompassed were 1995 and 2000-2005.

The results of the study showed that the highest rates of PD cases were found in the Midwest and the Northeast. Somewhat surprisingly, the study showed that rates were, in general, significantly higher in urban counties than in rural ones.

As for the causes of PD, no concrete conclusions were reached, but the geographic concentrations appear to indicate that exposure to agricultural pesticides and herbicides, long suspected culprits, and industrial toxins, such as chemicals and metals, are likely triggers. Both factors would help to explain the high number of cases in Western New York.

The roles of race and gender in PD diagnoses still raise questions, but a few findings did stand out. Whites and Hispanics were found to be far more prone to the disease than Blacks or Asians. Blacks, though, did show a higher disease-related death rate than Whites.

The reasons for these differences remain to be determined, as the clustering of cases could be either cultural or geographic and the genetic equation is still being addressed. Regarding gender, males are still considered higher risks for PD than females.

All of the information for this article, including the map, was taken from “Geographic and Ethnic Variation in Parkinson’s disease: A Population-Based Study of US Medicare Beneficiaries.” The lead author is Dr. Allison Wright Willis. The study was published by Washington University School of Medicine, St. Louis, Missouri. It is copyrighted by S. Karger AG, Basel. The complete article can be found by going to the website listed below.