Is Parkinson's disease acquired? Evidence from a geographic comparison with multiple sclerosis

In the coterminous United States, MS mortality rates demonstrate a north-south gradient, which is confirmed by more sophisticated—and more expensive—prevalence studies. Mortality rates from idiopathic Parkinson9s disease show a similar north-south gradient, and they correlate significantly with the MS mortality and prevalence data. This demonstration that Parkinson9s disease may be place-related provides support for the hypothesis that Parkinson9s disease, like MS, is an acquired, environmental illness.