The answer to your question can be deduced by comparing the number of people with Chiari Malformation vs. the number with Parkinsons. There are far too many people with Parkinsons and far to few with Chiari for them to be directly related. Also, Parkinsons is a very heavily researched disease compared to Chiari. It might be possible that if there are environmental toxins responsible for one, that same toxin might also be responsible for the other. The leading candidates for causes of Parkinsons are a combination of genetic susceptibility and toxins in the environment. You know, all those pesticides and artificial **** in our food that everyone says are safe?