The whole puzzle hasn't come together. There is no cure, and drug and surgical therapies tend to lose effectiveness over time. In about 10 percent of patients, Parkinson's strikes before age 50. However, most patients show their first Parkinson's symptoms after age 60. Researchers believe older patients may have suffered brain damage from chronic exposure to unspecified toxins.
Rotenone is an organic product made from extracts of tropical plants.
Whether the pesticide would have the same effect in people via normal routes of exposure is not clear.