What role do toxins or illicit drugs play in causing Parkinson's?

What role do toxins or illicit drugs play in causing Parkinson's?

Neal Hermanowicz (Director of the Movement Disorders Program) gives expert video advice on: What causes Parkinson's?; What role does race play in Parkinson's?; What is a 'parkinsonian personality'? and more...

We're not sure yet of the role of toxins in Parkinson's disease. There was a clue in the '80s that environmental toxins may be contributing to some people getting Parkinson's disease. This clue was arrived at in kind of a peculiar way, in that some people who were abusing drugs, mostly in the San Francisco area, unintentionally injected themselves with a toxin called "MPTP". In a small percentage of these people who were exposed to "MPTP", they very abruptly, suddenly became severely Parkinsonian, or stiff and slow, to the point of immobility. But this concept--the idea that there was a toxin that very specifically injured this part of the brain, the "substantia niagra", revived this idea-- put a lot of emphasis on this idea that there may be other things in the environment that some of us are unusually sensitive to, that could be injuring the brain in a very specific way, leading to Parkinson's disease. There may be pesticides, or herbicides that we're putting into the environment that some people--not all, but some people are having brain injury, or changes as a consequence of exposure to these things. This is an active area of research currently--not yet settled, we don't yet know if such things exist, but it is being investigated agressively now.