Parkinson’s Disease, paraquat, and your health

by Steve Wagner

Xuemei Huang is a firm believer in documentation, and often makes her case with graphics that can be vivid in their depictions. Huang is with Penn State University’s Hershey Medical Center, serving as co-director of the Center for Movement Disorders. She is also a Professor of Pharmacology, Neurosurgery, Radiology and Kinesiology. “All of us know that injury or insult to the brain can cause long-term consequences,” said Huang.

Citing football players whose collective concussions and their consequences have been given wide press coverage during the past few years, Huang also footnotes that such a condition used to be called Boxer’s Brain. Prize fighter Muhammad Ali was the unofficial poster boy for what has been re-dubbed Boxer’s Dementia.

Speaking before a group at the 2017 PA Farm Bureau’s annual meeting, Huang showed two photos of a ‘normal’ brain, and compared it to the concussed brain of 66-year-old Greg Ploetz who used to play football for the University of Texas. Huang described the normal brain as nice and tight with the look of healthy brain matter. “You see the brain shrinking,” she said, referencing a slide, “in the football player’s brain.” Clearly, there was ventricular enlargement as well as signs of atrophy.

Parkinson’s Disease was discovered 200 years ago (1817). James Parkinson described it as a “shaking palsy.” Currently, it affects between 500,000 and one million people in the U.S. and the number is expected to triple or quadruple over the next few decades. Early clinical symptoms for PD are wide-ranging:

  • lack of expression
  • difficulty getting out of the car or chair
  • hunching over
  • small steps
  • aches and pains
  • depression
  • sleep disorders
  • loss of smell
  • and constipation

However, they are not limited to that. The roster could also include double vision, fatigue, sleep apnea, problems with urinating, skin changes, hallucinations & delusions, and sexual dysfunctions. Sometimes, Parkinson’s can be diagnosed earlier than it usually is. Usual means that PD has often gained a foothold in a patient before it is officially diagnosed.

In a 2017 Research Synopsis, Huang wrote that in “2009 we reported that there was marked asymmetry in the arm swing of Parkinson’s patients, even those who are newly diagnosed. Since then we have been delving into the underlying physiological mechanisms, specifically focusing on something called motor synergies. You can think of this as how we use our hands, fingers, and/or body most efficiently. This has led to recent breakthroughs in understanding overall motor changes and new methods to measure these deficits. We believe that motor synergy measurements have the potential to detect pre-clinical Parkinson’s disease and predict the occurrence of clinical symptoms.”

Huang says she was challenged here. She was looking for someone, a PD victim, who happened to be videoed before Parkinson’s had taken its toll in that individual. Arm swing changes, in other words. That person, on film rather than video, turned out to be actor Michael J. Fox, which we will look at in more depth, momentarily.

At the beginning of the 1980s, research indicated that perhaps there was an element of the environment that might be culpable in the onset of Parkinson’s. One of the reasons for Huang’s remarks before her Farm Bureau audience was a broad-spectrum herbicide called Paraquat. Online research shows that in 2011, a U.S. National Institutes of Health study showed a link between paraquat use and Parkinson’s disease in farm workers. A co-author of the paper said that paraquat increases production of certain oxygen derivatives that may harm cellular structures, and that people who used paraquat, or other pesticides with a similar mechanism of action, were more likely to develop the disease. An agricultural map showed that paraquat was widely disseminated on the east coast, including Hershey, and in the Midwest. Paraquat has been used to induce Parkinson’s-like pathology in animals, yet animal research has been challenged as being irrelevant to humans. Chronic low-level paraquat exposure leads to changes in the brain similar to those seen in PD. The slightest deviation was bound to show up. Welding-related metal fumes have also been found in some brain disorders similar to PD.

Combing through Fox’s films beginning with his stint as a childhood actor, Huang and her team studied his movements from early on. Though Fox was diagnosed much later than his childhood years, Huang felt it offered a sound hypothesis. Particular attention was paid to Fox’s arm swing. “After he made Back to the Future, parts one, two and three,” Huang said, “he seemed to get tired more and more. But he was diagnosed after he made Doc Hollywood. After the movie’s premiere, Fox had settled down to relax, and wondered why butterflies were fluttering nearby and causing some annoyance. There were no butterflies. Six months later he was officially diagnosed at the age of 29.”

Huang had studied the actor’s movies from 10 years before diagnosis, and showed her audience evidentiary clips illustrating her points. “He had tremors on his left side first,” she said. “Two years later, and eight years before diagnosis, there was a change in the arm swing.” It was barely noticeable. “The right arm swings freely,” she says. “In Back to the Future, he is 22 or 23 years old. He moves like an old man, an 80 year old man.”

She asked the audience to also study the other actors in those video clips to serve as a contrast. There was a cart in one scene that runs into Fox. “See the right arm swing? The left arm didn’t do anything. It just dragged.” Huang said such studies give rise to hope that there is opportunity to detect Parkinson’s a little earlier.

The Michael J. Fox Foundation for Parkinson’s Research this past July urged the Environmental Protection Agency not to re-register paraquat, saying, “On behalf of the Unified Parkinson’s Advocacy Council, we write to express our concern with paraquat dichloride, which is shown to increase risk of Parkinson’s disease (PD). We ask the Environmental Protection Agency (EPA) to deny the re-registration of this herbicide based on strong evidence of paraquat’s harm to human health. …The EPA recently introduced policies to protect people who work with paraquat from exposure to the herbicide, including restricting its use to certified individuals and requiring them to participate in additional training. While we support these mitigations, several epidemiologic studies have associated Parkinson’s disease with rural living, well water exposure and farming. Studies also indicate that exposure to paraquat, either directly or through air or clothing-borne herbicide drift, markedly increases risk of developing Parkinson’s. Restricting the use of the chemical to those with a license is therefore insufficient to protect all people.”

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