Dire warnings about the “next pandemic” have been circulating almost from the beginning of our current struggle with COVID-19, as epidemiologists argue that it’s not a matter of if but only of when a new virus emerges to test our public-health (and political) systems. Some research, however, suggests that it’s already arrived — and it’s only tangentially linked to a bug.
And, of course, it’s hitting those of us here in Geezerville the hardest.
Parkinson’s disease (PD) is the world’s fastest-growing neurological syndrome, increasing by 35 percent in the last 10 years in the United States and expected to strike more than 12 million people worldwide by 2040. And, to hear neuroscientist Leah Beauchamp, PhD, and her team of Australian researchers tell it, COVID is likely to accelerate that trend.
Writing in the Journal of Parkinson’s Disease, Beauchamp describes the neurological toll the novel coronavirus exacts on its sufferers and notes similar patterns and outcomes during other major influenza outbreaks, including the 1918 pandemic. In each of these cases, scientists documented instances in which the virus entered the brain and triggered the kind of neuroinflammation thought to play a role in the onset of Parkinson’s.
“A single pathogen is unlikely to be responsible for the entire pathogenesis of PD, but there is some evidence that certain viral infections may increase the susceptibility of PD and parkinsonism,” she writes. Some research suggests that the virus delivers a “first hit” that activates certain cells that make the brain more predisposed to damage from a later second strike.
Beauchamp cites recent research showing neurological damage in COVID-19 patients and notes that, despite the lack of a control group in these studies, certain symptoms — especially an inability to smell — may point to a link between the virus and PD. “One of the commonest causes of impaired olfactory function are the neurodegenerative disorders of Alzheimer’s and Parkinson’s disease,” she notes. “Patients with PD who exhibit decreased olfactory ability appear to have a significant increase in their risk of progression in the disease.”
Much more research will be needed to solidify such a hypothesis, Beauchamp admits, but with Parkinson’s cases already surging, the potential COVID link does little to calm fears of another major public-health issue. “With more than 23 million people infected with COVID-19 worldwide,” she notes, “the potential increase in the number of cases of parkinsonism in the coming years is going to have serious ramifications for the healthcare systems of many countries, and a well-considered proactive response should be implemented.”
Ray Dorsey, MD, a neurologist at the University of Rochester, shares Beauchamp’s concerns about the surging Parkinson’s rates, but he suggests that the proper response is more environmental than epidemiological. “Numerous byproducts of the Industrial Revolution, including specific pesticides, solvents, and heavy metals, have been linked to Parkinson’s disease,” he noted in a 2018 study. “Countries that have undergone the most rapid industrialization have seen the greatest increase in the rates of Parkinson’s disease.”
The primary culprit may be trichloroethylene (TCE), a chemical found in numerous household products and also used in dry cleaning and industrial degreasing operations. A 2011 study in the Annals of Neurology linked TCE exposure in the workplace with a six-fold increase in risk of developing Parkinson’s and sparked a U.S. Department of Labor warning of its dangers. The European Union has banned the use of the chemical, as have lawmakers in Minnesota and New York.
Still, the EPA estimates some 250 million pounds of TCE are deployed annually in the United States and the chemical is present in about 30 percent of the nation’s groundwater. “We are undersampling how many people are exposed to TCE,” University of Alabama toxicologist Briana de Miranda tells The Guardian. “It’s probably a lot more than we guess.”
And Dorsey believes it’s not just TCE that may be driving the growth in Parkinson’s cases. “Numerous studies have linked well water to Parkinson’s disease, and it’s not just TCE in those cases,” he says. “It can be pesticides like paraquat, too.”
Part of the trend, Dorsey admits, may be linked to increased lifespans, as the condition primarily descends upon seniors. He also points to a dramatic drop in smoking in recent decades as a possible link. Smokers, ironically, are 40 percent less likely to develop the disease than non-smokers, though it’s tempting to note that smokers tend to expire earlier. Scientists have thus far fallen short in their search for a cure, though some medications may slow the advance of the disease.
I mentioned some of this over coffee the other day with my old pal Leo, who has been gamely coping with Parkinson’s for a few years. He listened patiently.
“It’s too bad you never took up smoking,” I quipped. “Maybe it’s not too late.”
He rolled his eyes.
“And I read somewhere that there’s a boxing gym in town that specializes in training Parkinson’s patients in the pugilistic arts,” I added. “Intense exercise is supposed to mitigate its effects.”
“I climb 150 steps in my apartment building every day,” he countered. “That’s intense enough for me.”
The conversation soon drifted off toward more pleasant topics, but as we were getting ready to leave, he pointed a shaky digit finger at my left hand, twitching slightly as I reached for my coffee cup. “I’m worried about that tremor, Boss,” he noted.
“You’ve got enough to worry about, Leo,” I said. “It’s probably just the caffeine.”
“I sure hope so,” he sighed.