Slowing the ‘Parkinson’s pandemic’
Roughly 12 million people worldwide are living with Parkinson’s disease — nearly double the number from just six years ago — and researchers at UCLA Health are working to understand why the neurological disease is increasing so quickly.
“We believe that both environmental and genetic factors are behind the Parkinson’s pandemic,” said Jeff Bronstein, MD, PhD, director of the UCLA Howard and Irene Levine Family Center for Movement Disorders. “Several studies have tied environmental exposures to the disease, but the mechanisms underlying these risks still remain unclear.”
UCLA Health is tackling the problem from multiple angles. To investigate possible links between Parkinson’s and air pollutants and certain pesticides, Dr. Bronstein is leading a three-year project being conducted with researchers at Cedars-Sinai and the University of Münster in Germany. The effort was recently awarded $9 million by Aligning Science Across Parkinson’s and The Michael J. Fox Foundation for Parkinson’s Research.
While Dr. Bronstein’s team investigates what’s behind the rise in new cases, Katy Cross, MD, PhD, assistant professor of neurology at the David Geffen School of Medicine at UCLA, is focused on developing better ways to help patients who are already living with Parkinson’s today. Together, their work spans the full arc of the fight against the disease — from preventing it to treating it.
A pesticide under suspicion
Dr. Bronstein’s team has zeroed in on chlorpyrifos, a widely used agricultural pesticide already known to harm developing brains. Its connection to Parkinson’s, however, had never been closely studied.
Drawing on years of data from UCLA’s Parkinson’s Environment and Genes study, which tracks residents of California’s Central Valley agricultural region, researchers compared pesticide exposure records against those residents who were later diagnosed with Parkinson’s.
The results, published in Molecular Neurodegeneration, were striking: Residents with the longest-term exposure to chlorpyrifos were more than 2½ times as likely to develop Parkinson’s disease.
“Our findings strongly support a causal association between chlorpyrifos exposure and the development of Parkinson’s disease,” Dr. Bronstein said. “We established chlorpyrifos as a risk factor for Parkinson’s disease, but also uncovered new targets for future therapies.”
That second part matters enormously. In studying how the pesticide damages brain cells, Dr. Bronstein’s team found a breakdown in the cells’ own cleanup system — the process that normally clears out damaged material before it builds up and causes harm. A drug that restores this process could protect the brain, whether the damage comes from pesticide exposure or Parkinson’s itself.
Dr. Bronstein’s team is now studying whether other common pesticides cause similar harm, and whether restoring that cleanup process could lower risk in people already exposed.
Helping patients living with Parkinson’s today
While Dr. Bronstein searches for what’s driving Parkinson’s cases, Dr. Cross is focused on helping patients facing the disease right now, specifically by diagnosing it earlier and addressing one of its most frightening symptoms: freezing of gait.
To address freezing of gait, in which a patient’s body suddenly and without warning stops responding in midstep, Dr. Cross’s team is studying deep brain stimulation (DBS). This treatment uses implanted electrodes to change how the brain’s circuits fire. DBS improves walking, mood, mobility, and bladder control in many patients, though no one fully understands why it works as well as it does.
By recording brain activity during freezing episodes, the team is starting to pinpoint the specific signals associated with these moments. This work could eventually lead to devices that detect a freezing episode before it happens — or even prevent it.
“When we implant electrodes in the human brain, we can learn a lot about the disease,” Dr. Cross said. “Our goal is to treat patients using electrophysiological signals, with a focus on improving their ability to walk, restoring balance, and unfreezing of movement.”
Dr. Cross is also looking into how to detect Parkinson’s earlier. Her lab is developing a rapid test for alpha-synuclein, a protein closely tied to Parkinson’s. Catching elevated levels early could allow doctors to diagnose the disease sooner and start treatment before more damage occurs.
“Alpha-synuclein biomarker tests could be a major game changer for Parkinson’s disease detection and treatment,” Dr. Cross said. “We are really excited about its future potential, and more research is currently being carried out.”
Two fronts, one fight
Dr. Bronstein and Dr. Cross represent two ends of the same mission: stopping Parkinson’s before it starts, and improving life for the millions already facing it.
“Our goal is to make sure patients are aware of effective therapies and to keep expanding those options,” Dr. Cross said. “We are constantly innovating with new preventive and treatment options that help patients avoid symptoms and improve their quality of life.”
For a disease spreading this quickly, neither front can move fast enough.
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