CLEARER DISEASE DIAGNOSIS
THE MICHAEL J. FOX FOUNDATION 2025 YEAR IN REVIEW
What Is Parkinson’ s, Really? Research Zeroes in on Better Defining the Disease
From person to person, Parkinson’ s symptoms Q & A vary. For decades, this truth has suggested that
Parkinson’ s is more than one uniform disease: Rather, it’ s a spectrum of subtypes presenting differently based on an individual person’ s unique biology.
At The Michael J. Fox Foundation, we’ re working to increase understanding of these subtypes— work that will eventually provide patients and their doctors clarity about the course the disease may take and open the door to precision medicine treatments tailored to each individual’ s unique experience with PD.
Brian Fiske, PhD, chief scientist at the Foundation, explains.
As we look at Parkinson’ s as a spectrum of diseases, how is this impacting diagnosis and treatment?
Historically, we have long known that Parkinson’ s disease is a spectrum— a disease that can look different from person to person. In some people, Parkinson’ s progresses more slowly, while others experience quicker progression. Some people tend to develop more tremors( involuntary shaking while at rest) while others develop more walking and balance symptoms; thinking problems affect some people with the disease, but not others.
We also knew that a key issue in the brains of people with PD is the loss of certain cell types— including dopamine-producing cells, which coordinate movement, motivation and more— and the presence of clumped alpha-synuclein( a protein found
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