Parkinson’s disease is a serious condition that affects more than 1.1 million people in the United States.
It slowly damages brain cells that control movement.
By the time someone begins to show common symptoms like shaking hands or stiff muscles, nearly half of those brain cells are already gone. That’s why early detection is so important.
Now, scientists have used brain scans to discover how Parkinson’s disease changes the way certain brain systems work together.
Their study, published in the journal Movement Disorders, used a type of brain imaging called PET scans.
PET stands for positron emission tomography, and it helps researchers see how different parts of the brain are functioning.
In this study, researchers looked at two important markers inside the brain. The first is called dopamine transporter, a protein that helps move dopamine—a key brain chemical involved in movement and mood.
The second is synaptic density, which shows how many connections exist between brain cells. These connections help brain cells talk to each other and are important for thinking, moving, and memory.
In healthy people, these two markers usually go up and down together. When the brain has more dopamine transporters, it usually also has more synaptic connections, especially in a brain area called the striatum. This region is one of the first places affected by Parkinson’s disease.
But in people with Parkinson’s, this healthy pattern falls apart. The researchers found that the normal relationship between dopamine and synaptic density was disrupted. This suggests that Parkinson’s disease changes how brain cells work together—not just how many of them are lost.
Dr. Tommaso Volpi, one of the study’s authors, said that this breakdown shows how Parkinson’s disease harms the brain in complex ways. “It’s not just about losing brain cells—it’s about how the remaining cells stop working together properly,” he explained.
Detecting Parkinson’s disease early is difficult. Many early symptoms, such as muscle stiffness or slow movements, can also happen in other diseases.
According to co-author Dr. Faranak Ebrahimian Sadabad, current brain scans that focus only on dopamine may not always catch the earliest signs. That’s why the researchers decided to look at how different markers in the brain relate to each other, rather than using only one measurement.
The study involved 30 people with Parkinson’s disease and 13 healthy volunteers. Each person had two different PET scans. One scan measured dopamine transporter levels, while the other measured synaptic density. The researchers then compared the results.
In healthy people, the two brain markers had a strong connection. But in people with Parkinson’s, that link was weaker.
The scientists also found that as the disease progressed, dopamine loss was much greater than the loss of synaptic connections. This suggests that the disease damages the dopamine system more severely and earlier than it does other parts of the brain.
Dr. David Matuskey, the senior author of the study, said that this finding is a big step forward. By looking at multiple brain changes at once, doctors and researchers can get a clearer picture of how Parkinson’s disease develops and changes over time.
Understanding how different types of brain damage happen—and when—could lead to better ways to diagnose the disease early.
It could also help scientists discover which biological processes are driving the disease. If they can figure out why dopamine cells die and why brain connections break down, they might be able to stop or slow down the disease.
In summary, this study shows that combining different types of brain scans gives a better view of what’s happening in Parkinson’s disease. It fills an important gap in what we know about how the disease progresses. And one day, it could help doctors treat Parkinson’s before the symptoms become too serious.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more information about brain health, please see recent studies that blueberry supplements may prevent cognitive decline, and results showing Plant-based diets could protect cognitive health from air pollution.
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