New tools may help diagnose Parkinson’s earlier than ever

Neurologist David Standaert can often tell if someone has Parkinson’s disease in a matter of minutes. Maybe their hand trembles and one of their arms doesn’t swing as much as the other when they walk. Maybe their voice sounds softer than usual, and they have a stillness to their body and a masklike look on their face, with little expressivity or blinking. “I always tell patients, ‘It’s not any one thing that tells me you have Parkinson’s. It’s all of these things together,’ ” he says. 

But Standaert’s is a rare skill. A movement disorder specialist at the University of Alabama at Birmingham, he has been diagnosing people with the disease for decades. He’s one of fewer than 1,000 doctors in the United States trained to spot and treat the sometimes-subtle signs of Parkinson’s. That’s a problem because more than 1 million people in the country have the disease, and the number is climbing as the population ages. “There are nowhere near enough movement disorder specialists to go diagnosing all these people,” Standaert says.

But Parkinson’s disease varies tremendously, Standaert says. Which symptoms arise, how severe they are and how quickly they progress differ from person to person. “I have seen tens of thousands of patients with Parkinson’s disease, and no two are the same,” he says.

This variability can make the disease tricky to spot. There’s no simple screening test that offers a yes/no answer. But a confluence of factors now seems to be driving a deluge of diagnostic ideas. There’s growing optimism about finding treatments to slow the disease, for one, Standaert says. While existing treatments can address people’s symptoms, the possibility of delaying disease progression has ignited interest in early diagnosis. At the same time, technological advances are letting scientists capture signs of disease that were once undetectable. Preliminary concepts in the works aim to tap into signals that span the body, from our breath and bodily fluids to motions and more.

Although many of these approaches are still in their infancy, their development alongside treatments that seek to address the root causes of Parkinson’s could one day be a major boon for people with the disease. Dozens of new drugs that attempt to stop Parkinson’s in its tracks are now in clinical trials.

These therapeutics “are totally different than what we’re currently using in the clinic,” says Stanford movement disorder specialist Kathleen Poston. “We’re testing things in people that have never been tried before.”

Monitoring movements

For Robert Goings, an early sign of Parkinson’s disease came from his handwriting. A former draftsman and civil engineering technician, his lines were straight and his lettering was precise. But around age 60, Goings noticed that his writing looked a bit off, he says.

The first inkling for Gary Gilson, a former surgical assistant, also had to do with his work. “I was in the operating room, and I was trying to shake a doctor’s hand,” he says. “My hand was shaking.”

Linda Grant has a similar story. In her mid-60s, she noticed a tremble in her left hand. “I knew something was wrong and I had to get in to a doctor,” she says.

Along with family history and other risk factors for the disease, Standaert and other specialists look for ways that the disease might be affecting movement. This includes symptoms like tremors and performance on physical tests, such as tapping the fingers together or screwing in an imaginary light bulb. On the light bulb test, people with Parkinson’s usually make one good screwing motion before their hand movements start to shrink, Standaert says.

Standaert will at times use an imaging test called a DaTscan to look at the dopamine system in the brain. Healthy brains “light up” on the scan, indicating an abundance of dopamine-producing nerve cells. In Parkinson’s, these cells tend to die, so a dimmer signal can indicate disease. But the test costs about $3,000 and requires multiple hours to perform. What’s more, drops in dopamine can also occur in other neurodegenerative diseases. Because of those limitations, Standaert uses the scan only when there’s a question about diagnosis.

Given that most diagnoses today rely heavily on symptoms related to movement, it’s no surprise that ideas for new and simple diagnostics also focus on movement — aiming to pick up subtle changes before they become obvious. Bioengineer Jun Chen’s idea for an at-home Parkinson’s test began brewing in his mind as he watched his grandfather develop the disease. Chen remembers his grandfather’s hands shaking and frequent trips to the hospital to evaluate the disease’s progression. Years later, that experience bubbled up into a project at the University of California, Los Angeles, that harnesses a phenomenon called magnetoelasticity in soft matter.

In February, Chen’s team reported the creation of a squishy ball that can sense minute hand tremors. When a person holds or squeezes the ball, its soft, magnetic layer deforms in a way that produces measurable electrical signals. It’s sensitive to the slightest of pressures, less than one kilopascal, like the touch of a very gentle fingertip, Chen’s team reported in Cell Biomaterials. That could make the ball useful in detecting early-stage tremors, he says.

A similar idea is at play in two of Chen’s other proof-of-concept devices. One is a pen that can detect tremors while a person is writing. The other is an intelligent keyboard that logs pressure-based signals when a person types. “You just type every day and record your typing patterns,” he says. The keyboard could alert users when there’s a change, potentially catching signs of Parkinson’s disease early, his team reported in 2025 in Science Advances.

The researchers tested both devices in a few Parkinson’s patients, but they will need to validate the findings in larger groups of people. Chen says that could take five years. If the results hold up, these or similar devices could one day make Parkinson’s easier to spot — for specialists and nonspecialists alike.

With the shortage of specialists, the field needs a way for nonspecialists to identify the disease, Poston says. She’s had patients who’ve bounced from doctor to doctor, waiting years before finally getting a diagnosis. Having a primary care doctor that can diagnose cases with the help of tools like these or even flag cases earlier could speed up the process, getting patients’ symptoms treated sooner and saving them the emotional turmoil of not knowing.

Movement data collected by existing wearables like smartwatches could also help by picking up signs of Parkinson’s in people who wouldn’t otherwise be evaluated, Standaert says. In one study reported in 2023 in Nature Medicine, data collected from thousands of people wearing movement-tracking devices showed that, in the years before a Parkinson’s diagnosis, people tend to be less physically active than those who don’t develop the disease.

Other ideas include analyzing people’s voices or even monitoring gait via radio signals pinging off the body. These tools are a type of passive monitoring. It’s an approach that means people don’t have to perform a specific task or undergo any test, which makes for an effective public health tool, Poston says. Imagine if your smartwatch said, “Hey your gait has changed. Maybe you should see your doctor,” she says.

Chemical clues

In an ideal world, doctors would be able to diagnose Parkinson’s disease and intervene at an early stage — when changes begin happening in the brain but before even the most subtle symptoms appear. The gap between the two could be five to 10 years, or maybe even longer. “It’s a pretty big time window,” Poston says.

One existing test can flag cases before symptoms appear by looking for clumps of alpha-synuclein, a protein that misfolds and accumulates in the brains of people with Parkinson’s and is thought to play a role in the disease. “It’s the closest we have to a definitive diagnosis,” says Poston, who helped validate the test, called a seed amplification assay. But it’s generally not covered by insurance, and it requires a sample of cerebrospinal fluid, the liquid cushioning the brain and spinal cord. That means patients must undergo a spinal tap, which is invasive and can be uncomfortable or even painful. 

A truly transformative screening test would need to be simple and inexpensive. Perhaps it could even be incorporated into regular healthcare appointments, such as an annual exam or a dental cleaning, Poston and colleagues suggested in 2025 in the Journal of Parkinson’s Disease.

Some researchers think chemical cues have potential. Detecting fatty molecules exhaled while breathing, for example, could be one approach. Chemical analysis of the breath of people with and without Parkinson’s predicted which people had the disease, researchers reported in January in npj Parkinson’s Disease. The team also spotted Parkinson’s-linked molecules in the breath of people who appeared healthy but carried gene variants known to increase a person’s risk of the disease. Whether the molecules can forecast who will go on to develop the disease, however, is not yet clear. 

Potential early warning signs could also come from people’s mix of gut microbes, or molecular markers present in their tears, earwax or stool, research suggests. These are just a smattering of the proof-of-concept diagnostics under investigation, Poston says. The field “has really exploded.”

For her part, Poston is working with a National Institutes of Health consortium on a study that piggybacks on routine colonoscopies to look for abnormal alpha-synuclein protein in colon tissue. The clumping protein has been detected in the skin and gut of people with Parkinson’s. But as with many potential markers, it’s not yet clear at what point in disease progression clumps might appear.

In fact, whether the disease begins in the brain or elsewhere in the body is still one of many open questions, Poston says. Another is that scientists still don’t fully understand the myriad elements that contribute to Parkinson’s. Age and genetics factor in, and exposure to environmental toxicants like pesticides and herbicides can have a part, recent work suggests. That uncertainty adds to the challenge of identifying Parkinson’s biomarkers, Standaert says.

If abnormal alpha-synuclein is consistently present in the colon of Parkinson’s patients, it would be an appealing biomarker because doctors might be able to integrate screening into an already established system. Poston plans to start recruiting participants this month; she’s expecting to see results in the next two years.

Halting disease progression

As drugs to hold off the disease’s progression advance, the demand for early testing will take on new urgency, Standaert says. Any speedup of the diagnosis journey will offer new opportunities to test therapeutics in people who are still at an early stage of the disease.

Diagnostics and therapeutics need to be developed in parallel, says Poston, who calls drugs that could stop progression “our biggest immediate need and my biggest hope.”

Dozens of such drugs are in clinical trials, and a handful have advanced far enough that researchers may soon be able to gauge how well they work. One binds to alpha-synuclein clumps directly, attempting to slow their buildup and spread. Another seeks to surgically replace the nerve cells lost in Parkinson’s, using cells derived from human embryonic stem cells. Yet another strategy ramps up cells’ recycling machinery, so it can clear out alpha-synuclein and other protein garbage clogging the brain.

“There’s a whole series of different strategies,” Standaert says. “None of them is proven to work yet.” Still, he’s optimistic that, eventually, one of them will.

The knowledge a diagnosis brings can be “a very powerful thing.”

Kathleen Poston
Stanford movement disorder specialist

Patients have varied feelings about earlier diagnosis. Goings says that getting an earlier diagnosis would make sense if there are treatment options that slow the disease. But for others, Eskandar points out, just knowing what’s in store can be helpful. People can plan for what’s next in their family life and career, try to prepare themselves mentally and physically, or start looking for specialists.

Gilson says an early diagnosis might have spurred some changes in his habits. He might have started eating better or trying to get more sleep, he says.

Standaert champions exercise, especially in people with sleep disorders that often precede other Parkinson’s symptoms. “That has been shown time and time again to improve the outcome of Parkinson’s,” he says.

Grant also says she’d have been eager to find out, so she could have tapped into existing therapies sooner. “It would have been a blessing,” she says.

Identifying the cause of their symptoms can help people feel more in control of what’s happening, Poston says. The knowledge a diagnosis brings, she says, can be “a very powerful thing.”