New Parkinson’s disease test can help refine treatments and support more efficient research

[5 min read]

In this article:

  • A new, relatively painless skin biopsy test is a major advance in the diagnosis of Parkinson's disease. 
  • Swedish participated in the clinical trials of this promising new test. 
  • A Swedish neurology expert explains how the screening works and how it can benefit patients, caregivers, clinicians and researchers. 

According to the American Parkinson Disease Association, it’s estimated that some 90,000 people are diagnosed with Parkinson’s disease every year. To diagnose Parkinson’s disease, doctors perform a battery of tests and work with patients to identify symptoms. Sometimes, because of significant similarity with other neurodegenerative and physical conditions, the diagnosis can be challenging and may be delayed.

Recently, Swedish participated in the clinical trial of a promising new skin test that may help diagnose Parkinson’s more quickly and with greater accuracy, allowing for faster treatment and more targeted research of Parkinson’s and its symptoms. To learn more, we spoke with neurologist Pravin Khemani, M.D., medical director of the movement disorders clinic at the Swedish Neuroscience Institute.

What is Parkinson’s disease?

Parkinson's disease is a neurodegenerative disorder which causes progressive problems with mobility as well as other vital bodily functions. Early signs of the disease can include tremor, trouble moving or walking, vocal issues, or balance issues. The progression of Parkinson’s is thought to be due to a protein called alpha synuclein. It somehow gets twisted and its shape changes, which makes it accumulate in the bin the nervous system and ultimately result in cell death and disease progression.  The same protein is also associated with Lewy body dementia, multiple system atrophy, pure autonomic failure, and REM sleep behavior disorder. Now interestingly, this protein was discovered in other parts of the body including the small nerves that supply the skin which makes it accessible for testing.

How is Parkinson’s diagnosed?

Before this test was available, the only way to be certain about a diagnosis of Parkinson’s disease or dementia was to look at a piece of the brain after a patient died. Since we obviously can’t do that when we are evaluating the patient, we diagnosed Parkinson's disease primarily through a clinical examination. We often had cases that were confusing or seemed like two or three things were going on at the same time. Parkinson’s symptoms are not clear cut. We have used another test called the dopamine transporter scan, however, that test is not very specific for Parkinson's disease either and does not allow us to diagnose Parkinson's with high degree of certainty.

This new skin test is a major scientific advancement because it increases the probability of accurate diagnosis. As with any test in medicine, it is also important to remember that it's not a stand-alone test and needs to be interpreted in a clinical context. You can’t just administer it and say, “Oh, you do or don’t have Parkinson’s.” Because there are so many diseases that look like Parkinson’s, confidence in diagnosis is very important. In this case, when clinical signs are highly suggestive of Parkinson’s, this test significantly increases diagnostic certainty. Additionally, symptoms of Parkinson’s can also be caused by certain drugs, strokes, psychological conditions and other diseases; this test can be effectively used to confirm or refute the diagnosis in these cases.

How does this new test work?

At our clinic it’s a very simple skin punch biopsy that’s relatively painless. The skin is numbed with lidocaine, and we take three samples: one from the leg, one from the thigh and one from the back of the neck. It can be done at the bedside in the clinic. The results are interpreted by experienced pathologists who look for the alpha synuclein protein in the nerves we biopsy.

What does this mean for patients and caregivers?

Up until now, patients and caregivers were told, “You have Parkinson's disease, but we need to follow your clinical course for a few years to be certain.” This increase in diagnostic certainty helps a lot. You know, it puts their mind at ease, and they also know that one test is not everything. That clinical exam is important, but this is one big leap ahead in terms of the confirmation of the diagnosis, and that is helpful because it provides [a more conclusive] answer to the question, “Do I have Parkinson's disease?”

It's also another important tool in the toolbox of the provider. It helps the physician themselves. It helps them devise a multidisciplinary treatment more quickly. The patient is given all the resources to educate themselves about Parkinsons and improve their quality of life early in the disease course.  There's less intuition and there's more confidence as you move forward with the treatment right away.

And lastly, this test is now being used as a screen for enrollment of subjects and research trials.
And that becomes really important because when you're studying a treatment for Parkinson's disease, you only want people with Parkinson's disease in that particular research study. This test allows you to diagnose the people with a high degree of accuracy and reduces the error rate of recruiting people with Parkinson's disease, so study results are accurate and more interpretable. There is less confusion in studies, which ultimately helps us move research forward faster so we can have a better understanding of the disease and how to treat it.

Learn more and find a practitioner

To learn more or make an appointment with one of our specialists at Swedish's Movement Disorders Clinic call 206-320-5331. Our experts at the Swedish Neuroscience Institute offer comprehensive, progressive diagnosis and treatment for a wide range of spine, brain and central nervous system conditions. Telehealth options are available. Visit us on the web or call 206-320-3940. You can also use our provider directory to find the doctor that’s right for you. 

Swedish Virtual Care connects you face-to-face with a nurse practitioner who can review your symptoms, provide instruction, and follow up as needed. If you need to find a provider, you can use our provider directory.

Additional resources

Parkinson's Foundation designates Swedish's Movement Disorders Program as a Comprehensive Care Center

Living well with Parkinson’s disease

Swedish is a destination for innovative, world-class care

Three sisters find hope at the Swedish Neuroscience Institute

This information is not intended as a substitute for professional medical care. Always follow your health care professional’s instructions.

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About the Author

From deep brain stimulation to focused ultrasound to pediatric neurology, The Swedish Neuroscience Team is recognized as national experts to help people address a wide array of neurological conditions. Our goal is to provide useful and helpful advice and tips on non-surgical and surgical options to treat any disease of the mind.

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