PARKINSON’S DISEASE CAN NOW BE DETECTED THROUGH THE SKIN

New test identifies Parkinson’s by a protein rather than waiting for symptoms that can take years to appear. Betsy McKay for the Wall Street Journal.

Debi Lucas had a tremor in her arm. Her feet froze when she tried to walk and she fell into her coffee table, busting her lip. 

She went to a neurologist who thought she had Parkinson’s disease. Doctors normally diagnose the neurodegenerative condition by symptoms. Lucas, 59, had them. 

But the neurologist, Dr. Jason Crowell, couldn’t be sure. The symptoms might be related to a traumatic brain injury Lucas suffered in a car accident decades earlier, he thought. Or they might be from her medications. 

To find an answer, Crowell turned to a new test: a skin biopsy that can detect an abnormal protein people with Parkinson’s have inside their nerves. He took samples of skin near her ankle, knee and shoulder and sent them to a lab. 

The results confirmed that Lucas has Parkinson’s. The diagnosis was scary, but Lucas finally knew what was causing her symptoms. “I was glad to have name on it,” she said.

The skin test is an important part of progress researchers are making against Parkinson’s, the second-most common age-related neurodegenerative condition, which is on the rise and a major driver of disability, dementia and death. The test Lucas received, made by CND Life Sciences, a medical technology company in Scottsdale, Ariz., is one of a few in use or development to allow doctors to diagnose Parkinson’s based on biology rather than symptoms that can take years to appear.

 “The skin test basically is a window into the brain,” said Dr. Joseph Jankovic, professor of neurology at Baylor College of Medicine in Houston,  where the test is  used to diagnose patients and conduct research.

The test accurately detected the abnormal alpha-synuclein protein in 93% of people who had already been diagnosed by their symptoms with Parkinson’s, according to a study  published Wednesday in the JAMA. It detected the protein at high rates in participants with similar disorders, including dementia with Lewy bodies. 

The test can help doctors rule out diseases with similar symptoms that might be treated differently or have different prognoses. Patients with symptoms of Parkinson’s are often misdiagnosed, according to data from autopsies, said Dr. Christopher Gibbons, a neurologist at Beth Israel Deaconess Medical  Center in Boston and the study’s lead author. He is also an adviser to CND Life Sciences. More than 20% of participants in the study had received a wrong diagnosis, he said. Another test finds the protein in spinal fluid. Researchers are also working on tests using blood, nasal swabs and tears. The goal is to detect the protein in people years before they develop symptoms and treat them with drugs that could slow or stop the disease, said Dr. Todd Levine, chief medical officer of CND Life Sciences. Studies on early detection with the skin test are underway, he said. “What we’re hoping for is within the next few years, we’ll have some disease-modifying therapies,” he said.

The skin test costs just under $1,500 but is usually covered mostly or all by insurance, Levine said. The spinal-fluid test is $1,500 if billed to insurance, or $995 for patients who pay on their own.

Not all patients need the test, said Dr. Joy Antonelle de Marcaida, who uses it as medical director of the David & Rhoda Chase Family Movement Disorders Center at Hartford Healthcare. The diagnosis is clear for many from symptoms, she said. But others have subtler symptoms or other possible explanations, and it can take time to diagnose them. “We used to have to tell them, come back in six months, a year and I’ll look again,” she said.

Michael Dale learned six months ago that he is in the early stages of Parkinson’s. The 77-year-old, who lives in Houston, had balance problems and tremors. A neurologist at Baylor suggested he get the skin test. It was like a ballpoint pen pushing into his skin, he said. Now Dale is doing exercises and monitoring his symptoms. “There’s a lot of anxiety about what the future holds,” he said. 

He’s glad to know his diagnosis. “You know what’s going on and you can kind of prepare,” he said.