A Parkinson's Life
Front cover

Return to home page

Current articles:
All articles
Articles on Caregiving
Caregiving Tips
Articles on Parkinson's

Articles from 2017
Articles from 2016

If you'd like me to let you know when I post a new article, please click here.

Please share this with others
you think might like it.

Facebook Twitter LinkedIn Email

The Search for a Biomarker

Article on Parkinson's. June 18, 2018

One of the frustrations for medical professionals in dealing with Parkinson's disease is the lack of a biomarker, a medical test result that indicates there may be a problem. For example, high blood sugar on a fasting glucose tolerance test is a biomarker for diabetes. A shadow on an X-ray is a biomarker for a tumor. These test results don't prove you have the disease, just that you might and more tests are needed.

But as I noted in a previous post, there is no biomarker for Parkinson's. This means that diagnosis depends on symptoms, which may indicate other conditions, and judgment, which not all doctors have equally. According to one estimate, up to twenty percent of Parkinson's cases are misdiagnosed.

So the search is on to find a biomarker, one that leads to valid diagnoses and prompter treatments. Here are some recent developments.

There is evidence that Parkinson's patients have a distinct odor, which is too faint for most of us to detect. So some researchers are working with dogs, which have an acute sense of smell, to sniff out the disease. In England, a woman claimed she could smell her husband's Parkinson's. When researchers presented her with a collection of T-shirts, some from Parkinson's patients and others from healthy controls, she only got one wrong. But to the astonishment of the researchers, that exception was diagnosed with PD shortly afterward. Identifying the molecular base of the odor could lead to a simple perspiration test.

Another area of research focuses on the protein alpha-synuclein. In Parkinson's patients, it misfolds and clumps together forming Lewy bodies. This can happen without Parkinson's, when the clumping leads to Lewy Body Dementia. Some research is looking at ways to identify alpha-synuclein levels as an early indicator of PD. To date, promising areas for study include spinal fluid and the retina.

A third area is the connection between the gut and the disease. Researchers suspect that Parkinson's might have its origin in the digestive tract and migrate to the brain along the vagus nerve. While this research is complex because of the variety of bacteria in the gut, researchers are starting to understand the difference between a normal, healthy gut and that of a PD patient. A recent study suggests that viruses attack essential bacteria, reducing their numbers and making the disease more likely.

A fourth area is for those who have already been diagnosed with Parkinson's. The course of the disease varies with different outcomes and, right now, there are no indications of what symptoms will develop or how severe they will be. So research is studying biomarkers not for the disease, but for its progression.

There is still a long way to go, but the goal is to have a simple test that any lab can perform and any doctor can say, "Looks like Parkinson's." And the sooner the diagnosis, the better.