Parkinson's disease may soon have a smell test

Starre Vartan - December 29, 2017

Scottish woman's keen nose unlocks possible route to early detection.

Researchers put Joy Milne, here with her late husband Les, through several tests to see if her sense of smell could actually help in the detection of Parkinson's. (Parkinson's UK in Scotland/Facebook)

If you thought your sense of smell was pretty good, meet Joy Milne of Perth, Scotland. Her nose really does know.

After her husband Les was diagnosed with Parkinson's disease, Joy noticed others at a charity event for Parkinson's had his same smell. She mentioned it to researchers, who wanted to find out whether she really could sniff out the disorder. Les died in 2015, but scientists have continued to delve into Joy's unique ability. That research may now lead to the first diagnostic test for the disease.

The scientific trail

Scientists at Manchester University tested Joy's sense of smell by asking her to sniff skin swabs taken from people who were already diagnosed with Parkinson's, as well as control subjects (so she also smelled swabs from people who didn't have the disease, though scientists didn't tell her which swabs were which).

Milne was able to correctly identify the swabs that came from people with Parkinson's. She did the test at Edinburgh University, too, with t-shirts and was again able not only to discern people with the disease, but correctly identify everyone in the test that didn't have the disease. The super-sniffer was even able to identify Parkinson's in someone who didn't have any symptoms and hadn't been diagnosed yet, but later was.

Milne's unique capacity tipped researchers off that there were 10 "signature molecules" that may allow scientists to diagnose the disease before symptoms started.

"For all the serendipity, it was Joy and Les who were absolutely convinced that what she could smell would be something that could be used in a clinical context," Manchester University's Perdita Barran, told the Telegraph, "and so now we are beginning to do that."

What a diagnostic test could mean

No test exists for Parkinson's, and it's not until more than half of certain types of the brain's nerve cells have been destroyed by Parkinson's that symptoms show. So if smellable molecules related to Parkinson's exist, scientists may be able to isolate one or more via mass spectrometry, or perhaps dogs could be trained to smell for them, before symptoms begin.

Whatever diagnostic tests might be developed from what started with one woman's great nose could be a boon for people who will get Parkinson's. Earlier interventions could be helpful in improving quality of life for the 60,000 Americans that are diagnosed with the disease every year. Even more impactful could be identifying the disease in the thousands of cases in the United States that don't get diagnosed before people are suffering acutely — and that number stretches into the millions worldwide.

https://www.mnn.com/health/fitness-well-being/blogs/parkinsons-disease-smell-test