It's said some people can smell a rat. Well, Joy Milne can smell Parkinson's.
Milne's husband, Les, died last June at age 65 after 20 years with the disease. But about six years before he was diagnosed, Milne said she noticed a subtle shift in the way he smelled.
"His smell changed and it seemed difficult to describe. It wasn't all of a sudden. It was very subtle -- a musky smell," Milne told BBC Scotland. "I got an occasional smell."
She didn't connect the dots until she joined the charity Parkinson's UK and at a meeting picked up the same distinctive scent on people there who had the condition.
Parkinson's is a chronic, degenerative neurological disorder. It strikes one in 100 people over age 60 -- the average age of onset -- but sometimes it occurs earlier in life. There is no objective test or biomarker for Parkinson's disease, so the rate of misdiagnosis can be relatively high, according to the Michael J. Fox Foundation for Parkinson's Research. Estimates of the number of people living with the disease vary, but recent research indicates that at least one million people in the United States, and more than five million worldwide, have Parkinson's disease.
Symptoms can include a slowing down and loss of movement, limb stiffness, tremor, difficulty walking, and trouble with balance and swallowing, among other problems.
Milne, who told Sky News she'd had an acute sense of smell since her teens, mentioned the odor connection to scientists at the talk and their interest was piqued. "I stood up and I said, 'Why are we not using the smell of Parkinson's? I can smell it in this room all around me.'"
Dr. Tilo Kunath, a Parkinson's UK fellow at the School of Biological Sciences at Edinburgh University, told the BBC, "The first time we tested Joy, we recruited six people with Parkinson's and six without."
The researchers had the patients wear a t-shirt for a day then retrieved the t-shirts, bagged them and coded them.
"Her job was to tell us who had Parkinson's and who didn't," said Kunath. "Her accuracy was 11 out of 12. We were quite impressed."
Kunath said she also pegged one of the control group subjects as having Parkinson's -- Milne was "adamant," he said -- even though the scientists and the participant insisted he did not have the disease. Eight months later, that individual was diagnosed with Parkinson's.
People with early Parkinson's may produce a subtle, particular odor linked to the condition and scientists hope to find the molecular signature responsible for the scent and then develop a simple test, which could possibly involve simply wiping a person's forehead with a swab.
The BBC reported that the charity Parkinson's UK is now funding researchers to study about 200 people with and without Parkinson's.
A simple test for Parkinson's could be life changing, Katherine Crawford, the Scotland director of Parkinson's UK, told the BBC news network.
"This study is potentially transformational for the lives of people living with Parkinson's," she said. "Parkinson's is an incredibly difficult disease to diagnose."
Crawford said a simple swab/odor diagnostic test could cut through the more lengthy evaluations people now go through, which involve medical observation and describing symptoms.
It might have been an accidental discovery, but Milne hopes the finding will make a difference to people with Parkinson's and their families.