What an incredible story - let's hope it leads to a reliable way of testing for this horrible disease!
Currently there is no definitive test for the disease...However, that could change because of Joy, whose husband was told he had Parkinson's at age 45. About a decade before her husband was diagnosed, Joy noticed she could detect an unusual smell. [She] only linked the odour to the disease after meeting people with the same distinctive smell at a Parkinson's support group. ...subsequent tests carried out by Edinburgh University confirmed her ability. Joy was given 12 unmarked T-shirts to smell - six worn by Parkinson's patients and six worn by volunteers without the disease. She correctly identified the six worn by Parkinson's patients, but could also smell the odour on a T-shirt worn by someone in the group without Parkinson's. Joy was told three months later that this person had in fact been diagnosed with Parkinson's after the T-shirt tests.