If the goal is early diagnosis and the separate detections aren't getting confounded, why does it matter what parallel chain of causation leads to Parkinson in the patient and a correlating reading in the nose or other test?
If no one in a normal state has the same mix of fear, anger and confusion and this leads to a microbial change around sweat glands, then that is a valid test of greater accuracy than many existing medical tests.
If no one in a normal state has the same mix of fear, anger and confusion and this leads to a microbial change around sweat glands, then that is a valid test of greater accuracy than many existing medical tests.