Woman can identify early-stage Parkinson's by smell

A woman noticed that her husband had a "musty, yeasty" smell despite practicing good hygiene. Ten years later, he developed Parkinson's disease. She attended a Parkinson's support group with him and noticed that everyone smelled like her husband. Now, doctors are working with her to try to understand how to use the faint odor of pre-Parkinson's to stave off the disease.