A simple blood test may be as accurate as a spinal fluid test when trying to determine whether symptoms are caused by Parkinson’s disease or another atypical parkinsonism disorder, according to a new study published in the February 8, 2017, online issue of Neurology, the medical journal of the American Academy of Neurology. In early stages of disease, it can be difficult to differentiate between Parkinson’s disease and atypical parkinsonism disorders like multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration, because symptoms can overlap.