Doctors have a new tool to diagnose Parkinson’s disease, which (behind Alzheimer’s) is the second-most common neurodegenerative disorder in the US. Per the Wall Street Journal, a paper published in the medical journal JAMA this week says the Syn-One Test accurately detected a buildup of proteins in the nerves that indicated Parkinson’s in 93% of participants. “The skin test basically is a window into the brain,” neurology professor Dr. Joseph Jankovic tells the Journal. Specifically, it looks for an abnormal protein linked to degenerative brain disorders called phosphorylated alpha-synuclein, …