Central and peripheral α‐synuclein in Parkinson disease detected by seed amplification assay oleh Lana M. Chahine, Thomas G. Beach, Charles H. Adler, Monica Hepker, Anumantha Kanthasamy, Scott Appel, Sandra Pritzkow, Michelle Pinho, Sherri Mosovsky, Geidy E. Serrano, Christopher Coffey, Michael C. Brumm, Luis M. A. Oliveira, Jamie Eberling, Brit Mollenhauer, For the Systemic Synuclein Sampling Study