Clinical and Imaging Characteristics of Parkinson's Disease with Negative Alpha-Synuclein Seed Amplification Assay
BACKGROUND: The cerebrospinal fluid alpha-synuclein seed amplification assay (CSFasynSAA) detects alpha-synuclein aggregation in over 90% of individuals with sporadic PD (sPD). However, the clinical characteristics of sPD with negative CSFasynSAA remain undefined.