Baseline Prevalence and Longitudinal Evolution of Non-Motor Symptoms in Early Parkinson’s Disease: The PPMI Cohort

Simuni T, Caspell-Garcia C, Walker M, Coffey, C, Weintraub D, Mollenhauer B, Lasch S, Tanner C, Jennings D, Kieburtz K, Chahine L, and Marek K on behalf of the PPMI Investigators