1. Memory and Executive Function Impairment Predict Dementia in Parkinson's Disease Levy, Gilberto; Jacobs, Diane; Tang, Mingxin; Cote, Lucien J.; Louis, Elan D.; Alfaro, Brenda; Mejia-Santana, Helen; Stern, Yaakov; Marder, Karen 2002 Articles Movement disordersParkinson's diseaseExecutive functions (Neuropsychology)DementiaNeurology