 He is the David M. Levy Professor of Neurology and Director of the Center for Health and Technology at the University of Rochester Medical Center. He's also one of the co-authors of Ending Parkinson's Disease, a Prescription for Action. Dr. Dorsey, let's start with maybe a bit of a primer for those who may not know everything there is to know about Parkinson's disease. Tell us a bit about the disease and the typical effects of it.