1 Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada.
2 Department of Ophthalmology and Vision Sciences, Toronto Western Hospital and The Hospital for Sick Children, University of Toronto, Canada.
3 Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Canada; Krembil Research Institute, Toronto, Ontario, Canada.
4 Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada; Krembil Research Institute, Toronto, Ontario, Canada. Electronic address: alfonso.fasano@uhn.ca.