Affiliation: | 1. Department of Neurology, Mayo Clinic, , Rochester, Minnesota, 55905 USA;2. Department of Neurology, University of Michigan, , Ann Arbor, Michigan, USA;3. Department of Neurology, Queen's University, , Kingston, Ontario, Canada;4. Department of Neurology, University of Maryland, , Baltimore, Maryland, USA;5. Division of Biomedical Statistics and Informatics, Mayo Clinic, , Rochester, USA;6. Division of Epidemiology, Mayo Clinic, , Rochester, Minnesota, USA |