1 From the Department of Neurology (M.A., M.K.), University Hospital of Zurich, Switzerland; and Department of Epidemiology and Biostatistics (D.G.), School of Public Health, Imperial College London, UK. markus.arnold@usz.ch.
2 From the Department of Neurology (M.A., M.K.), University Hospital of Zurich, Switzerland; and Department of Epidemiology and Biostatistics (D.G.), School of Public Health, Imperial College London, UK.