1. Department of Neurology, Klinikum Großhadern Ludwig-Maximilians-University Munich, Germany.
2. Neurology Practice, Munich, Germany.
3. Institute of Epidemiology, Helmholtz Zentrum München, German Research Centre for Environmental Health (GmbH), Neuherberg, Germany.
4. Institute for Community Medicine, University of Greifswald, Greifswald, Germany.
5. Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany.