1. Department of Neurology, Medical University of Vienna, Vienna, Austria
2. Department of Neurology, University of Rostock, Rostock, Germany
3. Department of Neurology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
4. Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
5. Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
6. Neurology Section, VA North Texas Health Care System, Dallas VA Medical Center, Dallas, TX, USA