1. Departments of Neurology, University of Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany
2. Departments of Gastroenterology, University of Düsseldorf, Moorenstrasse 5, D-40225 Düsseldorf, Germany
3. Department of Neurology, Kliniken Maria Hilf GmbH Mönchengladbach, 41063 Mönchengladbach, Germany
4. Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Unverstät zu Berlin, Experimental and Clinical Research Center, 13125 Berlin, Germany
5. Department of Regional Health Research and Molecular Medicine, University of Southern Denmark, 5230 Odense, Denmark
6. Department of Neurology, Slagelse Hospital, 4200 Slagelse, Denmark