[1] Univ Marburg, Dept Neurol, D-35033 Marburg, Germany
[2] Univ Marburg, Inst Med Biometry & Epidemiol, D-35033 Marburg, Germany
[3] Klinikum Lippe, Dept Internal Med, Div Gastroenterol, Detmold, Germany
[4] Univ Marburg, Dept Internal Med, Div Gastroenterol & Endocrinol, D-3550 Marburg, Germany
[5] Univ Marburg, Dept Diagnost Radiol, D-35033 Marburg, Germany