1. Department of Neurosurgery, University Medicine Rostock, Rostock, Germany;
2. Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany;
3. Department of Neurosurgery, Göttingen University Hospital, Göttingen, Germany;
4. Department of Neurosurgery, Brigham and Women`s Hospital, Harvard Medical School, Boston, USA;
5. Department of Neurosurgery, University Hospital, Goethe-University, Frankfurt, Germany;
6. Department of Neurosurgery, Jena University Hospital, Jena, Germany;
7. Department of Neurosurgery, University Medical Center Schleswig-Holstein, Kiel, Germany;
8. Department of Neurosurgery, BG Klinikum Unfallkrankenhaus Berlin, Berlin, Germany;
9. Department of Medicine, Institute of Biostatistics and Mathematical Modelling, Goethe University, Frankfurt am Main, Germany;
10. Department of Anesthesiology and Intensive Care, University Hospital Bonn, Bonn, Germany;
11. Department of Neurosurgery, University Hospital Mainz, Germany;
12. Department of Neurosurgery, University Hospital Bonn, Bonn, Germany