1. Department of Neurosurgery, Inselspital Bern, University of Bern;
2. Cardiocentro Ticino, Lugano;
3. Institute of Pathology, University of Bern, Switzerland;
4. Department of Neurosurgery, Washington University School of Medicine, St. Louis, Missouri; and
5. Department of Neurosurgery, Heinrich-Heine-Universität, Düsseldorf, Germany