1. Service of Neurosurgery, Department of Clinical Neuroscience, Faculty of Human Medicine and Biology, University Hospital of Lausanne, 46 rue du Bugnon, 1011 Lausanne, Switzerland
2. Department of Neurosurgery, University Hospital of Bicetre, Faculty of Medicine of Paris Sud, 78 rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France