University of Duisburg-Essen - Department of Neurosurgery, University of Lausanne - Lausanne University Hospital, University of Basel - University Hospital Basel, University of Lausanne - Lausanne University Hospital, University of Basel - University Hospital Basel, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Freiburg - Department of Neurosurgery, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - Department of Neurosurgery, University of Duisburg-Essen - Department of Neurosurgery and University of Lausanne - Lausanne University Hospital

affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, University of Lausanne - Lausanne University Hospital, University of Lausanne - Lausanne University Hospital and affiliation not provided to SSRN