Heidelberg University - University Medical Centre Mannheim, Leiden University - Department of Neurosurgery, IRCCS Istituto Giannina Gaslini, Hospital Universitario Virgen de la Victoria, affiliation not provided to SSRN, affiliation not provided to SSRN, Otto von Guericke University Magdeburg, KU Leuven - University Hospitals Leuven, University of Tokyo - The University of Tokyo Hospital, affiliation not provided to SSRN and Guy's and St Thomas' NHS Foundation Trust - Evelina London Children's Hospital