Leiden University - Department of Neurology, Leiden University - Department of Neurology, Leiden University - Department of Neurology, Canisius-Wilhelmina Hospital - Department of Neurology, Maastricht University Medical Center - Department of Neurosurgery, Leiden University Medical Center (LUMC) - Department of Anaesthesiology, Alrijne Hospital - Department of Anaesthesiology, Diakonessenhuis Hospital - Department of Anaesthesiology, Radboud University Medical Center - Department of Anaesthesiology, Radboud University Medical Center - Department of Neurosurgery, Maastricht University Medical Center - Department of Neurosurgery, Leiden University - Department of Neurology, Leiden University - Department of Medical Statistics, Erasmus Medical Center (MC) - Department of Anaesthesiology, Leiden University - Department of Neurology and Independent