1 Department of Neurosurgery, Heinrich-Heine University Medical Center, Moorenstraße 5, 40225, Düsseldorf, Germany. Hendrik-Jan.Mijderwijk@med.uni-duesseldorf.de.
2 Department of Neurosurgery, Heinrich-Heine University Medical Center, Moorenstraße 5, 40225, Düsseldorf, Germany.
3 Department of Public Health, Erasmus MC, University Medical Center Rotterdam, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.