1 Department of Neurosurgery, Leiden University Medical Center, Albinusdreef 2, 2333ZA, Leiden, Zuid-Holland, The Netherlands.
2 Department of Neurosurgery, Haaglanden Medical Center, Lijnbaan 32, 2512VA, The Hague, Zuid-Holland, The Netherlands.
3 Department of Neurosurgery, Leiden University Medical Center, Albinusdreef 2, 2333ZA, Leiden, Zuid-Holland, The Netherlands. m.broekman@haaglandenmc.nl.
4 Department of Neurosurgery, Haaglanden Medical Center, Lijnbaan 32, 2512VA, The Hague, Zuid-Holland, The Netherlands. m.broekman@haaglandenmc.nl.