1 Department of Neurosurgery, Medical Center Haaglanden, The Hague, The Netherlands.
2 Department of Neurosurgery, Brain Center Rudolph Magnus, University Medical Center Utrecht, HP G03.124, PO Box 85500, 3508 GA, Utrecht, The Netherlands. M.L.D.Broekman-4@umcutrecht.nl.
3 Department of Neurology, Massachusetts General Hospital/ Harvard Medical School, Boston, MA, USA. M.L.D.Broekman-4@umcutrecht.nl.