1. 1Department of Neurosurgery, University of Erlangen, Germany;
2. 2Department of Neurosurgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts;
3. 3Department of Neurosurgery, Fondazione IRCC Istituto Neurologico, Milano, Italy; and
4. 4Department of Neurosurgery, University of Southern California, Los Angeles, California