1. Carle Illinois College of Medicine, University of Illinois Urbana-Champaign, Champaign, Illinois, USA;
2. University of Minnesota Medical School, University of Minnesota Twin-Cities, Minneapolis, Minnesota, USA;
3. Department of Neurosurgery, Carle Foundation Hospital, Urbana, Illinois, USA;
4. Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA