1. Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, New York
2. Department of Neurosurgery, Blida University Hospital, Faculty of Medicine, University Saad Dahlab de Bilda, Blida, Algeria
3. Department of Neurosurgery, Justus-Liebig-University Giessen, Giessen, Germany