Dimitrios Chytas1, Marios Salmas2, Georgios P Skandalakis3, Theodore G Troupis2. 1. Department of Anatomy, School of Physiotherapy, University of Peloponnese, Sparta, Greece. 2. Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece. 3. Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York.