1. Department of Neurosurgery, Children's Hospital "Aghia Sofia", Athens, Greece
2. Neurochirurgische Klinik of Klinikum Rechts der Isar, Munich, Germany
3. Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, United States
4. Department of Neurosurgery, University Hospital of Ioannina, Ioannina, Greece
5. Department of Neurosurgery, Evangelismos Hospital, National & Kapodistrian University of Athens, Greece