1. Postgraduate Program “Metabolic Bone Diseases”, National and Kapodistrian University of Athens, Medical School, Athens, Greece
2. Department of Neurosurgery, National and Kapodistrian University of Athens, Medical School, Athens, Greece
3. Klinik für Innere Medizin, Evangelisches Klinikum Bethel OWL, Bielefeld, Germany
4. Rehabilitation following Spinal Cord lesion, Spinal Pain Management, National and Kapodistrian University of Athens, Medical School, Athens, Greece