1. Neurosurgery Department, Venizeleio General Hospital, 71409 Heraklion, Greece
2. Neurosurgery Department, University of Verona, Piazzale Stefani 1, 37126 Verona, Italy
3. Intensive Care Department, University College Hospital, NHS Trust, London NW1 2BU, UK
4. School of Medicine, University of Cagliari, 09124 Cagliari, Italy