1 Department of Neurosurgery, IRCCS A. Gemelli University Polyclinic Foundation, Sacred Heart Catholic University, Rome, Italy - cropcircle.2000@virgilio.it.
2 Department of Neurosurgery, Zurich University Hospital, Zurich, Switzerland.
3 Department of Neurosurgery, IRCCS A. Gemelli University Polyclinic Foundation, Sacred Heart Catholic University, Rome, Italy.