1. 1st Department of Neurosurgery, Evangelismos Hospital, National and Kapodistrian University of Athens, Greece
2. Department of Internal Medicine, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118,
USA
3. Department of Cardiology, Emory University, Atlanta, GA 30322, USA
4. 2nd Department of Neurosurgery, Attiko Hospital, National and Kapodistrian University of Athens, Greece