1. Neurological Institute, Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
2. Department of Neurorehabilitation, IRCCS San Raffaele Pisana, Rome, Italy.
3. Post-Coma and Rehabilitation Care Unit, Hospital San Raffaele, Cassino, Italy.
4. Post-Coma and Rehabilitation Care Unit, IRCCS Maugeri Foundation, Pavia, Italy.
5. Medical Statistics and Information Technology, Fatebenefratelli Foundation for Health Research and Education, AFaR Division, Rome, Italy.
6. Unit of Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Rome, Italy.