1. Department of Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
2. Department of Biostatistics, Indiana University R. M. Fairbanks School of Public Health
3. Department of Biostatistics, Indiana University School of Medicine, Indianapolis
4. Neuroradiology Unit, San Raffaele Scientific Institute, Milano
5. San Patrignano Medical Center, Ospitaletto di Rimini
6. Laboratory of Neuroimmunology, ‘C. Mondino’ National Neurological Institute, Pavia, Italy