1. Division of Developmental Neurology, National Neurological Institute C. Besta, Milan, Italy
2. Department of Pediatrics, Epidemiology and Community Medicine Unit, University of Padua, Padua, Italy
3. Scientific Research Institute Eugenio Medea, Bosisio Parini, Lecco, Italy
4. Department of Child Neurology and Psychiatry, IRCCS C. Mondino Institute of Neurology, University of Pavia, Pavia, Italy