1 Neurology Unit, Department of Medicine, S. Anna Hospital, Como, Italy.
2 Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genoa, "G. Gaslini" Institute, Genova, Italy.
3 Child Neurology & Paediatric Headache Centre, Chair of Paediatrics, NESMOS Dpt, University of Rome 'Sapienza', Faculty of Medicine & Psychology, c/o "S. Andrea" Hospital, Rome, Italy.