1. Department of Cardiovascular and Neurological Science, Multiple Sclerosis Centre, University of Cagliari, Cagliari, Italy
2. Department of Public Health, University of Cagliari, Cagliari, Italy
3. Multiple Sclerosis Centre of the Veneto Region, First Neurology Clinic, University Hospital of Padova, Padova, Italy
4. Department of Neurology, Multiple Sclerosis Centre, Ospedali Civili di Brescia, Brescia, Italy
5. Department of Neurology, University of Florence, Florence, Italy
6. Department of Neurological Sciences, University of Bari, Bari, Italy
7. Department of Neurosciences, Ophthalmology and Genetics, University of Genova, Genova, Italy