1. Department of Neurology, School of Medicine, Kitasato University, Sagamihara, Japan
2. Department of Neurology, Ibaraki Prefectural Central Hospital, Ibaraki, Japan
3. Department of Neurology, School of Medicine, St Marianna University, Kawasaki, Japan
4. Institut d’Investigacións Biomèdicques August Pi i Sunyer, Barcelona, Spain5Department of Neurology, University of Pennsylvania, Philadelphia6Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain