1 Section of Neurology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy.
2 Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Napoli, Italy.
3 Section of Neuroradiology, Santa Maria della Misericordia Hospital, Perugia, Italy.
4 Section of Neurology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy. Electronic address: massimiliano.difilippo@unipg.it.