Massimo Filippi1,2, Maria A Rocca3. 1. Neuroimaging Research Unit and Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy. filippi.massimo@hsr.it. 2. Vita-Salute San Raffaele University, Vita-Salute San Raffaele University, Milan, Italy. filippi.massimo@hsr.it. 3. Neuroimaging Research Unit and Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.