1 From the Unit of Neurology and Clinical Neurophysiology, Department of Medical Science, Surgical Science and Neuroscience, Policlinico Le Scotte, University of Siena, Italy. rossisimo@unisi.it.
2 From the Unit of Neurology and Clinical Neurophysiology, Department of Medical Science, Surgical Science and Neuroscience, Policlinico Le Scotte, University of Siena, Italy.