[1] AOB S Michele Gen Hosp, Dept Neurosci, I-09134 Cagliari, Sardinia, Italy
[2] AOB S Michele Gen Hosp, Dept Nucl Med, I-09134 Cagliari, Sardinia, Italy
[3] Reg Ctr Multiple Sclerosis, Cagliari, Sardinia, Italy
[4] Ist Clin Perfezionamento, Parkinson Ctr, Milan, Italy